More summaries. Through chapter 10.

4 files changed, 838 insertions, 348 deletions

diff --git a/doc/ChangeLog b/doc/ChangeLog
index 026be8aa..bb9d4f29 100644
--- a/doc/ChangeLog
+++ b/doc/ChangeLog
@@ -1,3 +1,7 @@
+2014-06-11         Arnold D. Robbins     <arnold@skeeve.com>
+
+	* gawktexi.in: More "Summary" sections. Through chapter 10.
+
 2014-06-10         Arnold D. Robbins     <arnold@skeeve.com>
 
 	* gawktexi.in: Update docbook figure markup.
diff --git a/doc/gawk.info b/doc/gawk.info
index 9d472b67..ff50955b 100644
--- a/doc/gawk.info
+++ b/doc/gawk.info
@@ -10522,6 +10522,7 @@ cannot have a variable and an array with the same name in the same
 * Multidimensional::            Emulating multidimensional arrays in
                                 `awk'.
 * Arrays of Arrays::            True multidimensional arrays.
+* Arrays Summary::              Summary of arrays.
 
 
 File: gawk.info,  Node: Array Basics,  Next: Delete,  Up: Arrays
@@ -11312,7 +11313,7 @@ The result is to set `separate[1]' to `"1"' and `separate[2]' to
 recovered.
 
 
-File: gawk.info,  Node: Arrays of Arrays,  Prev: Multidimensional,  Up: Arrays
+File: gawk.info,  Node: Arrays of Arrays,  Next: Arrays Summary,  Prev: Multidimensional,  Up: Arrays
 
 8.6 Arrays of Arrays
 ====================
@@ -11434,6 +11435,54 @@ by creating an arbitrary index:
      -| a
 
 
+File: gawk.info,  Node: Arrays Summary,  Prev: Arrays of Arrays,  Up: Arrays
+
+8.7 Summary
+===========
+
+   * Standard `awk' provides one-dimensional associative arrays (arrays
+     indexed by string values).  All arrays are associative; numeric
+     indices are converted automatically to strings.
+
+   * Array elements are referenced as `ARRAY[INDX]'.  Referencing an
+     element creates it if it did not exist previously.
+
+   * The proper way to see if an array has an element with a given index
+     is to use the `in' operator: `INDX in ARRAY'.
+
+   * Use `for (INDX in ARRAY) ...' to scan through all the individual
+     elements of an array. In the body of the loop, INDX takes on the
+     value of each element's index in turn.
+
+   * The order in which a `for (INDX in ARRAY)' loop traverses an array
+     is undefined in POSIX `awk' and varies among implementations.
+     `gawk' lets you control the order by assigning special predefined
+     values to `PROCINFO["sorted_in"]'.
+
+   * Use `delete ARRAY[INDX]' to delete an individual element.  You may
+     also use `delete ARRAY' to delete all of the elements in the
+     array.  This latter feature has been a common extension for many
+     years and is now standard, but may not be supported by all
+     commercial versions of `awk'.
+
+   * Standard `awk' simulates multidimensional arrays by separating
+     subscript values with a comma.  The values are concatenated into a
+     single string, separated by the value of `SUBSEP'.  The fact that
+     such a subscript was created in this way is not retained; thus
+     changing `SUBSEP' may have unexpected consequences.  You can use
+     `(SUB1, SUB2, ...) in ARRAY' to see if such a multidimensional
+     subscript exists in ARRAY.
+
+   * `gawk' provides true arrays of arrays. You use a separate set of
+     square brackets for each dimension in such an array:
+     `data[row][col]', for example. Array elements may thus be either
+     scalar values (number or string) or another array.
+
+   * Use the `isarray()' built-in function to determine if an array
+     element is itself a subarray.
+
+
+
 File: gawk.info,  Node: Functions,  Next: Library Functions,  Prev: Arrays,  Up: Top
 
 9 Functions
@@ -11453,6 +11502,7 @@ major node describes these "user-defined" functions.
 * Built-in::                    Summarizes the built-in functions.
 * User-defined::                Describes User-defined functions in detail.
 * Indirect Calls::              Choosing the function to call at runtime.
+* Functions Summary::           Summary of functions.
 
 
 File: gawk.info,  Node: Built-in,  Next: User-defined,  Up: Functions
@@ -13652,7 +13702,7 @@ call, though, then `awk' does report the second error.
 of them.
 
 
-File: gawk.info,  Node: Indirect Calls,  Prev: User-defined,  Up: Functions
+File: gawk.info,  Node: Indirect Calls,  Next: Functions Summary,  Prev: User-defined,  Up: Functions
 
 9.3 Indirect Function Calls
 ===========================
@@ -13940,6 +13990,63 @@ example, in the following case:
 `gawk' will look up the actual function to call only once.
 
 
+File: gawk.info,  Node: Functions Summary,  Prev: Indirect Calls,  Up: Functions
+
+9.4 Summary
+===========
+
+   * `awk' provides built-in functions and lets you define your own
+     functions.
+
+   * POSIX `awk' provides three kinds of built-in functions: numeric,
+     string, and I/O.  `gawk' provides functions that work with values
+     representing time, do bit manipulation, sort arrays, and
+     internationalize and localize programs.  `gawk' also provides
+     several extensions to some of standard functions, typically in the
+     form of additional arguments.
+
+   * Functions accept zero or more arguments and return a value.  The
+     expressions that provide the argument values are comnpletely
+     evaluated before the function is called. Order of evaluation is
+     not defined.  The return value can be ignored.
+
+   * The handling of backslash in `sub()' and `gsub()' is not simple.
+     It is more straightforward in `gawk''s `gensub()' function, but
+     that function still requires care in its use.
+
+   * User-defined functions provide important capabilities but come
+     with some syntactic inelegancies. In a function call, there cannot
+     be any space between the function name and the opening left
+     parethesis of the argument list.  Also, there is no provision for
+     local variables, so the convention is to add extra parameters, and
+     to separate them visually from the real parameters by extra
+     whitespace.
+
+   * User-defined functions may call other user-defined (and built-in)
+     functions and may call themselves recursively. Function parameters
+     "hide" any global variables of the same names.
+
+   * Scalar values are passed to user-defined functions by value. Array
+     parameters are passed by reference; any changes made by the
+     function to array parameters are thus visible after the function
+     has returned.
+
+   * Use the `return' statement to return from a user-defined function.
+     An optional expression becomes the function's return value.  Only
+     scalar values may be returned by a function.
+
+   * If a variable that has never been used is passed to a user-defined
+     function, how that function treats the variable can set its
+     nature: either scalar or array.
+
+   * `gawk' provides indirect function calls using a special syntax.
+     By setting a variable to the name of a user-defined function, you
+     can determine at runtime what function will be called at that
+     point in the program. This is equivalent to function pointers in C
+     and C++.
+
+
+
 File: gawk.info,  Node: Library Functions,  Next: Sample Programs,  Prev: Functions,  Up: Top
 
 10 A Library of `awk' Functions
@@ -14015,6 +14122,7 @@ for different implementations of `awk' is pretty straightforward.
 * Passwd Functions::            Functions for getting user information.
 * Group Functions::             Functions for getting group information.
 * Walking Arrays::              A function to walk arrays of arrays.
+* Library Functions Summary::   Summary of library functions.
 
