Move to 2.13.3 (from 2.13.tar.gz - sigh).

1 files changed, 2742 insertions, 722 deletions

diff --git a/gawk.texinfo b/gawk.texinfo
index fda27951..00a8ada5 100644
--- a/gawk.texinfo
+++ b/gawk.texinfo
@@ -1,6 +1,6 @@
 \input texinfo   @c -*-texinfo-*-
 @c %**start of header (This is for running Texinfo on a region.)
-@setfilename gawk-info
+@setfilename gawk.info
 @settitle The GAWK Manual
 @c %**end of header (This is for running Texinfo on a region.)
 
@@ -21,7 +21,7 @@
 This file documents @code{awk}, a program that you can use to select
 particular records in a file and perform operations upon them.
 
-Copyright (C) 1989 Free Software Foundation, Inc.
+Copyright (C) 1989,1991 Free Software Foundation, Inc.
 
 Permission is granted to make and distribute verbatim copies of
 this manual provided the copyright notice and this permission notice
@@ -52,36 +52,31 @@ by the Foundation.
 
 @setchapternewpage odd
 @titlepage
-@sp 11
-@center @titlefont{The GAWK Manual}
-@sp 4
-@center by
-@center Diane Barlow Close
-@center Arnold D. Robbins
-@center Paul H. Rubin
-@center Richard Stallman
-@sp 2
-@center Edition 0.12 Beta
-@sp 2
-@center October 1989
+@title The GAWK Manual
+@subtitle Edition 0.13 Beta
+@subtitle October 1991
+@author Diane Barlow Close
+@author Arnold D. Robbins
+@author Paul H. Rubin
+@author Richard Stallman
 
 @c Include the Distribution inside the titlepage environment so
 @c that headings are turned off.  Headings on and off do not work.
 
 @page
 @vskip 0pt plus 1filll
-Copyright @copyright{} 1989 Free Software Foundation, Inc.
+Copyright @copyright{} 1989, 1991 Free Software Foundation, Inc.
 @sp 2
 
-This is Edition 0.12 Beta of @cite{The GAWK Manual}, @*
-for the 2.11.1 version of the GNU implementation @*
+This is Edition 0.13 Beta of @cite{The GAWK Manual}, @*
+for the 2.13.3 version of the GNU implementation @*
 of AWK.
 
 @sp 2
 Published by the Free Software Foundation @*
 675 Massachusetts Avenue, @*
 Cambridge, MA 02139 USA @*
-Printed copies are available for $10 each.
+Printed copies are available for $15 each.
 
 Permission is granted to make and distribute verbatim copies of
 this manual provided the copyright notice and this permission notice
@@ -98,12 +93,13 @@ except that this permission notice may be stated in a translation approved
 by the Foundation.
 @end titlepage
 
+@ifinfo
 @node Top, Preface, (dir), (dir)
 @comment  node-name,  next,  previous,  up
+@top General Introduction
 @c Preface or Licensing nodes should come right after the Top
 @c node, in `unnumbered' sections, then the chapter, `What is gawk'.
 
-@ifinfo
 This file documents @code{awk}, a program that you can use to select
 particular records in a file and perform operations upon them; it
 contains the following chapters:
@@ -152,10 +148,14 @@ contains the following chapters:
 
 * Language History::   The evolution of the @code{awk} language.
 
+* Installation::       Installing @code{gawk} under various operating systems.
+
 * Gawk Summary::       @code{gawk} Options and Language Summary.
 
 * Sample Program::     A sample @code{awk} program with a complete explanation.
 
+* Bugs::               Reporting Problems and Bugs.
+
 * Notes::              Something about the implementation of @code{gawk}.
 
 * Glossary::           An explanation of some unfamiliar terms.
@@ -167,7 +167,9 @@ contains the following chapters:
 @comment  node-name,  next,  previous,  up
 @unnumbered Preface
 
-@c @cindex what is @code{awk}
+@iftex
+@cindex what is @code{awk}
+@end iftex
 If you are like many computer users, you frequently would like to make
 changes in various text files wherever certain patterns appear, or
 extract data from parts of certain lines while discarding the rest.  To
@@ -180,11 +182,12 @@ that makes it possible to handle simple data-reformatting jobs easily
 with just a few lines of code.
 
 The GNU implementation of @code{awk} is called @code{gawk}; it is fully
-upward compatible with the System V Release 3.1 and later
-version of @code{awk}.  All properly written
-@code{awk} programs should work with @code{gawk}.  So we usually don't
-distinguish between @code{gawk} and other @code{awk} implementations in
-this manual.@refill
+upward compatible with the System V Release 4 version of
+@code{awk}.  @code{gawk} is also upward compatible with the @sc{POSIX}
+(draft) specification of the @code{awk} language.  This means that all
+properly written @code{awk} programs should work with @code{gawk}.
+So we usually don't distinguish between @code{gawk} and other @code{awk}
+implementations in this manual.@refill
 
 @cindex uses of @code{awk}
 This manual teaches you what @code{awk} does and how you can use
@@ -208,6 +211,13 @@ even experiment with algorithms that can be adapted later to other computer
 languages!
 @end itemize
 
+@iftex
+This manual has the difficult task of being both tutorial and reference.
+If you are a novice, feel free to skip over details that seem too complex.
+You should also ignore the many cross references; they are for the
+expert user, and for the on-line Info version of the manual.
+@end iftex
+
 @menu
 * History::  The history of @code{gawk} and @code{awk}.  Acknowledgements.
 @end menu
@@ -225,69 +235,79 @@ language more powerful, introducing user-defined functions, multiple input
 streams, and computed regular expressions.
 This new version became generally available with System V Release 3.1.
 The version in System V Release 4 added some new features and also cleaned
-up the behaviour in some of the ``dark corners'' of the language.@refill
-@comment We don't refer people to non-free information
-@comment  In 1988, the original authors
-@comment published @cite{The AWK Programming Language} (Addison-Wesley, ISBN
-@comment 0-201-07981-X), as a definitive description of the @code{awk} language.
+up the behavior in some of the ``dark corners'' of the language.
+The specification for @code{awk} in the @sc{POSIX} Command Language
+and Utilities standard further clarified the language based on feedback
+from both the @code{gawk} designers, and the original @code{awk}
+designers.@refill
 
 The GNU implementation, @code{gawk}, was written in 1986 by Paul Rubin
 and Jay Fenlason, with advice from Richard Stallman.  John Woods
 contributed parts of the code as well.  In 1988 and 1989, David Trueman, with
 help from Arnold Robbins, thoroughly reworked @code{gawk} for compatibility
-with the newer @code{awk}.
+with the newer @code{awk}.  Current development focuses on bug fixes,
+performance improvements, and standards compliance.
 
 Many people need to be thanked for their assistance in producing this
 manual.  Jay Fenlason contributed many ideas and sample programs.  Richard
-Mlynarik and Robert Chassell gave helpful comments on drafts of this
+Mlynarik and Robert Chassell gave helpful comments on early drafts of this
 manual.  The paper @cite{A Supplemental Document for @code{awk}} by John W.
 Pierce of the Chemistry Department at UC San Diego, pinpointed several
 issues relevant both to @code{awk} implementation and to this manual, that
-would otherwise have escaped us.
+would otherwise have escaped us.  David Trueman, Pat Rankin, and Michal
+Jaegermann also contributed portions of the manual.@refill
+
+The following people provided many helpful comments on this edition of
+the manual: Rick Adams, Michael Brennan, Rich Burridge, Diane Close,
+Christopher (``Topher'') Eliot, Michael Lijewski, Pat Rankin, Miriam Robbins,
+and Michal Tomczak.
 
 Finally, we would like to thank Brian Kernighan of Bell Labs for invaluable
 assistance during the testing and debugging of @code{gawk}, and for
-help in clarifying several points about the language.@refill
+help in clarifying numerous points about the language.@refill
 
 @node Copying, This Manual, Preface, Top
-@unnumbered GNU General Public License
-@center Version 1, February 1989
+@unnumbered GNU GENERAL PUBLIC LICENSE
+@center Version 2, June 1991
 
 @display
-Copyright @copyright{} 1989 Free Software Foundation, Inc.
+Copyright @copyright{} 1989, 1991 Free Software Foundation, Inc.
 675 Mass Ave, Cambridge, MA 02139, USA
 
 Everyone is permitted to copy and distribute verbatim copies
 of this license document, but changing it is not allowed.
 @end display
 
-@c fakenode - this is for prepinfo.
+@c fakenode --- for prepinfo
 @unnumberedsec Preamble
 
-  The license agreements of most software companies try to keep users
-at the mercy of those companies.  By contrast, our General Public
+  The licenses for most software are designed to take away your
+freedom to share and change it.  By contrast, the GNU General Public
 License is intended to guarantee your freedom to share and change free
-software---to make sure the software is free for all its users.  The
-General Public License applies to the Free Software Foundation's
-software and to any other program whose authors commit to using it.
-You can use it for your programs, too.
+software---to make sure the software is free for all its users.  This
+General Public License applies to most of the Free Software
+Foundation's software and to any other program whose authors commit to
+using it.  (Some other Free Software Foundation software is covered by
+the GNU Library General Public License instead.)  You can apply it to
+your programs, too.
 
   When we speak of free software, we are referring to freedom, not
-price.  Specifically, the General Public License is designed to make
-sure that you have the freedom to give away or sell copies of free
-software, that you receive source code or can get it if you want it,
-that you can change the software or use pieces of it in new free
-programs; and that you know you can do these things.
+price.  Our General Public Licenses are designed to make sure that you
+have the freedom to distribute copies of free software (and charge for
+this service if you wish), that you receive source code or can get it
+if you want it, that you can change the software or use pieces of it
+in new free programs; and that you know you can do these things.
 
   To protect your rights, we need to make restrictions that forbid
 anyone to deny you these rights or to ask you to surrender the rights.
 These restrictions translate to certain responsibilities for you if you
 distribute copies of the software, or if you modify it.
 
-  For example, if you distribute copies of a such a program, whether
+  For example, if you distribute copies of such a program, whether
 gratis or for a fee, you must give the recipients all the rights that
 you have.  You must make sure that they, too, receive or can get the
-source code.  And you must tell them their rights.
+source code.  And you must show them these terms so they know their
+rights.
 
   We protect your rights with two steps: (1) copyright the software, and
 (2) offer you this license which gives you legal permission to copy,
@@ -300,129 +320,217 @@ want its recipients to know that what they have is not the original, so
 that any problems introduced by others will not reflect on the original
 authors' reputations.
 
+  Finally, any free program is threatened constantly by software
+patents.  We wish to avoid the danger that redistributors of a free
+program will individually obtain patent licenses, in effect making the
+program proprietary.  To prevent this, we have made it clear that any
+patent must be licensed for everyone's free use or not licensed at all.
+
   The precise terms and conditions for copying, distribution and
 modification follow.
 
 @iftex
-@c fakenode -- this is for prepinfo.
-@unnumberedsec TERMS AND CONDITIONS
+@c fakenode --- for prepinfo
+@unnumberedsec TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
 @end iftex
 @ifinfo
-@center TERMS AND CONDITIONS
+@center TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
 @end ifinfo
 
 @enumerate
 @item
-This License Agreement applies to any program or other work which
-contains a notice placed by the copyright holder saying it may be
-distributed under the terms of this General Public License.  The
-``Program'', below, refers to any such program or work, and a ``work based
-on the Program'' means either the Program or any work containing the
-Program or a portion of it, either verbatim or with modifications.  Each
-licensee is addressed as ``you''.
+This License applies to any program or other work which contains
+a notice placed by the copyright holder saying it may be distributed
+under the terms of this General Public License.  The ``Program'', below,
+refers to any such program or work, and a ``work based on the Program''
+means either the Program or any derivative work under copyright law:
+that is to say, a work containing the Program or a portion of it,
+either verbatim or with modifications and/or translated into another
+language.  (Hereinafter, translation is included without limitation in
+the term ``modification''.)  Each licensee is addressed as ``you''.
+
+Activities other than copying, distribution and modification are not
+covered by this License; they are outside its scope.  The act of
+running the Program is not restricted, and the output from the Program
+is covered only if its contents constitute a work based on the
+Program (independent of having been made by running the Program).
+Whether that is true depends on what the Program does.
 
 @item
-You may copy and distribute verbatim copies of the Program's source
-code as you receive it, in any medium, provided that you conspicuously and
-appropriately publish on each copy an appropriate copyright notice and
-disclaimer of warranty; keep intact all the notices that refer to this
-General Public License and to the absence of any warranty; and give any
-other recipients of the Program a copy of this General Public License
-along with the Program.  You may charge a fee for the physical act of
-transferring a copy.
+You may copy and distribute verbatim copies of the Program's
+source code as you receive it, in any medium, provided that you
+conspicuously and appropriately publish on each copy an appropriate
+copyright notice and disclaimer of warranty; keep intact all the
+notices that refer to this License and to the absence of any warranty;
+and give any other recipients of the Program a copy of this License
+along with the Program.
 
-@item
-You may modify your copy or copies of the Program or any portion of
-it, and copy and distribute such modifications under the terms of Paragraph
-1 above, provided that you also do the following:
+You may charge a fee for the physical act of transferring a copy, and
+you may at your option offer warranty protection in exchange for a fee.
 
-@itemize @bullet
 @item
-cause the modified files to carry prominent notices stating that
-you changed the files and the date of any change; and
+You may modify your copy or copies of the Program or any portion
+of it, thus forming a work based on the Program, and copy and
+distribute such modifications or work under the terms of Section 1
+above, provided that you also meet all of these conditions:
 
+@enumerate A
 @item
-cause the whole of any work that you distribute or publish, that
-in whole or in part contains the Program or any part thereof, either
-with or without modifications, to be licensed at no charge to all
-third parties under the terms of this General Public License (except
-that you may choose to grant warranty protection to some or all
-third parties, at your option).
+You must cause the modified files to carry prominent notices
+stating that you changed the files and the date of any change.
 
 @item
-If the modified program normally reads commands interactively when
-run, you must cause it, when started running for such interactive use
-in the simplest and most usual way, to print or display an
-announcement including an appropriate copyright notice and a notice
-that there is no warranty (or else, saying that you provide a
-warranty) and that users may redistribute the program under these
-conditions, and telling the user how to view a copy of this General
-Public License.
+You must cause any work that you distribute or publish, that in
+whole or in part contains or is derived from the Program or any
+part thereof, to be licensed as a whole at no charge to all third
+parties under the terms of this License.
 
 @item
-You may charge a fee for the physical act of transferring a
-copy, and you may at your option offer warranty protection in
-exchange for a fee.
-@end itemize
+If the modified program normally reads commands interactively
+when run, you must cause it, when started running for such
+interactive use in the most ordinary way, to print or display an
+announcement including an appropriate copyright notice and a
+notice that there is no warranty (or else, saying that you provide
+a warranty) and that users may redistribute the program under
+these conditions, and telling the user how to view a copy of this
+License.  (Exception: if the Program itself is interactive but
+does not normally print such an announcement, your work based on
+the Program is not required to print an announcement.)
+@end enumerate
 
-Mere aggregation of another independent work with the Program (or its
-derivative) on a volume of a storage or distribution medium does not bring
-the other work under the scope of these terms.
+These requirements apply to the modified work as a whole.  If
+identifiable sections of that work are not derived from the Program,
+and can be reasonably considered independent and separate works in
+themselves, then this License, and its terms, do not apply to those
+sections when you distribute them as separate works.  But when you
+distribute the same sections as part of a whole which is a work based
+on the Program, the distribution of the whole must be on the terms of
+this License, whose permissions for other licensees extend to the
+entire whole, and thus to each and every part regardless of who wrote it.
+
+Thus, it is not the intent of this section to claim rights or contest
+your rights to work written entirely by you; rather, the intent is to
+exercise the right to control the distribution of derivative or
+collective works based on the Program.
+
+In addition, mere aggregation of another work not based on the Program
+with the Program (or with a work based on the Program) on a volume of
+a storage or distribution medium does not bring the other work under
+the scope of this License.
 
 @item
-You may copy and distribute the Program (or a portion or derivative of
-it, under Paragraph 2) in object code or executable form under the terms of
-Paragraphs 1 and 2 above provided that you also do one of the following:
+You may copy and distribute the Program (or a work based on it,
+under Section 2) in object code or executable form under the terms of
+Sections 1 and 2 above provided that you also do one of the following:
 
-@itemize @bullet
+@enumerate A
 @item
-accompany it with the complete corresponding machine-readable
-source code, which must be distributed under the terms of
-Paragraphs 1 and 2 above; or,
+Accompany it with the complete corresponding machine-readable
+source code, which must be distributed under the terms of Sections
+1 and 2 above on a medium customarily used for software interchange; or,
 
 @item
-accompany it with a written offer, valid for at least three
-years, to give any third party free (except for a nominal charge
-for the cost of distribution) a complete machine-readable copy of the
-corresponding source code, to be distributed under the terms of
-Paragraphs 1 and 2 above; or,
+Accompany it with a written offer, valid for at least three
+years, to give any third party, for a charge no more than your
+cost of physically performing source distribution, a complete
+machine-readable copy of the corresponding source code, to be
+distributed under the terms of Sections 1 and 2 above on a medium
+customarily used for software interchange; or,
 
 @item
-accompany it with the information you received as to where the
-corresponding source code may be obtained.  (This alternative is
+Accompany it with the information you received as to the offer
+to distribute corresponding source code.  (This alternative is
 allowed only for noncommercial distribution and only if you
-received the program in object code or executable form alone.)
-@end itemize
+received the program in object code or executable form with such
+an offer, in accord with Subsection b above.)
+@end enumerate
 
-Source code for a work means the preferred form of the work for making
-modifications to it.  For an executable file, complete source code means
-all the source code for all modules it contains; but, as a special
-exception, it need not include source code for modules which are standard
-libraries that accompany the operating system on which the executable
-file runs, or for standard header files or definitions files that
-accompany that operating system.
+The source code for a work means the preferred form of the work for
+making modifications to it.  For an executable work, complete source
+code means all the source code for all modules it contains, plus any
+associated interface definition files, plus the scripts used to
+control compilation and installation of the executable.  However, as a
+special exception, the source code distributed need not include
+anything that is normally distributed (in either source or binary
+form) with the major components (compiler, kernel, and so on) of the
+operating system on which the executable runs, unless that component
+itself accompanies the executable.
+
+If distribution of executable or object code is made by offering
+access to copy from a designated place, then offering equivalent
+access to copy the source code from the same place counts as
+distribution of the source code, even though third parties are not
+compelled to copy the source along with the object code.
 
 @item
-You may not copy, modify, sublicense, distribute or transfer the
-Program except as expressly provided under this General Public License.
-Any attempt otherwise to copy, modify, sublicense, distribute or transfer
-the Program is void, and will automatically terminate your rights to use
-the Program under this License.  However, parties who have received
-copies, or rights to use copies, from you under this General Public
-License will not have their licenses terminated so long as such parties
-remain in full compliance.
+You may not copy, modify, sublicense, or distribute the Program
+except as expressly provided under this License.  Any attempt
+otherwise to copy, modify, sublicense or distribute the Program is
+void, and will automatically terminate your rights under this License.
+However, parties who have received copies, or rights, from you under
+this License will not have their licenses terminated so long as such
+parties remain in full compliance.
 
 @item
-By copying, distributing or modifying the Program (or any work based
-on the Program) you indicate your acceptance of this license to do so,
-and all its terms and conditions.
+You are not required to accept this License, since you have not
+signed it.  However, nothing else grants you permission to modify or
+distribute the Program or its derivative works.  These actions are
+prohibited by law if you do not accept this License.  Therefore, by
+modifying or distributing the Program (or any work based on the
+Program), you indicate your acceptance of this License to do so, and
+all its terms and conditions for copying, distributing or modifying
+the Program or works based on it.
 
 @item
 Each time you redistribute the Program (or any work based on the
-Program), the recipient automatically receives a license from the original
-licensor to copy, distribute or modify the Program subject to these
-terms and conditions.  You may not impose any further restrictions on the
-recipients' exercise of the rights granted herein.
+Program), the recipient automatically receives a license from the
+original licensor to copy, distribute or modify the Program subject to
+these terms and conditions.  You may not impose any further
+restrictions on the recipients' exercise of the rights granted herein.
+You are not responsible for enforcing compliance by third parties to
+this License.
+
+@item
+If, as a consequence of a court judgment or allegation of patent
+infringement or for any other reason (not limited to patent issues),
+conditions are imposed on you (whether by court order, agreement or
+otherwise) that contradict the conditions of this License, they do not
+excuse you from the conditions of this License.  If you cannot
+distribute so as to satisfy simultaneously your obligations under this
+License and any other pertinent obligations, then as a consequence you
+may not distribute the Program at all.  For example, if a patent
+license would not permit royalty-free redistribution of the Program by
+all those who receive copies directly or indirectly through you, then
+the only way you could satisfy both it and this License would be to
+refrain entirely from distribution of the Program.
+
+If any portion of this section is held invalid or unenforceable under
+any particular circumstance, the balance of the section is intended to
+apply and the section as a whole is intended to apply in other
+circumstances.
+
+It is not the purpose of this section to induce you to infringe any
+patents or other property right claims or to contest validity of any
+such claims; this section has the sole purpose of protecting the
+integrity of the free software distribution system, which is
+implemented by public license practices.  Many people have made
+generous contributions to the wide range of software distributed
+through that system in reliance on consistent application of that
+system; it is up to the author/donor to decide if he or she is willing
+to distribute software through any other system and a licensee cannot
+impose that choice.
+
+This section is intended to make thoroughly clear what is believed to
+be a consequence of the rest of this License.
+
+@item
+If the distribution and/or use of the Program is restricted in
+certain countries either by patents or by copyrighted interfaces, the
+original copyright holder who places the Program under this License
+may add an explicit geographical distribution limitation excluding
+those countries, so that distribution is permitted only in or among
+countries not thus excluded.  In such case, this License incorporates
+the limitation as if written in the body of this License.
 
 @item
 The Free Software Foundation may publish revised and/or new versions
@@ -431,11 +539,11 @@ be similar in spirit to the present version, but may differ in detail to
 address new problems or concerns.
 
 Each version is given a distinguishing version number.  If the Program
-specifies a version number of the license which applies to it and ``any
+specifies a version number of this License which applies to it and ``any
 later version'', you have the option of following the terms and conditions
 either of that version or of any later version published by the Free
 Software Foundation.  If the Program does not specify a version number of
-the license, you may choose any version ever published by the Free Software
+this License, you may choose any version ever published by the Free Software
 Foundation.
 
 @item
@@ -448,7 +556,7 @@ of preserving the free status of all derivatives of our free software and
 of promoting the sharing and reuse of software generally.
 
 @iftex
-@c fakenode -- this is for prepinfo.
+@c fakenode --- for prepinfo
 @heading NO WARRANTY
 @end iftex
 @ifinfo
@@ -467,19 +575,19 @@ PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
 REPAIR OR CORRECTION.
 
 @item
-IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL
-ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
+IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
 REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
-INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES
-ARISING OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT
-LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES
-SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE
-WITH ANY OTHER PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN
-ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
+INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
+OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
+TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
+YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
+PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGES.
 @end enumerate
 
 @iftex
-@c fakenode -- this is for prepinfo.
+@c fakenode --- for prepinfo
 @heading END OF TERMS AND CONDITIONS
 @end iftex
 @ifinfo
@@ -487,18 +595,17 @@ ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
 @end ifinfo
 
 @page
-@c fakenode -- this is for prepinfo.
-@unnumberedsec Appendix: Using These Terms in New Programs
+@c fakenode --- for prepinfo
+@unnumberedsec How to Apply These Terms to Your New Programs
 
   If you develop a new program, and you want it to be of the greatest
-possible use to humanity, the best way to achieve this is to make it
-free software which everyone can redistribute and change under these
-terms.
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
 
-  To do so, attach the following notices to the program.  It is safest to
-attach them to the start of each source file to most effectively convey
-the exclusion of warranty; and each file should have at least the
-``copyright'' line and a pointer to where the full notice is found.
+  To do so, attach the following notices to the program.  It is safest
+to attach them to the start of each source file to most effectively
+convey the exclusion of warranty; and each file should have at least
+the ``copyright'' line and a pointer to where the full notice is found.
 
 @smallexample
 @var{one line to give the program's name and a brief idea of what it does.}
@@ -506,8 +613,8 @@ Copyright (C) 19@var{yy}  @var{name of author}
 
 This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 1, or (at your option)
-any later version.
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
 
 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ -531,26 +638,29 @@ This is free software, and you are welcome to redistribute it
 under certain conditions; type `show c' for details.
 @end smallexample
 
-The hypothetical commands `show w' and `show c' should show the
-appropriate parts of the General Public License.  Of course, the
-commands you use may be called something other than `show w' and `show
-c'; they could even be mouse-clicks or menu items---whatever suits your
-program.
+The hypothetical commands @samp{show w} and @samp{show c} should show
+the appropriate parts of the General Public License.  Of course, the
+commands you use may be called something other than @samp{show w} and
+@samp{show c}; they could even be mouse-clicks or menu items---whatever
+suits your program.
 
 You should also get your employer (if you work as a programmer) or your
 school, if any, to sign a ``copyright disclaimer'' for the program, if
-necessary.  Here a sample; alter the names:
+necessary.  Here is a sample; alter the names:
 
 @example
-Yoyodyne, Inc., hereby disclaims all copyright interest in the
-program `Gnomovision' (a program to direct compilers to make passes
-at assemblers) written by James Hacker.
+Yoyodyne, Inc., hereby disclaims all copyright interest in the program
+`Gnomovision' (which makes passes at compilers) written by James Hacker.
 
 @var{signature of Ty Coon}, 1 April 1989
 Ty Coon, President of Vice
 @end example
 
-That's all there is to it!
+This General Public License does not permit incorporating your program into
+proprietary programs.  If your program is a subroutine library, you may
+consider it more useful to permit linking proprietary applications with the
+library.  If this is what you want to do, use the GNU Library General
+Public License instead of this License.
 
 @node This Manual, Getting Started, Copying, Top
 @chapter Using This Manual
@@ -561,12 +671,17 @@ That's all there is to it!
 @cindex @code{awk} language
 @cindex @code{awk} program
 
-The term @code{gawk} refers to a particular program (a version of
-@code{awk}, developed as part the GNU project), and to the language you
-use to tell this program what to do.  When we need to be careful, we
-call the program ``the @code{awk} utility'' and the language ``the
-@code{awk} language''.  The purpose of this manual is to explain the
-@code{awk} language and how to run the @code{awk} utility.
+The term @code{awk} refers to a particular program, and to the language you
+use to tell this program what to do.  When we need to be careful, we call
+the program ``the @code{awk} utility'' and the language ``the @code{awk}
+language.''  The term @code{gawk} refers to a version of @code{awk}, developed
+as part the GNU project.  The purpose of this manual is to explain the
+@code{awk} language and how to run the @code{awk} utility.@refill
+
+While concentrating on the features of @code{gawk}, the manual will also
+attempt to describe important differences between @code{gawk} and other
+@code{awk} implementations.  In particular, any features that are not
+in the @sc{POSIX} standard for @code{awk} will be noted.  @refill
 
 The term @dfn{@code{awk} program} refers to a program written by you in
 the @code{awk} programming language.@refill
@@ -579,8 +694,8 @@ Some useful ``one-liners'' are included to give you a feel for the
 
 @ignore
 @strong{I deleted four paragraphs here because they would confuse the
-beginner more than help him.  They mention terms such as ``field'',
-``pattern'', ``action'', ``built-in function'' which the beginner
+beginner more than help him.  They mention terms such as ``field,''
+``pattern,'' ``action,'' ``built-in function'' which the beginner
 doesn't know.}
 
 @strong{If you can find a way to introduce several of these concepts here,
@@ -591,12 +706,16 @@ space than ought to be used here.  There may be no way to win.}
 @strong{ADR: I'd like to tackle this in phase 2 of my editing.}
 @end ignore
 
-A sizable sample @code{awk} program has been provided for you (@pxref{Sample
-Program}).@refill
+A sample @code{awk} program has been provided for you
+(@pxref{Sample Program}).@refill
 
 If you find terms that you aren't familiar with, try looking them
 up in the glossary (@pxref{Glossary}).@refill
 
+The entire @code{awk} language is summarized for quick reference in
+@ref{Gawk Summary}.  Look there if you just need to refresh your memory
+about a particular feature.@refill
+
 Most of the time complete @code{awk} programs are used as examples, but in
 some of the more advanced sections, only the part of the @code{awk} program
 that illustrates the concept being described is shown.@refill
@@ -616,7 +735,7 @@ This chapter contains the following sections:
 @cindex @file{BBS-list} file
 Many of the examples in this manual take their input from two sample
 data files.  The first, called @file{BBS-list}, represents a list of
-computer bulletin board systems and information about those systems.
+computer bulletin board systems together with information about those systems.
 The second data file, called @file{inventory-shipped}, contains
 information about shipments on a monthly basis.  Each line of these
 files is one @dfn{record}.
@@ -624,7 +743,7 @@ files is one @dfn{record}.
 In the file @file{BBS-list}, each record contains the name of a computer
 bulletin board, its phone number, the board's baud rate, and a code for
 the number of hours it is operational.  An @samp{A} in the last column
-means the board operates 24 hours all week.  A @samp{B} in the last
+means the board operates 24 hours a day.  A @samp{B} in the last
 column means the board operates evening and weekend hours, only.  A
 @samp{C} means the board operates only on weekends.
 
