diff options
Diffstat (limited to 'doc/gawk.info')
| -rw-r--r-- | doc/gawk.info | 551 |
1 files changed, 279 insertions, 272 deletions
diff --git a/doc/gawk.info b/doc/gawk.info index 275188ef..30ff2c26 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -8948,37 +8948,35 @@ starts processing it with the first rule in the program. File: gawk.info, Node: Nextfile Statement, Next: Exit Statement, Prev: Next Statement, Up: Statements -7.4.9 Using `gawk''s `nextfile' Statement ------------------------------------------ +7.4.9 The `nextfile' Statement +------------------------------ -`gawk' provides the `nextfile' statement, which is similar to the -`next' statement. (c.e.) However, instead of abandoning processing of -the current record, the `nextfile' statement instructs `gawk' to stop -processing the current data file. - - The `nextfile' statement is a `gawk' extension. In most other `awk' -implementations, or if `gawk' is in compatibility mode (*note -Options::), `nextfile' is not special. - - Upon execution of the `nextfile' statement, any `ENDFILE' rules are -executed except in the case as mentioned below, `FILENAME' is updated -to the name of the next data file listed on the command line, `FNR' is -reset to one, `ARGIND' is incremented, any `BEGINFILE' rules are -executed, and processing starts over with the first rule in the program. -(`ARGIND' hasn't been introduced yet. *Note Built-in Variables::.) If -the `nextfile' statement causes the end of the input to be reached, -then the code in any `END' rules is executed. An exception to this is -when the `nextfile' is invoked during execution of any statement in an -`END' rule; In this case, it causes the program to stop immediately. +The `nextfile' statement is similar to the `next' statement. However, +instead of abandoning processing of the current record, the `nextfile' +statement instructs `awk' to stop processing the current data file. + + Upon execution of the `nextfile' statement, `FILENAME' is updated to +the name of the next data file listed on the command line, `FNR' is +reset to one, and processing starts over with the first rule in the +program. If the `nextfile' statement causes the end of the input to be +reached, then the code in any `END' rules is executed. An exception to +this is when `nextfile' is invoked during execution of any statement in +an `END' rule; In this case, it causes the program to stop immediately. *Note BEGIN/END::. The `nextfile' statement is useful when there are many data files to process but it isn't necessary to process every record in every file. -Normally, in order to move on to the next data file, a program has to -continue scanning the unwanted records. The `nextfile' statement -accomplishes this much more efficiently. +Without `nextfile', in order to move on to the next data file, a program +would have to continue scanning the unwanted records. The `nextfile' +statement accomplishes this much more efficiently. + + In `gawk', execution of `nextfile' causes additional things to +happen: any `ENDFILE' rules are executed except in the case as +mentioned below, `ARGIND' is incremented, and any `BEGINFILE' rules are +executed (`ARGIND' hasn't been introduced yet. *Note Built-in +Variables::.) - In addition, `nextfile' is useful inside a `BEGINFILE' rule to skip + With `gawk', `nextfile' is useful inside a `BEGINFILE' rule to skip over a file that would otherwise cause `gawk' to exit with a fatal error. In this case, `ENDFILE' rules are not executed. *Note BEGINFILE/ENDFILE::. @@ -8989,6 +8987,11 @@ files, pipes, and coprocesses that are opened with redirections. It is not related to the main processing that `awk' does with the files listed in `ARGV'. + NOTE: For many years, `nextfile' was a `gawk' extension. As of + September, 2012, it was accepted for inclusion into the POSIX + standard. See the Austin Group website + (http://austingroupbugs.net/view.php?id=607). + The current version of the Brian Kernighan's `awk' (*note Other Versions::) also supports `nextfile'. However, it doesn't allow the `nextfile' statement inside function bodies (*note User-defined::). @@ -10105,18 +10108,22 @@ However, if `--lint' is provided on the command line (*note Options::), array is deleted. All the elements of an array may be deleted with a single statement -(c.e.) by leaving off the subscript in the `delete' statement, as -follows: +by leaving off the subscript in the `delete' statement, as follows: delete ARRAY - This ability is a `gawk' extension; it is not available in -compatibility mode (*note Options::). - Using this version of the `delete' statement is about three times more efficient than the equivalent loop that deletes each element one at a time. + NOTE: For many years, using `delete' without a subscript was a + `gawk' extension. As of September, 2012, it was accepted for + inclusion into the POSIX standard. See the Austin Group website + (http://austingroupbugs.net/view.php?id=544). This form of the + `delete' statement is also supported by Brian Kernighan's `awk' + and `mawk', as well as by a number of other implementations (*note + Other Versions::). + The following statement provides a portable but nonobvious way to clear out an array:(1) @@ -25263,7 +25270,7 @@ Index * Brennan, Michael <1>: Other Versions. (line 6) * Brennan, Michael <2>: Simple Sed. (line 25) * Brennan, Michael <3>: Two-way I/O. (line 6) -* Brennan, Michael: Delete. (line 52) +* Brennan, Michael: Delete. (line 56) * Brian Kernighan's awk, extensions <1>: Other Versions. (line 13) * Brian Kernighan's awk, extensions: BTL. (line 6) * Broder, Alan J.: Contributors. (line 88) @@ -26040,7 +26047,7 @@ Index * functions, user-defined, counts: Profiling. (line 132) * functions, user-defined, library of: Library Functions. (line 6) * functions, user-defined, next/nextfile statements and <1>: Nextfile Statement. - (line 44) + (line 47) * functions, user-defined, next/nextfile statements and: Next Statement. (line 45) * G-d: Acknowledgments. (line 81) @@ -26554,7 +26561,7 @@ Index * nextfile statement, BEGINFILE/ENDFILE patterns and: BEGINFILE/ENDFILE. (line 26) * nextfile statement, user-defined functions and: Nextfile Statement. - (line 44) + (line 47) * nexti debugger command: Dgawk Execution Control. (line 49) * NF variable <1>: Auto-set. (line 107) @@ -26743,7 +26750,7 @@ Index * portability, close() function and: Close Files And Pipes. (line 81) * portability, data files as single record: Records. (line 180) -* portability, deleting array elements: Delete. (line 52) +* portability, deleting array elements: Delete. (line 56) * portability, example programs: Library Functions. (line 31) * portability, fflush() function and: I/O Functions. (line 29) * portability, functions, defining: Definition Syntax. (line 99) @@ -27149,7 +27156,7 @@ Index * Spencer, Henry: Glossary. (line 12) * split utility: Split Program. (line 6) * split() function: String Functions. (line 315) -* split() function, array elements, deleting: Delete. (line 57) +* split() function, array elements, deleting: Delete. (line 61) * split.awk program: Split Program. (line 30) * sprintf() function <1>: String Functions. (line 380) * sprintf() function: OFMT. (line 15) @@ -27654,242 +27661,242 @@ Node: Break Statement372503 Node: Continue Statement374493 Node: Next Statement376286 Node: Nextfile Statement378676 -Node: Exit Statement381221 -Node: Built-in Variables383637 -Node: User-modified384732 -Ref: User-modified-Footnote-1392758 -Node: Auto-set392820 -Ref: Auto-set-Footnote-1402111 -Node: ARGC and ARGV402316 -Node: Arrays406167 -Node: Array Basics407672 -Node: Array Intro408498 -Node: Reference to Elements412816 -Node: Assigning Elements415086 -Node: Array Example415577 -Node: Scanning an Array417309 -Node: Controlling Scanning419623 -Ref: Controlling Scanning-Footnote-1424556 -Node: Delete424872 -Ref: Delete-Footnote-1427307 -Node: Numeric Array Subscripts427364 -Node: Uninitialized Subscripts429547 -Node: Multi-dimensional431175 -Node: Multi-scanning434269 -Node: Arrays of Arrays435860 -Node: Functions440505 -Node: Built-in441327 -Node: Calling Built-in442405 -Node: Numeric Functions444393 -Ref: Numeric Functions-Footnote-1448225 -Ref: Numeric Functions-Footnote-2448582 -Ref: Numeric Functions-Footnote-3448630 -Node: String Functions448899 -Ref: String Functions-Footnote-1472396 -Ref: String Functions-Footnote-2472525 -Ref: String Functions-Footnote-3472773 -Node: Gory Details472860 -Ref: table-sub-escapes474539 -Ref: table-sub-posix-92475893 -Ref: table-sub-proposed477236 -Ref: table-posix-sub478586 -Ref: table-gensub-escapes480132 -Ref: Gory Details-Footnote-1481339 -Ref: Gory Details-Footnote-2481390 -Node: I/O Functions481541 -Ref: I/O Functions-Footnote-1488196 -Node: Time Functions488343 -Ref: Time Functions-Footnote-1499235 -Ref: Time Functions-Footnote-2499303 -Ref: Time Functions-Footnote-3499461 -Ref: Time Functions-Footnote-4499572 -Ref: Time Functions-Footnote-5499684 -Ref: Time Functions-Footnote-6499911 -Node: Bitwise Functions500177 -Ref: table-bitwise-ops500735 -Ref: Bitwise Functions-Footnote-1504895 -Node: Type Functions505079 -Node: I18N Functions505549 -Node: User-defined507176 -Node: Definition Syntax507980 -Ref: Definition Syntax-Footnote-1512890 -Node: Function Example512959 -Node: Function Caveats515553 -Node: Calling A Function515974 -Node: Variable Scope517089 -Node: Pass By Value/Reference519064 -Node: Return Statement522504 -Node: Dynamic Typing525485 -Node: Indirect Calls526220 -Node: Internationalization535905 -Node: I18N and L10N537331 -Node: Explaining gettext538017 -Ref: Explaining gettext-Footnote-1543083 -Ref: Explaining gettext-Footnote-2543267 -Node: Programmer i18n543432 -Node: Translator i18n547632 -Node: String Extraction548425 -Ref: String Extraction-Footnote-1549386 -Node: Printf Ordering549472 -Ref: Printf Ordering-Footnote-1552256 -Node: I18N Portability552320 -Ref: I18N Portability-Footnote-1554769 -Node: I18N Example554832 -Ref: I18N Example-Footnote-1557467 -Node: Gawk I18N557539 -Node: Advanced Features558156 -Node: Nondecimal Data559669 -Node: Array Sorting561252 -Node: Controlling Array Traversal561949 -Node: Array Sorting Functions570186 -Ref: Array Sorting Functions-Footnote-1573860 -Ref: Array Sorting Functions-Footnote-2573953 -Node: Two-way I/O574147 -Ref: Two-way I/O-Footnote-1579579 -Node: TCP/IP Networking579649 -Node: Profiling582493 -Node: Library Functions589967 -Ref: Library Functions-Footnote-1592974 -Node: Library Names593145 -Ref: Library Names-Footnote-1596616 -Ref: Library Names-Footnote-2596836 -Node: General Functions596922 -Node: Strtonum Function597875 -Node: Assert Function600805 -Node: Round Function604131 -Node: Cliff Random Function605674 -Node: Ordinal Functions606690 -Ref: Ordinal Functions-Footnote-1609760 -Ref: Ordinal Functions-Footnote-2610012 -Node: Join Function610221 -Ref: Join Function-Footnote-1611992 -Node: Gettimeofday Function612192 -Node: Data File Management615907 -Node: Filetrans Function616539 -Node: Rewind Function620678 -Node: File Checking622065 -Node: Empty Files623159 -Node: Ignoring Assigns625389 -Node: Getopt Function626942 -Ref: Getopt Function-Footnote-1638246 -Node: Passwd Functions638449 -Ref: Passwd Functions-Footnote-1647424 -Node: Group Functions647512 -Node: Walking Arrays655596 -Node: Sample Programs657165 -Node: Running Examples657830 -Node: Clones658558 -Node: Cut Program659782 -Node: Egrep Program669627 -Ref: Egrep Program-Footnote-1677400 -Node: Id Program677510 -Node: Split Program681126 -Ref: Split Program-Footnote-1684645 -Node: Tee Program684773 -Node: Uniq Program687576 -Node: Wc Program695005 -Ref: Wc Program-Footnote-1699271 -Ref: Wc Program-Footnote-2699471 -Node: Miscellaneous Programs699563 -Node: Dupword Program700751 -Node: Alarm Program702782 -Node: Translate Program707531 -Ref: Translate Program-Footnote-1711918 -Ref: Translate Program-Footnote-2712146 -Node: Labels Program712280 -Ref: Labels Program-Footnote-1715651 -Node: Word Sorting715735 -Node: History Sorting719619 -Node: Extract Program721458 -Ref: Extract Program-Footnote-1728941 -Node: Simple Sed729069 -Node: Igawk Program732131 -Ref: Igawk Program-Footnote-1747288 -Ref: Igawk Program-Footnote-2747489 -Node: Anagram Program747627 -Node: Signature Program750695 -Node: Debugger751795 -Node: Debugging752706 -Node: Debugging Concepts753119 -Node: Debugging Terms754975 -Node: Awk Debugging757598 -Node: Sample dgawk session758490 -Node: dgawk invocation758982 -Node: Finding The Bug760164 -Node: List of Debugger Commands766650 -Node: Breakpoint Control767961 -Node: Dgawk Execution Control771597 -Node: Viewing And Changing Data774948 -Node: Dgawk Stack778285 -Node: Dgawk Info779745 -Node: Miscellaneous Dgawk Commands783693 -Node: Readline Support789121 -Node: Dgawk Limitations789959 -Node: Language History792148 -Node: V7/SVR3.1793660 -Node: SVR4795981 -Node: POSIX797423 -Node: BTL798431 -Node: POSIX/GNU799165 -Node: Common Extensions804316 -Node: Ranges and Locales805423 -Ref: Ranges and Locales-Footnote-1810041 -Ref: Ranges and Locales-Footnote-2810068 -Ref: Ranges and Locales-Footnote-3810328 -Node: Contributors810549 -Node: Installation814811 -Node: Gawk Distribution815705 -Node: Getting816189 -Node: Extracting817015 -Node: Distribution contents818707 -Node: Unix Installation823929 -Node: Quick Installation824546 -Node: Additional Configuration Options826508 -Node: Configuration Philosophy827985 -Node: Non-Unix Installation830327 -Node: PC Installation830785 -Node: PC Binary Installation832084 -Node: PC Compiling834099 -Node: PC Testing837043 -Node: PC Using838219 -Node: Cygwin842404 -Node: MSYS843404 -Node: VMS Installation843918 -Node: VMS Compilation844521 -Ref: VMS Compilation-Footnote-1845528 -Node: VMS Installation Details845586 -Node: VMS Running847221 -Node: VMS Old Gawk848828 -Node: Bugs849302 -Node: Other Versions853154 -Node: Notes858435 -Node: Compatibility Mode859127 -Node: Additions859910 -Node: Accessing The Source860722 -Node: Adding Code862147 -Node: New Ports868114 -Node: Dynamic Extensions872227 -Node: Internals873603 -Node: Plugin License882706 -Node: Sample Library883340 -Node: Internal File Description884026 -Node: Internal File Ops887741 -Ref: Internal File Ops-Footnote-1892522 -Node: Using Internal File Ops892662 -Node: Future Extensions895039 -Node: Basic Concepts897543 -Node: Basic High Level898300 -Ref: Basic High Level-Footnote-1902335 -Node: Basic Data Typing902520 -Node: Floating Point Issues907045 -Node: String Conversion Precision908128 -Ref: String Conversion Precision-Footnote-1909828 -Node: Unexpected Results909937 -Node: POSIX Floating Point Problems911763 -Ref: POSIX Floating Point Problems-Footnote-1915468 -Node: Glossary915506 -Node: Copying940482 -Node: GNU Free Documentation License978039 -Node: Index1003176 +Node: Exit Statement381317 +Node: Built-in Variables383733 +Node: User-modified384828 +Ref: User-modified-Footnote-1392854 +Node: Auto-set392916 +Ref: Auto-set-Footnote-1402207 +Node: ARGC and ARGV402412 +Node: Arrays406263 +Node: Array Basics407768 +Node: Array Intro408594 +Node: Reference to Elements412912 +Node: Assigning Elements415182 +Node: Array Example415673 +Node: Scanning an Array417405 +Node: Controlling Scanning419719 +Ref: Controlling Scanning-Footnote-1424652 +Node: Delete424968 +Ref: Delete-Footnote-1427733 +Node: Numeric Array Subscripts427790 +Node: Uninitialized Subscripts429973 +Node: Multi-dimensional431601 +Node: Multi-scanning434695 +Node: Arrays of Arrays436286 +Node: Functions440931 +Node: Built-in441753 +Node: Calling Built-in442831 +Node: Numeric Functions444819 +Ref: Numeric Functions-Footnote-1448651 +Ref: Numeric Functions-Footnote-2449008 +Ref: Numeric Functions-Footnote-3449056 +Node: String Functions449325 +Ref: String Functions-Footnote-1472822 +Ref: String Functions-Footnote-2472951 +Ref: String Functions-Footnote-3473199 +Node: Gory Details473286 +Ref: table-sub-escapes474965 +Ref: table-sub-posix-92476319 +Ref: table-sub-proposed477662 +Ref: table-posix-sub479012 +Ref: table-gensub-escapes480558 +Ref: Gory Details-Footnote-1481765 +Ref: Gory Details-Footnote-2481816 +Node: I/O Functions481967 +Ref: I/O Functions-Footnote-1488622 +Node: Time Functions488769 +Ref: Time Functions-Footnote-1499661 +Ref: Time Functions-Footnote-2499729 +Ref: Time Functions-Footnote-3499887 +Ref: Time Functions-Footnote-4499998 +Ref: Time Functions-Footnote-5500110 +Ref: Time Functions-Footnote-6500337 +Node: Bitwise Functions500603 +Ref: table-bitwise-ops501161 +Ref: Bitwise Functions-Footnote-1505321 +Node: Type Functions505505 +Node: I18N Functions505975 +Node: User-defined507602 +Node: Definition Syntax508406 +Ref: Definition Syntax-Footnote-1513316 +Node: Function Example513385 +Node: Function Caveats515979 +Node: Calling A Function516400 +Node: Variable Scope517515 +Node: Pass By Value/Reference519490 +Node: Return Statement522930 +Node: Dynamic Typing525911 +Node: Indirect Calls526646 +Node: Internationalization536331 +Node: I18N and L10N537757 +Node: Explaining gettext538443 +Ref: Explaining gettext-Footnote-1543509 +Ref: Explaining gettext-Footnote-2543693 +Node: Programmer i18n543858 +Node: Translator i18n548058 +Node: String Extraction548851 +Ref: String Extraction-Footnote-1549812 +Node: Printf Ordering549898 +Ref: Printf Ordering-Footnote-1552682 +Node: I18N Portability552746 +Ref: I18N Portability-Footnote-1555195 +Node: I18N Example555258 +Ref: I18N Example-Footnote-1557893 +Node: Gawk I18N557965 +Node: Advanced Features558582 +Node: Nondecimal Data560095 +Node: Array Sorting561678 +Node: Controlling Array Traversal562375 +Node: Array Sorting Functions570612 +Ref: Array Sorting Functions-Footnote-1574286 +Ref: Array Sorting