    ---------- Footnotes ----------
 
@@ -14912,8 +15020,8 @@ intervening value in `ARGV' is a variable assignment.
 
 File: gawk.info,  Node: Ignoring Assigns,  Prev: Empty Files,  Up: Data File Management
 
-10.3.5 Treating Assignments as File Name
-----------------------------------------
+10.3.5 Treating Assignments as File Names
+-----------------------------------------
 
 Occasionally, you might not want `awk' to process command-line variable
 assignments (*note Assignment Options::).  In particular, if you have a
@@ -15727,7 +15835,7 @@ Suppose that the first time there were no names. This code adds the
 names with a leading comma. It also doesn't check that there is a `$4'.
 
 
-File: gawk.info,  Node: Walking Arrays,  Prev: Group Functions,  Up: Library Functions
+File: gawk.info,  Node: Walking Arrays,  Next: Library Functions Summary,  Prev: Group Functions,  Up: Library Functions
 
 10.7 Traversing Arrays of Arrays
 ================================
@@ -15790,6 +15898,43 @@ user-defined function that expects to receive an index and a value, and
 then processes the element.
 
 
+File: gawk.info,  Node: Library Functions Summary,  Prev: Walking Arrays,  Up: Library Functions
+
+10.8 Summary
+============
+
+   * Reading programs is an excellent way to learn Good Programming.
+     The functions provided in this major node and the next are intended
+     to serve that purpose.
+
+   * When writing general-purpose library functions, put some thought
+     into how to name any global variables so that they won't conflict
+     with variables from a user's program.
+
+   * The functions presented here fit into the following categories:
+
+    General problems
+          Number to string conversion, assertions, rounding, random
+          number generation, converting characters to numbers, joining
+          strings, getting easily usable time-of-day information, and
+          reading a whole file in one shot.
+
+    Managing data files
+          Noting data file boundaries, rereading the current file,
+          checking for readable files, checking for zero-length files,
+          and treating assignments as file names.
+
+    Processing command-line options
+          An `awk' version of the standard C `getopt()' function.
+
+    Reading the user and group databases
+          Two sets of routines that parallel the C library versions.
+
+    Traversing arrays of arrays
+          A simple function to traverse an array of arrays to any depth.
+
+
+
 File: gawk.info,  Node: Sample Programs,  Next: Advanced Features,  Prev: Library Functions,  Up: Top
 
 11 Practical `awk' Programs
@@ -19868,8 +20013,8 @@ File: gawk.info,  Node: Gawk I18N,  Prev: I18N Example,  Up: Internationalizatio
 `gawk' itself has been internationalized using the GNU `gettext'
 package.  (GNU `gettext' is described in complete detail in *note (GNU
 `gettext' utilities)Top:: gettext, GNU gettext tools.)  As of this
-writing, the latest version of GNU `gettext' is version 0.19
-(ftp://ftp.gnu.org/gnu/gettext/gettext-0.19.tar.gz).
+writing, the latest version of GNU `gettext' is version 0.19.1
+(ftp://ftp.gnu.org/gnu/gettext/gettext-0.19.1.tar.gz).
 