@@ -651,7 +770,7 @@ also one record.  Each record contains the month of the year, the number
 of green crates shipped, the number of red boxes shipped, the number of
 orange bags shipped, and the number of blue packages shipped,
 respectively.  There are 16 entries, covering the 12 months of one year
-and 4 months of the next year.
+and 4 months of the next year.@refill
 
 @group
 @example
@@ -784,7 +903,7 @@ empty action that does nothing; then no lines would be printed.
 @cindex how @code{awk} works
 
 The @code{awk} utility reads the input files one line at a
-time.  For each line, @code{awk} tries the patterns of all the rules.
+time.  For each line, @code{awk} tries the patterns of each of the rules.
 If several patterns match then several actions are run, in the order in
 which they appear in the @code{awk} program.  If no patterns match, then
 no actions are run.
@@ -859,12 +978,12 @@ ls -l | awk '$5 == "Nov" @{ sum += $4 @}
 This command prints the total number of bytes in all the files in the
 current directory that were last modified in November (of any year).
 (In the C shell you would need to type a semicolon and then a backslash
-at the end of the first line; in the Bourne shell or the Bourne-Again
-shell, you can type the example as shown.)
+at the end of the first line; in a @sc{POSIX}-compliant shell, such as the
+Bourne shell or the Bourne-Again shell, you can type the example as shown.)
 
 The @w{@samp{ls -l}} part of this example is a command that gives you a full
 listing of all the files in a directory, including file size and date.
-Its output looks like this:
+Its output looks like this:@refill
 
 @example
 -rw-r--r--  1 close        1933 Nov  7 13:05 Makefile
@@ -892,7 +1011,8 @@ matches the string @samp{Nov}.  Each time a line has the string
 performed.  This adds the fourth field (the file size) to the variable
 @code{sum}.  As a result, when @code{awk} has finished reading all the
 input lines, @code{sum} is the sum of the sizes of files whose
-lines matched the pattern.@refill
+lines matched the pattern.  (This works because @code{awk} variables
+are automatically initialized to zero.)@refill
 
 After the last line of output from @code{ls} has been processed, the
 @code{END} rule is executed, and the value of @code{sum} is
@@ -905,10 +1025,23 @@ displays your output.  By manipulating fields and using @code{print}
 statements, you can produce some very useful and spectacular looking
 reports.@refill
 
-
 @node Running gawk, Comments, More Complex, Getting Started
 @section How to Run @code{awk} Programs
 
+@ignore
+Date: Mon, 26 Aug 91 09:48:10 +0200
+From: gatech!vsoc07.cern.ch!matheys (Jean-Pol Matheys (CERN - ECP Division))
+To: uunet.UU.NET!skeeve!arnold
+Subject: RE: status check
+
+The introduction of Chapter 2 (i.e. before 2.1) should include
+the whole of section 2.4  -  it's better to tell people how to run awk programs
+before giving any examples
+
+ADR --- he's right.  but for now, don't do this because the rest of the
+chapter would need some rewriting.
+@end ignore
+
 @cindex command line formats
 @cindex running @code{awk} programs
 There are several ways to run an @code{awk} program.  If the program is
@@ -923,7 +1056,7 @@ awk '@var{program}' @var{input-file1} @var{input-file2} @dots{}
 where @var{program} consists of a series of patterns and actions, as
 described earlier.
 
-When the program is long, you would probably prefer to put it in a file
+When the program is long, it is usually more convenient to put it in a file
 and run it with a command like this:
 
 @example
@@ -953,13 +1086,12 @@ where @var{program} consists of a series of @var{patterns} and
 @var{actions}, as described earlier.
 
 @cindex single quotes, why needed
-This command format tells the shell to start @code{awk} and use the
+This command format instructs the shell to start @code{awk} and use the
 @var{program} to process records in the input file(s).  There are single
-quotes around the @var{program} so that the shell doesn't interpret any
-@code{awk} characters as special shell characters.  They cause the
+quotes around @var{program} so that the shell doesn't interpret any
+@code{awk} characters as special shell characters.  They also cause the
 shell to treat all of @var{program} as a single argument for
-@code{awk}.  They also allow @var{program} to be more than one line
-long.@refill
+@code{awk} and allow @var{program} to be more than one line long.@refill
 
 This format is also useful for running short or medium-sized @code{awk}
 programs from shell scripts, because it avoids the need for a separate
@@ -971,7 +1103,7 @@ reliable since there are no other files to misplace.
 
 @cindex standard input
 @cindex input, standard
-You can also use @code{awk} without any input files.  If you type the
+You can also run @code{awk} without any input files.  If you type the
 command line:@refill
 
 @example
@@ -1037,7 +1169,7 @@ more convenient to put the program into a separate file.  To tell
 awk -f @var{source-file} @var{input-file1} @var{input-file2} @dots{}
 @end example
 
-The @samp{-f} tells the @code{awk} utility to get the @code{awk} program
+The @samp{-f} instructs the @code{awk} utility to get the @code{awk} program
 from the file @var{source-file}.  Any file name can be used for
 @var{source-file}.  For example, you could put the program:@refill
 
@@ -1063,7 +1195,9 @@ awk '/th/'
 which was explained earlier (@pxref{Read Terminal}).  Note that you
 don't usually need single quotes around the file name that you specify
 with @samp{-f}, because most file names don't contain any of the shell's
-special characters.
+special characters.  Notice that in @file{th-prog}, the @code{awk}
+program did not have single quotes around it.  The quotes are only needed
+for programs that are provided on the @code{awk} command line.
 
 If you want to identify your @code{awk} program files clearly as such,
 you can add the extension @file{.awk} to the file name.  This doesn't
@@ -1081,7 +1215,9 @@ affect the execution of the @code{awk} program, but it does make
 
 Once you have learned @code{awk}, you may want to write self-contained
 @code{awk} scripts, using the @samp{#!} script mechanism.  You can do
-this on BSD Unix systems and (someday) on GNU.
+this on many Unix systems @footnote{The @samp{#!} mechanism works on
+Unix systems derived from BSD Unix, System V Release 4, and some System
+V Release 3 systems.} and (someday) on GNU.@refill
 
 For example, you could create a text file named @file{hello}, containing
 the following (where @samp{BEGIN} is a feature we have not yet
@@ -1103,8 +1239,14 @@ hello
 @end example
 
 @noindent
-at the shell, and the system will arrange to run @code{awk} as if you
-had typed:
+at the shell, and the system will arrange to run @code{awk} @footnote{The
+line beginning with @samp{#!} lists the full pathname of an interpreter
+to be run, and an optional initial command line argument to pass to that
+interpreter.  The operating system then runs the interpreter with the given
+argument and the full argument list of the executed program.  The first argument
+in the list is the full pathname of the @code{awk} program.  The rest of the
+argument list will either be options to @code{awk}, or data files,
+or both.} as if you had typed:@refill
 
 @example
 awk -f hello
@@ -1128,7 +1270,7 @@ awk '@var{program}' "$@@"
 
 Using this technique, it is @emph{vital} to enclose the @var{program} in
 single quotes to protect it from interpretation by the shell.  If you
-omit the quotes, only a shell wizard can predict the result.
+omit the quotes, only a shell wizard can predict the results.
 
 The @samp{"$@@"} causes the shell to forward all the command line
 arguments to the @code{awk} program, without interpretation.  The first
@@ -1136,17 +1278,9 @@ line, which starts with a colon, is used so that this shell script will
 work even if invoked by a user who uses the C shell.
 @c Someday: (See @cite{The Bourne Again Shell}, by ??.)
 
-@c We don't refer to hoarded information.
-@c  (See
-@c @cite{The UNIX Programming Environment} by Brian Kernighan and Rob Pike,
-@c Prentice-Hall, 1984, for more information on writing shell programs that
-@c use the Unix utilities.  The most powerful version of the shell is the
-@c Korn shell.  A detailed description of the Korn shell can be found in
-@c @cite{The KornShell Command and Programming Language} by Morris Bolsky
-@c and David Korn, Prentice-Hall, 1989.)
-
 @node Comments, Statements/Lines, Running gawk, Getting Started
 @section Comments in @code{awk} Programs
+@cindex @samp{#}
 @cindex comments
 @cindex use of comments
 @cindex documenting @code{awk} programs
@@ -1156,7 +1290,7 @@ A @dfn{comment} is some text that is included in a program for the sake
 of human readers, and that is not really part of the program.  Comments
 can explain what the program does, and how it works.  Nearly all
 programming languages have provisions for comments, because programs are
-hard to understand without their extra help.
+typically hard to understand without their extra help.
 
 In the @code{awk} language, a comment starts with the sharp sign
 character, @samp{#}, and continues to the end of the line.  The
@@ -1172,7 +1306,7 @@ For example, we could have put the following into @file{th-prog}:@refill
 You can put comment lines into keyboard-composed throw-away @code{awk}
 programs also, but this usually isn't very useful; the purpose of a
 comment is to help you or another person understand the program at
-another time.
+a later time.@refill
 
 @node Statements/Lines, When, Comments, Getting Started
 @section @code{awk} Statements versus Lines
@@ -1187,7 +1321,7 @@ awk '/12/  @{ print $0 @}
 
 But sometimes statements can be more than one line, and lines can
 contain several statements.  You can split a statement into multiple
-lines by inserting a newline after any of the following:
+lines by inserting a newline after any of the following:@refill
 
 @example
 ,    @{    ?    :    ||    &&    do    else
@@ -1195,6 +1329,9 @@ lines by inserting a newline after any of the following:
 
 @noindent
 A newline at any other point is considered the end of the statement.
+(Splitting lines after @samp{?} and @samp{:} is a minor @code{gawk}
+extension.  The @samp{?} and @samp{:} referred to here is the 
+three operand coditional expression described in @ref{Conditional Exp}.)
 
 @cindex backslash continuation
 @cindex continuation of lines
@@ -1211,25 +1348,30 @@ awk '/This program is too long, so continue it\
 
 @noindent
 We have generally not used backslash continuation in the sample programs in
-this manual.  Since there is no limit on the length of a line, it is never
-strictly necessary; it just makes programs prettier.  We have preferred to
-make them even more pretty by keeping the statements short.  Backslash
-continuation is most useful when your @code{awk} program is in a separate
-source file, instead of typed in on the command line.
+this manual.  Since in @code{gawk} there is no limit on the length of a line,
+it is never strictly necessary; it just makes programs prettier.  We have
+preferred to make them even more pretty by keeping the statements short.
+Backslash continuation is most useful when your @code{awk} program is in a
+separate source file, instead of typed in on the command line.  You should
+also note that many @code{awk} implementations are more picky about where
+you may use backslash continuation.  For maximal portability of your @code{awk}
+programs, it is best not to split your lines in the middle of a regular
+expression or a string.@refill
 
 @strong{Warning: backslash continuation does not work as described above
 with the C shell.}  Continuation with backslash works for @code{awk}
 programs in files, and also for one-shot programs @emph{provided} you
-are using the Bourne shell or the Bourne-again shell.  But the C shell
-used on Berkeley Unix behaves differently!  There, you must use two
-backslashes in a row, followed by a newline.@refill
+are using a @sc{POSIX}-compliant shell, such as the Bourne shell or the
+Bourne-again shell.  But the C shell used on Berkeley Unix behaves
+differently!  There, you must use two backslashes in a row, followed by
+a newline.@refill
 
 @cindex multiple statements on one line
 When @code{awk} statements within one rule are short, you might want to put
 more than one of them on a line.  You do this by separating the statements
-with semicolons, @samp{;}.
+with a semicolon, @samp{;}.
 This also applies to the rules themselves.
-Thus, the above example program could have been written:@refill
+Thus, the previous program could have been written:@refill
 
 @example
 /12/ @{ print $0 @} ; /21/ @{ print $0 @}
@@ -1251,7 +1393,7 @@ programs, more advanced patterns, field separators, arithmetic
 statements, and other selection criteria, you can produce much more
 complex output.  The @code{awk} language is very useful for producing
 reports from large amounts of raw data, such as summarizing information
-from the output of other utility programs such as @code{ls}.
+from the output of other utility programs like @code{ls}.
 (@xref{More Complex, , A More Complex Example}.)
 
 Programs written with @code{awk} are usually much smaller than they would
@@ -1286,18 +1428,17 @@ easier to maintain and usually run more efficiently.@refill
 @cindex standard input
 @vindex FILENAME
 In the typical @code{awk} program, all input is read either from the
-standard input (usually the keyboard) or from files whose names you
-specify on the @code{awk} command line.  If you specify input files,
-@code{awk} reads data from the first one until it reaches the end; then
-it reads the second file until it reaches the end, and so on.  The name
-of the current input file can be found in the built-in variable
-@code{FILENAME} (@pxref{Built-in Variables}).@refill
+standard input (by default the keyboard, but often a pipe from another
+command) or from files whose names you specify on the @code{awk} command
+line.  If you specify input files, @code{awk} reads them in order, reading
+all the data frome one before going on to the next.  The name of the current
+input file can be found in the built-in variable @code{FILENAME}
+(@pxref{Built-in Variables}).@refill
 
 The input is read in units called @dfn{records}, and processed by the
 rules one record at a time.  By default, each record is one line.  Each
-record read is split automatically into @dfn{fields}, to make it more
-convenient for a rule to work on parts of the record under
-consideration.
+record is split automatically into @dfn{fields}, to make it more
+convenient for a rule to work on its parts.
 
 On rare occasions you will need to use the @code{getline} command,
 which can do explicit input from any number of files (@pxref{Getline}).
@@ -1308,6 +1449,7 @@ which can do explicit input from any number of files (@pxref{Getline}).
 * Non-Constant Fields:: Non-constant Field Numbers.
 * Changing Fields::     Changing the Contents of a Field.
 * Field Separators::    The field separator and how to change it.
+* Constant Size::       Reading constant width data.
 * Multiple Line::       Reading multi-line records.
 
 * Getline::             Reading files under explicit program control
@@ -1323,18 +1465,18 @@ which can do explicit input from any number of files (@pxref{Getline}).
 @cindex record separator
 The @code{awk} language divides its input into records and fields.
 Records are separated by a character called the @dfn{record separator}.
-By default, the record separator is the newline character.  Therefore,
-normally, a record is a line of text.@refill
+By default, the record separator is the newline character, defining
+a record to be a single line of text.@refill
 
-@c @cindex changing the record separator
+@iftex
+@cindex changing the record separator
+@end iftex
 @vindex RS
 Sometimes you may want to use a different character to separate your
-records.  You can use different characters by changing the built-in
-variable @code{RS}.  
-
-The value of @code{RS} is a string that says how to separate records;
-the default value is @code{"\n"}, the string of just a newline
-character.  This is why records are, by default, single lines.
+records.  You can use a different character by changing the built-in
+variable @code{RS}.  The value of @code{RS} is a string that says how
+to separate records; the default value is @code{"\n"}, the string containing
+just a newline character.  This is why records are, by default, single lines.
 
 @code{RS} can have any string as its value, but only the first character
 of the string is used as the record separator.  The other characters are
@@ -1381,13 +1523,29 @@ Another way to change the record separator is on the command line,
 using the variable-assignment feature (@pxref{Command Line}).
 
 @example
-awk '@dots{}' RS="/" @var{source-file}
+awk '@{ print $0 @}' RS="/" BBS-list
 @end example
 
 @noindent
-This sets @code{RS} to @samp{/} before processing @var{source-file}.
+This sets @code{RS} to @samp{/} before processing @file{BBS-list}.
+
+Reaching the end of an input file terminates the current input record,
+even if the last character in the file is not the character in @code{RS}.
+
+@ignore
+@c merge the preceding paragraph and this stuff into one paragraph
+@c and put it in an `expert info' section.
+This produces correct behavior in the vast majority of cases, although
+the following (extreme) pipeline prints a suprising @samp{1}.  (There
+is one field, consisting of a newline.)
+
+@example
+echo | awk 'BEGIN @{ RS = "a" @} ; @{ print NF @}'
+@end example
 
-The empty string (a string of no characters) has a special meaning
+@end ignore
+
+The empty string, @code{""} (a string of no characters), has a special meaning
 as the value of @code{RS}: it means that records are separated only
 by blank lines.  @xref{Multiple Line}, for more details.
 
@@ -1403,7 +1561,7 @@ but is never automatically reset to zero.
 
 If you change the value of @code{RS} in the middle of an @code{awk} run,
 the new value is used to delimit subsequent records, but the record
-currently being processed (and records already finished) are not
+currently being processed (and records already processed) are not
 affected.
 
 @node Fields, Non-Constant Fields, Records, Reading Files
@@ -1413,13 +1571,13 @@ affected.
 @cindex fields
 @cindex accessing fields
 When @code{awk} reads an input record, the record is
-automatically separated or @dfn{parsed} by the interpreter into pieces
+automatically separated or @dfn{parsed} by the interpreter into chunks
 called @dfn{fields}.  By default, fields are separated by whitespace,
 like words in a line.
 Whitespace in @code{awk} means any string of one or more spaces and/or
 tabs; other characters such as newline, formfeed, and so on, that are
 considered whitespace by other languages are @emph{not} considered
-whitespace by @code{awk}.
+whitespace by @code{awk}.@refill
 
 The purpose of fields is to make it more convenient for you to refer to
 these pieces of the record.  You don't have to use them---you can
@@ -1449,7 +1607,7 @@ represented by @code{$NF}.  So, in the example above, @code{$NF} would
 be the same as @code{$7}, which is @samp{example.}.  Why this works is
 explained below (@pxref{Non-Constant Fields}).  If you try to refer to a
 field beyond the last one, such as @code{$8} when the record has only 7
-fields, you get the empty string.
+fields, you get the empty string.@refill
 
 @vindex NF
 @cindex number of fields, @code{NF}
@@ -1458,7 +1616,7 @@ is the number of fields in the current record.
 
 @code{$0}, which looks like an attempt to refer to the zeroth field, is
 a special case: it represents the whole input record.  This is what you
-would use when you aren't interested in fields.
+would use if you weren't interested in fields.
 
 Here are some more examples:
 
@@ -1470,7 +1628,7 @@ awk '$1 ~ /foo/ @{ print $0 @}' BBS-list
 This example prints each record in the file @file{BBS-list} whose first
 field contains the string @samp{foo}.  The operator @samp{~} is called a
 @dfn{matching operator} (@pxref{Comparison Ops}); it tests whether a
-string (here, the field @code{$1}) contains a match for a given regular
+string (here, the field @code{$1}) matches a given regular
 expression.@refill
 
 By contrast, the following example:
@@ -1539,7 +1697,7 @@ You can change the contents of a field as seen by @code{awk} within an
 current input record.  (The actual input is untouched: @code{awk} never
 modifies the input file.)
 
-Look at this example:
+Consider this example:
 
 @example
 awk '@{ $3 = $2 - 10; print $2, $3 @}' inventory-shipped
@@ -1613,13 +1771,38 @@ should print @samp{everything is normal}, because @code{NF+1} is certain
 to be out of range.  (@xref{If Statement}, for more information about
 @code{awk}'s @code{if-else} statements.)
 
-@node Field Separators, Multiple Line, Changing Fields, Reading Files
+It is important to note that assigning to a field will change the
+value of @code{$0}, but will not change the value of @code{NF},
+even when you assign the null string to a field.  For example:
+
+@example
+echo a b c d | awk '@{ OFS = ":"; $2 = "" ; print ; print NF @}'
+@end example
+
+@noindent
+prints
+
+@example
+a::c:d
+4
+@end example
+
+@noindent
+The field is still there, it just has an empty value.  You can tell
+because there are two colons in a row.
+
+@node Field Separators, Constant Size, Changing Fields, Reading Files
 @section Specifying How Fields Are Separated
 @vindex FS
 @cindex fields, separating
 @cindex field separator, @code{FS}
 @cindex @samp{-F} option
 
+(This section is rather long; it describes one of the most fundamental
+operations in @code{awk}.  If you are a novice with @code{awk}, we
+recommend that you re-read this section after you have studied the
+section on regular expressions, @ref{Regexp}.)
+
 The way @code{awk} splits an input record into fields is controlled by
 the @dfn{field separator}, which is a single character or a regular
 expression.  @code{awk} scans the input record for matches for the
@@ -1635,8 +1818,8 @@ would be split into three fields: @samp{m}, @samp{@ g} and @samp{@ gai@
 pan}.
 
 The field separator is represented by the built-in variable @code{FS}.
-Shell programmers take note!  @code{awk} does not use the name
-@code{IFS} which is used by the shell.@refill
+Shell programmers take note!  @code{awk} does not use the name @code{IFS}
+which is used by the shell.@refill
 
 You can change the value of @code{FS} in the @code{awk} program with the
 assignment operator, @samp{=} (@pxref{Assignment Ops}).  Often the right
@@ -1658,7 +1841,7 @@ John Q. Smith, 29 Oak St., Walamazoo, MI 42139
 @end example
 
 @noindent
-this @code{awk} program extracts the string @samp{29 Oak St.}.
+this @code{awk} program extracts the string @samp{@ 29 Oak St.}.
 
 @cindex field separator, choice of
 @cindex regular expressions as field separators
@@ -1673,8 +1856,8 @@ John Q. Smith, LXIX, 29 Oak St., Walamazoo, MI 42139
 @end example
 
 @noindent
-the previous sample program would extract @samp{LXIX}, instead of
-@samp{29 Oak St.}.  If you were expecting the program to print the
+the previous sample program would extract @samp{@ LXIX}, instead of
+@samp{@ 29 Oak St.}.  If you were expecting the program to print the
 address, you would be surprised.  So choose your data layout and
 separator characters carefully to prevent such problems.
 
@@ -1728,14 +1911,33 @@ a capital @samp{F}.  Contrast this with @samp{-f}, which specifies a file
 containing an @code{awk} program.  Case is significant in command options:
 the @samp{-F} and @samp{-f} options have nothing to do with each other.
 You can use both options at the same time to set the @code{FS} argument
-@emph{and} get an @code{awk} program from a file.
+@emph{and} get an @code{awk} program from a file.@refill
+
+@c begin expert info
+The value used for the argument to @samp{-F} is processed in exactly the
+same way as assignments to the built-in variable @code{FS}.  This means that
+if the field separator contains special characters, they must be escaped
+appropriately.  For example, to use a @samp{\} as the field separator, you
+would have to type:
+
+@example
+# same as FS = "\\" 
+awk -F\\\\ '@dots{}' files @dots{}
+@end example
+
+@noindent
+Since @samp{\} is used for quoting in the shell, @code{awk} will see
+@samp{-F\\}.  Then @code{awk} processes the @samp{\\} for escape
+characters (@pxref{Constants}), finally yielding a single @samp{\} to
+be used for the field separator.
+@c end expert info
 
 As a special case, in compatibility mode (@pxref{Command Line}), if the
 argument to @samp{-F} is @samp{t}, then @code{FS} is set to the tab
 character.  (This is because if you type @samp{-F\t}, without the quotes,
 at the shell, the @samp{\} gets deleted, so @code{awk} figures that you
 really want your fields to be separated with tabs, and not @samp{t}s.
-Use @samp{FS="t"} on the command line if you really do want to separate
+Use @samp{-v FS="t"} on the command line if you really do want to separate
 your fields with @samp{t}s.)
 
 For example, let's use an @code{awk} program file called @file{baud.awk}
@@ -1798,7 +2000,192 @@ separator.  Note that fields in @file{/etc/passwd} are separated by
 colons.  The second field represents a user's encrypted password, but if
 the field is empty, that user has no password.
 
-@node Multiple Line, Getline, Field Separators, Reading Files
+@c begin expert info
+According to the @sc{POSIX} standard, @code{awk} is supposed to behave
+as if each record is split into fields at the time that it is read.
+In particular, this means that you can change the value of @code{FS}
+after a record is read, but before any of the fields are referenced.
+The value of the fields (i.e. how they were split) should reflect the
+old value of @code{FS}, not the new one.
+
+However, many implementations of @code{awk} do not do this.  Instead,
+they defer splitting the fields until a field reference actually happens,
+using the @emph{current} value of @code{FS}!  This behavior can be difficult
+to diagnose. The following example illustrates the results of the two methods.
+(The @code{sed} command prints just the first line of @file{/etc/passwd}.)
+
+@example
+sed 1q /etc/passwd | awk '@{ FS = ":" ; print $1 @}'
+@end example
+
+@noindent
+will usually print
+
+@example
+root
+@end example
+
+@noindent
+on an incorrect implementation of @code{awk}, while @code{gawk}
+will print something like
+
+@example
+root:nSijPlPhZZwgE:0:0:Root:/:
+@end example
+@c end expert info
+
+@c begin expert info
+There is an important difference between the two cases of @samp{FS = @w{" "}}
+and @samp{FS = @w{"[ \t]+"}} (which is a regular expression matching one or
+more blanks or tabs).  For both values of @code{FS}, fields are separated
+by runs of blanks and/or tabs.  However, when the value of @code{FS} is
+@code{" "}, @code{awk} will strip leading and trailing whitespace from the
+record, and then decide where the fields are.
+
+@example
+echo ' a b c d ' | awk '@{ print $2 @}'
+@end example
+
+@noindent
+prints @samp{b}.  However, this example
+
+@example
+echo ' a b c d ' | awk 'BEGIN @{ FS = "[ \t]+" @} ; @{ print $2 @}'
+@end example
+
+@noindent
+prints @samp{a}.  In this case, the first field is null.
+
+The stripping of leading and trailing whitespace also comes into
+play whenever @code{$0} is recomputed.  For instance, this pipeline
+
+@example
+echo '   a b c d' | awk '@{ print; $2 = $2; print @}'
+@end example
+
+@noindent
+produces this output:
+
+@example
+   a b c d
+a b c d
+@end example
+
+@noindent
+The first @code{print} statement prints the record as it was read,
+with leading whitespace intact.  The assignment to @code{$2} rebuilds
+@code{$0} by concatentating @code{$1} through @code{$NF} together,
+separated by the value of @code{OFS}.  Since the leading whitespace
+was ignored when finding @code{$1}, it is not part of the new @code{$0}.
+Finally, the last @code{print} statement prints the new @code{$0}.
+@c end expert info
+
+The following table summarizes how fields are split, based on the
+value of @code{FS}.
+
+@table @code
+@item FS == " "
+Fields are separated by runs of whitespace.  Leading and trailing
+whitespace are ignored.  This is the default.
+
+@item FS == @var{any single character}
+Fields are separated by each occurrence of the character.  Multiple
+successive occurrences delimit empty fields, as do leading and
+trailing occurrences.
+
+@item FS == @var{regexp}
+Fields are separated by occurrences of characters that match @var{regexp}.
+Leading and trailing matches of @var{regexp} delimit empty fields.
+@end table
+
+@node Constant Size, Multiple Line, Field Separators, Reading Files
+@section Reading Constant Width Data
+
+(This section discusses an advanced, experimental feature.  If you are
+a novice @code{awk} user, you may wish to skip it on the first reading.)
+
+@code{gawk} 2.13 introduced a new facility for dealing with fixed-width fields
+with no distinctive field separator.  Data of this nature arises typically
+in one of at least two ways:  the input for old FORTRAN programs where
+numbers are run together, and the output of programs that did not anticipate
+the use of their output as input for other programs.
+
+An example of the latter is a table where all the columns are lined up by
+the use of a variable number of spaces and @emph{empty fields are just
+spaces}.  Clearly, @code{awk}'s normal field splitting based on @code{FS}
+will not work well in this case.  (Although a portable @code{awk} program
+can use a series of @code{substr} calls on @code{$0}, this is awkward and
+inefficient for a large number of fields.)@refill
+
+The splitting of an input record into fixed-width fields is specified by
+assigning a string containing space-separated numbers to the built-in
+variable @code{FIELDWIDTHS}.  Each number specifies the width of the field
+@emph{including} columns between fields.  If you want to ignore the columns
+between fields, you can specify the width as a separate field that is
+subsequently ignored.
+
+The following data is the output of the @code{w} utility.  It is useful
+to illustrate the use of @code{FIELDWIDTHS}.
+
+@example
+ 10:06pm  up 21 days, 14:04,  23 users,  load average: 1.21, 1.36, 1.43
+User     tty       login@  idle   JCPU   PCPU  what
+hzuo     ttyV0     8:58pm            9      5  vi p24.tex 
+hzang    ttyV3     6:37pm    50                -csh 
+eklye    ttyV5     9:53pm            7      1  em thesis_11jul91.tex 
+dportein ttyV6     8:17pm  1:47                -csh 
+gierd    ttyD3    10:00pm     1                elm 
+dave     ttyD4     9:47pm            4      4  w 
+brent    ttyp0    26Jun91  4:46  26:46   4:41  bash 
+dave     ttyq4    26Jun9115days     46     46  wnewmail 
+@end example
+
+The following program takes the above input, converts the idle time to
+number of seconds and prints out the first two fields and the calculated
+idle time.  (This program uses a number of @code{awk} features that
+haven't been introduced yet.)@refill
+
+@example
+BEGIN  @{ FIELDWIDTHS = "9 6 10 6 7 7 35" @}
+NR > 2 @{
+         idle = $4
+         sub(/^  */, "", idle)   # strip leading spaces
+         if (idle == "") idle = 0
+         if (idle ~ /:/) @{ split(idle, t, ":"); idle = t[1] * 60 + t[2] @}
+         if (idle ~ /days/) @{ idle *= 24 * 60 * 60 @}
+ 
+         print $1, $2, idle
+       @}
+@end example
+
+Here is the result of running the program on the data:
+
+@example
+hzuo      ttyV0  0
+hzang     ttyV3  50
+eklye     ttyV5  0
+dportein  ttyV6  107
+gierd     ttyD3  1
+dave      ttyD4  0
+brent     ttyp0  286
+dave      ttyq4  1296000
+@end example
+
+Another (possibly more practical) example of fixed-width input data
+would be the input from a deck of balloting cards.  In some parts of
+the United States, voters make their choices by punching holes in computer
+cards.  These cards are then processed to count the votes for any particular
+candidate or on any particular issue.  Since a voter may choose not to
+vote on some issue, any column on the card may be empty.  An @code{awk}
+program for processing such data could use the @code{FIELDWIDTHS} feature
+to simplify reading the data.@refill
+
+@c of course, getting gawk to run on a system with card readers is
+@c another story!
+
+This feature is still experimental, and will likely evolve over time.
+
+@node Multiple Line, Getline, Constant Size, Reading Files
 @section Multiple-Line Records
 
 @cindex multiple line records
@@ -1819,7 +2206,7 @@ records.  For example, you could use the formfeed character (written
 a page of the file.  To do this, just set the variable @code{RS} to
 @code{"\f"} (a string containing the formfeed character).  Any
 other character could equally well be used, as long as it won't be part
-of the data in a record.
+of the data in a record.@refill
 
 @ignore
 Another technique is to have blank lines separate records.  The string
@@ -1839,22 +2226,23 @@ records are separated by one or more blank lines.  If you set @code{RS}
 to the null string, a record always ends at the first blank line
 encountered.  And the next record doesn't start until the first nonblank
 line that follows---no matter how many blank lines appear in a row, they
-are considered one record-separator.
+are considered one record-separator. (End of file is also considered
+a record separator.)@refill
 
 The second step is to separate the fields in the record.  One way to do
 this is to put each field on a separate line: to do this, just set the
 variable @code{FS} to the string @code{"\n"}.  (This simple regular
 expression matches a single newline.)
 