    If a translation of `gawk''s messages exists, then `gawk' produces
 usage messages, warnings, and fatal errors in the local language.
@@ -33737,342 +33882,345 @@ Ref: Auto-set-Footnote-2441927
 Node: ARGC and ARGV441983
 Node: Pattern Action Summary445822
 Node: Arrays448045
-Node: Array Basics449543
-Node: Array Intro450369
-Ref: figure-array-elements452342
-Node: Reference to Elements454749
-Node: Assigning Elements457022
-Node: Array Example457513
-Node: Scanning an Array459245
-Node: Controlling Scanning462260
-Ref: Controlling Scanning-Footnote-1467433
-Node: Delete467749
-Ref: Delete-Footnote-1470514
-Node: Numeric Array Subscripts470571
-Node: Uninitialized Subscripts472754
-Node: Multidimensional474379
-Node: Multiscanning477472
-Node: Arrays of Arrays479061
-Node: Functions483701
-Node: Built-in484520
-Node: Calling Built-in485598
-Node: Numeric Functions487586
-Ref: Numeric Functions-Footnote-1491420
-Ref: Numeric Functions-Footnote-2491777
-Ref: Numeric Functions-Footnote-3491825
-Node: String Functions492094
-Ref: String Functions-Footnote-1515105
-Ref: String Functions-Footnote-2515234
-Ref: String Functions-Footnote-3515482
-Node: Gory Details515569
-Ref: table-sub-escapes517238
-Ref: table-sub-posix-92518592
-Ref: table-sub-proposed519943
-Ref: table-posix-sub521297
-Ref: table-gensub-escapes522842
-Ref: Gory Details-Footnote-1524018
-Ref: Gory Details-Footnote-2524069
-Node: I/O Functions524220
-Ref: I/O Functions-Footnote-1531343
-Node: Time Functions531490
-Ref: Time Functions-Footnote-1541954
-Ref: Time Functions-Footnote-2542022
-Ref: Time Functions-Footnote-3542180
-Ref: Time Functions-Footnote-4542291
-Ref: Time Functions-Footnote-5542403
-Ref: Time Functions-Footnote-6542630
-Node: Bitwise Functions542896
-Ref: table-bitwise-ops543458
-Ref: Bitwise Functions-Footnote-1547703
-Node: Type Functions547887
-Node: I18N Functions549029
-Node: User-defined550674
-Node: Definition Syntax551478
-Ref: Definition Syntax-Footnote-1556403
-Node: Function Example556472
-Ref: Function Example-Footnote-1559116
-Node: Function Caveats559138
-Node: Calling A Function559656
-Node: Variable Scope560611
-Node: Pass By Value/Reference563599
-Node: Return Statement567107
-Node: Dynamic Typing570091
-Node: Indirect Calls571020
-Node: Library Functions580707
-Ref: Library Functions-Footnote-1584220
-Ref: Library Functions-Footnote-2584363
-Node: Library Names584534
-Ref: Library Names-Footnote-1588007
-Ref: Library Names-Footnote-2588227
-Node: General Functions588313
-Node: Strtonum Function589341
-Node: Assert Function592271
-Node: Round Function595597
-Node: Cliff Random Function597138
-Node: Ordinal Functions598154
-Ref: Ordinal Functions-Footnote-1601231
-Ref: Ordinal Functions-Footnote-2601483
-Node: Join Function601694
-Ref: Join Function-Footnote-1603465
-Node: Getlocaltime Function603665
-Node: Readfile Function607401
-Node: Data File Management609240
-Node: Filetrans Function609872
-Node: Rewind Function613927
-Node: File Checking615314
-Ref: File Checking-Footnote-1616446
-Node: Empty Files616647
-Node: Ignoring Assigns618870
-Node: Getopt Function620401
-Ref: Getopt Function-Footnote-1631697
-Node: Passwd Functions631900
-Ref: Passwd Functions-Footnote-1640879
-Node: Group Functions640967
-Ref: Group Functions-Footnote-1648909
-Node: Walking Arrays649122
-Node: Sample Programs651258
-Node: Running Examples651932
-Node: Clones652660
-Node: Cut Program653884
-Node: Egrep Program663745
-Ref: Egrep Program-Footnote-1671674
-Node: Id Program671784
-Node: Split Program675448
-Ref: Split Program-Footnote-1678979
-Node: Tee Program679107
-Node: Uniq Program681914
-Node: Wc Program689344
-Ref: Wc Program-Footnote-1693612
-Ref: Wc Program-Footnote-2693812
-Node: Miscellaneous Programs693904
-Node: Dupword Program695092
-Node: Alarm Program697123
-Node: Translate Program701937
-Ref: Translate Program-Footnote-1706328
-Ref: Translate Program-Footnote-2706598
-Node: Labels Program706732
-Ref: Labels Program-Footnote-1710103
-Node: Word Sorting710187
-Node: History Sorting714230
-Node: Extract Program716066
-Ref: Extract Program-Footnote-1723641
-Node: Simple Sed723770
-Node: Igawk Program726832
-Ref: Igawk Program-Footnote-1742008
-Ref: Igawk Program-Footnote-2742209
-Node: Anagram Program742347
-Node: Signature Program745415
-Node: Advanced Features746662
-Node: Nondecimal Data748548
-Node: Array Sorting750125
-Node: Controlling Array Traversal750822
-Node: Array Sorting Functions759102
-Ref: Array Sorting Functions-Footnote-1763009
-Node: Two-way I/O763203
-Ref: Two-way I/O-Footnote-1768719
-Node: TCP/IP Networking768801
-Node: Profiling771645
-Node: Internationalization779153
-Node: I18N and L10N780578
-Node: Explaining gettext781264
-Ref: Explaining gettext-Footnote-1786404
-Ref: Explaining gettext-Footnote-2786588
-Node: Programmer i18n786753
-Node: Translator i18n790978
-Node: String Extraction791772
-Ref: String Extraction-Footnote-1792733
-Node: Printf Ordering792819
-Ref: Printf Ordering-Footnote-1795601
-Node: I18N Portability795665
-Ref: I18N Portability-Footnote-1798114
-Node: I18N Example798177
-Ref: I18N Example-Footnote-1800899
-Node: Gawk I18N800971
-Node: Debugger801584
-Node: Debugging802555
-Node: Debugging Concepts802996
-Node: Debugging Terms804852
-Node: Awk Debugging807449
-Node: Sample Debugging Session808341
-Node: Debugger Invocation808861
-Node: Finding The Bug810194
-Node: List of Debugger Commands816676
-Node: Breakpoint Control818008
-Node: Debugger Execution Control821672
-Node: Viewing And Changing Data825032
-Node: Execution Stack828390
-Node: Debugger Info829903
-Node: Miscellaneous Debugger Commands833897
-Node: Readline Support839081
-Node: Limitations839973
-Node: Arbitrary Precision Arithmetic842221
-Ref: Arbitrary Precision Arithmetic-Footnote-1843870
-Node: General Arithmetic844018
-Node: Floating Point Issues845738
-Node: String Conversion Precision846619
-Ref: String Conversion Precision-Footnote-1848324
-Node: Unexpected Results848433
-Node: POSIX Floating Point Problems850586
-Ref: POSIX Floating Point Problems-Footnote-1854407
-Node: Integer Programming854445
-Node: Floating-point Programming856256
-Ref: Floating-point Programming-Footnote-1862584
-Ref: Floating-point Programming-Footnote-2862854
-Node: Floating-point Representation863118
-Node: Floating-point Context864283
-Ref: table-ieee-formats865122
-Node: Rounding Mode866506
-Ref: table-rounding-modes866985
-Ref: Rounding Mode-Footnote-1870000
-Node: Gawk and MPFR870179
-Node: Arbitrary Precision Floats871588
-Ref: Arbitrary Precision Floats-Footnote-1874031
-Node: Setting Precision874352
-Ref: table-predefined-precision-strings875036
-Node: Setting Rounding Mode877181
-Ref: table-gawk-rounding-modes877585
-Node: Floating-point Constants878772
-Node: Changing Precision880224
-Ref: Changing Precision-Footnote-1881616
-Node: Exact Arithmetic881790
-Node: Arbitrary Precision Integers884924
-Ref: Arbitrary Precision Integers-Footnote-1887939
-Node: Dynamic Extensions888086
-Node: Extension Intro889544
-Node: Plugin License890809
-Node: Extension Mechanism Outline891494
-Ref: figure-load-extension891918
-Ref: figure-load-new-function893403
-Ref: figure-call-new-function894405
-Node: Extension API Description896389
-Node: Extension API Functions Introduction897839
-Node: General Data Types902705
-Ref: General Data Types-Footnote-1908398
-Node: Requesting Values908697
-Ref: table-value-types-returned909434
-Node: Memory Allocation Functions910392
-Ref: Memory Allocation Functions-Footnote-1913139
-Node: Constructor Functions913235
-Node: Registration Functions914993
-Node: Extension Functions915678
-Node: Exit Callback Functions917980
-Node: Extension Version String919230
-Node: Input Parsers919880
-Node: Output Wrappers929683
-Node: Two-way processors934199
-Node: Printing Messages936403
-Ref: Printing Messages-Footnote-1937480
-Node: Updating `ERRNO'937632
-Node: Accessing Parameters938371
-Node: Symbol Table Access939601
-Node: Symbol table by name940115
-Node: Symbol table by cookie942091
-Ref: Symbol table by cookie-Footnote-1946224
-Node: Cached values946287
-Ref: Cached values-Footnote-1949792
-Node: Array Manipulation949883
-Ref: Array Manipulation-Footnote-1950981
-Node: Array Data Types951020
-Ref: Array Data Types-Footnote-1953723
-Node: Array Functions953815
-Node: Flattening Arrays957689
-Node: Creating Arrays964541
-Node: Extension API Variables969272
-Node: Extension Versioning969908
-Node: Extension API Informational Variables971809
-Node: Extension API Boilerplate972895
-Node: Finding Extensions976699
-Node: Extension Example977259
-Node: Internal File Description977989
-Node: Internal File Ops982080
-Ref: Internal File Ops-Footnote-1993626
-Node: Using Internal File Ops993766
-Ref: Using Internal File Ops-Footnote-1996113
-Node: Extension Samples996381
-Node: Extension Sample File Functions997905
-Node: Extension Sample Fnmatch1005473
-Node: Extension Sample Fork1006940
-Node: Extension Sample Inplace1008153
-Node: Extension Sample Ord1009919
-Node: Extension Sample Readdir1010755
-Ref: table-readdir-file-types1011604
-Node: Extension Sample Revout1012403
-Node: Extension Sample Rev2way1012994
-Node: Extension Sample Read write array1013735
-Node: Extension Sample Readfile1015614
-Node: Extension Sample API Tests1016714
-Node: Extension Sample Time1017239
-Node: gawkextlib1018554
-Node: Language History1021341
-Node: V7/SVR3.11022935
-Node: SVR41025255
-Node: POSIX1026697
-Node: BTL1028083
-Node: POSIX/GNU1028817
-Node: Feature History1034416
-Node: Common Extensions1047528
-Node: Ranges and Locales1048840
-Ref: Ranges and Locales-Footnote-11053457
-Ref: Ranges and Locales-Footnote-21053484
-Ref: Ranges and Locales-Footnote-31053718
-Node: Contributors1053939
-Node: Installation1059377
-Node: Gawk Distribution1060271
-Node: Getting1060755
-Node: Extracting1061581
-Node: Distribution contents1063223
-Node: Unix Installation1068940
-Node: Quick Installation1069557
-Node: Additional Configuration Options1071999
-Node: Configuration Philosophy1073737
-Node: Non-Unix Installation1076088
-Node: PC Installation1076546
-Node: PC Binary Installation1077857
-Node: PC Compiling1079705
-Ref: PC Compiling-Footnote-11082704
-Node: PC Testing1082809
-Node: PC Using1083985
-Node: Cygwin1088143
-Node: MSYS1088952
-Node: VMS Installation1089466
-Node: VMS Compilation1090262
-Ref: VMS Compilation-Footnote-11091477
-Node: VMS Dynamic Extensions1091535
-Node: VMS Installation Details1092908
-Node: VMS Running1095154
-Node: VMS GNV1097988
-Node: VMS Old Gawk1098711
-Node: Bugs1099181
-Node: Other Versions1103185
-Node: Notes1109410
-Node: Compatibility Mode1110210
-Node: Additions1110992
-Node: Accessing The Source1111917
-Node: Adding Code1113353
-Node: New Ports1119531
-Node: Derived Files1124012
-Ref: Derived Files-Footnote-11129093
-Ref: Derived Files-Footnote-21129127
-Ref: Derived Files-Footnote-31129723
-Node: Future Extensions1129837
-Node: Implementation Limitations1130443
-Node: Extension Design1131691
-Node: Old Extension Problems1132845
-Ref: Old Extension Problems-Footnote-11134362
-Node: Extension New Mechanism Goals1134419
-Ref: Extension New Mechanism Goals-Footnote-11137780
-Node: Extension Other Design Decisions1137969
-Node: Extension Future Growth1140075
-Node: Old Extension Mechanism1140911
-Node: Basic Concepts1142651
-Node: Basic High Level1143332
-Ref: figure-general-flow1143604
-Ref: figure-process-flow1144203
-Ref: Basic High Level-Footnote-11147432
-Node: Basic Data Typing1147617
-Node: Glossary1150944
-Node: Copying1176096
-Node: GNU Free Documentation License1213652
-Node: Index1238788
+Node: Array Basics449594
+Node: Array Intro450420
+Ref: figure-array-elements452393
+Node: Reference to Elements454800
+Node: Assigning Elements457073
+Node: Array Example457564
+Node: Scanning an Array459296
+Node: Controlling Scanning462311
+Ref: Controlling Scanning-Footnote-1467484
+Node: Delete467800
+Ref: Delete-Footnote-1470565
+Node: Numeric Array Subscripts470622
+Node: Uninitialized Subscripts472805
+Node: Multidimensional474430
+Node: Multiscanning477523
+Node: Arrays of Arrays479112
+Node: Arrays Summary483775
+Node: Functions485880
+Node: Built-in486753
+Node: Calling Built-in487831
+Node: Numeric Functions489819
+Ref: Numeric Functions-Footnote-1493653
+Ref: Numeric Functions-Footnote-2494010
+Ref: Numeric Functions-Footnote-3494058
+Node: String Functions494327
+Ref: String Functions-Footnote-1517338
+Ref: String Functions-Footnote-2517467
+Ref: String Functions-Footnote-3517715
+Node: Gory Details517802
+Ref: table-sub-escapes519471
+Ref: table-sub-posix-92520825
+Ref: table-sub-proposed522176
+Ref: table-posix-sub523530
+Ref: table-gensub-escapes525075
+Ref: Gory Details-Footnote-1526251
+Ref: Gory Details-Footnote-2526302
+Node: I/O Functions526453
+Ref: I/O Functions-Footnote-1533576
+Node: Time Functions533723
+Ref: Time Functions-Footnote-1544187
+Ref: Time Functions-Footnote-2544255
+Ref: Time Functions-Footnote-3544413
+Ref: Time Functions-Footnote-4544524
+Ref: Time Functions-Footnote-5544636
+Ref: Time Functions-Footnote-6544863
+Node: Bitwise Functions545129
+Ref: table-bitwise-ops545691
+Ref: Bitwise Functions-Footnote-1549936
+Node: Type Functions550120
+Node: I18N Functions551262
+Node: User-defined552907
+Node: Definition Syntax553711
+Ref: Definition Syntax-Footnote-1558636
+Node: Function Example558705
+Ref: Function Example-Footnote-1561349
+Node: Function Caveats561371
+Node: Calling A Function561889
+Node: Variable Scope562844
+Node: Pass By Value/Reference565832
+Node: Return Statement569340
+Node: Dynamic Typing572324
+Node: Indirect Calls573253
+Node: Functions Summary582966
+Node: Library Functions585505
+Ref: Library Functions-Footnote-1589080
+Ref: Library Functions-Footnote-2589223
+Node: Library Names589394
+Ref: Library Names-Footnote-1592867
+Ref: Library Names-Footnote-2593087
+Node: General Functions593173
+Node: Strtonum Function594201
+Node: Assert Function597131
+Node: Round Function600457
+Node: Cliff Random Function601998
+Node: Ordinal Functions603014
+Ref: Ordinal Functions-Footnote-1606091
+Ref: Ordinal Functions-Footnote-2606343
+Node: Join Function606554
+Ref: Join Function-Footnote-1608325
+Node: Getlocaltime Function608525
+Node: Readfile Function612261
+Node: Data File Management614100
+Node: Filetrans Function614732
+Node: Rewind Function618787
+Node: File Checking620174
+Ref: File Checking-Footnote-1621306
+Node: Empty Files621507
+Node: Ignoring Assigns623730
+Node: Getopt Function625263
+Ref: Getopt Function-Footnote-1636559
+Node: Passwd Functions636762
+Ref: Passwd Functions-Footnote-1645741
+Node: Group Functions645829
+Ref: Group Functions-Footnote-1653771
+Node: Walking Arrays653984
+Node: Library Functions Summary656154
+Node: Sample Programs657516
+Node: Running Examples658190
+Node: Clones658918
+Node: Cut Program660142
+Node: Egrep Program670003
+Ref: Egrep Program-Footnote-1677932
+Node: Id Program678042
+Node: Split Program681706
+Ref: Split Program-Footnote-1685237
+Node: Tee Program685365
+Node: Uniq Program688172
+Node: Wc Program695602
+Ref: Wc Program-Footnote-1699870
+Ref: Wc Program-Footnote-2700070
+Node: Miscellaneous Programs700162
+Node: Dupword Program701350
+Node: Alarm Program703381
+Node: Translate Program708195
+Ref: Translate Program-Footnote-1712586
+Ref: Translate Program-Footnote-2712856