-Another idea is to divide each of the lines into fields in the normal
-manner.  This happens by default as a result of a special feature: when
-@code{RS} is set to the null string, the newline character @emph{always}
-acts as a field separator.  This is in addition to whatever field
-separations result from @code{FS}.
+Another way to separate fields is to divide each of the lines into fields
+in the normal manner.  This happens by default as a result of a special
+feature: when @code{RS} is set to the null string, the newline character
+@emph{always} acts as a field separator.  This is in addition to whatever
+field separations result from @code{FS}.
 
 The original motivation for this special exception was probably so that
-you get useful behavior in the default case (i.e., @w{@code{FS == "
-"}}).  This feature can be a problem if you really don't want the
+you get useful behavior in the default case (i.e., @w{@code{FS == " "}}).
+This feature can be a problem if you really don't want the
 newline character to separate fields, since there is no way to
 prevent it.  However, you can work around this by using the @code{split}
 function to break up the record manually (@pxref{String Functions}).
@@ -1893,7 +2281,7 @@ So far we have been getting our input files from @code{awk}'s main
 input stream---either the standard input (usually your terminal) or the
 files specified on the command line.  The @code{awk} language has a
 special built-in command called @code{getline} that
-can be used to read input under your explicit control.
+can be used to read input under your explicit control.@refill
 
 This command is quite complex and should @emph{not} be used by
 beginners.  It is covered here because this is the chapter on input.
@@ -1921,17 +2309,17 @@ example:@refill
 @example
 awk '@{
      if (t = index($0, "/*")) @{
-          if(t > 1)
+          if (t > 1)
                tmp = substr($0, 1, t - 1)
           else
                tmp = ""
           u = index(substr($0, t + 2), "*/")
-          while (! u) @{
+          while (u == 0) @{
                getline
                t = -1
                u = index($0, "*/")
           @}
-          if(u <= length($0) - 2)
+          if (u <= length($0) - 2)
                $0 = tmp substr($0, t + u + 3)
           else
                $0 = tmp
@@ -1940,11 +2328,15 @@ awk '@{
 @}'
 @end example
 
-This @code{awk} program deletes all comments, @samp{/* @dots{}
+This @code{awk} program deletes all C-style comments, @samp{/* @dots{}
 */}, from the input.  By replacing the @samp{print $0} with other
 statements, you could perform more complicated processing on the
-decommented input, such as searching it for matches for a regular
-expression.
+decommented input, such as searching it for matches of a regular
+expression.  (This program has a subtle problem---can you spot it?)
+
+@c the program to remove comments doesn't work if one
+@c comment ends and another begins on the same line.  (Your
+@c idea for restart would be useful here).  --- brennan@boeing.com
 
 This form of the @code{getline} command sets @code{NF} (the number of
 fields; @pxref{Fields}), @code{NR} (the number of records read so far;
@@ -2023,11 +2415,11 @@ file.@refill
 
 @example
 awk '@{
-if ($1 == 10) @{
-     getline < "foo.input"
-     print
-@} else
-     print
+    if ($1 == 10) @{
+         getline < "foo.input"
+         print
+    @} else
+         print
 @}'
 @end example
 
@@ -2045,7 +2437,7 @@ the new record is tested against any subsequent rules, just as when
 @item getline @var{var} < @var{file}
 This form of the @code{getline} function takes its input from the file
 @var{file} and puts it in the variable @var{var}.  As above, @var{file}
-is a string-valued expression that specifies the file to read from.
+is a string-valued expression that specifies the file from which to read.
 
 In this version of @code{getline}, none of the built-in variables are
 changed, and the record is not split into fields.  The only variable
@@ -2069,11 +2461,11 @@ awk '@{
 
 Note here how the name of the extra input file is not built into
 the program; it is taken from the data, from the second field on
-the @samp{@@include} line.
+the @samp{@@include} line.@refill
 
 The @code{close} function is called to ensure that if two identical
 @samp{@@include} lines appear in the input, the entire specified file is
-included twice.  @xref{Close Input}.
+included twice.  @xref{Close Input}.@refill
 
 One deficiency of this program is that it does not process nested
 @samp{@@include} statements the way a true macro preprocessor would.
@@ -2134,7 +2526,7 @@ bletch
 @noindent
 Notice that this program ran the command @code{who} and printed the result.
 (If you try this program yourself, you will get different results, showing
-you logged in.)
+you who is logged in on your system.)
 
 This variation of @code{getline} splits the record into fields, sets the
 value of @code{NF} and recomputes the value of @code{$0}.  The values of
@@ -2144,7 +2536,7 @@ value of @code{NF} and recomputes the value of @code{$0}.  The values of
 The output of the command @var{command} is sent through a pipe to
 @code{getline} and into the variable @var{var}.  For example, the
 following program reads the current date and time into the variable
-@code{current_time}, using the utility called @code{date}, and then
+@code{current_time}, using the @code{date} utility, and then
 prints it.@refill
 
 @group
@@ -2174,9 +2566,9 @@ The next time the same file or command is used in @code{getline}, another
 record is read from it, and so on.
 
 This implies that if you want to start reading the same file again from
-the beginning, or if you want to rerun a shell command (rather that
+the beginning, or if you want to rerun a shell command (rather than
 reading more output from the command), you must take special steps.
-What you can do is use the @code{close} function, as follows:
+What you must do is use the @code{close} function, as follows:
 
 @example
 close(@var{filename})
@@ -2221,6 +2613,7 @@ Both are described in this chapter.
 * Print::              The @code{print} statement.
 * Print Examples::     Simple examples of @code{print} statements.
 * Output Separators::  The output separators and how to change them.
+* OFMT::               Controlling Numeric Output With @code{print}.
 * Printf::             The @code{printf} statement.
 * Redirection::        How to redirect output to multiple files and pipes.
 * Special Files::      File name interpretation in @code{gawk}.  @code{gawk}
@@ -2251,11 +2644,12 @@ relational operator; otherwise it could be confused with a redirection
 The items printed can be constant strings or numbers, fields of the
 current record (such as @code{$1}), variables, or any @code{awk}
 expressions.  The @code{print} statement is completely general for
-computing @emph{what} values to print.  With one exception
-(@pxref{Output Separators}), what you can't do is specify @emph{how} to
-print them---how many columns to use, whether to use exponential
-notation or not, and so on.  For that, you need the @code{printf}
-statement (@pxref{Printf}).
+computing @emph{what} values to print.  With two exceptions
+(@pxref{Output Separators},
+and @pxref{OFMT}), what you can't do is
+specify @emph{how} to print them---how many columns to use, whether to
+use exponential notation or not, and so on.  For that, you need the
+@code{printf} statement (@pxref{Printf}).@refill
 
 The simple statement @samp{print} with no items is equivalent to
 @samp{print $0}: it prints the entire current record.  To print a blank
@@ -2332,9 +2726,8 @@ Neither example's output makes much sense to someone unfamiliar with the
 file @file{inventory-shipped}.  A heading line at the beginning would make
 it clearer.  Let's add some headings to our table of months (@code{$1}) and
 green crates shipped (@code{$2}).  We do this using the @code{BEGIN} pattern
-(@pxref{BEGIN/END}) to cause the headings to be printed only once:
+(@pxref{BEGIN/END}) to force the headings to be printed only once:
 
-@c the formatting is strange here because the @{ becomes just a brace.
 @example
 awk 'BEGIN @{  print "Month Crates"
               print "----- ------" @}
@@ -2370,9 +2763,9 @@ complicated when you have many columns to fix.  Counting spaces for two
 or three columns can be simple, but more than this and you can get
 ``lost'' quite easily.  This is why the @code{printf} statement was
 created (@pxref{Printf}); one of its specialties is lining up columns of
-data.
+data.@refill
 
-@node Output Separators, Printf, Print Examples, Printing
+@node Output Separators, OFMT, Print Examples, Printing
 @section Output Separators
 
 @cindex output field separator, @code{OFS}
@@ -2385,7 +2778,7 @@ separated by single spaces.  But they do not have to be spaces; a
 single space is only the default.  You can specify any string of
 characters to use as the @dfn{output field separator} by setting the
 built-in variable @code{OFS}.  The initial value of this variable
-is the string @w{@code{" "}}.
+is the string @w{@code{" "}}, that is, just a single space.@refill
 
 The output from an entire @code{print} statement is called an
 @dfn{output record}.  Each @code{print} statement outputs one output
@@ -2414,7 +2807,33 @@ If the value of @code{ORS} does not contain a newline, all your output
 will be run together on a single line, unless you output newlines some
 other way.
 
-@node Printf, Redirection, Output Separators, Printing
+@node OFMT, Printf, Output Separators, Printing
+@section Controlling Numeric Output With @code{print}
+@vindex OFMT
+When you use the @code{print} statement to print numeric values,
+@code{awk} internally converts the number to a string of characters,
+and prints that string.  @code{awk} uses the @code{sprintf} function
+to do this conversion.  For now, it suffices to say that the @code{sprintf}
+function accepts a @dfn{format specification} that tells it how to format
+numbers (or strings), and that there are a number of different ways that
+numbers can be formatted.  The different format specifications are discussed
+more fully in @ref{Printf}.@refill
+
+The built-in variable @code{OFMT} contains the default format specification
+that @code{print} uses with @code{sprintf} when it wants to convert a
+number to a string for printing.  By supplying different format specifications
+as the value of @code{OFMT}, you can change how @code{print} will print
+your numbers.  As a brief example:
+
+@example
+awk 'BEGIN @{ OFMT = "%d"  # print numbers as integers
+             print 17.23 @}'
+@end example
+
+@noindent
+will print @samp{17}.
+
+@node Printf, Redirection, OFMT, Printing
 @section Using @code{printf} Statements For Fancier Printing
 @cindex formatted output
 @cindex output, formatted
@@ -2455,21 +2874,21 @@ relational operator; otherwise it could be confused with a redirection
 
 @cindex format string
 The difference between @code{printf} and @code{print} is the argument
-@var{format}.  This is an expression whose value is taken as a string; its
-job is to say how to output each of the other arguments.  It is called
+@var{format}.  This is an expression whose value is taken as a string; it
+specifies how to output each of the other arguments.  It is called
 the @dfn{format string}.
 
-The format string is essentially the same as in the C library function
+The format string is the same as in the @sc{ANSI} C library function
 @code{printf}.  Most of @var{format} is text to be output verbatim.
 Scattered among this text are @dfn{format specifiers}, one per item.
 Each format specifier says to output the next item at that place in the
 format.@refill
 
 The @code{printf} statement does not automatically append a newline to its
-output.  It outputs nothing but what the format specifies.  So if you want
+output.  It outputs only what the format specifies.  So if you want
 a newline, you must include one in the format.  The output separator
 variables @code{OFS} and @code{ORS} have no effect on @code{printf}
-statements.
+statements.@refill
 
 @node Control Letters, Format Modifiers, Basic Printf, Printf
 @subsection Format-Control Letters
@@ -2481,7 +2900,7 @@ A format specifier starts with the character @samp{%} and ends with a
 to output one item.  (If you actually want to output a @samp{%}, write
 @samp{%%}.)  The format-control letter specifies what kind of value to
 print.  The rest of the format specifier is made up of optional
-@dfn{modifiers} which are parameters such as the field width to use.
+@dfn{modifiers} which are parameters such as the field width to use.@refill
 
 Here is a list of the format-control letters:
 
@@ -2514,8 +2933,27 @@ discussed below.
 This prints a number in floating point notation.
 
 @item g
-This prints either scientific notation or floating point notation, whichever
-is shorter.
+This prints a number in either scientific notation or floating point
+notation, whichever uses fewer characters.
+@ignore
+From: gatech!ames!elroy!cit-vax!EQL.Caltech.Edu!rankin (Pat Rankin)
+
+In the description of printf formats (p.43), the information for %g
+is incorrect (mainly, it's too much of an oversimplification).  It's
+wrong in the AWK book too, and in the gawk man page.  I suggested to
+David Trueman before 2.13 was released that the latter be revised, so
+that it matched gawk's behavior (rather than trying to change gawk to
+match the docs ;-).  The documented description is nice and simple, but
+it doesn't match the actual underlying behavior of %g in the various C
+run-time libraries that gawk relies on.  The precision value for g format
+is different than for f and e formats, so it's inaccurate to say 'g' is
+the shorter of 'e' or 'f'.  For 'g', precision represents the number of
+significant digits rather than the number of decimal places, and it has
+special rules about how to format numbers with range between 10E-1 and
+10E-4.  All in all, it's pretty messy, and I had to add that clumsy
+GFMT_WORKAROUND code because the VMS run-time library doesn't conform to
+the ANSI-C specifications.
+@end ignore
 
 @item o
 This prints an unsigned octal integer.
@@ -2582,8 +3020,10 @@ printf "%4s", "foobar"
 @end example
 
 @noindent
-prints @samp{foobar}.  Preceding the @var{width} with a minus sign causes
-the output to be padded with spaces on the right, instead of on the left.
+prints @samp{foobar}.
+
+Preceding the @var{width} with a minus sign causes the output to be
+padded with spaces on the right, instead of on the left.
 
 @item .@var{prec}
 This is a number that specifies the precision to use when printing.
@@ -2593,9 +3033,43 @@ characters from the string that should be printed.
 @end table
 
 The C library @code{printf}'s dynamic @var{width} and @var{prec}
-capability (for example, @code{"%*.*s"}) is not yet supported.  However, it can
-easily be simulated using concatenation to dynamically build the
-format string.@refill
+capability (for example, @code{"%*.*s"}) is supported.  Instead of
+supplying explicit @var{width} and/or @var{prec} values in the format
+string, you pass them in the argument list.  For example:@refill
+
+@example
+w = 5
+p = 3
+s = "abcdefg"
+printf "<%*.*s>\n", w, p, s
+@end example
+
+@noindent
+is exactly equivalent to
+
+@example
+s = "abcdefg"
+printf "<%5.3s>\n", s
+@end example
+
+@noindent
+Both programs output @samp{@w{<@bullet{}@bullet{}abc>}}.  (We have
+used the bullet symbol ``@bullet{}'' to represent a space, to clearly
+show you that there are two spaces in the output.)@refill
+
+Earlier versions of @code{awk} did not support this capability.  You may
+simulate it by using concatenation to build up the format string,
+like so:@refill
+
+@example
+w = 5
+p = 3
+s = "abcdefg"
+printf "<%" w "." p "s>\n", s
+@end example
+
+@noindent
+This is not particularly easy to read, however.
 
 @node Printf Examples, , Format Modifiers, Printf
 @subsection Examples of Using @code{printf}
@@ -2610,7 +3084,7 @@ awk '@{ printf "%-10s %s\n", $1, $2 @}' BBS-list
 prints the names of bulletin boards (@code{$1}) of the file
 @file{BBS-list} as a string of 10 characters, left justified.  It also
 prints the phone numbers (@code{$2}) afterward on the line.  This
-produces an aligned two-column table of names and phone numbers:
+produces an aligned two-column table of names and phone numbers:@refill
 
 @example
 aardvark   555-5553
@@ -2637,7 +3111,7 @@ last things on their lines.  We don't need to put spaces after them.
 
 We could make our table look even nicer by adding headings to the tops
 of the columns.  To do this, use the @code{BEGIN} pattern
-(@pxref{BEGIN/END}) to cause the header to be printed only once, at the
+(@pxref{BEGIN/END}) to force the header to be printed only once, at the
 beginning of the @code{awk} program:
 
 @example
@@ -2681,9 +3155,9 @@ section on the @code{print} statement (@pxref{Print}).
 @cindex output redirection
 @cindex redirection of output
 So far we have been dealing only with output that prints to the standard
-output, usually your terminal.  Both @code{print} and @code{printf} can be
-told to send their output to other places.  This is called
-@dfn{redirection}.@refill
+output, usually your terminal.  Both @code{print} and @code{printf} can
+also send their output to other places.
+This is called @dfn{redirection}.@refill
 
 A redirection appears after the @code{print} or @code{printf} statement.
 Redirections in @code{awk} are written just like redirections in shell
@@ -2699,7 +3173,7 @@ commands, except that they are written inside the @code{awk} program.
 
 Here are the three forms of output redirection.  They are all shown for
 the @code{print} statement, but they work identically for @code{printf}
-also.
+also.@refill
 
 @table @code
 @item print @var{items} > @var{output-file}
@@ -2770,7 +3244,8 @@ the pipe as soon as all the intended output has been sent to it.
 
 Redirecting output using @samp{>}, @samp{>>}, or @samp{|} asks the system
 to open a file or pipe only if the particular @var{file} or @var{command}
-you've specified has not already been written to by your program.@refill
+you've specified has not already been written to by your program, or if
+it has been closed since it was last written to.@refill
 
 @node Close Output, , File/Pipe Redirection, Redirection
 @subsection Closing Output Files and Pipes
@@ -2821,7 +3296,7 @@ you can start reading it with @code{getline} (@pxref{Getline}).
 
 @item
 To write numerous files, successively, in the same @code{awk}
-program.  If you don't close the files, eventually you will exceed the
+program.  If you don't close the files, eventually you may exceed a
 system limit on the number of open files in one process.  So close
 each one when you are finished writing it.
 
@@ -2860,7 +3335,9 @@ is used only for writing error messages; the reason we have two separate
 streams, standard output and standard error, is so that they can be
 redirected separately.
 
-@c @cindex differences between @code{gawk} and @code{awk}
+@iftex
+@cindex differences between @code{gawk} and @code{awk}
+@end iftex
 In other implementations of @code{awk}, the only way to write an error
 message to standard error in an @code{awk} program is as follows:
 
@@ -2931,6 +3408,15 @@ NF != 4 @{
 Recognition of these special file names is disabled if @code{gawk} is in
 compatibility mode (@pxref{Command Line}).
 
+@strong{Note}:  Unless your system actually has a @file{/dev/fd} directory,
+the interpretation of these file names is done by @code{gawk} itself.
+For example, using @samp{/dev/fd/4} for output will actually write on
+file descriptor 4, and not on a new file descriptor that was @code{dup}'ed
+from file descriptor 4.  Most of the time this does not matter; however, it
+is important to @emph{not} close any of the files related to file descriptors
+0, 1, and 2.  If you do close one of these files, unpredictable behavior
+will result.
+
 @node One-liners, Patterns, Printing, Top
 @chapter Useful ``One-liners''
 
@@ -2942,9 +3428,9 @@ of the program will give you a good idea of what is going on, but please
 read the rest of the manual to become an @code{awk} expert!
 
 @table @code
-@item awk '@{ num_fields = num_fields + NF @}
-@itemx @ @ @ @ @ END @{ print num_fields @}'
-This program prints the total number of fields in all input lines.
+@item awk '@{ if (NF > max) max = NF @}
+@itemx @ @ @ @ @ END @{ print max @}'
+This program prints the maximum number of fields on any input line.
 
 @item awk 'length($0) > 80'
 This program prints every line longer than 80 characters.  The sole
@@ -2974,6 +3460,21 @@ This program prints the total number of bytes used by @var{files}.
 This program prints the maximum line length of @var{file}.  The input
 is piped through the @code{expand} program to change tabs into spaces,
 so the widths compared are actually the right-margin columns.
+
+@item awk 'BEGIN @{ FS = ":" @}
+@itemx @ @ @ @ @ @{ print $1 | "sort" @}' /etc/passwd
+This program prints a sorted list of the login names of all users.
+
+@item awk '@{ nlines++ @}
+@itemx @ @ @ @ @ END@ @{ print nlines @}'
+This programs counts lines in a file.
+
+@item awk 'END @{ print NR @}'
+This program also counts lines in a file, but lets @code{awk} do the work.
+
+@item awk '@{ print NR, $0 @}'
+This program concatenates and line numbers all its input files,
+similar to @samp{cat -n}.
 @end table
 
 @node Patterns, Actions, One-liners, Top
@@ -3012,13 +3513,13 @@ Here is a summary of the types of patterns supported in @code{awk}.
 @table @code
 @item /@var{regular expression}/
 A regular expression as a pattern.  It matches when the text of the
-input record fits the regular expression.  (@xref{Regexp, , Regular
-Expressions as Patterns}.)
+input record fits the regular expression.
+(@xref{Regexp, , Regular Expressions as Patterns}.)@refill
 
 @item @var{expression}
 A single expression.  It matches when its value, converted to a number,
-is nonzero (if a number) or nonnull (if a string).  (@xref{Expression
-Patterns}.)
+is nonzero (if a number) or nonnull (if a string).
+(@xref{Expression Patterns}.)@refill
 
 @item @var{pat1}, @var{pat2}
 A pair of patterns separated by a comma, specifying a range of records.
@@ -3030,8 +3531,8 @@ Special patterns to supply start-up or clean-up information to
 @code{awk}.  (@xref{BEGIN/END}.)
 
 @item @var{null}
-The empty pattern matches every input record.  (@xref{Empty, , The Empty
-Pattern}.)
+The empty pattern matches every input record.
+(@xref{Empty, , The Empty Pattern}.)@refill
 @end table
 
 @node Empty, Regexp, Kinds of Patterns, Patterns
@@ -3047,7 +3548,7 @@ awk '@{ print $1 @}' BBS-list
 @end example
 
 @noindent
-prints just the first field of every record.
+prints the first field of every record.
 
 @node Regexp, Comparison Patterns, Empty, Patterns
 @section Regular Expressions as Patterns
@@ -3077,10 +3578,10 @@ classes of strings.
 @subsection How to Use Regular Expressions
 
 A regular expression can be used as a pattern by enclosing it in
-slashes.  Then the regular expression is matched against the entire text
-of each record.  (Normally, it only needs to match some part of the text
-in order to succeed.)  For example, this prints the second field of each
-record that contains @samp{foo} anywhere:
+slashes.  Then the regular expression is matched against the
+entire text of each record.  (Normally, it only needs
+to match some part of the text in order to succeed.)  For example, this
+prints the second field of each record that contains @samp{foo} anywhere:
 
 @example
 awk '/foo/ @{ print $2 @}' BBS-list
@@ -3094,7 +3595,7 @@ awk '/foo/ @{ print $2 @}' BBS-list
 Regular expressions can also be used in comparison expressions.  Then
 you can specify the string to match against; it need not be the entire
 current input record.  These comparison expressions can be used as
-patterns or in @code{if} and @code{while} statements.
+patterns or in @code{if}, @code{while}, @code{for}, and @code{do} statements.
 
 @table @code
 @item @var{exp} ~ /@var{regexp}/
@@ -3201,7 +3702,7 @@ characters that are enclosed in the square brackets.  For example:
 @end example
 
 @noindent
-matches any of the characters @samp{M}, @samp{V}, or @samp{X} in a
+matches any one of the characters @samp{M}, @samp{V}, or @samp{X} in a
 string.@refill
 
 Ranges of characters are indicated by using a hyphen between the beginning
@@ -3223,29 +3724,25 @@ character set, put a @samp{\} in front of it.  For example:
 @end example
 
 @noindent
-matches either @samp{]}, or @samp{d}.@refill
+matches either @samp{d}, or @samp{]}.@refill
 
 This treatment of @samp{\} is compatible with other @code{awk}
-implementations but incompatible with the proposed POSIX specification
-for @code{awk}.  The current draft specifies the use of the same syntax
-used in @code{egrep}.
-
-We may change @code{gawk} to fit the standard, once we are sure it will
-no longer change.  For the meanwhile, the @samp{-a} option specifies the
-traditional @code{awk} syntax described above (which is also the
-default), while the @samp{-e} option specifies @code{egrep} syntax.
-@xref{Options}.
+implementations, and is also mandated by the @sc{POSIX} Command Language
+and Utilities standard.  The regular expressions in @code{awk} are a superset
+of the @sc{POSIX} specification for Extended Regular Expressions (EREs).
+@sc{POSIX} EREs are based on the regular expressions accepted by the
+traditional @code{egrep} utility.
 
 In @code{egrep} syntax, backslash is not syntactically special within
 square brackets.  This means that special tricks have to be used to
 represent the characters @samp{]}, @samp{-} and @samp{^} as members of a
 character set.
 
-To match @samp{-}, write it as @samp{---}, which is a range containing
-only @samp{-}.  You may also give @samp{-} as the first or last
-character in the set.  To match @samp{^}, put it anywhere except as the
-first character of a set.  To match a @samp{]}, make it the first
-character in the set.  For example:
+In @code{egrep} syntax, to match @samp{-}, write it as @samp{---},
+which is a range containing only @samp{-}.  You may also give @samp{-}
+as the first or last character in the set.  To match @samp{^}, put it
+anywhere except as the first character of a set.  To match a @samp{]},
+make it the first character in the set.  For example:@refill
 
 @example
 []d^]
@@ -3257,7 +3754,7 @@ matches either @samp{]}, @samp{d} or @samp{^}.@refill
 @item [^ @dots{}]
 This is a @dfn{complemented character set}.  The first character after
 the @samp{[} @emph{must} be a @samp{^}.  It matches any characters
-@emph{except} those in the square brackets.  For example:
+@emph{except} those in the square brackets (or newline).  For example:
 
 @example
 [^0-9]
@@ -3335,7 +3832,7 @@ fe?d
 @end example
 
 @noindent
-will match @samp{fed} or @samp{fd}, but nothing else.@refill
+will match @samp{fed} and @samp{fd}, but nothing else.@refill
 
 @item \
 This is used to suppress the special meaning of a character when
@@ -3402,7 +3899,7 @@ case-insensitive and other rules case-sensitive, because there is no way
 to set @code{IGNORECASE} just for the pattern of a particular rule.  To
 do this, you must use character sets or @code{tolower}.  However, one
 thing you can do only with @code{IGNORECASE} is turn case-sensitivity on
-or off dynamically for all the rules at once.
+or off dynamically for all the rules at once.@refill
 
 @code{IGNORECASE} can be set on the command line, or in a @code{BEGIN}
 rule.  Setting @code{IGNORECASE} from the command line is a way to make
@@ -3453,11 +3950,12 @@ True if @var{x} does not match the regular expression described by @var{y}.
 
 The operands of a relational operator are compared as numbers if they
 are both numbers.  Otherwise they are converted to, and compared as,
-strings (@pxref{Conversion}).  Strings are compared by comparing the
-first character of each, then the second character of each, and so on,
-until there is a difference.  If the two strings are equal until the
-shorter one runs out, the shorter one is considered to be less than the
-longer one.  Thus, @code{"10"} is less than @code{"9"}.
+strings (@pxref{Conversion}, for the detailed rules).  Strings are compared
+by comparing the first character of each, then the second character of each,
+and so on, until there is a difference.  If the two strings are equal until
+the shorter one runs out, the shorter one is considered to be less than the
+longer one.  Thus, @code{"10"} is less than @code{"9"}, and @code{"abc"}
+is less than @code{"abcd"}.@refill
 
 The left operand of the @samp{~} and @samp{!~} operators is a string.
 The right operand is either a constant regular expression enclosed in
@@ -3524,7 +4022,7 @@ boolean operators.  @xref{Boolean Ops}, for complete information on
 the boolean operators.
 
 The subpatterns of a boolean pattern can be constant regular
-expressions, comparisons, or any other @code{gawk} expressions.  Range
+expressions, comparisons, or any other @code{awk} expressions.  Range
 patterns are not expressions, so they cannot appear inside boolean
 patterns.  Likewise, the special patterns @code{BEGIN} and @code{END},
 which never match any input record, are not expressions and cannot
@@ -3533,7 +4031,7 @@ appear inside boolean patterns.
 @node Expression Patterns, Ranges, Boolean Patterns, Patterns
 @section Expressions as Patterns
 
-Any @code{awk} expression is valid also as a pattern in @code{gawk}.
+Any @code{awk} expression is also valid as an @code{awk} pattern.
 Then the pattern ``matches'' if the expression's value is nonzero (if a
 number) or nonnull (if a string).
 
@@ -3555,10 +4053,10 @@ pattern.  @code{/foo/} as an expression has the value 1 if @samp{foo}
 appears in the current input record; thus, as a pattern, @code{/foo/}
 matches any record containing @samp{foo}.
 
-Other implementations of @code{awk} are less general than @code{gawk}:
-they allow comparison expressions, and boolean combinations thereof
-(optionally with parentheses), but not necessarily other kinds of
-expressions.
+Other implementations of @code{awk} that are not yet @sc{POSIX} compliant
+are less general than @code{gawk}: they allow comparison expressions, and
+boolean combinations thereof (optionally with parentheses), but not
+necessarily other kinds of expressions.
 
 @node Ranges, BEGIN/END, Expression Patterns, Patterns
 @section Specifying Record Ranges With Patterns
@@ -3618,8 +4116,8 @@ awk 'BEGIN @{ print "Analysis of `foo'" @}
 @end example
 @end group
 
-This program finds out how many times the string @samp{foo} appears in
-the input file @file{BBS-list}.  The @code{BEGIN} rule prints a title
+This program finds the number of records in the input file @file{BBS-list}
+that contain the string @samp{foo}.  The @code{BEGIN} rule prints a title
 for the report.  There is no need to use the @code{BEGIN} rule to
 initialize the counter @code{foobar} to zero, as @code{awk} does this
 for us automatically (@pxref{Variables}).
@@ -3629,7 +4127,7 @@ record containing the pattern @samp{foo} is read.  The @code{END} rule
 prints the value of @code{foobar} at the end of the run.@refill
 
 The special patterns @code{BEGIN} and @code{END} cannot be used in ranges
-or with boolean operators.
+or with boolean operators (indeed, they cannot be used with any operators).
 
 An @code{awk} program may have multiple @code{BEGIN} and/or @code{END}
 rules.  They are executed in the order they appear, all the @code{BEGIN}
@@ -3641,7 +4139,7 @@ library functions, since each library can have its own @code{BEGIN} or
 the order in which library functions are named on the command line
 controls the order in which their @code{BEGIN} and @code{END} rules are
 executed.  Therefore you have to be careful to write such rules in
-library files so that it doesn't matter what order they are executed in.
+library files so that the order in which they are executed doesn't matter.
 @xref{Command Line}, for more information on using library functions.
 
 If an @code{awk} program only has a @code{BEGIN} rule, and no other
@@ -3656,7 +4154,7 @@ the program.  This is necessary in case the @code{END} rule checks the
 action for these rules since there is no current record when they run.
 
 @node Actions, Expressions, Patterns, Top
-@chapter Actions: Overview
+@chapter Overview of Actions
 @cindex action, definition of
 @cindex curly braces
 @cindex action, curly braces
@@ -3689,7 +4187,7 @@ contains only one statement, or even if it contains no statements at
 all.  However, if you omit the action entirely, omit the curly braces as
 well.  (An omitted action is equivalent to @samp{@{ print $0 @}}.)
 
-Here are the kinds of statement supported in @code{awk}:
+Here are the kinds of statements supported in @code{awk}:
 
 @itemize @bullet
 @item
@@ -3711,7 +4209,7 @@ statements together in the body of an @code{if}, @code{while}, @code{do}
 or @code{for} statement.
 
 @item
-Input control, using the @code{getline} function (@pxref{Getline}),
+Input control, using the @code{getline} command (@pxref{Getline}),
 and the @code{next} statement (@pxref{Next Statement}).
 
 @item
@@ -3729,7 +4227,7 @@ to discuss how to define your own functions.
 @end iftex
 
 @node Expressions, Statements, Actions, Top
-@chapter Actions: Expressions
+@chapter Expressions as Action Statements
 @cindex expression
 
 Expressions are the basic building block of @code{awk} actions.  An
@@ -3740,7 +4238,7 @@ But, beyond that, an expression can assign a new value to a variable
 or a field, with an assignment operator.
 
 An expression can serve as a statement on its own.  Most other kinds of
-statement contain one or more expressions which specify data to be
+statements contain one or more expressions which specify data to be
 operated on.  As in other languages, expressions in @code{awk} include
 variables, array references, constants, and function calls, as well as
 combinations of these with various operators.
@@ -3770,7 +4268,7 @@ combinations of these with various operators.
 @cindex string constants
 
 The simplest type of expression is the @dfn{constant}, which always has
-the same value.  There are three types of constant: numeric constants,
+the same value.  There are three types of constants: numeric constants,
 string constants, and regular expression constants.
 
 @cindex numeric constant
@@ -3795,7 +4293,9 @@ double-quote marks.  For example:
 @end example
 
 @noindent
-@c @cindex differences between @code{gawk} and @code{awk}
+@iftex
+@cindex differences between @code{gawk} and @code{awk}
+@end iftex
 represents the string whose contents are @samp{parrot}.  Strings in
 @code{gawk} can be of any length and they can contain all the possible
 8-bit ASCII characters including ASCII NUL.  Other @code{awk}
@@ -3853,20 +4353,92 @@ digits between 0 and 7.  For example, the code for the ASCII ESC
 @item \x@var{hh@dots{}}
 Represents the hexadecimal value @var{hh}, where @var{hh} are hexadecimal
 digits (@samp{0} through @samp{9} and either @samp{A} through @samp{F} or
-@samp{a} through @samp{f}).  Like the same construct in ANSI C, the escape
+@samp{a} through @samp{f}).  Like the same construct in @sc{ANSI} C, the escape
 sequence continues until the first non-hexadecimal digit is seen.  However,
-using more than two hexadecimal digits produces undefined results.@refill
+using more than two hexadecimal digits produces undefined results.  (The
+@samp{\x} escape sequence is not allowed in @sc{POSIX} @code{awk}.)@refill
 @end table
 
 A constant regexp is a regular expression description enclosed in
 slashes, such as @code{/^beginning and end$/}.  Most regexps used in
 @code{awk} programs are constant, but the @samp{~} and @samp{!~}
-operators can also match computed or ``dynamic'' regexps (@pxref{Regexp
-Usage}).
+operators can also match computed or ``dynamic'' regexps (@pxref{Regexp Usage}).
+
+Constant regexps may be used like simple expressions.  When a
+constant regexp is not on the right hand side of the @samp{~} or
+@samp{!~} operators, it has the same meaning as if it appeared
+in a pattern, i.e. @samp{($0 ~ /foo/)} (@pxref{Expression Patterns}).
+This means that the following two code segments:@refill
+
+@example
+if ($0 ~ /barfly/ || $0 ~ /camelot/)
+    print "found"
+@end example
+
+@noindent
+and
+
+@example
+if (/barfly/ || /camelot/)
+    print "found"
+@end example
+
+@noindent
+are exactly equivalent.  One rather bizarre consequence of this rule is
+that the following boolean expression is legal, but does not do what the user
+intended:@refill
+
+@example
+if (/foo/ ~ $1) print "found foo"
+@end example
+
+This code is ``obviously'' testing @code{$1} for a match against the regexp
+@code{/foo/}.  But in fact, the expression @code{(/foo/ ~ $1)} actually means
+@code{(($0 ~ /foo/) ~ $1)}.  In other words, first match the input record
+against the regexp @code{/foo/}.  The result will be either a 0 or a 1,
+depending upon the success or failure of the match.  Then match that result
+against the first field in the record.@refill
+
+Since it is unlikely that you would ever really wish to make this kind of
+test, @code{gawk} will issue a warning when it sees this construct in
+a program.@refill
+
+Another consequence of this rule is that the assignment statement
+
+@example
+matches = /foo/
+@end example
+
+@noindent
+will assign either 0 or 1 to the variable @code{matches}, depending
+upon the contents of the current input record.
 
-Constant regexps are useful only with the @samp{~} and @samp{!~} operators;
-you cannot assign them to variables or print them.  They are not truly
-expressions in the usual sense.
+Constant regular expressions are also used as the first argument for
+the @code{sub} and @code{gsub} functions (@pxref{String Functions}).
+
+This feature of the language was never well documented until the
+@sc{POSIX} specification.
+
+You may be wondering, when is
+
+@example
+$1 ~ /foo/ @{ @dots{} @}
+@end example
+
+@noindent
+preferable to
+
+@example
+$1 ~ "foo" @{ @dots{} @}
+@end example
+
+Since the right-hand sides of both @samp{~} operators are constants,
+it is more efficient to use the @samp{/foo/} form: @code{awk} can note
+that you have supplied a regexp and store it internally in a form that
+makes pattern matching more efficient.  In the second form, @code{awk}
+must first convert the string into this internal form, and then perform
+the pattern matching.  The first form is also better ``style;'' it is
+clear that you intend a regexp match.
 
 @node Variables, Arithmetic Ops, Constants, Expressions
 @section Variables
@@ -3928,7 +4500,7 @@ If you precede the assignment with the @samp{-v} option, like this:
 @noindent
 then the variable is set at the very beginning, before even the
 @code{BEGIN} rules are run.  The @samp{-v} option and its assignment
-must precede all the file name arguments.
+must precede all the file name arguments, as well as the program text.
 
 Otherwise, the variable assignment is performed at a time determined by
 its position among the input file arguments: after the processing of the
@@ -3947,8 +4519,11 @@ but before the second file is started, @code{n} is set to 2, so that the
 second field is printed in lines from @file{BBS-list}.
 
 Command line arguments are made available for explicit examination by
-the @code{awk} program in an array named @code{ARGV} (@pxref{Built-in
-Variables}).
+the @code{awk} program in an array named @code{ARGV}
+(@pxref{Built-in Variables}).@refill
+
+@code{awk} processes the values of command line assignments for escape
+sequences (@pxref{Constants}).
 
 @node Arithmetic Ops, Concatenation, Variables, Expressions
 @section Arithmetic Operators
@@ -3984,6 +4559,9 @@ Subtraction.
 @item - @var{x}
 Negation.
 
+@item + @var{x}
+Unary plus.  No real effect on the expression.
+
 @item @var{x} * @var{y}
 Multiplication.
 
@@ -3993,17 +4571,19 @@ floating point, the result is not rounded to an integer: @code{3 / 4}
 has the value 0.75.
 
 @item @var{x} % @var{y}
-@c @cindex differences between @code{gawk} and @code{awk}
+@iftex
+@cindex differences between @code{gawk} and @code{awk}
+@end iftex
 Remainder.  The quotient is rounded toward zero to an integer,
 multiplied by @var{y} and this result is subtracted from @var{x}.
-This operation is sometimes known as ``trunc-mod''.  The following
+This operation is sometimes known as ``trunc-mod.''  The following
 relation always holds:
 
 @example
 b * int(a / b) + (a % b) == a
 @end example
 
-One undesirable effect of this definition of remainder is that
+One possibly undesirable effect of this definition of remainder is that
 @code{@var{x} % @var{y}} is negative if @var{x} is negative.  Thus,
 
 @example
@@ -4017,7 +4597,8 @@ may be machine dependent.
 @itemx @var{x} ** @var{y}
 Exponentiation: @var{x} raised to the @var{y} power.  @code{2 ^ 3} has
 the value 8.  The character sequence @samp{**} is equivalent to
-@samp{^}.
+@samp{^}.  (The @sc{POSIX} standard only specifies the use of @samp{^}
+for exponentiation.)
 @end table
 
 @node Concatenation, Comparison Ops, Arithmetic Ops, Expressions
@@ -4127,12 +4708,64 @@ True if array @var{array} has an element with the subscript @var{subscript}.
 
 Comparison expressions have the value 1 if true and 0 if false.
 
-The operands of a relational operator are compared as numbers if they
-are both numbers.  Otherwise they are converted to, and compared as,
-strings (@pxref{Conversion}).  Strings are compared by comparing the
-first character of each, then the second character of each, and so on.
-Thus, @code{"10"} is less than @code{"9"}.
+The rules @code{gawk} uses for performing comparisons are based on those
+in draft 11.1 of the @sc{POSIX} standard.  The @sc{POSIX} standard introduced
+the concept of a @dfn{numeric string}, which is simply a string that looks
+like a number, for example, @code{@w{" +2"}}.
+
+@vindex CONVFMT
+When performing a relational operation, @code{gawk} considers the type of an
+operand to be the type it received on its last @emph{assignment}, rather
+than the type of its last @emph{use}.  If one operand of a comparison is
+numeric, and the other operand is either numeric or a numeric string,
+then @code{gawk} does a numeric comparison.  Otherwise, it does a string
+comparison.  The numeric operand will be converted to a string using
+the value of @code{CONVFMT} (@pxref{Conversion}).  Strings are compared
+by comparing the first character of each, then the second character of each,
+and so on.  Thus @code{"10"} is less than @code{"9"}.  If there are two
+strings where one is a prefix of the other, the shorter string is less than
+the longer one.  Thus @code{"abc"} is less than @code{"abcd"}.@refill
+
+Here are some sample expressions, how @code{gawk} compares them, and what
+the result of the comparison is.
+
+@table @code
+@item 1.5 <= 2.0
+numeric comparison (true)
+
+@item "abc" >= "xyz"
+string comparison (false)
+
+@item 1.5 != " +2"
+numeric comparison (true)
+
+@item "1e2" < "3"
+string comparison (true)
 
+@item a = 2; b = "2"
+@itemx a == b
+numeric comparison (true)
+@end table
+
+It is important to note that the concept of ``numeric string'' applies
+only to constants in the @code{awk} program source.  Input data is somewhat
+different.  In reality, all input data to @code{awk} is character data
+(as opposed to binary data).  However, @code{awk} interprets characters in
+the input data that look like numbers @emph{as numbers}, and not as numeric
+strings.  Thus,
+
+@example
+echo 1e2 3 | awk '@{ print ($1 < $2) ? "true" : "false" @}'
+@end example
+
+@noindent
+prints @samp{false}.
+
+The purpose of the comparison rules and the use of numeric strings is
+to attempt to produce the behavior that is ``least surprising,'' while
+still ``doing the right thing.''
+
+String comparisons and regular expression comparisons are very different.
 For example,
 
 @example
@@ -4148,7 +4781,7 @@ $1 ~ /foo/
 @end example
 
 @noindent
-has the value 1 if the first field contains @samp{foo}.
+has the value 1 if the first field contains @samp{foo}, such as @samp{foobar}.
 
 The right hand operand of the @samp{~} and @samp{!~} operators may be
 either a constant regexp (@code{/@dots{}/}), or it may be an ordinary
@@ -4171,7 +4804,7 @@ regexp to avoid confusing the @code{gawk} parser.  For example,
 
 One special place where @code{/foo/} is @emph{not} an abbreviation for
 @code{$0 ~ /foo/} is when it is the right-hand operand of @samp{~} or
-@samp{!~}!
+@samp{!~}! @xref{Constants}, where this is discussed in more detail.
 
 @node Boolean Ops, Assignment Ops, Comparison Ops, Expressions
 @section Boolean Expressions
@@ -4191,10 +4824,10 @@ parentheses to control nesting.  The truth of the boolean expression is
 computed by combining the truth values of the component expressions.
 
 Boolean expressions can be used wherever comparison and matching
-expressions can be used.  They can be used in @code{if} and @code{while}
-statements.  They have numeric values (1 if true, 0 if false), which
-come into place if the result of the boolean expression is stored in a
-variable, or used in arithmetic.
+expressions can be used.  They can be used in @code{if}, @code{while}
+@code{do} and @code{for} statements.  They have numeric values (1 if true,
+0 if false), which come into play if the result of the boolean expression
+is stored in a variable, or used in arithmetic.@refill
 
 In addition, every boolean expression is also a valid boolean pattern, so
 you can use it as a pattern to control the execution of rules.
@@ -4286,13 +4919,13 @@ makes itself felt through the alteration of the variable.  We call this
 a @dfn{side effect}.
 
 @cindex lvalue
-The left-hand operand of an assignment need not be a variable
-(@pxref{Variables}); it can also be a field (@pxref{Changing Fields}) or
+The left-hand operand of an assignment need not be a variable (@pxref{Variables});
+it can also be a field (@pxref{Changing Fields}) or
 an array element (@pxref{Arrays}).  These are all called @dfn{lvalues},
 which means they can appear on the left-hand side of an assignment operator.
 The right-hand operand may be any expression; it produces the new value
 which the assignment stores in the specified variable, field or array
-element.
+element.@refill
 
 It is important to note that variables do @emph{not} have permanent types.
 The type of a variable is simply the type of whatever value it happens
@@ -4374,8 +5007,25 @@ Sets @var{lvalue} to its remainder by @var{modulus}.
 @item @var{lvalue} ^= @var{power}
 @itemx @var{lvalue} **= @var{power}
 Raises @var{lvalue} to the power @var{power}.
+(Only the @code{^=} operator is specified by @sc{POSIX}.)
 @end table
 
+@ignore
+From: gatech!ames!elroy!cit-vax!EQL.Caltech.Edu!rankin (Pat Rankin)
+     In the discussion of assignment operators, it states that
+``foo += 5'' "is precisely equivalent to" ``foo = foo + 5'' (p.77).  That
+may be true for simple variables, but it's not true for expressions with
+side effects, like array references.  For proof, try
+  BEGIN {
+	  foo[rand()] += 5;               for (x in foo) print x, foo[x]
+	  bar[rand()] = bar[rand()] + 5;  for (x in bar) print x, bar[x]
+  }
+I suspect that the original statement is simply untrue--that '+=' is more
+efficient in all cases.
+
+ADR --- Try to add something about this here for the next go 'round.
+@end ignore
+
 @node Increment Ops, Conversion, Assignment Ops, Expressions
 @section Increment Operators
 
@@ -4397,7 +5047,7 @@ equivalent.
 Writing the @samp{++} after the variable specifies post-increment.  This
 increments the variable value just the same; the difference is that the
 value of the increment expression itself is the variable's @emph{old}
-value.  Thus, if @code{foo} has value 4, then the expression @code{foo++}
+value.  Thus, if @code{foo} has the value 4, then the expression @code{foo++}
 has the value 4, but it changes the value of @code{foo} to 5.
 
 The post-increment @code{foo++} is nearly equivalent to writing @code{(foo
@@ -4407,7 +5057,10 @@ not necessarily equal @code{foo}.  But the difference is minute as
 long as you stick to numbers that are fairly small (less than a trillion).
 
 Any lvalue can be incremented.  Fields and array elements are incremented
-just like variables.
+just like variables.  (Use @samp{$(i++)} when you wish to do a field reference
+and a variable increment at the same time.  The parentheses are necessary
+because of the precedence of the field reference operator, @samp{$}.)
+@c expert information in the last parenthetical remark
 
 The decrement operator @samp{--} works just like @samp{++} except that
 it subtracts 1 instead of adding.  Like @samp{++}, it can be used before
@@ -4465,23 +5118,56 @@ Strings are converted to numbers by interpreting them as numerals:
 Strings that can't be interpreted as valid numbers are converted to
 zero.
 
-@vindex OFMT
+@vindex CONVFMT
 The exact manner in which numbers are converted into strings is controlled
-by the @code{awk} built-in variable @code{OFMT} (@pxref{Built-in Variables}).
+by the @code{awk} built-in variable @code{CONVFMT} (@pxref{Built-in Variables}).
 Numbers are converted using a special
-version of the @code{sprintf} function (@pxref{Built-in}) with @code{OFMT}
+version of the @code{sprintf} function (@pxref{Built-in}) with @code{CONVFMT}
 as the format specifier.@refill
 
-@code{OFMT}'s default value is @code{"%.6g"}, which prints a value with
+@code{CONVFMT}'s default value is @code{"%.6g"}, which prints a value with
 at least six significant digits.  For some applications you will want to
 change it to specify more precision.  Double precision on most modern
 machines gives you 16 or 17 decimal digits of precision.
 
-Strange results can happen if you set @code{OFMT} to a string that doesn't
+Strange results can happen if you set @code{CONVFMT} to a string that doesn't
 tell @code{sprintf} how to format floating point numbers in a useful way.
 For example, if you forget the @samp{%} in the format, all numbers will be
 converted to the same constant string.@refill
 
+As a special case, if a number is an integer, then the result of converting
+it to a string is @emph{always} an integer, no matter what the value of
+@code{CONVFMT} may be.  Given the following code fragment:
+
+@example
+CONVFMT = "%2.2f"
+a = 12
+b = a ""
+@end example
+
+@noindent
+@code{b} has the value @code{"12"}, not @code{"12.00"}.
+
+@ignore
+For the 2.14 version, describe the ``stickyness'' of conversions.  Right now
+the manual assumes everywhere that variables are either numbers or strings;
+in fact both kinds of values may be valid.  If both happen to be valid, a
+conversion isn't necessary and isn't done.  Revising the manual to be
+consistent with this, though, is too big a job to tackle at the moment.
+@end ignore
+
+@vindex OFMT
+Prior to the @sc{POSIX} standard, @code{awk} specified that the value
+of @code{OFMT} was used for converting numbers to strings.  @code{OFMT}
+specifies the output format to use when printing numbers with @code{print}.
+@code{CONVFMT} was introduced in order to separate the semantics of
+conversions from the semantics of printing.  Both @code{CONVFMT} and
+@code{OFMT} have the same default value: @code{"%.6g"}.  In the vast majority
+of cases, old @code{awk} programs will not change their behavior.
+However, this use of @code{OFMT} is something to keep in mind if you must
+port your program to other implementations of @code{awk}; we recommend
+that instead of changing your programs, you just port @code{gawk} itself!@refill
+
 @node Conditional Exp, Function Calls, Conversion, Expressions
 @section Conditional Expressions
 @cindex conditional expression
@@ -4499,10 +5185,10 @@ The conditional expression looks the same as in the C language:
 
 @noindent
 There are three subexpressions.  The first, @var{selector}, is always
-computed first.  If it is ``true'' (not zero) then @var{if-true-exp} is
-computed next and its value becomes the value of the whole expression.
-Otherwise, @var{if-false-exp} is computed next and its value becomes the
-value of the whole expression.
+computed first.  If it is ``true'' (not zero and not null) then
+@var{if-true-exp} is computed next and its value becomes the value of
+the whole expression.  Otherwise, @var{if-false-exp} is computed next
+and its value becomes the value of the whole expression.@refill
 
 For example, this expression produces the absolute value of @code{x}:
 
@@ -4534,7 +5220,7 @@ A @dfn{function} is a name for a particular calculation.  Because it has
 a name, you can ask for it by name at any point in the program.  For
 example, the function @code{sqrt} computes the square root of a number.
 
-A fixed set of functions are @dfn{built in}, which means they are
+A fixed set of functions are @dfn{built-in}, which means they are
 available in every @code{awk} program.  The @code{sqrt} function is one
 of these.  @xref{Built-in}, for a list of built-in functions and their
 descriptions.  In addition, you can define your own functions in the
@@ -4551,7 +5237,7 @@ there are no arguments, write just @samp{()} after the function name.
 Here are some examples:
 
 @example
-sqrt(x**2 + y**2)    # @r{One argument}
+sqrt(x^2 + y^2)      # @r{One argument}
 atan2(y, x)          # @r{Two arguments}
 rand()               # @r{No arguments}
 @end example
@@ -4592,7 +5278,7 @@ awk '@{ print "The square root of", $1, "is", sqrt($1) @}'
 @end example
 
 @node Precedence,, Function Calls, Expressions
-@section Operator Precedence: How Operators Nest
+@section Operator Precedence (How Operators Nest)
 @cindex precedence
 @cindex operator precedence
 
@@ -4600,10 +5286,10 @@ awk '@{ print "The square root of", $1, "is", sqrt($1) @}'
 different operators appear close by in one expression.  For example,
 @samp{*} has higher precedence than @samp{+}; thus, @code{a + b * c}
 means to multiply @code{b} and @code{c}, and then add @code{a} to the
-product.
+product (i.e., @code{a + (b * c)}).
 
-You can overrule the precedence of the operators by writing parentheses
-yourself.  You can think of the precedence rules as saying where the
+You can overrule the precedence of the operators by using parentheses.
+You can think of the precedence rules as saying where the
 parentheses are assumed if you do not write parentheses yourself.  In
 fact, it is wise always to use parentheses whenever you have an unusual
 combination of operators, because other people who read the program may
@@ -4613,17 +5299,17 @@ any such mistake.
 
 When operators of equal precedence are used together, the leftmost
 operator groups first, except for the assignment, conditional and
-and exponentiation operators, which group in the opposite order.
+exponentiation operators, which group in the opposite order.
 Thus, @code{a - b + c} groups as @code{(a - b) + c};
-@code{a = b = c} groups as @code{a = (b = c)}.
+@code{a = b = c} groups as @code{a = (b = c)}.@refill
 
 The precedence of prefix unary operators does not matter as long as only
 unary operators are involved, because there is only one way to parse
 them---innermost first.  Thus, @code{$++i} means @code{$(++i)} and
 @code{++$x} means @code{++($x)}.  However, when another operator follows
 the operand, then the precedence of the unary operators can matter.
-Thus, @code{$x**2} means @code{($x)**2}, but @code{-x**2} means
-@code{-(x**2)}, because @samp{-} has lower precedence than @samp{**}
+Thus, @code{$x^2} means @code{($x)^2}, but @code{-x^2} means
+@code{-(x^2)}, because @samp{-} has lower precedence than @samp{^}
 while @samp{$} has higher precedence.
 
 Here is a table of the operators of @code{awk}, in order of increasing
@@ -4633,6 +5319,7 @@ precedence:
 @item assignment
 @samp{=}, @samp{+=}, @samp{-=}, @samp{*=}, @samp{/=}, @samp{%=},
 @samp{^=}, @samp{**=}.  These operators group right-to-left.
+(The @samp{**=} operator is not specified by @sc{POSIX}.)
 
 @item conditional
 @samp{?:}.  These operators group right-to-left.
@@ -4644,7 +5331,7 @@ precedence:
 @samp{&&}.
 
 @item array membership
-@code{in}.
+@samp{in}.
 