+Node: Labels Program712990
+Ref: Labels Program-Footnote-1716361
+Node: Word Sorting716445
+Node: History Sorting720488
+Node: Extract Program722324
+Ref: Extract Program-Footnote-1729899
+Node: Simple Sed730028
+Node: Igawk Program733090
+Ref: Igawk Program-Footnote-1748266
+Ref: Igawk Program-Footnote-2748467
+Node: Anagram Program748605
+Node: Signature Program751673
+Node: Advanced Features752920
+Node: Nondecimal Data754806
+Node: Array Sorting756383
+Node: Controlling Array Traversal757080
+Node: Array Sorting Functions765360
+Ref: Array Sorting Functions-Footnote-1769267
+Node: Two-way I/O769461
+Ref: Two-way I/O-Footnote-1774977
+Node: TCP/IP Networking775059
+Node: Profiling777903
+Node: Internationalization785411
+Node: I18N and L10N786836
+Node: Explaining gettext787522
+Ref: Explaining gettext-Footnote-1792662
+Ref: Explaining gettext-Footnote-2792846
+Node: Programmer i18n793011
+Node: Translator i18n797236
+Node: String Extraction798030
+Ref: String Extraction-Footnote-1798991
+Node: Printf Ordering799077
+Ref: Printf Ordering-Footnote-1801859
+Node: I18N Portability801923
+Ref: I18N Portability-Footnote-1804372
+Node: I18N Example804435
+Ref: I18N Example-Footnote-1807157
+Node: Gawk I18N807229
+Node: Debugger807846
+Node: Debugging808817
+Node: Debugging Concepts809258
+Node: Debugging Terms811114
+Node: Awk Debugging813711
+Node: Sample Debugging Session814603
+Node: Debugger Invocation815123
+Node: Finding The Bug816456
+Node: List of Debugger Commands822938
+Node: Breakpoint Control824270
+Node: Debugger Execution Control827934
+Node: Viewing And Changing Data831294
+Node: Execution Stack834652
+Node: Debugger Info836165
+Node: Miscellaneous Debugger Commands840159
+Node: Readline Support845343
+Node: Limitations846235
+Node: Arbitrary Precision Arithmetic848483
+Ref: Arbitrary Precision Arithmetic-Footnote-1850132
+Node: General Arithmetic850280
+Node: Floating Point Issues852000
+Node: String Conversion Precision852881
+Ref: String Conversion Precision-Footnote-1854586
+Node: Unexpected Results854695
+Node: POSIX Floating Point Problems856848
+Ref: POSIX Floating Point Problems-Footnote-1860669
+Node: Integer Programming860707
+Node: Floating-point Programming862518
+Ref: Floating-point Programming-Footnote-1868846
+Ref: Floating-point Programming-Footnote-2869116
+Node: Floating-point Representation869380
+Node: Floating-point Context870545
+Ref: table-ieee-formats871384
+Node: Rounding Mode872768
+Ref: table-rounding-modes873247
+Ref: Rounding Mode-Footnote-1876262
+Node: Gawk and MPFR876441
+Node: Arbitrary Precision Floats877850
+Ref: Arbitrary Precision Floats-Footnote-1880293
+Node: Setting Precision880614
+Ref: table-predefined-precision-strings881298
+Node: Setting Rounding Mode883443
+Ref: table-gawk-rounding-modes883847
+Node: Floating-point Constants885034
+Node: Changing Precision886486
+Ref: Changing Precision-Footnote-1887878
+Node: Exact Arithmetic888052
+Node: Arbitrary Precision Integers891186
+Ref: Arbitrary Precision Integers-Footnote-1894201
+Node: Dynamic Extensions894348
+Node: Extension Intro895806
+Node: Plugin License897071
+Node: Extension Mechanism Outline897756
+Ref: figure-load-extension898180
+Ref: figure-load-new-function899665
+Ref: figure-call-new-function900667
+Node: Extension API Description902651
+Node: Extension API Functions Introduction904101
+Node: General Data Types908967
+Ref: General Data Types-Footnote-1914660
+Node: Requesting Values914959
+Ref: table-value-types-returned915696
+Node: Memory Allocation Functions916654
+Ref: Memory Allocation Functions-Footnote-1919401
+Node: Constructor Functions919497
+Node: Registration Functions921255
+Node: Extension Functions921940
+Node: Exit Callback Functions924242
+Node: Extension Version String925492
+Node: Input Parsers926142
+Node: Output Wrappers935945
+Node: Two-way processors940461
+Node: Printing Messages942665
+Ref: Printing Messages-Footnote-1943742
+Node: Updating `ERRNO'943894
+Node: Accessing Parameters944633
+Node: Symbol Table Access945863
+Node: Symbol table by name946377
+Node: Symbol table by cookie948353
+Ref: Symbol table by cookie-Footnote-1952486
+Node: Cached values952549
+Ref: Cached values-Footnote-1956054
+Node: Array Manipulation956145
+Ref: Array Manipulation-Footnote-1957243
+Node: Array Data Types957282
+Ref: Array Data Types-Footnote-1959985
+Node: Array Functions960077
+Node: Flattening Arrays963951
+Node: Creating Arrays970803
+Node: Extension API Variables975534
+Node: Extension Versioning976170
+Node: Extension API Informational Variables978071
+Node: Extension API Boilerplate979157
+Node: Finding Extensions982961
+Node: Extension Example983521
+Node: Internal File Description984251
+Node: Internal File Ops988342
+Ref: Internal File Ops-Footnote-1999888
+Node: Using Internal File Ops1000028
+Ref: Using Internal File Ops-Footnote-11002375
+Node: Extension Samples1002643
+Node: Extension Sample File Functions1004167
+Node: Extension Sample Fnmatch1011735
+Node: Extension Sample Fork1013202
+Node: Extension Sample Inplace1014415
+Node: Extension Sample Ord1016181
+Node: Extension Sample Readdir1017017
+Ref: table-readdir-file-types1017866
+Node: Extension Sample Revout1018665
+Node: Extension Sample Rev2way1019256
+Node: Extension Sample Read write array1019997
+Node: Extension Sample Readfile1021876
+Node: Extension Sample API Tests1022976
+Node: Extension Sample Time1023501
+Node: gawkextlib1024816
+Node: Language History1027603
+Node: V7/SVR3.11029197
+Node: SVR41031517
+Node: POSIX1032959
+Node: BTL1034345
+Node: POSIX/GNU1035079
+Node: Feature History1040678
+Node: Common Extensions1053790
+Node: Ranges and Locales1055102
+Ref: Ranges and Locales-Footnote-11059719
+Ref: Ranges and Locales-Footnote-21059746
+Ref: Ranges and Locales-Footnote-31059980
+Node: Contributors1060201
+Node: Installation1065639
+Node: Gawk Distribution1066533
+Node: Getting1067017
+Node: Extracting1067843
+Node: Distribution contents1069485
+Node: Unix Installation1075202
+Node: Quick Installation1075819
+Node: Additional Configuration Options1078261
+Node: Configuration Philosophy1079999
+Node: Non-Unix Installation1082350
+Node: PC Installation1082808
+Node: PC Binary Installation1084119
+Node: PC Compiling1085967
+Ref: PC Compiling-Footnote-11088966
+Node: PC Testing1089071
+Node: PC Using1090247
+Node: Cygwin1094405
+Node: MSYS1095214
+Node: VMS Installation1095728
+Node: VMS Compilation1096524
+Ref: VMS Compilation-Footnote-11097739
+Node: VMS Dynamic Extensions1097797
+Node: VMS Installation Details1099170
+Node: VMS Running1101416
+Node: VMS GNV1104250
+Node: VMS Old Gawk1104973
+Node: Bugs1105443
+Node: Other Versions1109447
+Node: Notes1115672
+Node: Compatibility Mode1116472
+Node: Additions1117254
+Node: Accessing The Source1118179
+Node: Adding Code1119615
+Node: New Ports1125793
+Node: Derived Files1130274
+Ref: Derived Files-Footnote-11135355
+Ref: Derived Files-Footnote-21135389
+Ref: Derived Files-Footnote-31135985
+Node: Future Extensions1136099
+Node: Implementation Limitations1136705
+Node: Extension Design1137953
+Node: Old Extension Problems1139107
+Ref: Old Extension Problems-Footnote-11140624
+Node: Extension New Mechanism Goals1140681
+Ref: Extension New Mechanism Goals-Footnote-11144042
+Node: Extension Other Design Decisions1144231
+Node: Extension Future Growth1146337
+Node: Old Extension Mechanism1147173
+Node: Basic Concepts1148913
+Node: Basic High Level1149594
+Ref: figure-general-flow1149866
+Ref: figure-process-flow1150465
+Ref: Basic High Level-Footnote-11153694
+Node: Basic Data Typing1153879
+Node: Glossary1157206
+Node: Copying1182358
+Node: GNU Free Documentation License1219914
+Node: Index1245050
 