 @item matching
 @samp{~}, @samp{!~}.
@@ -4668,16 +5355,9 @@ redirection operator near another operator of lower precedence, without
 parentheses.  Such combinations, for example @samp{print foo > a ? b :
 c}, result in syntax errors.
 
-@item concatentation
+@item concatenation
 No special token is used to indicate concatenation.
 The operands are simply written side by side.
-@c This is supposedly being fixed
-@ignore
-Concatenation has the same precedence as relational and redirection
-operators.  These operators nest left to right.  Thus, @code{4 5 > 6}
-concatenates first, yielding 1, while @code{6 < 4 5} compares first, and
-yields @code{"05"}.
-@end ignore
 
 @item add, subtract
 @samp{+}, @samp{-}.
@@ -4690,6 +5370,7 @@ yields @code{"05"}.
 
 @item exponentiation
 @samp{^}, @samp{**}.  These operators group right-to-left.
+(The @samp{**} operator is not specified by @sc{POSIX}.)
 
 @item increment, decrement
 @samp{++}, @samp{--}.
@@ -4699,7 +5380,7 @@ yields @code{"05"}.
 @end table
 
 @node Statements, Arrays, Expressions, Top
-@chapter Actions: Control Statements
+@chapter Control Statements in Actions
 @cindex control statement
 
 @dfn{Control statements} such as @code{if}, @code{while}, and so on
@@ -4949,11 +5630,12 @@ for (i = 1; i <= 100; i *= 2)
   print i
 @end example
 
-Any of the three expressions in the parentheses following @code{for} may
+Any of the three expressions in the parentheses following the @code{for} may
 be omitted if there is nothing to be done there.  Thus, @w{@samp{for (;x
 > 0;)}} is equivalent to @w{@samp{while (x > 0)}}.  If the
 @var{condition} is omitted, it is treated as @var{true}, effectively
-yielding an infinite loop.@refill
+yielding an @dfn{infinite loop} (i.e., a loop that will never
+terminate).@refill
 
 In most cases, a @code{for} loop is an abbreviation for a @code{while}
 loop, as shown here:
@@ -5079,6 +5761,18 @@ for (x in names)
     print names[x]
 @end example
 
+@ignore
+from brennan@boeing.com:
+
+page 90, section 9.6.  The example is too artificial as
+the one line program
+
+	!/ignore/
+
+does the same thing.
+@end ignore
+@c ADR --- he's right, but don't worry about this for now
+
 The @code{continue} statement in a @code{for} loop directs @code{awk} to
 skip the rest of the body of the loop, and resume execution with the
 increment-expression of the @code{for} statement.  The following program
@@ -5131,7 +5825,7 @@ Contrast this with the effect of the @code{getline} function
 immediately, but it does not alter the flow of control in any way.  So
 the rest of the current action executes with a new input record.
 
-At the grossest level, @code{awk} program execution is a loop that reads
+At the highest level, @code{awk} program execution is a loop that reads
 an input record and then tests each rule's pattern against it.  If you
 think of this loop as a @code{for} statement whose body contains the
 rules, then the @code{next} statement is analogous to a @code{continue}
@@ -5154,8 +5848,13 @@ so that the following rules will not see the bad record.  The error
 message is redirected to the standard error output stream, as error
 messages should be.  @xref{Special Files}.
 
-The @code{next} statement is not allowed in a @code{BEGIN} or @code{END}
-rule.
+According to the @sc{POSIX} standard, the behavior is undefined if
+the @code{next} statement is used in a @code{BEGIN} or @code{END} rule.
+@code{gawk} will treat it as a syntax error.
+
+If the @code{next} statement causes the end of the input to be reached,
+then the code in the @code{END} rules, if any, will be executed.
+@ref{BEGIN/END}.
 
 @node Exit Statement, , Next Statement, Statements
 @section The @code{exit} Statement
@@ -5173,7 +5872,7 @@ read.  However, if an @code{END} rule is present, it is executed
 If @code{exit} is used as part of an @code{END} rule, it causes
 the program to stop immediately.
 
-An @code{exit} statement that is part an ordinary rule (that is, not part
+An @code{exit} statement that is part of an ordinary rule (that is, not part
 of a @code{BEGIN} or @code{END} rule) stops the execution of any further
 automatic rules, but the @code{END} rule is executed if there is one.
 If you don't want the @code{END} rule to do its job in this case, you
@@ -5202,7 +5901,7 @@ BEGIN @{
 @node Arrays, Built-in, Statements, Top
 @chapter Arrays in @code{awk}
 
-An @dfn{array} is a table of various values, called @dfn{elements}.  The
+An @dfn{array} is a table of values, called @dfn{elements}.  The
 elements of an array are distinguished by their @dfn{indices}.  Indices
 may be either numbers or strings.  Each array has a name, which looks
 like a variable name, but must not be in use as a variable name in the
@@ -5219,6 +5918,8 @@ same @code{awk} program.
 
 * Delete::                 The @code{delete} statement removes an element from an array.
 
+* Numeric Array Subscripts::  How to use numbers as subscripts in @code{awk}.
+
 * Multi-dimensional::      Emulating multi-dimensional arrays in @code{awk}.
 * Multi-scanning::         Scanning multi-dimensional arrays.
 @end menu
@@ -5238,11 +5939,11 @@ as a variable) in one @code{awk} program.
 Arrays in @code{awk} superficially resemble arrays in other programming
 languages; but there are fundamental differences.  In @code{awk}, you
 don't need to specify the size of an array before you start to use it.
-What's more, in @code{awk} any number or even a string may be used as an
+What's more, in @code{awk} any number or string may be used as an
 array index.
 
 In most other languages, you have to @dfn{declare} an array and specify
-how many elements or components it has.  In such languages, the
+how many elements or components it contains.  In such languages, the
 declaration causes a contiguous block of memory to be allocated for that
 many elements.  An index in the array must be a positive integer; for
 example, the index 0 specifies the first element in the array, which is
@@ -5280,11 +5981,10 @@ array element value:
 @end example
 
 @noindent
-We have shown the pairs in jumbled order because their order doesn't
-mean anything.
+We have shown the pairs in jumbled order because their order is irrelevant.
 
 One advantage of an associative array is that new pairs can be added
-at any time.  For example, suppose we add to that array a tenth element
+at any time.  For example, suppose we add to the above array a tenth element
 whose value is @w{@code{"number ten"}}.  The result is this:
 
 @example
@@ -5297,7 +5997,7 @@ whose value is @w{@code{"number ten"}}.  The result is this:
 
 @noindent
 Now the array is @dfn{sparse} (i.e., some indices are missing): it has
-elements 4 and 10, but doesn't have elements 5, 6, 7, 8, or 9.@refill
+elements 1--4 and 10, but doesn't have elements 5, 6, 7, 8, or 9.@refill
 
 Another consequence of associative arrays is that the indices don't
 have to be positive integers.  Any number, or even a string, can be
@@ -5421,13 +6121,6 @@ END @{
 @}
 @end example
 
-@ignore
-The first rule just initializes the variable @code{max}.  (This is not
-strictly necessary, since an uninitialized variable has the null string
-as its value, and the null string is effectively zero when used in
-a context where a number is required.)
-@end ignore
-
 The first rule keeps track of the largest line number seen so far;
 it also stores each line into the array @code{arr}, at an index that
 is the line's number.
@@ -5513,7 +6206,6 @@ function @code{length}.
 
 # Find number of distinct words more than 10 characters long.
 END @{
-  num_long_words = 0
   for (x in used)
     if (length(x) > 10) @{
       ++num_long_words
@@ -5534,7 +6226,7 @@ problems if new elements are added to @var{array} by statements in
 reach them.  Similarly, changing @var{var} inside the loop can produce
 strange results.  It is best to avoid such things.@refill
 
-@node Delete, Multi-dimensional, Scanning an Array, Arrays
+@node Delete, Numeric Array Subscripts, Scanning an Array, Arrays
 @section The @code{delete} Statement
 @cindex @code{delete} statement
 @cindex deleting elements of arrays
@@ -5572,7 +6264,61 @@ if (4 in foo)
   print "This will never be printed"
 @end example
 
-@node Multi-dimensional, Multi-scanning, Delete, Arrays
+It is not an error to delete an element which does not exist.
+
+@node Numeric Array Subscripts, Multi-dimensional, Delete, Arrays
+@section Using Numbers to Subscript Arrays
+
+An important aspect of arrays to remember is that array subscripts
+are @emph{always} strings.  If you use a numeric value as a subscript,
+it will be converted to a string value before it is used for subscripting
+(@pxref{Conversion}).
+
+@cindex conversions, during subscripting
+@cindex numbers, used as subscripts
+@vindex CONVFMT
+This means that the value of the @code{CONVFMT} can potentially
+affect how your program accesses elements of an array.  For example:
+
+@example
+a = b = 12.153
+data[a] = 1
+CONVFMT = "%2.2f"
+if (b in data)
+    printf "%s is in data", b
+else
+    printf "%s is not in data", b
+@end example
+
+@noindent
+should print @samp{12.15 is not in data}.  The first statement gives
+both @code{a} and @code{b} the same numeric value.  Assigning to
+@code{data[a]} first gives @code{a} the string value @code{"12.153"}
+(using the default conversion value of @code{CONVFMT}, @code{"%.6g"}),
+and then assigns 1 to @code{data["12.153"]}.  The program then changes
+the value of @code{CONVFMT}.  The test @samp{(b in data)} forces @code{b}
+to be converted to a string, this time @code{"12.15"}, since the value of
+@code{CONVFMT} only allows two significant digits.  This test fails,
+since @code{"12.15"} is a different string from @code{"12.153"}.@refill
+
+Following the rules for conversions (@pxref{Conversion}), integer
+values are always converted to strings as integers, no matter what the
+value of @code{CONVFMT} may happen to be.  So the usual case of
+
+@example
+for (i = 1; i <= maxsub; i++)
+    @i{do something with} array[i]
+@end example
+
+@noindent
+will work, no matter what the value of @code{CONVFMT}.
+
+Like many things in @code{awk}, the majority of the time things work
+as you would expect them to work.  But it is useful to have a precise
+knowledge of the actual rules, since sometimes they can have a subtle
+effect on your programs.
+
+@node Multi-dimensional, Multi-scanning, Numeric Array Subscripts, Arrays
 @section Multi-dimensional Arrays
 
 @cindex subscripts, multi-dimensional in arrays
@@ -5597,15 +6343,16 @@ variable @code{SUBSEP}.
 
 For example, suppose we evaluate the expression @code{foo[5,12]="value"}
 when the value of @code{SUBSEP} is @code{"@@"}.  The numbers 5 and 12 are
+converted to strings and
 concatenated with a comma between them, yielding @code{"5@@12"}; thus,
-the array element @code{foo["5@@12"]} is set to @code{"value"}.
+the array element @code{foo["5@@12"]} is set to @code{"value"}.@refill
 
 Once the element's value is stored, @code{awk} has no record of whether
 it was stored with a single index or a sequence of indices.  The two
 expressions @code{foo[5,12]} and @w{@code{foo[5 SUBSEP 12]}} always have
 the same value.
 
-The default value of @code{SUBSEP} is actually the string @code{"\034"},
+The default value of @code{SUBSEP} is the string @code{"\034"},
 which contains a nonprinting character that is unlikely to appear in an
 @code{awk} program or in the input data.
 
@@ -5615,7 +6362,7 @@ combined strings that are ambiguous.  Suppose that @code{SUBSEP} were
 @code{"@@"}; then @w{@code{foo["a@@b", "c"]}} and @w{@code{foo["a",
 "b@@c"]}} would be indistinguishable because both would actually be
 stored as @code{foo["a@@b@@c"]}.  Because @code{SUBSEP} is
-@code{"\034"}, such confusion can actually happen only when an index
+@code{"\034"}, such confusion can arise only when an index
 contains the character with ASCII code 034, which is a rare
 event.@refill
 
@@ -5737,7 +6484,9 @@ new functions yourself.  @xref{User-defined}.)
 * String Functions::   Functions for string manipulation,
                        such as @code{split}, @code{match}, and @code{sprintf}.
 
-* I/O Functions::      Functions for files and shell commands
+* I/O Functions::      Functions for files and shell commands.
+
+* Time Functions::     Functions for dealing with time stamps.
 @end menu
 
 @node Calling Built-in, Numeric Functions, Built-in, Built-in
@@ -5804,8 +6553,7 @@ This gives you the sine of @var{x}, with @var{x} in radians.
 This gives you the cosine of @var{x}, with @var{x} in radians.
 
 @item atan2(@var{y}, @var{x})
-This gives you the arctangent of @code{@var{y} / @var{x}}, with the
-quotient understood in radians.
+This gives you the arctangent of @code{@var{y} / @var{x}} in radians.
 
 @item rand()
 This gives you a random number.  The values of @code{rand} are
@@ -5827,7 +6575,8 @@ than @var{n}.  We then make it an integer (using @code{int}) between 0
 and @code{@var{n} @minus{} 1}.
 
 Here is an example where a similar function is used to produce
-random integers between 1 and @var{n}:
+random integers between 1 and @var{n}.  Note that this program will
+print a new random number for each input record.
 
 @example
 awk '
@@ -5864,29 +6613,20 @@ numbers that are truly unpredictable.
 The return value of @code{srand} is the previous seed.  This makes it
 easy to keep track of the seeds for use in consistently reproducing
 sequences of random numbers.
-
-@item time()
-The function @code{time} (not in all versions of @code{awk}) returns the
-current time in seconds since January 1, 1970.
-
-@item ctime(@var{then})
-The function @code{ctime} (not in all versions of @code{awk}) takes an numeric
-argument in seconds and returns a string representing the corresponding date,
-suitable for printing or further processing.
 @end table
 
 @node String Functions, I/O Functions, Numeric Functions, Built-in
 @section Built-in Functions for String Manipulation
 
-  The functions in this section look at the text of one or more
+The functions in this section look at or change the text of one or more
 strings.
 
 @table @code
 @item index(@var{in}, @var{find})
 @findex match
 This searches the string @var{in} for the first occurrence of the string
-@var{find}, and returns the position where that occurrence begins in the
-string @var{in}.  For example:@refill
+@var{find}, and returns the position in characters where that occurrence
+begins in the string @var{in}.  For example:@refill
 
 @example
 awk 'BEGIN @{ print index("peanut", "an") @}'
@@ -5894,6 +6634,7 @@ awk 'BEGIN @{ print index("peanut", "an") @}'
 
 @noindent
 prints @samp{3}.  If @var{find} is not found, @code{index} returns 0.
+(Remember that string indices in @code{awk} start at 1.)
 
 @item length(@var{string})
 @findex length
@@ -5906,6 +6647,11 @@ three characters.
 
 If no argument is supplied, @code{length} returns the length of @code{$0}.
 
+In older versions of @code{awk}, you could call the @code{length} function
+without any parentheses.  However, this is not allowed by the @sc{POSIX}
+specification, and for maximal portability of your @code{awk} programs
+you should always supply the parentheses.
+
 @item match(@var{string}, @var{regexp})
 @findex match
 The @code{match} function searches the string, @var{string}, for the
@@ -5918,8 +6664,8 @@ where that substring begins (1, if it starts at the beginning of
 @vindex RLENGTH
 The @code{match} function sets the built-in variable @code{RSTART} to
 the index.  It also sets the built-in variable @code{RLENGTH} to the
-length of the matched substring.  If no match is found, @code{RSTART}
-is set to 0, and @code{RLENGTH} to @minus{}1.
+length in characters of the matched substring.  If no match is found,
+@code{RSTART} is set to 0, and @code{RLENGTH} to @minus{}1.
 
 For example:
 
@@ -5964,8 +6710,9 @@ Match of Melvin found at 26 in This file created by Melvin.
 This divides @var{string} up into pieces separated by @var{fieldsep},
 and stores the pieces in @var{array}.  The first piece is stored in
 @code{@var{array}[1]}, the second piece in @code{@var{array}[2]}, and so
-forth.  The string value of the third argument, @var{fieldsep}, is used
-as a regexp to search for to find the places to split @var{string}.  If
+forth.  The string value of the third argument, @var{fieldsep}, is
+a regexp describing where to split @var{string} (much as @code{FS} can
+be a regexp describing where to split input records).  If
 the @var{fieldsep} is omitted, the value of @code{FS} is used.
 @code{split} returns the number of elements created.@refill
 
@@ -5989,6 +6736,10 @@ a[3] = "fe"
 @noindent
 The value returned by this call to @code{split} is 3.
 
+As with input field-splitting, when the value of @var{fieldsep} is
+@code{" "}, leading and trailing whitespace is ignored, and the elements
+are separated by runs of whitespace.
+
 @item sprintf(@var{format}, @var{expression1},@dots{})
 @findex sprintf
 This returns (without printing) the string that @code{printf} would
@@ -6044,7 +6795,21 @@ awk '@{ sub(/candidate/, "& and his wife"); print @}'
 changes the first occurrence of @samp{candidate} to @samp{candidate
 and his wife} on each input line.
 
-The effect of this special character can be turned off by putting a
+Here is another example:
+
+@example
+awk 'BEGIN @{
+        str = "daabaaa"
+        sub(/a*/, "c&c", str)
+        print str
+@}'
+@end example
+
+@noindent
+prints @samp{dcaacbaaa}.  This show how @samp{&} can represent a non-constant
+string, and also illustrates the ``leftmost, longest'' rule.
+
+The effect of this special character (@samp{&}) can be turned off by putting a
 backslash before it in the string.  As usual, to insert one backslash in
 the string, you must write two backslashes.  Therefore, write @samp{\\&}
 in a string constant to include a literal @samp{&} in the replacement.
@@ -6075,7 +6840,7 @@ But that is considered erroneous in @code{gawk}.
 This is similar to the @code{sub} function, except @code{gsub} replaces
 @emph{all} of the longest, leftmost, @emph{nonoverlapping} matching
 substrings it can find.  The @samp{g} in @code{gsub} stands for
-``global'', which means replace everywhere.  For example:@refill
+``global,'' which means replace everywhere.  For example:@refill
 
 @example
 awk '@{ gsub(/Britain/, "United Kingdom"); print @}'
@@ -6101,7 +6866,9 @@ string is character number one.  For example,
 
 If @var{length} is not present, this function returns the whole suffix of
 @var{string} that begins at character number @var{start}.  For example,
-@code{substr("washington", 5)} returns @code{"ington"}.
+@code{substr("washington", 5)} returns @code{"ington"}.  This is also
+the case if @var{length} is greater than the number of characters remaining
+in the string, counting from character number @var{start}.
 
 @item tolower(@var{string})
 @findex tolower
@@ -6118,7 +6885,7 @@ Nonalphabetic characters are left unchanged.  For example,
 @code{toupper("MiXeD cAsE 123")} returns @code{"MIXED CASE 123"}.
 @end table
 
-@node I/O Functions, , String Functions, Built-in
+@node I/O Functions, Time Functions, String Functions, Built-in
 @section Built-in Functions For Input/Output
 
 @table @code
@@ -6160,6 +6927,253 @@ Some operating systems cannot implement the @code{system} function.
 @code{system} causes a fatal error if it is not supported.
 @end table
 
+@node Time Functions,  , I/O Functions, Built-in
+@section Functions For Dealing With Time Stamps
+
+@cindex time stamps
+@cindex time of day
+A common use for @code{awk} programs is the processing of log files.
+Log files often contain time stamp information, indicating when a
+particular log record was written.  Many programs log their time stamp
+in the form returned by the @code{time} system call, which is the
+number of seconds since a particular epoch.  On @sc{POSIX} systems,
+it is the number of seconds since Midnight, January 1, 1970, UTC.
+
+In order to make it easier to process such log files, and to easily produce
+useful reports, @code{gawk} provides two functions for working with time
+stamps.  Both of these are @code{gawk} extensions; they are not specified
+in the @sc{POSIX} standard, nor are they in any other known version
+of @code{awk}.
+
+@table @code
+@item systime()
+@findex systime
+This function returns the current time as the number of seconds since
+the system epoch.  On @sc{POSIX} systems, this is the number of seconds
+since Midnight, January 1, 1970, UTC.  It may be a different number on
+other systems.
+
+@item strftime(@var{format}, @var{timestamp})
+@findex strftime
+This function returns a string.  It is similar to the function of the
+same name in the @sc{ANSI} C standard library.  The time specified by
+@var{timestamp} is used to produce a string, based on the contents
+of the @var{format} string.
+@end table
+
+The @code{systime} function allows you to compare a time stamp from a
+log file with the current time of day.  In particular, it is easy to
+determine how long ago a particular record was logged.  It also allows
+you to produce log records using the ``seconds since the epoch'' format.
+
+The @code{strftime} function allows you to easily turn a time stamp
+into human-readable information.  It is similar in nature to the @code{sprintf}
+function, copying non-format specification characters verbatim to the
+returned string, and substituting date and time values for format
+specifications in the @var{format} string.  If no @var{timestamp} argument
+is supplied, @code{gawk} will use the current time of day as the
+time stamp.@refill
+
+@code{strftime} is guaranteed by the @sc{ANSI} C standard to support
+the following date format specifications:
+
+@table @code
+@item %a
+The locale's abbreviated weekday name.
+
+@item %A
+The locale's full weekday name.
+
+@item %b
+The locale's abbreviated month name.
+
+@item %B
+The locale's full month name.
+
+@item %c
+The locale's ``appropriate'' date and time representation.
+
+@item %d
+The day of the month as a decimal number (01--31).
+
+@item %H
+The hour (24-hour clock) as a decimal number (00--23).
+
+@item %I
+The hour (12-hour clock) as a decimal number (01--12).
+
+@item %j
+The day of the year as a decimal number (001--366).
+
+@item %m
+The month as a decimal number (01--12).
+
+@item %M
+The minute as a decimal number (00--59).
+
+@item %p
+The locale's equivalent of the AM/PM designations associated
+with a 12-hour clock.
+
+@item %S
+The second as a decimal number (00--61).  (Occasionally there are
+minutes in a year with one or two leap seconds, which is why the
+seconds can go from 0 all the way to 61.)
+
+@item %U
+The week number of the year (the first Sunday as the first day of week 1)
+as a decimal number (00--53).
+
+@item %w
+The weekday as a decimal number (0--6).  Sunday is day 0.
+
+@item %W
+The week number of the year (the first Monday as the first day of week 1)
+as a decimal number (00--53).
+
+@item %x
+The locale's ``appropriate'' date representation.
+
+@item %X
+The locale's ``appropriate'' time representation.
+
+@item %y
+The year without century as a decimal number (00--99).
+
+@item %Y
+The year with century as a decimal number.
+
+@item %Z
+The time zone name or abbreviation, or no characters if
+no time zone is determinable.
+
+@item %%
+A literal @samp{%}.
+@end table
+
+If a conversion specifier is not one of the above, the behavior is undefined.
+@footnote{This is because the @sc{ANSI} standard for C leaves the behavior
+of the C version of @code{strftime} undefined, and @code{gawk} will use the
+system's version of @code{strftime} if it's there.  Typically, the conversion
+specifier will either not appear in the returned string, or it will appear
+literally.}
+
+Informally, a @dfn{locale} is the geographic place in which a program
+is meant to run.  For example, a common way to abbreviate the date
+September Fourth, 1991 in the United States would be ``9/4/91''.
+In many countries in Europe, however, it would be abbreviated ``4.9.91''.
+Thus, the @samp{%x} specification in a @code{"US"} locale might produce
+@samp{9/4/91}, while in a @code{"EUROPE"} locale, it might produce
+@samp{4.9.91}.  The @sc{ANSI} C standard defines a default @code{"C"}
+locale, which is an environment that is typical of what most C programmers
+are used to.
+
+A public-domain C version of @code{strftime} is shipped with @code{gawk}
+for systems that are not yet fully @sc{ANSI}-compliant.  If that version is
+used to compile @code{gawk} (@pxref{Installation}), then the following
+additional format specifications are available:
+
+@table @code
+@item %D
+Equivalent to specifying @samp{%m/%d/%y}.
+
+@item %e
+The day of the month, padded with a blank if it is only one digit.
+
+@item %h
+Equivalent to @samp{%b}, above.
+
+@item %n
+A newline character (ASCII LF).
+
+@item %r
+Equivalent to specifying @samp{%I:%M:%S %p}.
+
+@item %R
+Equivalent to specifying @samp{%H:%M}.
+
+@item %T
+Equivalent to specifying @samp{%H:%M:%S}.
+
+@item %t
+A TAB character.
+
+@item %C
+The century, as a number between 00 and 99.
+
+@item %Ec %EC %Ex %Ey %EY %Od %Oe %OH
+@itemx %OI %Om %OM %OS %OU %Ow %OW %Oy
+These are ``alternate representations'' for the specifications
+that use only the second letter (@samp{%c}, @samp{%C}, and so on).
+They are recognized, but their normal representations are used.
+(These facilitate compliance with the @sc{POSIX} @code{date}
+utility.)@refill
+
+@item %V
+The date in VMS format (e.g. 20-JUN-1991).
+@end table
+
+Here are two examples that use @code{strftime}.  The first is an
+@code{awk} version of the C @code{ctime} function.
+
+@example
+# ctime.awk
+#
+# awk version of C ctime(3) function
+
+function ctime(    format)
+@{
+    format = "%a %b %e %H:%M:%S %Z %Y"
+
+    return strftime(format)    # defaults to current time
+@}
+@end example
+
+This next example is an @code{awk} implementation of the @sc{POSIX}
+@code{date} utility.  Normally, the @code{date} utility prints the
+current date and time of day in a well known format.  However, if you
+provide an argument to it that begins with a @samp{+}, @code{date}
+will copy non-format specifier characters to the standard output, and
+will interpret the current time according to the format specifiers in
+the string.  For example:
+
+@example
+date '+Today is %A, %B %d, %Y.'
+@end example
+
+@noindent
+might print
+
+@example
+Today is Thursday, July 11, 1991.
+@end example
+
+Here is the @code{awk} version of the @code{date} utility.
+
+@example
+#! /usr/bin/gawk -f
+#
+# date --- implement the P1003.2 Draft 11 'date' command
+#
+# Bug: does not recognize the -u argument.
+
+BEGIN    \
+@{
+    format = "%a %b %e %H:%M:%S %Z %Y"
+    exitval = 0
+
+    if (ARGC > 2)
+        exitval = 1
+    else if (ARGC == 2) @{
+        format = ARGV[1]
+        if (format ~ /^\+/)
+            format = substr(format, 2)    # remove leading +
+    @}
+    print strftime(format)
+    exit exitval
+@}
+@end example
+
 @node User-defined, Built-in Variables, Built-in, Top
 @chapter User-defined Functions
 
@@ -6196,11 +7210,10 @@ function @var{name} (@var{parameter-list}) @{
 @end example
 
 @noindent
-The keyword @code{function} may be abbreviated @code{func}.
-
 @var{name} is the name of the function to be defined.  A valid function
 name is like a valid variable name: a sequence of letters, digits and
-underscores, not starting with a digit.
+underscores, not starting with a digit.  Functions share the same pool
+of names as variables and arrays.
 
 @var{parameter-list} is a list of the function's arguments and local
 variable names, separated by commas.  When the function is called,
@@ -6250,6 +7263,24 @@ There is no need in @code{awk} to put the definition of a function
 before all uses of the function.  This is because @code{awk} reads the
 entire program before starting to execute any of it.
 
+In many @code{awk} implementations, the keyword @code{function} may be
+abbreviated @code{func}.  However, @sc{POSIX} only specifies the use of
+the keyword @code{function}.  This actually has some practical implications.
+If @code{gawk} is in @sc{POSIX}-compatibility mode (@pxref{Command Line}),
+then the following statement will @emph{not} define a function:@refill
+
+@example
+func foo() @{ a = sqrt($1) ; print a @}
+@end example
+
+@noindent
+Instead it defines a rule that, for each record, concatenates the value
+of the variable @samp{func} with the return value of the function @samp{foo},
+and based on the truth value of the result, executes the corresponding action.
+This is probably not what was desired.  (@code{awk} accepts this input as
+syntactically valid, since functions may be used before they are defined
+in @code{awk} programs.)
+
 @node Function Example, Function Caveats, Definition Syntax, User-defined
 @section Function Definition Example
 
@@ -6276,9 +7307,9 @@ This program prints, in our special format, all the third fields that
 contain a positive number in our input.  Therefore, when given:
 
 @example
- 1.2   3.4   5.6   7.8
- 9.10 11.12 13.14 15.16
-17.18 19.20 21.22 23.24
+ 1.2   3.4    5.6   7.8
+ 9.10 11.12 -13.14 15.16
+17.18 19.20  21.22 23.24
 @end example
 
 @noindent
@@ -6286,7 +7317,6 @@ this program, using our function to format the results, prints:
 
 @example
    5.6
-  13.1
   21.2
 @end example
 
@@ -6342,7 +7372,7 @@ z = myfunc(foo)
 
 @noindent
 then you should not think of the argument to @code{myfunc} as being
-``the variable @code{foo}''.  Instead, think of the argument as the
+``the variable @code{foo}.''  Instead, think of the argument as the
 string value, @code{"bar"}.
 
 If the function @code{myfunc} alters the values of its local variables,
@@ -6407,7 +7437,9 @@ value is undefined and, therefore, unpredictable.
 
 A @code{return} statement with no value expression is assumed at the end of
 every function definition.  So if control reaches the end of the function
-definition, then the function returns an unpredictable value.
+body, then the function returns an unpredictable value.  @code{awk}
+will not warn you if you use the return value of such a function; you will
+simply get unpredictable or unexpected results.
 
 Here is an example of a user-defined function that returns a value
 for the largest number among the elements of an array:@refill
@@ -6481,8 +7513,8 @@ is the largest number in our array.
 @cindex built-in variables
 
 Most @code{awk} variables are available for you to use for your own
-purposes; they never change except when your program assigns them, and
-never affect anything except when your program examines them.
+purposes; they never change except when your program assigns values to
+them, and never affect anything except when your program examines them.
 
 A few variables have special built-in meanings.  Some of them @code{awk}
 examines automatically, so that they enable you to tell @code{awk} how
@@ -6508,9 +7540,33 @@ This is a list of the variables which you can change to control how
 @code{awk} does certain things.
 
 @table @code
-@c it's unadvisable to have multiple index entries for the same name
-@c since in Info there is no way to distinguish the two.
-@c @vindex FS
+@iftex
+@vindex CONVFMT
+@end iftex
+@item CONVFMT
+This string is used by @code{awk} to control conversion of numbers to
+strings (@pxref{Conversion}).  It works by being passed, in effect, as
+the first argument to the @code{sprintf} function.  Its default value
+is @code{"%.6g"}.  @code{CONVFMT} was introduced by the @sc{POSIX}
+standard.@refill
+
+@iftex
+@vindex FIELDWIDTHS
+@end iftex
+@item FIELDWIDTHS
+This is a space separated list of columns that tells @code{gawk}
+how to manage input with fixed, columnar boundaries.  It is an
+experimental feature that is still evolving.  Assigning to @code{FIELDWIDTHS}
+overrides the use of @code{FS} for field splitting.
+@xref{Constant Size}, for more information.@refill
+
+If @code{gawk} is in compatibility mode (@pxref{Command Line}), then
+@code{FIELDWIDTHS} has no special meaning, and field splitting operations are
+done based exclusively on the value of @code{FS}.
+
+@iftex
+@vindex FS
+@end iftex
 @item FS
 @code{FS} is the input field separator (@pxref{Field Separators}).
 The value is a single-character string or a multi-character regular
@@ -6529,8 +7585,14 @@ You can set the value of @code{FS} on the command line using the
 awk -F, '@var{program}' @var{input-files}
 @end example
 
+If @code{gawk} is using @code{FIELDWIDTHS} for field-splitting,
+assigning a value to @code{FS} will cause @code{gawk} to return to
+the normal, regexp-based, field splitting.
+
 @item IGNORECASE
-@c @vindex IGNORECASE
+@iftex
+@vindex IGNORECASE
+@end iftex
 If @code{IGNORECASE} is nonzero, then @emph{all} regular expression
 matching is done in a case-independent fashion.  In particular, regexp
 matching with @samp{~} and @samp{!~}, and the @code{gsub} @code{index},
@@ -6545,54 +7607,69 @@ If @code{gawk} is in compatibility mode (@pxref{Command Line}), then
 always case-sensitive.@refill
 
 @item OFMT
-@c @vindex OFMT
+@iftex
+@vindex OFMT
+@end iftex
 This string is used by @code{awk} to control conversion of numbers to
-strings (@pxref{Conversion}).  It works by being passed, in effect, as
-the first argument to the @code{sprintf} function.  Its default value
-is @code{"%.6g"}.@refill
+strings (@pxref{Conversion}) for printing with the @code{print} statement.
+It works by being passed, in effect, as the first argument to the
+@code{sprintf} function.  Its default value is @code{"%.6g"}.
+Earlier versions of @code{awk} also used @code{OFMT} to specify the
+format for converting numbers to strings in general expressions; this
+has been taken over by @code{CONVFMT}.@refill
 
 @item OFS
-@c @vindex OFS
+@iftex
+@vindex OFS
+@end iftex
 This is the output field separator (@pxref{Output Separators}).  It is
 output between the fields output by a @code{print} statement.  Its
 default value is @w{@code{" "}}, a string consisting of a single space.
 
 @item ORS
-@c @vindex ORS
+@iftex
+@vindex ORS
+@end iftex
 This is the output record separator.  It is output at the end of every
 @code{print} statement.  Its default value is a string containing a
 single newline character, which could be written as @code{"\n"}.
 (@xref{Output Separators}).@refill
 
 @item RS
-@c @vindex RS
-This is @code{awk}'s record separator.  Its default value is a string
+@iftex
+@vindex RS
+@end iftex
+This is @code{awk}'s input record separator.  Its default value is a string
 containing a single newline character, which means that an input record
 consists of a single line of text.  (@xref{Records}.)@refill
 
 @item SUBSEP
-@c @vindex SUBSEP
-@code{SUBSEP} is a subscript separator.  It has the default value of
+@iftex
+@vindex SUBSEP
+@end iftex
+@code{SUBSEP} is the subscript separator.  It has the default value of
 @code{"\034"}, and is used to separate the parts of the name of a
 multi-dimensional array.  Thus, if you access @code{foo[12,3]}, it
-really accesses @code{foo["12\0343"]}.  (@xref{Multi-dimensional}).@refill
+really accesses @code{foo["12\0343"]} (@pxref{Multi-dimensional}).@refill
 @end table
 
 @node Auto-set, , User-modified, Built-in Variables
 @section Built-in Variables That Convey Information to You
 
 This is a list of the variables that are set automatically by @code{awk}
-on certain occasions so as to provide information for your program.
+on certain occasions so as to provide information to your program.
 
 @table @code
 @item ARGC
 @itemx ARGV
-@c @vindex ARGC
-@c @vindex ARGV
-The command-line arguments available to @code{awk} are stored in an
-array called @code{ARGV}.  @code{ARGC} is the number of command-line
-arguments present.  @code{ARGV} is indexed from zero to @w{@code{ARGC - 1}}.
-@xref{Command Line}.  For example:
+@iftex
+@vindex ARGC
+@vindex ARGV
+@end iftex
+The command-line arguments available to @code{awk} programs are stored in
+an array called @code{ARGV}.  @code{ARGC} is the number of command-line
+arguments present.  @xref{Command Line}.  @code{ARGV} is indexed from zero
+to @w{@code{ARGC - 1}}.  For example:
 
 @example
 awk '@{ print ARGV[$1] @}' inventory-shipped BBS-list
@@ -6605,6 +7682,10 @@ contains @code{"inventory-shipped"}, and @code{ARGV[2]} contains
 index of the last element in @code{ARGV} since the elements are numbered
 from zero.@refill
 
+The names @code{ARGC} and @code{ARGV}, as well the convention of indexing
+the array from 0 to @w{@code{ARGC - 1}}, are derived from the C language's
+method of accessing command line arguments.@refill
+
 Notice that the @code{awk} program is not entered in @code{ARGV}.  The
 other special command line options, with their arguments, are also not
 entered.  But variable assignments on the command line @emph{are}
@@ -6628,6 +7709,10 @@ To eliminate a file from the middle of the list, store the null string
 special feature, @code{awk} ignores file names that have been
 replaced with the null string.
 
+@ignore
+see getopt.awk in the examples...
+@end ignore
+
 @item ENVIRON
 @vindex ENVIRON
 This is an array that contains the values of the environment.  The array
@@ -6642,42 +7727,54 @@ Some operating systems may not have environment variables.
 On such systems, the array @code{ENVIRON} is empty.
 
 @item FILENAME
-@c @vindex FILENAME
+@iftex
+@vindex FILENAME
+@end iftex
 This is the name of the file that @code{awk} is currently reading.
 If @code{awk} is reading from the standard input (in other words,
 there are no files listed on the command line),
 @code{FILENAME} is set to @code{"-"}.
-@code{FILENAME} is changed each time a new file is read (@pxref{Reading
-Files}).@refill
+@code{FILENAME} is changed each time a new file is read
+(@pxref{Reading Files}).@refill
 
 @item FNR
-@c @vindex FNR
+@iftex
+@vindex FNR
+@end iftex
 @code{FNR} is the current record number in the current file.  @code{FNR} is
 incremented each time a new record is read (@pxref{Getline}).
 It is reinitialized to 0 each time a new input file is started.
 
 @item NF
-@c @vindex NF
+@iftex
+@vindex NF
+@end iftex
 @code{NF} is the number of fields in the current input record.
 @code{NF} is set each time a new record is read, when a new field is
 created, or when @code{$0} changes (@pxref{Fields}).@refill
 
 @item NR
-@c @vindex NR
+@iftex
+@vindex NR
+@end iftex
 This is the number of input records @code{awk} has processed since
 the beginning of the program's execution.  (@pxref{Records}).
 @code{NR} is set each time a new record is read.@refill
 
 @item RLENGTH
-@c @vindex RLENGTH
+@iftex
+@vindex RLENGTH
+@end iftex
 @code{RLENGTH} is the length of the substring matched by the
 @code{match} function (@pxref{String Functions}).  @code{RLENGTH} is set
 by invoking the @code{match} function.  Its value is the length of the
 matched string, or @minus{}1 if no match was found.@refill
 
 @item RSTART
-@c @vindex RSTART
-@code{RSTART} is the start-index of the substring matched by the
+@iftex
+@vindex RSTART
+@end iftex
+@code{RSTART} is the start-index in characters of the substring matched by the
 @code{match} function (@pxref{String Functions}).  @code{RSTART} is set
 by invoking the @code{match} function.  Its value is the position of the
 string where the matched substring starts, or 0 if no match was
@@ -6697,8 +7794,8 @@ one or more program files.  Here are templates for both of them; items
 enclosed in @samp{@r{[}@dots{}@r{]}} in these templates are optional.
 
 @example
-awk @r{[@code{-F@var{fs}}] [@code{-v @var{var}=@var{val}}] [@code{-V}] [@code{-C}] [@code{-c}] [@code{-a}] [@code{-e}] [@code{--}]} '@var{program}' @var{file} @dots{}
-awk @r{[@code{-F@var{fs}}] @code{-f @var{source-file}} [@code{-f @var{source-file} @dots{}}] [@code{-v @var{var}=@var{val}}] [@code{-V}] [@code{-C}] [@code{-c}] [@code{-a}] [@code{-e}] [@code{--}]} @var{file} @dots{}
+awk @r{[@code{-F@var{fs}}] [@code{-W} @var{gawk-opts}] [@code{-v @var{var}=@var{val}}] [@code{--}]} '@var{program}' @var{file} @dots{}
+awk @r{[@code{-F@var{fs}}] [@code{-W} @var{gawk-opts}] [@code{-v @var{var}=@var{val}}] @code{-f @var{source-file}} [@code{-f @var{source-file} @dots{}}] [@code{--}]} @var{file} @dots{}
 @end example
 
 @menu
@@ -6727,62 +7824,88 @@ Sets the variable @var{var} to the value @var{val} @emph{before}
 execution of the program begins.  Such variable values are available
 inside the @code{BEGIN} rule (see below for a fuller explanation).
 
-The @samp{-v} option only has room to set one variable, but you can use
+The @samp{-v} option can only set one variable, but you can use
 it more than once, setting another variable each time, like this:
 @samp{@w{-v foo=1} @w{-v bar=2}}.
 
-@item -a
-Specifies use of traditional @code{awk} syntax for regular expressions.
-This means that @samp{\} can be used to quote any regular expression
-operators inside of square brackets, just as it can be outside of them.
-This mode is currently the default; the @samp{-a} option is useful in
-shell scripts so that they will not break if the default is changed.
-@xref{Regexp Operators}.
-
-@item -e
-Specifies use of @code{egrep} syntax for regular expressions.  This
-means that @samp{\} does not serve as a quoting character inside of
-square brackets; ideosyncratic techniques are needed to include various
-special characters within them.  This mode may become the default at
-some time in the future.  @xref{Regexp Operators}.
+@item -W @var{gawk-opt}
+Following the @sc{POSIX} standard, options that are specific to @code{gawk}
+are supplied as arguments to the @samp{-W} option.  These arguments
+may be separated by commas, or quoted and separated by whitespace.
+Case is ignored when processing these options.  The following options
+are available:
 
-@item -c
-@cindex @samp{-c} option
+@table @code
+@item compat
 Specifies @dfn{compatibility mode}, in which the GNU extensions in
 @code{gawk} are disabled, so that @code{gawk} behaves just like Unix
-@code{awk}.  These extensions are noted below, where their usage is
-explained.  @xref{Compatibility Mode}.
+@code{awk}.  @xref{POSIX/GNU}, which summarizes the extensions.
+Also see @ref{Compatibility Mode}.
 
-@item -V
-@cindex @samp{-V} option
+@item lint
+Provide warnings about constructs that are dubious or non-portable to
+other @code{awk} implementations.
+
+@item copyleft
+@itemx copyright
+Print the short version of the General Public License.
+This option may disappear in a future version of @code{gawk}.
+
+@item posix
+Operate in strict @sc{POSIX} mode.  This disables all @code{gawk}
+extensions (just like @code{compat}), and adds the following additional
+restrictions:
+
+@itemize @bullet{}
+@item
+@code{\x} escape sequences are not recognized (@pxref{Constants}).
+
+@item
+The synonym @code{func} for the keyword @code{function} is not
+recognized (@pxref{Definition Syntax}).
+
+@item
+The operators @samp{**} and @samp{**=} cannot be used in
+place of @samp{^} and @samp{^=} (@pxref{Arithmetic Ops}, and also
+@pxref{Assignment Ops}).@refill
+
+@item
+Specifying @samp{-Ft} on the command line does not set the value
+of @code{FS} to be a single tab character (@pxref{Field Separators}).
+@end itemize
+
+Although you can supply both @samp{-W compat} and @samp{-W posix} on the
+command line, @samp{-W posix} will take precedence.
+
+@item version
 Prints version information for this particular copy of @code{gawk}.
 This is so you can determine if your copy of @code{gawk} is up to date
 with respect to whatever the Free Software Foundation is currently
 distributing.  This option may disappear in a future version of @code{gawk}.
-
-@item -C
-@cindex @samp{-C} option
-Prints the short version of the General Public License.
-This option may disappear in a future version of @code{gawk}.
+@end table
 
 @item --
 Signals the end of the command line options.  The following arguments
 are not treated as options even if they begin with @samp{-}.  This
-interpretation of @samp{--} follows the POSIX argument parsing
+interpretation of @samp{--} follows the @sc{POSIX} argument parsing
 conventions.
 
 This is useful if you have file names that start with @samp{-},
 or in shell scripts, if you have file names that will be specified
-by the user and that might start with @samp{-}.
+by the user which could start with @samp{-}.
 @end table
 
+The @samp{-a}, @samp{-e}, @samp{-c}, @samp{-C}, and @samp{-V} options
+of @code{gawk} version 2.11.1 are recognized, but produce a warning
+message.  They will go away in the next major release of @code{gawk}.
+
 Any other options are flagged as invalid with a warning message, but
 are otherwise ignored.
 
 In compatibility mode, as a special case, if the value of @var{fs} supplied
 to the @samp{-F} option is @samp{t}, then @code{FS} is set to the tab
-character (@code{"\t"}).  Also, the @samp{-C} and @samp{-V} options
-are not recognized.@refill
+character (@code{"\t"}).  This is only true for @samp{-W compat}, and not
+for @samp{-W posix} (@pxref{Field Separators}).@refill
 
 If the @samp{-f} option is @emph{not} used, then the first non-option
 command line argument is expected to be the program text.
@@ -6797,6 +7920,9 @@ type in a program at the terminal and use library functions, by specifying
 @samp{-f /dev/tty}.  @code{awk} will read a file from the terminal
 to use as part of the @code{awk} program.  After typing your program,
 type @kbd{Control-d} (the end-of-file character) to terminate it.
+(You may also use @samp{-f -} to read program source from the standard
+input, but then you won't be able to also use the standard input as a
+source of data.)
 
 @node Other Arguments, AWKPATH Variable, Options, Command Line
 @section Other Command Line Arguments
@@ -6824,14 +7950,15 @@ Therefore, the variables actually receive the specified values after all
 previously specified files have been read.  In particular, the values of
 variables assigned in this fashion are @emph{not} available inside a
 @code{BEGIN} rule (@pxref{BEGIN/END}), since such rules are run before
-@code{awk} begins scanning the argument list.@refill
+@code{awk} begins scanning the argument list.  The values given on the
+command line are processed for escape sequences (@pxref{Constants}).@refill
 
 In some earlier implementations of @code{awk}, when a variable assignment
 occurred before any file names, the assignment would happen @emph{before}
 the @code{BEGIN} rule was executed.  Some applications came to depend
-upon this ``feature''.  When @code{awk} was changed to be more consistent,
+upon this ``feature.''  When @code{awk} was changed to be more consistent,
 the @samp{-v} option was added to accomodate applications that depended
-upon this old behaviour.
+upon this old behavior.
 
 The variable assignment feature is most useful for assigning to variables
 such as @code{RS}, @code{OFS}, and @code{ORS}, which control input and
@@ -6846,13 +7973,18 @@ awk 'pass == 1  @{ @var{pass 1 stuff} @}
      pass == 2  @{ @var{pass 2 stuff} @}' pass=1 datafile pass=2 datafile
 @end example
 
+Given the variable assignment feature, the @samp{-F} option is not
+strictly necessary.  It remains for historical compatibility.
+
 @node AWKPATH Variable,, Other Arguments, Command Line
 @section The @code{AWKPATH} Environment Variable
 @cindex @code{AWKPATH} environment variable
 @cindex search path
 @cindex directory search
 @cindex path, search
-@c @cindex differences between @code{gawk} and @code{awk}
+@iftex
+@cindex differences between @code{gawk} and @code{awk}
+@end iftex
 
 The previous section described how @code{awk} program files can be named
 on the command line with the @samp{-f} option.  In some @code{awk}
@@ -6864,11 +7996,13 @@ does not contain a @samp{/}, then @code{gawk} searches a list of
 directories (called the @dfn{search path}), one by one, looking for a
 file with the specified name.
 
-The search path is actually a string containing directory names
+The search path is actually a string consisting of directory names
 separated by colons.  @code{gawk} gets its search path from the
 @code{AWKPATH} environment variable.  If that variable does not exist,
 @code{gawk} uses the default path, which is
-@samp{.:/usr/lib/awk:/usr/local/lib/awk}.@refill
+@samp{.:/usr/lib/awk:/usr/local/lib/awk}.  (Programs written by
+system administrators should use an @code{AWKPATH} variable that
+does not include the current directory, @samp{.}.)@refill
 
 The search path feature is particularly useful for building up libraries
 of useful @code{awk} functions.  The library files can be placed in a
@@ -6877,6 +8011,7 @@ the command line with a short file name.  Otherwise, the full file name
 would have to be typed for each file.
 
 Path searching is not done if @code{gawk} is in compatibility mode.
+This is true for both @samp{-W compat} and @samp{-W posix}.
 @xref{Command Line}.
 
 @strong{Note:} if you want files in the current directory to be found,
@@ -6889,21 +8024,27 @@ found in the current directory.  This path search mechanism is identical
 to the shell's.
 @c someday, @cite{The Bourne Again Shell}....
 
-@node Language History, Gawk Summary, Command Line, Top
+@node Language History, Installation, Command Line, Top
 @chapter The Evolution of the @code{awk} Language
 
 This manual describes the GNU implementation of @code{awk}, which is patterned
-after the System V Release 4 version.  Many @code{awk} users are only familiar
+after the @sc{POSIX} specification.  Many @code{awk} users are only familiar
 with the original @code{awk} implementation in Version 7 Unix, which is also
-the basis for the version in Berkeley Unix.  This chapter briefly describes
-the evolution of the @code{awk} language.
+the basis for the version in Berkeley Unix (through 4.3--Reno).  This chapter
+briefly describes the evolution of the @code{awk} language.
 
 @menu
-* V7/S5R3.1::   The major changes between V7 and System V Release 3.1.
+* V7/S5R3.1::    The major changes between V7 and System V Release 3.1.
+
+* S5R4::         The minor changes between System V Releases 3.1 and 4.
+
+* POSIX::        New features from the @sc{POSIX} standard.
 
-* S5R4::        The minor changes between System V Releases 3.1 and 4.
+* POSIX/GNU::    The extensions in @code{gawk} not in @sc{POSIX} @code{awk}.
 
-* S5R4/GNU::    The extensions in @code{gawk} not in System V Release 4.
+* Obsolete::     Obsolete Options and/or features.
+
+* Undocumented:: Undocumented Options and Features.
 @end menu
 
 @node V7/S5R3.1, S5R4, Language History, Language History
@@ -6938,8 +8079,7 @@ The built-in functions @code{gsub}, @code{sub}, and @code{match}
 (@pxref{String Functions}).
 
 @item
-The built-in functions @code{close} and @code{system} (@pxref{I/O
-Functions}).
+The built-in functions @code{close} and @code{system} (@pxref{I/O Functions}).
 
 @item
 The @code{ARGC}, @code{ARGV}, @code{FNR}, @code{RLENGTH}, @code{RSTART},
@@ -6958,9 +8098,8 @@ C-compatible operator precedence, which breaks some old @code{awk}
 programs (@pxref{Precedence}).
 
 @item
-Regexps as the value of @code{FS} (@pxref{Field Separators}), or as the
-third argument to the @code{split} function (@pxref{String
-Functions}).@refill
+Regexps as the value of @code{FS} (@pxref{Field Separators}), and as the
+third argument to the @code{split} function (@pxref{String Functions}).@refill
 
 @item
 Dynamic regexps as operands of the @samp{~} and @samp{!~} operators
@@ -6983,10 +8122,11 @@ Multiple @code{BEGIN} and @code{END} rules (@pxref{BEGIN/END}).
 Simulation of multidimensional arrays (@pxref{Multi-dimensional}).
 @end itemize
 
-@node S5R4, S5R4/GNU, V7/S5R3.1, Language History
-@section Minor Changes between S5R3.1 and S5R4
+@node S5R4, POSIX, V7/S5R3.1, Language History
+@section Changes between S5R3.1 and S5R4
 
-The System V Release 4 version of Unix @code{awk} added these features:
+The System V Release 4 version of Unix @code{awk} added these features
+(some of which originated in @code{gawk}):
 
 @itemize @bullet
 @item
@@ -7018,13 +8158,47 @@ A cleaner specification for the @samp{%c} format-control letter in the
 @code{printf} function (@pxref{Printf}).
 
 @item
+The ability to dynamically pass the field width and precision (@code{"%*.*d"})
+in the argument list of the @code{printf} function (@pxref{Printf}).
+
+@item
 The use of constant regexps such as @code{/foo/} as expressions, where
 they are equivalent to use of the matching operator, as in @code{$0 ~
-/foo/}.
+/foo/} (@pxref{Constants}).
+@end itemize
+
+@node POSIX, POSIX/GNU, S5R4, Language History
+@section Changes Between S5R4 and the POSIX Standard for @code{awk}
+@c
+@c @section Changes Between S5R4 and the @sc{POSIX} Standard for @code{awk}
+@c
+@c when the POSIX is inside a @sc{} in a section, it comes out in
+@c a typewriter font, which isn't what we want. texinfo bug.
+
+The @sc{POSIX} Command Language And Utilities Standard for @code{awk}
+introduced the following changes into the language:
+
+@itemize @bullet{}
+@item
+The use of @samp{-W} for implementation-specific options.
+
+@item
+The use of @code{CONVFMT} for controlling the conversion of numbers
+to strings (@pxref{Conversion}).
+
+@item
+The concept of a numeric string, and tighter comparison rules to go
+with it (@pxref{Comparison Ops}).
+
+@item
+More complete documentation of many of the previously undocumented
+features of the language.
 @end itemize
 
-@node S5R4/GNU, , S5R4, Language History
-@section Extensions In @code{gawk} Not In S5R4
+@node POSIX/GNU, Obsolete, POSIX, Language History
+@section Extensions In @code{gawk} Not In POSIX @code{awk}
+@c
+@c @section Extensions In @code{gawk} Not In @sc{POSIX} @code{awk}
 
 The GNU implementation, @code{gawk}, adds these features:
 
@@ -7034,31 +8208,734 @@ The @code{AWKPATH} environment variable for specifying a path search for
 the @samp{-f} command line option (@pxref{Command Line}).
 
 @item
-The @samp{-C} and @samp{-V} command line options (@pxref{Command Line}).
+The various @code{gawk} specific features available via the @samp{-W}
+command line option (@pxref{Command Line}).
 
 @item
 The @code{IGNORECASE} variable and its effects (@pxref{Case-sensitivity}).
 
 @item
+The @code{FIELDWIDTHS} variable and its effects (@pxref{Constant Size}).
+
+@item
+The @code{systime} and @code{strftime} built-in functions for obtaining
+and printing time stamps (@pxref{Time Functions}).
+
+@item
 The @file{/dev/stdin}, @file{/dev/stdout}, @file{/dev/stderr}, and
 @file{/dev/fd/@var{n}} file name interpretation (@pxref{Special Files}).
 
 @item
-The @samp{-c} option to turn off these extensions (@pxref{Command Line}).
+The @samp{-W compat} option to turn off these extensions (@pxref{Command Line}).
 
 @item
-The @samp{-a} and @samp{-e} options to specify the syntax of regular
-expressions that @code{gawk} will accept (@pxref{Command Line}).
+The @samp{-W posix} option for full @sc{POSIX} compliance
+(@pxref{Command Line}).@refill
+
 @end itemize
 
-@node Gawk Summary, Sample Program, Language History, Top
-@appendix @code{gawk} Summary
+@node Obsolete, Undocumented, POSIX/GNU, Language History
+@section Obsolete Options and/or Features
+
+@cindex deprecated options
+@cindex obsolete options
+@cindex deprecated features
+@cindex obsolete features
+This section describes features and/or command line options from the
+previous release of @code{gawk} that are either not available in the
+current version, or that are still supported but deprecated (meaning that
+they will @emph{not} be in the next release).
+
+@c update this section for each release!
 