 End Tag Table
diff --git a/doc/gawk.texi b/doc/gawk.texi
index badfe5ac..c4e17b2b 100644
--- a/doc/gawk.texi
+++ b/doc/gawk.texi
@@ -15023,6 +15023,7 @@ same @command{awk} program.
 * Multidimensional::            Emulating multidimensional arrays in
                                 @command{awk}.
 * Arrays of Arrays::            True multidimensional arrays.
+* Arrays Summary::              Summary of arrays.
 @end menu
 
 @node Array Basics
@@ -16305,6 +16306,64 @@ creating an arbitrary index:
 $ @kbd{gawk 'BEGIN @{ b[1][1] = ""; split("a b c d", b[1]); print b[1][1] @}'}
 @print{} a
 @end example
+
+@node Arrays Summary
+@section Summary
+
+@itemize @value{BULLET}
+@item
+Standard @command{awk} provides one-dimensional associative arrays (arrays
+indexed by string values).  All arrays are associative; numeric indices
+are converted automatically to strings.
+
+@item
+Array elements are referenced as @code{@var{array}[@var{indx}]}.
+Referencing an element creates it if it did not exist previously.
+
+@item
+The proper way to see if an array has an element with a given index
+is to use the @code{in} operator: @samp{@var{indx} in @var{array}}.
+
+@item
+Use @samp{for (@var{indx} in @var{array}) @dots{}} to scan through all the
+individual elements of an array. In the body of the loop, @var{indx} takes
+on the value of each element's index in turn.
+
+@item
+The order in which a
+@samp{for (@var{indx} in @var{array})} loop traverses an array is
+undefined in POSIX @command{awk} and varies among implementations.
+@command{gawk} lets you control the order by assigning special predefined
+values to @code{PROCINFO["sorted_in"]}.
+
+@item
+Use @samp{delete @var{array}[@var{indx}]} to delete an
+individual element.  You may also use @samp{delete @var{array}}
+to delete all of the elements in the array.  This latter feature
+has been a common extension for many years and is now standard, but
+may not be supported by all commercial versions of @command{awk}.
+
+@item
+Standard @command{awk} simulates multidimensional arrays by separating
+subscript values with a comma.  The values are concatenated into a
+single string, separated by the value of @code{SUBSEP}.  The fact that
+such a subscript was created in this way is not retained; thus changing
+@code{SUBSEP} may have unexpected consequences.
+You can use @samp{(@var{sub1}, @var{sub2}, @dots{}) in @var{array}}
+to see if such a multidimensional subscript exists in @var{array}.
+
+@item
+@command{gawk} provides true arrays of arrays. You use a separate
+set of square brackets for each dimension in such an array:
+@code{data[row][col]}, for example. Array elements may thus be either
+scalar values (number or string) or another array.
+
+@item
+Use the @code{isarray()} built-in function to determine if an
+array element is itself a subarray.
+
+@end itemize
+
 @c ENDOFRANGE arrs
 