+For version 2.13 of @code{gawk}, the following command line options
+are recognized, but produce a warning message (@pxref{Command Line}).
+
+@table @samp
 @ignore
-See, man pages are good for something.  This chapter started life as the
-gawk.1 man page for 2.11.
+@item -nostalgia
+Use @samp{-W nostalgia} instead.
 @end ignore
 
+@item -c
+Use @samp{-W compat} instead.
+
+@item -V
+Use @samp{-W version} instead.
+
+@item -C
+Use @samp{-W copyright} instead.
+
+@item -a
+@itemx -e
+These options produce a warning message but have no effect on the
+execution of @code{gawk}.  The @sc{POSIX} standard now specifies
+traditional @code{awk} regular expressions for the @code{awk} utility.
+@end table
+
+@node Undocumented,  , Obsolete, Language History
+@section Undocumented Options and Features
+
+This section intentionally left blank.
+
+@c Read The Source, Luke!
+
+@ignore
+@c If these came out in the Info file or TeX manual, then they wouldn't
+@c be undocumented, would they?
+
+@code{gawk} has one undocumented option:
+
+@table @samp
+@item -W nostalgia
+Print the message @code{"awk: bailing out near line 1"} and dump core.
+This option was inspired by the common behavior of very early versions of
+Unix @code{awk}, and by a t--shirt.
+@end table
+
+Early versions of @code{awk} used to not require any separator (either
+a newline or @samp{;}) between the rules in @code{awk} programs.  Thus,
+it was common to see one-line programs like:
+
+@example
+awk '@{ sum += $1 @} END @{ print sum @}'
+@end example
+
+@code{gawk} actually supports this, but it is purposely undocumented
+since it is considered bad style.  The correct way to write such a program
+is either
+
+@example
+awk '@{ sum += $1 @} ; END @{ print sum @}'
+@end example
+
+@noindent
+or
+
+@example
+awk '@{ sum += $1 @}
+     END @{ print sum @}' data
+@end example
+
+@noindent
+@xref{Statements/Lines}, for a fuller explanation.
+
+As an accident of the implementation of the original Unix @code{awk}, if
+a built-in function used @code{$0} as its default argument, it was possible
+to call that function without the parentheses.  In particular, it was
+common practice to use the @code{length} function in this fashion.
+For example, the pipeline:
+
+@example
+echo abcdef | awk '@{ print length @}'
+@end example
+
+@noindent
+would print @samp{6}.
+
+For backwards compatibility with old programs, @code{gawk} supports
+this usage, but only for the @code{length} function.  New programs should
+@emph{not} call the @code{length} function this way.  In particular,
+this usage will not be portable to other @sc{POSIX} compliant versions
+of @code{awk}.  It is also poor style.
+
+@end ignore
+
+@node Installation, Gawk Summary, Language History, Top
+@chapter Installing @code{gawk}
+
+This chapter provides instructions for installing @code{gawk} on the
+various platforms that are supported by the developers.  The primary
+developers support Unix (and one day, GNU), while the other ports were
+contributed.  The file @file{ACKNOWLEDGMENT} in the @code{gawk}
+distribution lists the electronic mail addresses of the people who did
+the respective ports.@refill
+
+@menu
+* Gawk Distribution::   What is in the @code{gawk} distribution.
+
+* Unix Installation::   Installing @code{gawk} under various versions
+                        of Unix.
+
+* VMS Installation::    Installing @code{gawk} on VMS.
+
+* MS-DOS Installation:: Installing @code{gawk} on MS-DOS.
+
+* Atari Installation::  Installing @code{gawk} on the Atari ST.
+@end menu
+
+@node Gawk Distribution, Unix Installation, Installation, Installation
+@section The @code{gawk} Distribution
+
+@ifinfo
+This section first describes how to get and extract the @code{gawk}
+distribution, and then discusses what is in the various files and
+subdirectories.
+@end ifinfo
+
+@menu
+* Extracting::            How to get and extract the distribution.
+
+* Distribution contents:: What is in the distribution.
+@end menu
+
+@node Extracting, Distribution contents, Gawk Distribution, Gawk Distribution
+@subsection Getting The @code{gawk} Distribution
+
+@cindex getting gawk
+@cindex anonymous ftp
+@cindex anonymous uucp
+@cindex ftp, anonymous
+@cindex uucp, anonymous
+@code{gawk} is distributed as a compressed @code{tar} file.  You can
+get it via anonymous @code{ftp} to the Internet host @code{prep.ai.mit.edu}.
+Like all GNU software, it will be archived at other well known systems,
+from which it will be possible to use some sort of anonymous @code{uucp} to
+obtain the distribution as well.
+
+Once you have the distribution (for example, @file{gawk-2.13.3.tar.Z}), first
+use @code{uncompress} to expand the file, and then use @code{tar} to extract it.
+@code{uncompress} usually has a link named @code{zcat}, which causes it
+to decompress the file to the standard output.  You can use the following
+pipeline to produce the @code{gawk} distribution:
+
+@example
+# Under System V, add 'o' to the tar flags
+zcat gawk-2.13.3.tar.Z | tar -xvpf -
+@end example
+
+@noindent
+This will create a directory named @file{gawk-2.13} in the current
+directory.
+
+The distribution file name is of the form @file{gawk-2.13.@var{n}.tar.Z}.
+The @var{n} represents a @dfn{patchlevel}, meaning that minor bugs have
+been fixed in the major release.  The current patchlevel is 3, but when
+retrieving distributions, you should get the version with the highest
+patchlevel.@refill
+
+If you are not on a Unix system, you will need to make other arrangements
+for getting and extracting the @code{gawk} distribution.  You should consult
+a local expert.
+
+@node Distribution contents,  , Extracting, Gawk Distribution
+@subsection Contents Of The @code{gawk} Distribution
+
+@code{gawk} has a number of C source files, documentation files,
+subdirectories and files related to the configuration process
+(@pxref{Unix Installation}), and several subdirectories related to
+different, non-Unix, operating systems.@refill
+
+@table @asis
+@item The C and YACC source files
+The various @samp{.c}, @samp{.y}, and @samp{.h} files are the actual
+@code{gawk} source code.
+@end table
+
+@table @file
+@item README
+@itemx README.VMS
+@itemx README.dos
+@itemx README.rs6000
+@itemx README.ultrix
+Descriptive files: @file{README} for @code{gawk} under Unix, and the
+rest for the various hardware and software combinations.
+
+@item PORTS
+A list of systems to which @code{gawk} has been ported, and which
+have successfully run the test suite.
+
+@item ACKNOWLEDGMENT
+A list of the people who contributed major parts of the code or documentation.
+
+@item CHANGES
+A list of changes to @code{gawk} since the last release or patch.
+
+@item COPYING
+The GNU General Public License.
+
+@item FUTURES
+A brief list of features and/or changes being contemplated for future
+releases, with some indication of the time frame for the feature, based
+on its difficulty.
+
+@item LIMITATIONS
+A list of those factors that limit @code{gawk}'s performance.
+Most of these depend on the hardware or operating system software, and
+are not limits in @code{gawk} itself.@refill
+
+@item PROBLEMS
+A file describing known problems with the current release.
+
+@item gawk.1
+The @code{troff} source for a manual page describing @code{gawk}.
+
+@item gawk.texinfo
+@ifinfo
+The @code{texinfo} source file for this Info file.
+It should be processed with @TeX{} to produce a printed manual, and
+with @code{makeinfo} to produce the Info file.@refill
+@end ifinfo
+@iftex
+The @code{texinfo} source file for this manual.
+It should be processed with @TeX{} to produce a printed manual, and
+with @code{makeinfo} to produce the Info file.@refill
+@end iftex
+
+@item Makefile-dist
+@itemx config
+@itemx config.h-dist
+@itemx configure
+@itemx missing
+@itemx mkconf
+@itemx mungeconf
+These files and subdirectories are used when configuring @code{gawk}
+for various Unix systems.  They are explained in detail in
+@ref{Unix Installation}.@refill
+
+@item atari
+Files needed for building @code{gawk} on an Atari ST.
+@xref{Atari Installation}, for details.
+
+@item pc
+Files needed for building @code{gawk} under MS-DOS.
+@xref{MS-DOS Installation}, for details.
+
+@item vms
+Files needed for building @code{gawk} under VAX VMS.
+@xref{VMS Installation}, for details.
+
+@item test
+Many interesting @code{awk} programs, provided as a test suite for
+@code{gawk}.  You can use @samp{make test} from the top level @code{gawk}
+directory to run your version of @code{gawk} against the test suite.
+There are many programs here that are useful in their own right.
+If @code{gawk} successfully passes @samp{make bigtest} then you can
+be confident of a successful port.@refill
+@end table
+
+@node Unix Installation, VMS Installation, Gawk Distribution, Installation
+@section Compiling And Installing @code{gawk} on Unix
+
+@menu
+* Quick Installation::        Compiling @code{gawk} on a supported Unix version.
+
+* Configuration Philosophy::  How it's all supposed to work.
+
+* New Configurations::        What to do if there is no supplied configuration
+                              for your system.
+@end menu
+
+@node Quick Installation, Configuration Philosophy, Unix Installation, Unix Installation
+@subsection Compiling @code{gawk} For A Supported Unix Version
+
+@cindex installation, unix
+After you have extracted the @code{gawk} distribution, @code{cd}
+to @file{gawk-2.13}.  Look in the @file{config} subdirectory for a
+file that matches your hardware/software combination.  In general,
+only the software is relevant, for example @code{sunos41} is used
+for SunOS 4.1, on both Sun 3 and Sun 4 hardware.@refill
+
+If you find such a file, run the command:
+
+@example
+# assume you have SunOS 4.1
+./configure sunos41
+@end example
+
+This produces a @file{Makefile} and @file{config.h} tailored to your
+system.  You may wish to edit the @file{Makefile} to use a different
+C compiler, such as @code{gcc}, the GNU C compiler, if you have it.
+You may also wish to change the @code{CFLAGS} variable, which controls
+the command line options that are passed to the C compiler (such as
+optimization levels, or compiling for debugging).@refill
+
+After you have configured @file{Makefile} and @file{config.h}, type:
+
+@example
+make
+@end example
+
+@noindent
+and shortly thereafter, you should have an executable version of @code{gawk}.
+That's all there is to it!
+
+@node Configuration Philosophy, New Configurations, Quick Installation, Unix Installation
+@subsection The Configuration Process
+
+(This section is of interest only if you know something about using the
+C language and the Unix operating system.)
+
+The source code for @code{gawk} generally attempts to adhere to industry
+standards wherever possible.  This means that @code{gawk} uses library
+routines that are specified by the @sc{ANSI} C standard and by the @sc{POSIX}
+operating system interface standard.  When using an @sc{ANSI} C compiler,
+function prototypes are provided to help improve the compile-time checking.
+
+Many older Unix systems do not support all of either the @sc{ANSI} or the
+@sc{POSIX} standards.  The @file{missing} subdirectory in the @code{gawk}
+distribution contains replacement versions of those subroutines that are
+most likely to be missing.
+
+The @file{config.h} file that is created by the @code{configure} program
+contains definitions that describe features of the particular operating
+system where you are attempting to compile @code{gawk}.  For the most
+part, it lists which standard subroutines are @emph{not} available.
+For example, if your system lacks the @samp{getopt} routine, then
+@samp{GETOPT_MISSING} would be defined.
+
+@file{config.h} also defines constants that describe facts about your
+variant of Unix.  For example, there may not be an @samp{st_blksize}
+element in the @code{stat} structure.  In this case @samp{BLKSIZE_MISSING}
+would be defined.
+
+Based on the list in @file{config.h} of standard subroutines that are
+missing, @file{missing.c} will do a @samp{#include} of the appropriate
+file(s) from the @file{missing} subdirectory.@refill
+
+Conditionally compiled code in the other source files relies on the
+other definitions in the @file{config.h} file.
+
+Besides creating @file{config.h}, @code{configure} produces a @file{Makefile}
+from @file{Makefile-dist}.  There are a number of lines in @file{Makefile-dist}
+that are system or feature specific.  For example, there is line that begins
+with @samp{##MAKE_ALLOCA_C##}.  This is normally a comment line, since
+it starts with @samp{#}.  If a configuration file has @samp{MAKE_ALLOCA_C}
+in it, then @code{configure} will delete the @samp{##MAKE_ALLOCA_C##}
+from the beginning of the line.  This will enable the rules in the
+@file{Makefile} that use a C version of @samp{alloca}.  There are several
+similar features that work in this fashion.@refill
+
+The file @file{mkconf} is a link to @file{configure}.  This name for
+the program is left over from an earlier patchlevel of @code{gawk} 2.13.
+For the next release of @code{gawk}, the distribution will comply fully
+with the GNU standards for software distributions.  @file{Makefile-dist}
+will be renamed @file{Makefile.in}, and @file{mkconf} will go away.@refill
+
+@node New Configurations,  , Configuration Philosophy, Unix Installation
+@subsection Configuring @code{gawk} For A New System
+
+(This section is of interest only if you know something about using the
+C language and the Unix operating system, and if you have to install
+@code{gawk} on a system that is not supported by the @code{gawk} distribution.
+If you are a C or Unix novice, get help from a local expert.)
+
+If you need to configure @code{gawk} for a Unix system that is not
+supported in the distribution, first see @ref{Configuration Philosophy}.
+Then, copy @file{config.h-dist} to @file{config.h}, and copy
+@file{Makefile-dist} to @file{Makefile}.@refill
+
+Next, edit both files.  Both files are liberally commented, and the
+necessary changes should be straightforward.
+
+While editing @file{config.h}, you need to determine what library
+routines you do or do not have by consulting your system documentation, or
+by perusing your actual libraries using the @code{ar} or @code{nm} utilities.
+In the worst case, simply do not define @emph{any} of the macros for missing
+subroutines.  When you compile @code{gawk}, the final link-editing step
+will fail.  The link editor will provide you with a list of unresolved external
+references---these are the missing subroutines.  Edit @file{config.h} again
+and recompile, and you should be set.@refill
+
+Editing the @file{Makefile} should also be straightforward.  Enable or
+disable the lines that begin with @samp{##MAKE_@var{whatever}##}, as
+appropriate.  Select the correct C compiler and @code{CFLAGS} for it.
+Then run @code{make}.
+
+Getting a correct configuration is likely to be an iterative process.
+Do not be discouraged if it takes you several tries.  If you have no
+luck whatsoever, please report your system type, and the steps you took.
+Once you do have a working configuration, please send it to the maintainers
+so that support for your system can be added to the official release.
+
+@xref{Bugs}, for information on how to report problems in configuring
+@code{gawk}.  You may also use the same mechanisms for sending in new
+configurations.@refill
+
+@node VMS Installation, MS-DOS Installation, Unix Installation, Installation
+@section Compiling, Installing, and Running @code{gawk} on VMS
+
+@c based on material from
+@c Pat Rankin <gawk.rankin@eql.caltech.edu>
+
+@cindex installation, vms
+This section describes how to compile and install @code{gawk} under VMS.
+
+@menu
+* VMS Compilation::          How to compile @code{gawk} under VMS.
+
+* VMS Installation Details:: How to install @code{gawk} under VMS.
+
+* VMS Running::              How to run @code{gawk} under VMS.
+@end menu
+
+@node VMS Compilation, VMS Installation Details, VMS Installation, VMS Installation
+@subsection Compiling @code{gawk} under VMS
+
+To compile @code{gawk} under VMS, there is a @code{DCL} command procedure that
+will issue all the necessary @code{CC} and @code{LINK} commands, and there is
+also a @file{Makefile} for use with the @code{MMS} utility.  From the source
+directory, use either
+
+@example
+$ @@[.VMS]VMSBUILD.COM
+@end example
+
+@noindent
+or
+
+@example
+$ MMS/DESCRIPTION=[.VMS]DECSRIP.MMS GAWK
+@end example
+
+Depending upon which C compiler you are using, follow one of the sets
+of instructions in this table:
+
+@table @asis
+@item VAX C V3.x
+Use either @file{vmsbuild.com} or @file{descrip.mms} as is.  These use
+@code{CC/OPTIMIZE=NOLINE}, which is essential for version 3.0.
+
+@item VAX C V2.x
+You must have version 2.3 or 2.4; older ones won't work.  Edit either
+@file{vmsbuild.com} or @file{descrip.mms} according to the comments in them.
+For @file{vmsbuild.com}, this just entails removing two @samp{!} delimiters.
+Also edit @file{config.h} (which is a copy of file @file{[.config]vms-conf.h})
+and comment out or delete the two lines @samp{#define __STDC__ 0} and
+@samp{#define VAXC_BUILTINS} near the end.@refill
+
+@item GNU C
+Edit @file{vmsbuild.com} or @file{descrip.mms}; the changes are different
+from those for VAX C V2.x, but equally straightforward.  No changes to
+@file{config.h} should be needed.
+@end table
+
+@code{gawk} 2.13 has been tested under VMS V5.3 and V5.4-2 using VAX C V3.2,
+V3.1, and V2.3 and also GNU C V1.39.  It should work without modifications for
+VMS V4.6 and up.
+
+@node VMS Installation Details, VMS Running, VMS Compilation, VMS Installation
+@subsection Installing @code{gawk} on VMS
+
+To install @code{gawk}, all you need is a ``foreign'' command, which is
+a @code{DCL} symbol whose value begins with a dollar sign.
+
+@example
+$ GAWK :== $device:[directory]GAWK
+@end example
+
+@noindent
+(Substitute the actual location of @code{gawk.exe} for
+@samp{device:[directory]}.) The symbol should be placed in the
+@file{login.com} of any user who wishes to run @code{gawk},
+so that it will be defined every time the user logs on.
+Alternatively, the symbol may be placed in the system-wide
+@file{sylogin.com} procedure, which will allow all users
+to run @code{gawk}.@refill
+
+Optionally, the help entry can be loaded into a VMS help library:
+
+@example
+$ LIBRARY/HELP SYS$HELP:HELPLIB [.VMS]GAWK.HLP
+@end example
+
+@noindent
+(You may want to substitute a site-specific help library rather than
+the standard VMS library @samp{HELPLIB}.)  After loading the help text,
+
+@example
+$ HELP GAWK
+@end example
+
+@noindent
+will provide information about both the @code{gawk} implementation and the
+@code{awk} programming language.
+
+The logical name @samp{AWK_LIBRARY} can designate a default location
+for @code{awk} program files.  For the @samp{-f} option, if the specified
+filename has no device or directory path information in it, @code{gawk}
+will look in the current directory first, then in the directory specified
+by the translation of @samp{AWK_LIBRARY} if the file was not found.
+If after searching in both directories, the file still is not found,
+then @code{gawk} appends the suffix @samp{.awk} to the filename and the
+file search will be re-tried.  If @samp{AWK_LIBRARY} is not defined, that
+portion of the file search will fail benignly.@refill
+
+@node VMS Running,  , VMS Installation Details, VMS Installation
+@subsection Running @code{gawk} on VMS
+
+Command line parsing and quoting conventions are significantly different
+on VMS, so examples in this manual or from other sources often need minor
+changes.  They @emph{are} minor though, and all @code{awk} programs
+should run correctly.
+
+Here are a couple of trivial tests:
+
+@example
+$ gawk -- "BEGIN @{print ""Hello, World!""@}"
+$ gawk -"W" version     ! could also be -"W version" or "-W version"
+@end example
+
+@noindent
+Note that upper-case and mixed-case text must be quoted.
+
+The VMS port of @code{gawk} includes a @code{DCL}-style interface in addition
+to the original shell-style interface (see the help entry for details).
+One side-effect of dual command line parsing is that if there is only a
+single parameter (as in the quoted string program above), the command
+becomes ambiguous.  To work around this, the normally optional @samp{--}
+flag is required to force Unix style rather than @code{DCL} parsing.  If any
+other dash-type options (or multiple parameters such as data files to be
+processed) are present, there is no ambiguity and @samp{--} can be omitted.
+
+The default search path when looking for @code{awk} program files specified
+by the @samp{-f} option is @code{"SYS$DISK:[],AWK_LIBRARY:"}.  The logical
+name @samp{AWKPATH} can be used to override this default.  The format
+of @samp{AWKPATH} is a comma-separated list of directory specifications.
+When defining it, the value should be quoted so that it retains a single
+translation, and not a multi-translation @code{RMS} searchlist.
+
+@node MS-DOS Installation, Atari Installation, VMS Installation, Installation
+@section Installing @code{gawk} on MS-DOS
+
+@cindex installation, ms-dos
+The first step is to get all the files in the @code{gawk} distribution
+onto your PC.  Move all the files from the @file{pc} directory into
+the main directory where the other files are.  Edit the file
+@file{make.bat} so that it will be an acceptable MS-DOS batch file.
+This means making sure that all lines are terminated with ASCII
+Carriage Return and Line Feed characters.  Rename the Unix file
+@file{awk.tab.c} to @file{awktab.c}, since MS-DOS has file naming
+restrictions.
+
+@code{gawk} has only been compiled with version 5.1 of the Microsoft
+C compiler.  The file @file{make.bat} from the @file{pc} directory
+assumes that you have this compiler.
+
+Copy the file @file{setargv.obj} from the library directory where it
+resides to the @code{gawk} source code directory.
+
+Run @file{make.bat}.  This will compile @code{gawk} for you, and link it.
+That's all there is to it!
+
+@node Atari Installation,  , MS-DOS Installation, Installation
+@section Installing @code{gawk} on the Atari ST
+
+@c based on material from
+@c Michal Jaegermann <ntomczak@vm.ucs.ualberta.ca>
+
+@cindex installation, atari
+This section assumes that you are running TOS.  It applies to other Atari
+models (STe, TT) as well.
+
+In order to use @code{gawk}, you need to have a shell, either text or
+graphics, that does not map all the characters of a command line to
+upper case.  Maintaining case distinction in option flags is very
+important (@pxref{Command Line}).  Popular shells like @code{gulam}
+or @code{gemini} will work, as will newer versions of @code{desktop}.
+Support for I/O redirection is necessary to make it easy to import
+@code{awk} programs from other environments.  Pipes are nice to have,
+but not vital.
+
+If you have received an executable version of @code{gawk}, place it,
+as usual, anywhere in your @code{PATH} where your shell will find it.
+
+While executing, @code{gawk} creates a number of temporary files.
+@code{gawk} looks for either of the environment variables @code{TEMP}
+or @code{TMPDIR}, in that order.  If either one is found, its value
+is assumed to be a directory for temporary files.  This directory
+must exist, and if you can spare the memory, it is a good idea to
+put it on a @sc{RAM} drive.  If neither @code{TEMP} nor @code{TMPDIR}
+are found, then @code{gawk} uses the current directory for its
+temporary files.
+
+The ST version of @code{gawk} searches for its program files as
+described in @ref{AWKPATH Variable}.  On the ST, the default value for 
+@code{AWKPATH} is @code{@w{".,c:\lib\awk,c:\gnu\lib\awk"}}.
+The search path can be modified by explicitly setting @code{AWKPATH} to
+whatever you wish.  Note that colons cannot be used on the ST to separate
+elements in the @code{AWKPATH} variable, since they have another, reserved,
+meaning.  Instead, you must use a comma to separate elements in the path.
+If you are recompiling @code{gawk} on the ST, then you can choose a new
+default search path, by setting the value of @samp{DEFPATH} in the file
+@file{...\config\atari}.  You may choose a different separator character
+by setting the value of @samp{ENVSEP} in the same file.  The new values will
+be used when creating the header file @file{config.h}.@refill
+
+@ignore
+As a last resort, small
+adjustments can be made directly on the executable version of @code{gawk}
+using a binary editor.@refill
+@end ignore
+
+Although @code{awk} allows great flexibility in doing I/O redirections
+from within a program, this facility should be used with care on the ST.
+In some circumstances the OS routines for file handle pool processing
+lose track of certain events, causing the computer to crash, and requiring
+a reboot.  Often a warm reboot is sufficient.  Fortunately, this happens
+infrequently, and in rather esoteric situations.  In particular, avoid
+having one part of an @code{awk} program using @code{print}
+statements explicitly redirected to @code{"/dev/stdout"}, while other
+@code{print} statements use the default standard output, and a
+calling shell has redirected standard output to a file.@refill
+@c whew!
+
+When @code{gawk} is compiled with the ST version of @code{gcc} and its
+usual libraries, it will accept both @samp{/} and @samp{\} as path separators.
+While this is convenient, it should be remembered that this removes one,
+technically legal, character (@samp{/}) from your file names, and that
+it may create problems for external programs, called via the @code{system()}
+function, which may not support this convention.  Whenever it is possible
+that a file created by @code{gawk} will be used by some other program,
+use only backslashes.  Also remember that in @code{awk}, backslashes in
+strings have to be doubled in order to get literal backslashes.
+
+The initial port of @code{gawk} to the ST was done with @code{gcc}.
+If you wish to recompile @code{gawk} from scratch, you will need to use
+a compiler that accepts @sc{ANSI} standard C (such as @code{gcc}, Turbo C,
+or Prospero C).  If @code{sizeof(int) != @w{sizeof(int *)}}, the correctness
+of the generated code depends heavily on the fact that all function calls
+have function prototypes in the current scope.  If your compiler does
+not accept function prototypes, you will probably have to add a
+number of casts to the code.@refill
+
+If you are using @code{gcc}, make sure that you have up-to-date libraries.
+Older versions have problems with some library functions (@code{atan2()},
+@code{strftime()}, the @samp{%g} conversion in @code{sprintf()}) which
+may affect the operation of @code{gawk}.
+
+In the @file{atari} subdirectory of the @code{gawk} distribution is
+a version of the @code{system()} function that has been tested with
+@code{gulam} and @code{msh}; it should work with other shells as well.
+With @code{gulam}, it passes the string to be executed without spawning
+an extra copy of a shell.  It is possible to replace this version of
+@code{system()} with a similar function from a library or from some other
+source if that version would be a better choice for the shell you prefer.
+
+The files needed to recompile @code{gawk} on the ST can be found in
+the @file{atari} directory.  The provided files and instructions below
+assume that you have the GNU C compiler (@code{gcc}), the @code{gulam} shell,
+and an ST version of @code{sed}. The @file{Makefile} is set up to use
+@file{byacc} as a @file{yacc} replacement.  With a different set of tools some
+adjustments and/or editing will be needed.@refill
+
+@code{cd} to the @file{atari} directory.  Copy @file{Makefile.st} to
+@file{makefile} in the source (parent) directory.  Possibly adjust
+@file{../config/atari} to suit your system.  Execute the script @file{mkconf.g}
+which will create the header file @file{../config.h}.  Go back to the source
+directory.  If you are not using @code{gcc}, check the file @file{missing.c}.
+It may be necessary to change forward slashes in the references to files
+from the @file{atari} subdirectory into backslashes.  Type @code{make} and
+enjoy.@refill
+
+Compilation with @code{gcc} of some of the bigger modules, like
+@file{awk_tab.c}, may require a full four megabytes of memory.  On smaller
+machines you would need to cut down on optimizations, or you would have to
+switch to another, less memory hungry, compiler.@refill
+
+@node Gawk Summary, Sample Program, Installation, Top
+@appendix @code{gawk} Summary
+
 This appendix provides a brief summary of the @code{gawk} command line and the
 @code{awk} language.  It is designed to serve as ``quick reference.''  It is
 therefore terse, but complete.
@@ -7080,8 +8957,8 @@ values to be made available in the @code{ARGC} and @code{ARGV}
 predefined @code{awk} variables:
 
 @example
-awk @r{[@code{-F@var{fs}}] [@code{-v @var{var}=@var{val}}] [@code{-V}] [@code{-C}] [@code{-c}] [@code{-a}] [@code{-e}] [@code{--}]} '@var{program}' @var{file} @dots{}
-awk @r{[@code{-F@var{fs}}] @code{-f @var{source-file}} [@code{-f @var{source-file} @dots{}}] [@code{-v @var{var}=@var{val}}] [@code{-V}] [@code{-C}] [@code{-c}] [@code{-a}] [@code{-e}] [@code{--}]} @var{file} @dots{}
+awk @r{[@code{-F@var{fs}}] [@code{-W} @var{gawk-opts}] [@code{-v @var{var}=@var{val}}] [@code{--}]} '@var{program}' @var{file} @dots{}
+awk @r{[@code{-F@var{fs}}] [@code{-W} @var{gawk-opts}] [@code{-v @var{var}=@var{val}}]} @code{-f} @var{source-file} @r{[@code{-f @var{source-file} @dots{}}]} @var{file} @dots{}
 @end example
 
 The options that @code{gawk} accepts are:
@@ -7099,32 +8976,30 @@ of from the first command line argument.
 Assign the variable @var{var} the value @var{val} before program execution
 begins.
 
-@item -a
-Specifies use of traditional @code{awk} syntax for regular expressions.
-This means that @samp{\} can be used to quote regular expression
-operators inside of square brackets, just as it can be outside of them.
-
-@item -e
-Specifies use of @code{egrep} syntax for regular expressions.  This
-means that @samp{\} does not serve as a quoting character inside of
-square brackets.
-
-@item -c
+@item -W compat
 Specifies compatibility mode, in which @code{gawk} extensions are turned
 off.
 
-@item -V
+@item -W posix
+Specifies @sc{POSIX} compatibility mode, in which @code{gawk} extensions
+are turned off, and additional restrictions apply.
+
+@item -W version
 Print version information for this particular copy of @code{gawk} on the error
 output.  This option may disappear in a future version of @code{gawk}.
 
-@item -C
+@item -W copyleft
+@itemx -W copyright
 Print the short version of the General Public License on the error
 output.  This option may disappear in a future version of @code{gawk}.
 
+@item -W lint
+Give warnings about dubious or non-portable @code{awk} constructs.
+
 @item --
 Signal the end of options.  This is useful to allow further arguments to the
 @code{awk} program itself to start with a @samp{-}.  This is mainly for
-consistency with the argument parsing conventions of POSIX.
+consistency with the argument parsing conventions of @sc{POSIX}.
 @end table
 
 Any other options are flagged as invalid, but are otherwise ignored.
@@ -7151,16 +9026,14 @@ order they are specified.  This is useful for building libraries of
 @code{awk} functions, without having to include them in each new
 @code{awk} program that uses them.  To use a library function in a file
 from a program typed in on the command line, specify @samp{-f /dev/tty};
-then type your program, and end it with a @kbd{C-d}.  @xref{Command
-Line}.
+then type your program, and end it with a @kbd{Control-d}.  @xref{Command Line}.
 
 The environment variable @code{AWKPATH} specifies a search path to use
-when finding source files named with the @samp{-f} option.  If the
-variable @code{AWKPATH} is not set, @code{gawk} uses the default path,
-@samp{.:/usr/lib/awk:/usr/local/lib/awk}.  If a file name given to the
-@samp{-f} option contains a @samp{/} character, no path search is
-performed.  @xref{AWKPATH Variable}, for a full description of the
-@code{AWKPATH} environment variable.@refill
+when finding source files named with the @samp{-f} option.  The default path
+@samp{.:/usr/lib/awk:/usr/local/lib/awk} is used if @code{AWKPATH} is not set.
+If a file name given to the @samp{-f} option contains a @samp{/} character,
+no path search is performed.  @xref{AWKPATH Variable}, for a full description
+of the @code{AWKPATH} environment variable.@refill
 
 @code{gawk} compiles the program into an internal form, and then proceeds to
 read each file named in the @code{ARGV} array.  If there are no files named
@@ -7169,6 +9042,8 @@ on the command line, @code{gawk} reads the standard input.
 If a ``file'' named on the command line has the form
 @samp{@var{var}=@var{val}}, it is treated as a variable assignment: the
 variable @var{var} is assigned the value @var{val}.
+If any of the files have a value that is the null string, that
+element in the list is skipped.@refill
 
 For each line in the input, @code{gawk} tests to see if it matches any
 @var{pattern} in the @code{awk} program.  For each pattern that the line
@@ -7237,8 +9112,14 @@ The number of command line arguments (not including options or the
 
 @item ARGV
 The array of command line arguments.  The array is indexed from 0 to
-@code{ARGC} - 1.  Dynamically changing the contents of @code{ARGV} can control
-the files used for data.@refill
+@code{ARGC} @minus{} 1.  Dynamically changing the contents of @code{ARGV}
+can control the files used for data.@refill
+
+@item CONVFMT
+The conversion format to use when converting numbers to strings.
+
+@item FIELDWIDTHS
+A space separated list of numbers describing the fixed-width input data.
 
 @item ENVIRON
 An array containing the values of the environment variables.  The array
@@ -7278,7 +9159,8 @@ The number of fields in the current input record.
 The total number of input records seen so far.
 
 @item OFMT
-The output format for numbers, @code{"%.6g"} by default.
+The output format for numbers for the @code{print} statement,
+@code{"%.6g"} by default.
 
 @item OFS
 The output field separator, a blank by default.
@@ -7311,9 +9193,9 @@ default @code{"\034"}.
 @appendixsubsec Arrays
 
 Arrays are subscripted with an expression between square brackets
-(@samp{[} and @samp{]}).  The expression may be either a number or
-a string.  Since arrays are associative, string indices are meaningful
-and are not converted to numbers.
+(@samp{[} and @samp{]}).  Array subscripts are @emph{always} strings;
+numbers are converted to strings as necessary, following the standard
+conversion rules (@pxref{Conversion}).@refill
 
 If you use multiple expressions separated by commas inside the square
 brackets, then the array subscript is a string consisting of the
@@ -7353,7 +9235,8 @@ of the string as a numeral.  If the string does not look like a
 numeral, it converts to 0.
 
 Certain contexts (such as concatenation) require string values.
-They convert numbers to strings by effectively printing them.
+They convert numbers to strings by effectively printing them
+with @code{sprintf}. @xref{Conversion}, for the details.
 
 To force conversion of a string value to a number, simply add 0
 to it.  If the value you start with is already a number, this
@@ -7363,8 +9246,9 @@ To force conversion of a numeric value to a string, concatenate it with
 the null string.
 
 The @code{awk} language defines comparisons as being done numerically if
-possible, otherwise one or both operands are converted to strings and
-a string comparison is performed.
+both operands are numeric, or if one is numeric and the other is a numeric
+string.  Otherwise one or both operands are converted to strings and a
+string comparison is performed.
 
 Uninitialized variables have the string value @code{""} (the null, or
 empty, string).  In contexts where a number is required, this is
@@ -7442,14 +9326,14 @@ patterns cannot be combined with other patterns in pattern expressions.
 
 For @samp{/@var{regular-expression}/} patterns, the associated statement is
 executed for each input line that matches the regular expression.  Regular
-expressions are the same as those in @code{egrep}, and are summarized below.
+expressions are extensions of those in @code{egrep}, and are summarized below.
 
 A @var{relational expression} may use any of the operators defined below in
 the section on actions.  These generally test whether certain fields match
 certain regular expressions.
 
-The @samp{&&}, @samp{||}, and @samp{!} operators are logical ``and'',
-logical ``or'', and logical ``not'', respectively, as in C.  They do
+The @samp{&&}, @samp{||}, and @samp{!} operators are logical ``and,''
+logical ``or,'' and logical ``not,'' respectively, as in C.  They do
 short-circuit evaluation, also as in C, and are used for combining more
 primitive pattern expressions.  As in most languages, parentheses may be
 used to change the order of evaluation.
@@ -7538,6 +9422,7 @@ and input/output statements available are patterned after those in C.
 * Special File Summary::        Special file names interpreted internally.
 * Numeric Functions Summary::   Built-in numeric functions.
 * String Functions Summary::    Built-in string functions.
+* Time Functions Summary::      Built-in time functions.
 * String Constants Summary::    Escape sequences in strings.
 @end menu
 
@@ -7583,7 +9468,7 @@ Unary plus, unary minus, and logical negation.
 
 @item ^
 Exponentiation (@samp{**} may also be used, and @samp{**=} for the assignment
-operator).
+operator, but they are not specified in the @sc{POSIX} standard).
 
 @item ++ --
 Increment and decrement, both prefix and postfix.
@@ -7658,7 +9543,7 @@ Format and print on @var{file}.
 
 Other input/output redirections are also allowed.  For @code{print} and
 @code{printf}, @samp{>> @var{file}} appends output to the @var{file},
-while @samp{| @var{command}} writes on a pipe.  In a similar fashion,
+and @samp{| @var{command}} writes on a pipe.  In a similar fashion,
 @samp{@var{command} | getline} pipes input into @code{getline}.
 @code{getline} returns 0 on end of file, and @minus{}1 on an error.@refill
 
@@ -7680,11 +9565,9 @@ treated as a character and printed.  Otherwise, the argument is assumed to
 be a string, and the only first character of that string is printed.
 
 @item %d
+@itemx %i
 A decimal number (the integer part).
 
-@item %i
-Also a decimal integer.
-
 @item %e
 A floating point number of the form
 @samp{@r{[}-@r{]}d.ddddddE@r{[}+-@r{]}dd}.@refill
@@ -7694,8 +9577,8 @@ A floating point number of the form
 @r{[}@code{-}@r{]}@code{ddd.dddddd}.
 
 @item %g
-Use @samp{%e} or @samp{%f} conversion, whichever is shorter, with
-nonsignificant zeros suppressed.
+Use @samp{%e} or @samp{%f} conversion, whichever produces a shorter string,
+with nonsignificant zeros suppressed.
 
 @item %o
 An unsigned octal number (again, an integer).
@@ -7730,6 +9613,10 @@ A number indicating the maximum width of strings or digits to the right
 of the decimal point.
 @end table
 
+Either or both of the @var{width} and @var{prec} values may be specified
+as @samp{*}.  In that case, the particular value is taken from the argument
+list.
+
 @xref{Printf}, for examples and for a more detailed description.
 
 @node Special File Summary, Numeric Functions Summary, Printf Summary, Actions Summary
@@ -7797,7 +9684,7 @@ is provided, the time of day is used.  The return value is the previous
 seed for the random number generator.
 @end table
 
-@node String Functions Summary, String Constants Summary, Numeric Functions Summary, Actions Summary
+@node String Functions Summary, Time Functions Summary, Numeric Functions Summary, Actions Summary
 @appendixsubsubsec String Functions
 
 @code{awk} has the following predefined string functions:
@@ -7813,7 +9700,8 @@ returns the index of the string @var{t} in the string @var{s}, or 0 if
 @var{t} is not present.
 
 @item length(@var{s})
-returns the length of the string @var{s}.
+returns the length of the string @var{s}.  The length of @code{$0}
+is returned if no argument is supplied.
 
 @item match(@var{s}, @var{r})
 returns the position in @var{s} where the regular expression @var{r}
@@ -7850,9 +9738,29 @@ Nonalphabetic characters are left unchanged.
 Execute the command @var{cmd-line}, and return the exit status.
 @end table
 
+@node Time Functions Summary, String Constants Summary, String Functions Summary, Actions Summary
+@appendixsubsubsec  Built-in time functions
+
+The following two functions are available for getting the current
+time of day, and for formatting time stamps.
+
+@table @code
+@item systime
+returns the current time of day as the number of seconds since a particular
+epoch (Midnight, January 1, 1970 UTC, on @sc{POSIX} systems).
+
+@item strftime(@var{format}, @var{timestamp})
+formats @var{timestamp} according to the specification in @var{format}.
+The current time of day is used if no @var{timestamp} is supplied.
+@xref{Time Functions}, for the details on the conversion specifiers
+that @code{strftime} accepts.
+@end table
+
+@iftex
 @xref{Built-in}, for a description of all of @code{awk}'s built-in functions.
+@end iftex
 
-@node String Constants Summary, , String Functions Summary, Actions Summary
+@node String Constants Summary,  , Time Functions Summary, Actions Summary
 @appendixsubsubsec String Constants
 
 String constants in @code{awk} are sequences of characters enclosed
@@ -7886,10 +9794,11 @@ Vertical tab.
 
 @item \x@var{hex digits}
 The character represented by the string of hexadecimal digits following
-the @samp{\x}.  As in ANSI C, all following hexadecimal digits are
+the @samp{\x}.  As in @sc{ANSI} C, all following hexadecimal digits are
 considered part of the escape sequence.  (This feature should tell us
 something about language design by committee.)  E.g., @code{"\x1B"} is a
-string containing the ASCII ESC (escape) character.
+string containing the ASCII ESC (escape) character.  (The @samp{\x}
+escape sequence is not in @sc{POSIX} @code{awk}.)
 
 @item \@var{ddd}
 The character represented by the 1-, 2-, or 3-digit sequence of octal
@@ -7923,15 +9832,18 @@ If there are fewer arguments passed than there are names in @var{parameter-list}
 the extra names are given the null string as value.  Extra names have the
 effect of local variables.
 
-The open-parenthesis in a function call must immediately follow the
-function name, without any intervening white space.  This is to avoid a
-syntactic ambiguity with the concatenation operator.
+The open-parenthesis in a function call of a user-defined function must
+immediately follow the function name, without any intervening white space.
+This is to avoid a syntactic ambiguity with the concatenation operator.
 
-The word @code{func} may be used in place of @code{function}.
+The word @code{func} may be used in place of @code{function} (but not in
+@sc{POSIX} @code{awk}).
+
+Use the @code{return} statement to return a value from a function.
 
 @xref{User-defined}, for a more complete description.
 
-@node Sample Program, Notes, Gawk Summary, Top
+@node Sample Program, Bugs, Gawk Summary, Top
 @appendix Sample Program
 
 The following example is a complete @code{awk} program, which prints
@@ -7992,38 +9904,64 @@ interested in which words occur most frequently, or having an alphabetized
 table of how frequently each word occurs.@refill
 @end itemize
 
-The way to solve these problems is to use other system utilities to
-process the input and output of the @code{awk} script.  Suppose the
-script shown above is saved in the file @file{frequency.awk}.  Then the
-shell command:@refill
+The way to solve these problems is to use some of the more advanced
+features of the @code{awk} language.  First, we use @code{tolower} to remove
+case distinctions.  Next, we use @code{gsub} to remove punctuation
+characters.  Finally, we the system @code{sort} utility to process the
+output of the @code{awk} script.  First, here is the new version of
+the program:@refill
 
 @example
-tr A-Z a-z < file1 | tr -cd 'a-z\012' \
-  | awk -f frequency.awk \
-  | sort +1 -nr
+awk '
+# Print list of word frequencies
+@{
+    $0 = tolower($0)    # remove case distinctions
+    gsub(/[^a-z0-9_ \t]/, "", $0)  # remove punctuation
+    for (i = 1; i <= NF; i++)
+        freq[$i]++
+@}
+
+END @{
+    for (word in freq)
+        printf "%s\t%d\n", word, freq[word]
+@}'
+@end example
+
+Assuming we have saved this program in a file named @file{frequency.awk},
+and that the data is in @file{file1}, the following pipeline
+
+@example
+awk -f frequency.awk file1 | sort +1 -nr
 @end example
 
 @noindent
 produces a table of the words appearing in @file{file1} in order of
 decreasing frequency.
 
-The first @code{tr} command in this pipeline translates all the upper case
-characters in @file{file1} to lower case.  The second @code{tr} command
-deletes all the characters in the input except lower case characters and
-newlines.  The second argument to the second @code{tr} is quoted to protect
-the backslash in it from being interpreted by the shell.  The @code{awk}
-program reads this suitably massaged data and produces a word frequency
-table, which is not ordered.
+The @code{awk} program suitably massages the data and produces a word
+frequency table, which is not ordered.
 
-The @code{awk} script's output is now sorted by the @code{sort} command and
+The @code{awk} script's output is then sorted by the @code{sort} command and
 printed on the terminal.  The options given to @code{sort} in this example
 specify to sort by the second field of each input line (skipping one field),
 that the sort keys should be treated as numeric quantities (otherwise
 @samp{15} would come before @samp{5}), and that the sorting should be done
 in descending (reverse) order.@refill
 
+We could have even done the @code{sort} from within the program, by
+changing the @code{END} action to:
+
+@example
+END @{
+    sort = "sort +1 -nr"
+    for (word in freq)
+        printf "%s\t%d\n", word, freq[word] | sort
+    close(sort)
+@}'
+@end example
+
 See the general operating system documentation for more information on how
-to use the @code{tr} and @code{sort} commands.@refill
+to use the @code{sort} command.@refill
 
 @ignore
 @strong{ADR: I have some more substantial programs courtesy of Rick Adams
@@ -8032,9 +9970,48 @@ instead of this program.}
 
 @strong{I would also like to incorporate the general @code{translate}
 function that I have written.}
+
+@strong{I have a ton of other sample programs to include too.}
 @end ignore
 
-@node Notes, Glossary, Sample Program, Top
+@node Bugs, Notes, Sample Program, Top
+@appendix Reporting Problems and Bugs
+
+@c This chapter stolen shamelessly from the GNU m4 manual.
+
+If you have problems with @code{gawk} or think that you have found a bug,
+please report it to the developers; we don't promise to do anything
+but we might well want to fix it.
+
+Before reporting a bug, make sure you have actually found a real bug.
+Carefully reread the documentation and see if it really says you can do
+what you're trying to do.  If it's not clear whether you should be able
+to do something or not, report that too; it's a bug in the documentation!
+
+Before reporting a bug or trying to fix it yourself, try to isolate it
+to the smallest possible @code{awk} program and input data file that
+reproduces the problem.  Then send us the program and data file,
+some idea of what kind of Unix system you're using, and the exact results
+@code{gawk} gave you.  Also say what you expected to occur; this will help
+us decide whether the problem was really in the documentation.
+
+Once you have a precise problem, send e-mail to (Internet)
+@samp{bug-gnu-utils@@prep.ai.mit.edu} or (UUCP)
+@samp{mit-eddie!prep.ai.mit.edu!bug-gnu-utils}.  Please include the
+version number of @code{gawk} you are using.  You can get this information
+with the command @samp{gawk -W version '@{@}' /dev/null}.
+You should send carbon copies of your mail to David Trueman at
+@samp{david@@cs.dal.ca}, and to Arnold Robbins, at
+@samp{arnold@@skeeve.atl.ga.us}.  David is most likely to fix code
+problems, while Arnold is most likely to fix documentation problems.@refill
+
+Non-bug suggestions are always welcome as well.  If you have questions
+about things that are unclear in the documentation or are just obscure
+features, ask Arnold Robbins; he'll be happy to help you out (but no
+promises).  You can send him electronic mail at the Internet address
+above.
+
+@node Notes, Glossary, Bugs, Top
 @appendix Implementation Notes
 
 This appendix contains information mainly of interest to implementors and
@@ -8052,42 +10029,31 @@ maintainers of @code{gawk}.  Everything in it applies specifically to
 @node Compatibility Mode, Future Extensions, Notes, Notes
 @appendixsec Downwards Compatibility and Debugging
 
-@xref{S5R4/GNU}, for a summary of the GNU extensions to the @code{awk}
-language and program.  All of these features can be turned off either by
-compiling @code{gawk} with @samp{-DSTRICT} (not recommended), or by
-invoking @code{gawk} with the @samp{-c} option.@refill
+@xref{POSIX/GNU}, for a summary of the GNU extensions to the @code{awk}
+language and program.  All of these features can be turned off by
+invoking @code{gawk} with the @samp{-W compat} option, or with the
+@samp{-W posix} option.@refill
 
 If @code{gawk} is compiled for debugging with @samp{-DDEBUG}, then there
-are two more options available on the command line.
+is one more option available on the command line:
 
 @table @samp
-@item -d
-Print out debugging information during execution.
-
-@item -D
+@item -W debug
 Print out the parse stack information as the program is being parsed.
 @end table
 
-Both of these options are intended only for serious @code{gawk} developers,
-and not for the casual user.  They probably have not even been compiled into
-your version of @code{gawk}, since they slow down execution.
-
-The code for recognizing special file names such as @file{/dev/stdin}
-can be disabled at compile time with @samp{-DNO_DEV_FD}, or with
-@samp{-DSTRICT}.@refill
+This option is intended only for serious @code{gawk} developers,
+and not for the casual user.  It probably has not even been compiled into
+your version of @code{gawk}, since it slows down execution.
 
 @node Future Extensions, Improvements, Compatibility Mode, Notes
 @appendixsec Probable Future Extensions
 
 This section briefly lists extensions that indicate the directions we are
-currently considering for @code{gawk}.
+currently considering for @code{gawk}.  The file @file{FUTURES} in the
+@code{gawk} distributions lists these extensions, as well as several others.
 
 @table @asis
-@item ANSI C compatible @code{printf}
-The @code{printf} and @code{sprintf} functions may be enhanced to be
-fully compatible with the specification for the @code{printf} family
-of functions in ANSI C.@refill
-
 @item @code{RS} as a regexp
 The meaning of @code{RS} may be generalized along the lines of @code{FS}.
 
@@ -8096,7 +10062,7 @@ Changes made in @code{gawk} to the array @code{ENVIRON} may be
 propagated to subprocesses run by @code{gawk}.
 
 @item Data bases
-It may be possible to map an NDBM/GDBM file into an @code{awk} array.
+It may be possible to map a GDBM/NDBM/SDBM file into an @code{awk} array.
 
 @item Single-character fields
 The null string, @code{""}, as a field separator, will cause field
@@ -8104,14 +10070,29 @@ splitting and the split function to separate individual characters.
 Thus, @code{split(a, "abcd", "")} would yield @code{a[1] == "a"},
 @code{a[2] == "b"}, and so on.
 
-@item Fixed-length fields and records
-A mechanism may be provided to allow the specification of fixed length
-fields and records.
+@item More @code{lint} warnings
+There are more things that could be checked for portability.
+
+@item @code{RECLEN} variable for fixed length records
+Along with @code{FIELDWIDTHS}, this would speed up the processing of
+fixed-length records.
+
+@item A @code{restart} keyword
+After modifying @code{$0}, @code{restart} would restart the pattern
+matching loop, without reading a new record from the input.
+
+@item A @code{nextfile} keyword
+This would be like @code{next}, but instead of abandoning the current
+input record, it would abandon the entire current input file.
 
-@item Regexp syntax
-The @code{egrep} syntax for regular expressions, now specified
-with the @samp{-e} option, may become the default, since the
-POSIX standard may specify this.
+@item A @samp{|&} redirection
+The @samp{|&} redirection, in place of @samp{|}, would open a two-way
+pipeline for communication with a sub-process (via @code{getline} and
+@code{print} and @code{printf}).
+
+@item @code{IGNORECASE} affecting all comparisons
+The effects of the @code{IGNORECASE} variable may be generalized to
+all string comparisons, and not just regular expression operations.
 
 @c this is @emph{very} long term --- not worth including right now.
 @ignore
@@ -8134,21 +10115,11 @@ project.@refill
 
 @enumerate
 @item
-State machine regexp matcher: At present, @code{gawk} uses the
-backtracking regular expression matcher from the GNU subroutine library.
-If a regexp is really going to be used a lot of times, it is faster to
-convert it once to a description of a finite state machine, then run a
-routine simulating that machine every time you want to match the regexp.
-You might be able to use the matching routines used by GNU @code{egrep}.
-
-@item
 Compilation of @code{awk} programs: @code{gawk} uses a Bison (YACC-like)
 parser to convert the script given it into a syntax tree; the syntax
 tree is then executed by a simple recursive evaluator.  Both of these
-steps incur a lot of overhead, since parsing can be slow (especially if
-you also do the previous project and convert regular expressions to
-finite state machines at compile time) and the recursive evaluator
-performs many procedure calls to do even the simplest things.@refill
+steps incur a lot of overhead, since parsing can be slow and the recursive
+evaluator performs many procedure calls to do even the simplest things.@refill
 
 It should be possible for @code{gawk} to convert the script's parse tree
 into a C program which the user would then compile, using the normal
@@ -8163,10 +10134,23 @@ a straight line byte code interpreter that would be intermediate in speed
 between running a compiled program and doing what @code{gawk} does
 now.@refill
 
+This may actually happen for the 3.0 version of @code{gawk}.
+
 @item
 An error message section has not been included in this version of the
 manual.  Perhaps some nice beta testers will document some of the messages
 for the future.
+
+@item
+The programs in the test suite could use documenting in this manual.
+
+@item
+The programs and data files in the manual should be available in
+separate files to facilitate experimentation.
+
+@item
+See the @file{FUTURES} file for more ideas.  Contact us if you would
+seriously like to tackle any of the items listed there.
 @end enumerate
 
 @node Glossary, Index , Notes, Top
@@ -8183,8 +10167,12 @@ rule's action.  Actions are always enclosed in curly braces.
 Henry Spencer at the University of Toronto wrote a retargetable assembler
 completely as @code{awk} scripts.  It is thousands of lines long, including
 machine descriptions for several 8-bit microcomputers.  It is distributed
-with @code{gawk} and is a good example of a program that would have been
-better written in another language.@refill
+with @code{gawk} (as part of the test suite) and is a good example of a
+program that would have been better written in another language.@refill
+
+@item @sc{ANSI}
+The American National Standards Institute.  This organization produces
+many standards, among them the standard for the C programming language.
 
 @item Assignment
 An @code{awk} expression that changes the value of some @code{awk}
@@ -8205,22 +10193,31 @@ Another name for an @code{awk} program.
 
 @item Built-in Function
 The @code{awk} language provides built-in functions that perform various
-numerical and string computations.  Examples are @code{sqrt} (for the
-square root of a number) and @code{substr} (for a substring of a
-string).  @xref{Built-in}.@refill
+numerical, time stamp related, and string computations.  Examples are
+@code{sqrt} (for the square root of a number) and @code{substr} (for a
+substring of a string).  @xref{Built-in}.@refill
 
 @item Built-in Variable
-The variables @code{ARGC}, @code{ARGV}, @code{ENVIRON},  @code{FILENAME},
-@code{FNR}, @code{FS}, @code{NF}, @code{IGNORECASE}, @code{NR}, @code{OFMT},
-@code{OFS}, @code{ORS}, @code{RLENGTH}, @code{RSTART}, @code{RS}, and
-@code{SUBSEP}, have special meaning to @code{awk}.  Changing some of them
-affects @code{awk}'s running environment.  @xref{Built-in Variables}.@refill
+The variables @code{ARGC}, @code{ARGV}, @code{CONVFMT}, @code{FIELDWIDTHS},
+@code{ENVIRON},  @code{FILENAME}, @code{FNR}, @code{FS}, @code{IGNORECASE},
+@code{NF}, @code{NR}, @code{OFMT}, @code{OFS}, @code{ORS},
+@code{RLENGTH}, @code{RSTART}, @code{RS}, and @code{SUBSEP}, have special
+meaning to @code{awk}.  Changing some of them affects @code{awk}'s running
+environment.  @xref{Built-in Variables}.@refill
+
+@item Braces
+See ``Curly Braces.''
 
 @item C
 The system programming language that most GNU software is written in.  The
 @code{awk} programming language has C-like syntax, and this manual
 points out similarities between @code{awk} and C when appropriate.@refill
 
+@item CHEM
+A preprocessor for @code{pic} that reads descriptions of molecules
+and produces @code{pic} input for drawing them.  It was written by
+Brian Kernighan, and is distributed with the @code{gawk} test suite.@refill
+
 @item Compound Statement
 A series of @code{awk} statements, enclosed in curly braces.  Compound
 statements may be nested.  @xref{Statements}.@refill
@@ -8247,8 +10244,8 @@ its execution.  @xref{Regexp Usage}.
 
 @item Comparison Expression
 A relation that is either true or false, such as @code{(a < b)}.
-Comparison expressions are used in @code{if} and @code{while} statements,
-and in patterns to select which input records to process.
+Comparison expressions are used in @code{if}, @code{while}, and @code{for}
+statements, and in patterns to select which input records to process.
 @xref{Comparison Ops}.@refill
 
 @item Curly Braces
@@ -8275,13 +10272,14 @@ ESC (escape) character.  @xref{Constants}.
 When @code{awk} reads an input record, it splits the record into pieces
 separated by whitespace (or by a separator regexp which you can
 change by setting the built-in variable @code{FS}).  Such pieces are
-called fields.  @xref{Records}.@refill
+called fields.  If the pieces are of fixed length, you can use the built-in
+variable @code{FIELDWIDTHS} to describe their lengths.  @xref{Records}.@refill
 
 @item Format
 Format strings are used to control the appearance of output in the
 @code{printf} statement.  Also, data conversions from numbers to strings
 are controlled by the format string contained in the built-in variable
-@code{OFMT}.  @xref{Control Letters}; also @pxref{Output Separators}.@refill
+@code{CONVFMT}.  @xref{Control Letters}.@refill
 
 @item Function
 A specialized group of statements often used to encapsulate general
@@ -8300,7 +10298,7 @@ record consists of one line of text.  @xref{Records}.@refill
 In the @code{awk} language, a keyword is a word that has special
 meaning.  Keywords are reserved and may not be used as variable names.
 
-The keywords of @code{awk} are:
+@code{awk}'s keywords are:
 @code{if},
 @code{else},
 @code{while},
@@ -8334,6 +10332,12 @@ tested.  If the condition is satisfied, the pattern is said to @dfn{match}
 the input record.  A typical pattern might compare the input record against
 a regular expression.  @xref{Patterns}.@refill
 
+@item @sc{POSIX}
+The name for a series of standards being developed by the @sc{IEEE}
+that specify a Portable Operating System interface.  The ``IX'' denotes
+the Unix heritage of these standards.  The main standard of interest for
+@code{awk} users is P1003.2, the Command Language and Utilities standard.
+
 @item Range (of input lines)
 A sequence of consecutive lines from the input file.  A pattern
 can specify ranges of input lines for @code{awk} to process, or it can
@@ -8341,7 +10345,7 @@ specify single lines.  @xref{Patterns}.@refill
 
 @item Recursion
 When a function calls itself, either directly or indirectly.
-If this isn't clear, refer to the entry for ``recursion''.
+If this isn't clear, refer to the entry for ``recursion.''
 
 @item Redirection
 Redirection means performing input from other than the standard input
@@ -8353,7 +10357,7 @@ operators.  You can redirect input to the @code{getline} statement using
 the @samp{<} and @samp{|} operators.  @xref{Redirection}.@refill
 
 @item Regular Expression
-See ``regexp''.
+See ``regexp.''
 
 @item Regexp
 Short for @dfn{regular expression}.  A regexp is a pattern that denotes a
@@ -8390,7 +10394,7 @@ user.@refill
 @item String
 A datum consisting of a sequence of characters, such as @samp{I am a
 string}.  Constant strings are written with double-quotes in the
-@code{awk} language, and may contain @dfn{escape sequences}.
+@code{awk} language, and may contain escape sequences.
 @xref{Constants}.
 
 @item Whitespace
@@ -8405,3 +10409,19 @@ string.@refill
 @summarycontents
 @contents
 @bye
+
+Unresolved Issues:
+------------------
+1. From: ntomczak@vm.ucs.ualberta.ca
+   Examples of usage tend to suggest that /../ and ".." delimiters
+   can be used for regular expressions, even if definition is consistently
+   using /../.  I am not sure what the real rules are and in particular
+   what of the following is a bug and what is a feature:
+   # This program matches everything
+      '"\(" { print }'
+   # This one complains about mismatched parenthesis
+      '$0 ~ "\(" { print }'
+   # This one behaves in an expected manner
+      '/\(/ { print }'
+   You may also try to use "\(" as an argument to match() to see what
+   will happen.