 @node Functions
@@ -16329,6 +16388,7 @@ The second half of this @value{CHAPTER} describes these
 * Built-in::                    Summarizes the built-in functions.
 * User-defined::                Describes User-defined functions in detail.
 * Indirect Calls::              Choosing the function to call at runtime.
+* Functions Summary::           Summary of functions.
 @end menu
 
 @node Built-in
@@ -19887,6 +19947,68 @@ for (i = 1; i <= n; i++)
 @noindent
 @code{gawk} will look up the actual function to call only once.
 
+@node Functions Summary
+@section Summary
+
+@itemize @value{BULLET}
+@item
+@command{awk} provides built-in functions and lets you define your own
+functions.
+
+@item
+POSIX @command{awk} provides three kinds of built-in functions: numeric, string,
+and I/O.  @command{gawk} provides functions that work with values
+representing time, do bit manipulation, sort arrays, and internationalize
+and localize programs.
+@command{gawk} also provides several extensions to some of standard functions,
+typically in the form of additional arguments.
+
+@item
+Functions accept zero or more arguments and return a value.
+The expressions that provide the argument values are comnpletely evaluated
+before the function is called. Order of evaluation is not defined.
+The return value can be ignored.
+
+@item
+The handling of backslash in @code{sub()} and @code{gsub()} is
+not simple.  It is more straightforward in @command{gawk}'s @code{gensub()}
+function, but that function still requires care in its use.
+
+@item
+User-defined functions provide important capabilities but come with some
+syntactic inelegancies. In a function call, there cannot be any space
+between the function name and the opening left parethesis of the argument
+list.  Also, there is no provision for local variables, so the convention
+is to add extra parameters, and to separate them visually from the real
+parameters by extra whitespace.
+
+@item
+User-defined functions may call other user-defined (and built-in) functions
+and may call themselves recursively. Function parameters ``hide'' any global
+variables of the same names.
+
+@item
+Scalar values are passed to user-defined functions by value. Array parameters
+are passed by reference; any changes made by the function to array parameters
+are thus visible after the function has returned.
+
+@item
+Use the @code{return} statement to return from a user-defined function.
+An optional expression becomes the function's return value.
+Only scalar values may be returned by a function.
+
+@item
+If a variable that has never been used is passed to a user-defined function,
+how that function treats the variable can set its nature: either scalar or array.
+
+@item
+@command{gawk} provides indirect function calls using a special syntax.
+By setting a variable to the name of a user-defined function, you can
+determine at runtime what function will be called at that point in the
+program. This is equivalent to function pointers in C and C++.
+
+@end itemize
+
 @c ENDOFRANGE funcud
 
 @ifnotinfo
@@ -20012,6 +20134,7 @@ comparisons use only lowercase letters.
 * Passwd Functions::            Functions for getting user information.
 * Group Functions::             Functions for getting group information.
 * Walking Arrays::              A function to walk arrays of arrays.
+* Library Functions Summary::   Summary of library functions.
 @end menu
 
 @node Library Names
@@ -21215,7 +21338,7 @@ END @{
 @end ignore
 
 @node Ignoring Assigns
-@subsection Treating Assignments as @value{FFN}
+@subsection Treating Assignments as @value{FFN}s
 
 @cindex assignments as filenames
 @cindex filenames, assignments as
@@ -22422,6 +22545,7 @@ $ @kbd{gawk -f walk_array.awk}
 @print{} a[3] = 3
 @end example
 
+@c exercise!
 Walking an array and processing each element is a general-purpose
 operation.  You might want to consider generalizing the @code{walk_array()}
 function by adding an additional parameter named @code{process}.
@@ -22440,6 +22564,50 @@ the element.
 @c ENDOFRANGE flibgdata
 @c ENDOFRANGE gdatar
 @c ENDOFRANGE libf
+
+@node Library Functions Summary
+@section Summary
+
+@itemize @value{BULLET}
+@item
+Reading programs is an excellent way to learn Good Programming.
+The functions provided in this @value{CHAPTER} and the next are intended
+to serve that purpose.
+
+@item
+When writing general-purpose library functions, put some thought into
+how to name any global variables so that they won't conflict with
+variables from a user's program.
+
+@item
+The functions presented here fit into the following categories:
+
+@c nested list
+@table @asis
+@item General problems
+Number to string conversion, assertions, rounding, random number generation,
+converting characters to numbers, joining strings, getting easily usable
+time-of-day information, and reading a whole file in one shot.
+
+@item Managing @value{DF}s
+Noting @value{DF} boundaries, rereading the current file, checking for
+readable files, checking for zero-length files, and treating assignments
+as @value{FN}s.
+
+@item Processing command-line options
+An @command{awk} version of the standard C @code{getopt()} function.
+
+@item Reading the user and group databases
+Two sets of routines that parallel the C library versions.
+
+@item Traversing arrays of arrays
+A simple function to traverse an array of arrays to any depth.
+@end table
+@c end nested list
+
+@end itemize
+
+
 @c ENDOFRANGE flib
 @c ENDOFRANGE fudlib
 @c ENDOFRANGE datagr
@@ -27924,7 +28092,8 @@ complete detail in
 @cite{GNU gettext tools}}.)
 @end ifnotinfo
 As of this writing, the latest version of GNU @command{gettext} is
-@uref{ftp://ftp.gnu.org/gnu/gettext/gettext-0.19.tar.gz, @value{PVERSION} 0.19}.
+@uref{ftp://ftp.gnu.org/gnu/gettext/gettext-0.19.1.tar.gz,
+@value{PVERSION} 0.19.1}.
 
 If a translation of @command{gawk}'s messages exists,
 then @command{gawk} produces usage messages, warnings,
diff --git a/doc/gawktexi.in b/doc/gawktexi.in
index b6c3c3b7..e2d10da9 100644
--- a/doc/gawktexi.in
+++ b/doc/gawktexi.in
@@ -14357,6 +14357,7 @@ same @command{awk} program.
 * Multidimensional::            Emulating multidimensional arrays in
                                 @command{awk}.
 * Arrays of Arrays::            True multidimensional arrays.
+* Arrays Summary::              Summary of arrays.
 @end menu
 
 @node Array Basics
@@ -15639,6 +15640,64 @@ creating an arbitrary index:
 $ @kbd{gawk 'BEGIN @{ b[1][1] = ""; split("a b c d", b[1]); print b[1][1] @}'}
 @print{} a
 @end example
+
+@node Arrays Summary
+@section Summary
+
+@itemize @value{BULLET}
+@item
+Standard @command{awk} provides one-dimensional associative arrays (arrays
+indexed by string values).  All arrays are associative; numeric indices
+are converted automatically to strings.
+
+@item
+Array elements are referenced as @code{@var{array}[@var{indx}]}.
+Referencing an element creates it if it did not exist previously.
+
+@item
+The proper way to see if an array has an element with a given index
+is to use the @code{in} operator: @samp{@var{indx} in @var{array}}.
+
+@item
+Use @samp{for (@var{indx} in @var{array}) @dots{}} to scan through all the
+individual elements of an array. In the body of the loop, @var{indx} takes
+on the value of each element's index in turn.
+
+@item
+The order in which a
+@samp{for (@var{indx} in @var{array})} loop traverses an array is
+undefined in POSIX @command{awk} and varies among implementations.
+@command{gawk} lets you control the order by assigning special predefined
+values to @code{PROCINFO["sorted_in"]}.
+
+@item
+Use @samp{delete @var{array}[@var{indx}]} to delete an
+individual element.  You may also use @samp{delete @var{array}}
+to delete all of the elements in the array.  This latter feature
+has been a common extension for many years and is now standard, but
+may not be supported by all commercial versions of @command{awk}.
+
+@item
+Standard @command{awk} simulates multidimensional arrays by separating
+subscript values with a comma.  The values are concatenated into a
+single string, separated by the value of @code{SUBSEP}.  The fact that
+such a subscript was created in this way is not retained; thus changing
+@code{SUBSEP} may have unexpected consequences.
+You can use @samp{(@var{sub1}, @var{sub2}, @dots{}) in @var{array}}
+to see if such a multidimensional subscript exists in @var{array}.
+
+@item
+@command{gawk} provides true arrays of arrays. You use a separate
+set of square brackets for each dimension in such an array:
+@code{data[row][col]}, for example. Array elements may thus be either
+scalar values (number or string) or another array.
+
+@item
+Use the @code{isarray()} built-in function to determine if an
+array element is itself a subarray.
+
+@end itemize
+
 @c ENDOFRANGE arrs
 
 @node Functions
@@ -15663,6 +15722,7 @@ The second half of this @value{CHAPTER} describes these
 * Built-in::                    Summarizes the built-in functions.
 * User-defined::                Describes User-defined functions in detail.
 * Indirect Calls::              Choosing the function to call at runtime.
+* Functions Summary::           Summary of functions.
 @end menu
 
 @node Built-in
@@ -19060,6 +19120,68 @@ for (i = 1; i <= n; i++)
 @noindent
 @code{gawk} will look up the actual function to call only once.
 
+@node Functions Summary
+@section Summary
+
+@itemize @value{BULLET}
+@item
+@command{awk} provides built-in functions and lets you define your own
+functions.
+
+@item
+POSIX @command{awk} provides three kinds of built-in functions: numeric, string,
+and I/O.  @command{gawk} provides functions that work with values
+representing time, do bit manipulation, sort arrays, and internationalize
+and localize programs.
+@command{gawk} also provides several extensions to some of standard functions,
+typically in the form of additional arguments.
+
+@item
+Functions accept zero or more arguments and return a value.
+The expressions that provide the argument values are comnpletely evaluated
+before the function is called. Order of evaluation is not defined.
+The return value can be ignored.
+
+@item
+The handling of backslash in @code{sub()} and @code{gsub()} is
+not simple.  It is more straightforward in @command{gawk}'s @code{gensub()}
+function, but that function still requires care in its use.
+
+@item
+User-defined functions provide important capabilities but come with some
+syntactic inelegancies. In a function call, there cannot be any space
+between the function name and the opening left parethesis of the argument
+list.  Also, there is no provision for local variables, so the convention
+is to add extra parameters, and to separate them visually from the real
+parameters by extra whitespace.
+
+@item
+User-defined functions may call other user-defined (and built-in) functions
+and may call themselves recursively. Function parameters ``hide'' any global
+variables of the same names.
+
+@item
+Scalar values are passed to user-defined functions by value. Array parameters
+are passed by reference; any changes made by the function to array parameters
+are thus visible after the function has returned.
+
+@item
+Use the @code{return} statement to return from a user-defined function.
+An optional expression becomes the function's return value.
+Only scalar values may be returned by a function.
+
+@item
+If a variable that has never been used is passed to a user-defined function,
+how that function treats the variable can set its nature: either scalar or array.
+
+@item
+@command{gawk} provides indirect function calls using a special syntax.
+By setting a variable to the name of a user-defined function, you can
+determine at runtime what function will be called at that point in the
+program. This is equivalent to function pointers in C and C++.
+
+@end itemize
+
 @c ENDOFRANGE funcud
 
 @ifnotinfo
@@ -19185,6 +19307,7 @@ comparisons use only lowercase letters.
 * Passwd Functions::            Functions for getting user information.
 * Group Functions::             Functions for getting group information.
 * Walking Arrays::              A function to walk arrays of arrays.
+* Library Functions Summary::   Summary of library functions.
 @end menu
 
 @node Library Names
@@ -20359,7 +20482,7 @@ END @{
 @end ignore
 
 @node Ignoring Assigns
-@subsection Treating Assignments as @value{FFN}
+@subsection Treating Assignments as @value{FFN}s
 
 @cindex assignments as filenames
 @cindex filenames, assignments as
@@ -21566,6 +21689,7 @@ $ @kbd{gawk -f walk_array.awk}
 @print{} a[3] = 3
 @end example
 
+@c exercise!
 Walking an array and processing each element is a general-purpose
 operation.  You might want to consider generalizing the @code{walk_array()}
 function by adding an additional parameter named @code{process}.
@@ -21584,6 +21708,50 @@ the element.
 @c ENDOFRANGE flibgdata
 @c ENDOFRANGE gdatar
 @c ENDOFRANGE libf
+
+@node Library Functions Summary
+@section Summary
+
+@itemize @value{BULLET}
+@item
+Reading programs is an excellent way to learn Good Programming.
+The functions provided in this @value{CHAPTER} and the next are intended
+to serve that purpose.
+
+@item
+When writing general-purpose library functions, put some thought into
+how to name any global variables so that they won't conflict with
+variables from a user's program.
+
+@item
+The functions presented here fit into the following categories:
+
+@c nested list
+@table @asis
+@item General problems
+Number to string conversion, assertions, rounding, random number generation,
+converting characters to numbers, joining strings, getting easily usable
+time-of-day information, and reading a whole file in one shot.
+
+@item Managing @value{DF}s
+Noting @value{DF} boundaries, rereading the current file, checking for
+readable files, checking for zero-length files, and treating assignments
+as @value{FN}s.
+
+@item Processing command-line options
+An @command{awk} version of the standard C @code{getopt()} function.
+
+@item Reading the user and group databases
+Two sets of routines that parallel the C library versions.
+
+@item Traversing arrays of arrays
+A simple function to traverse an array of arrays to any depth.
+@end table
+@c end nested list
+
+@end itemize
+
+
 @c ENDOFRANGE flib
 @c ENDOFRANGE fudlib
 @c ENDOFRANGE datagr
@@ -27068,7 +27236,8 @@ complete detail in
 @cite{GNU gettext tools}}.)
 @end ifnotinfo
 As of this writing, the latest version of GNU @command{gettext} is
-@uref{ftp://ftp.gnu.org/gnu/gettext/gettext-0.19.tar.gz, @value{PVERSION} 0.19}.
+@uref{ftp://ftp.gnu.org/gnu/gettext/gettext-0.19.1.tar.gz,
+@value{PVERSION} 0.19.1}.
 
 If a translation of @command{gawk}'s messages exists,
 then @command{gawk} produces usage messages, warnings,