Functions-Footnote-2574379 +Node: Two-way I/O574573 +Ref: Two-way I/O-Footnote-1580005 +Node: TCP/IP Networking580075 +Node: Profiling582919 +Node: Library Functions590393 +Ref: Library Functions-Footnote-1593400 +Node: Library Names593571 +Ref: Library Names-Footnote-1597042 +Ref: Library Names-Footnote-2597262 +Node: General Functions597348 +Node: Strtonum Function598301 +Node: Assert Function601231 +Node: Round Function604557 +Node: Cliff Random Function606100 +Node: Ordinal Functions607116 +Ref: Ordinal Functions-Footnote-1610186 +Ref: Ordinal Functions-Footnote-2610438 +Node: Join Function610647 +Ref: Join Function-Footnote-1612418 +Node: Gettimeofday Function612618 +Node: Data File Management616333 +Node: Filetrans Function616965 +Node: Rewind Function621104 +Node: File Checking622491 +Node: Empty Files623585 +Node: Ignoring Assigns625815 +Node: Getopt Function627368 +Ref: Getopt Function-Footnote-1638672 +Node: Passwd Functions638875 +Ref: Passwd Functions-Footnote-1647850 +Node: Group Functions647938 +Node: Walking Arrays656022 +Node: Sample Programs657591 +Node: Running Examples658256 +Node: Clones658984 +Node: Cut Program660208 +Node: Egrep Program670053 +Ref: Egrep Program-Footnote-1677826 +Node: Id Program677936 +Node: Split Program681552 +Ref: Split Program-Footnote-1685071 +Node: Tee Program685199 +Node: Uniq Program688002 +Node: Wc Program695431 +Ref: Wc Program-Footnote-1699697 +Ref: Wc Program-Footnote-2699897 +Node: Miscellaneous Programs699989 +Node: Dupword Program701177 +Node: Alarm Program703208 +Node: Translate Program707957 +Ref: Translate Program-Footnote-1712344 +Ref: Translate Program-Footnote-2712572 +Node: Labels Program712706 +Ref: Labels Program-Footnote-1716077 +Node: Word Sorting716161 +Node: History Sorting720045 +Node: Extract Program721884 +Ref: Extract Program-Footnote-1729367 +Node: Simple Sed729495 +Node: Igawk Program732557 +Ref: Igawk Program-Footnote-1747714 +Ref: Igawk Program-Footnote-2747915 +Node: Anagram Program748053 +Node: Signature Program751121 +Node: Debugger752221 +Node: Debugging753132 +Node: Debugging Concepts753545 +Node: Debugging Terms755401 +Node: Awk Debugging758024 +Node: Sample dgawk session758916 +Node: dgawk invocation759408 +Node: Finding The Bug760590 +Node: List of Debugger Commands767076 +Node: Breakpoint Control768387 +Node: Dgawk Execution Control772023 +Node: Viewing And Changing Data775374 +Node: Dgawk Stack778711 +Node: Dgawk Info780171 +Node: Miscellaneous Dgawk Commands784119 +Node: Readline Support789547 +Node: Dgawk Limitations790385 +Node: Language History792574 +Node: V7/SVR3.1794086 +Node: SVR4796407 +Node: POSIX797849 +Node: BTL798857 +Node: POSIX/GNU799591 +Node: Common Extensions804742 +Node: Ranges and Locales805849 +Ref: Ranges and Locales-Footnote-1810467 +Ref: Ranges and Locales-Footnote-2810494 +Ref: Ranges and Locales-Footnote-3810754 +Node: Contributors810975 +Node: Installation815237 +Node: Gawk Distribution816131 +Node: Getting816615 +Node: Extracting817441 +Node: Distribution contents819133 +Node: Unix Installation824355 +Node: Quick Installation824972 +Node: Additional Configuration Options826934 +Node: Configuration Philosophy828411 +Node: Non-Unix Installation830753 +Node: PC Installation831211 +Node: PC Binary Installation832510 +Node: PC Compiling834525 +Node: PC Testing837469 +Node: PC Using838645 +Node: Cygwin842830 +Node: MSYS843830 +Node: VMS Installation844344 +Node: VMS Compilation844947 +Ref: VMS Compilation-Footnote-1845954 +Node: VMS Installation Details846012 +Node: VMS Running847647 +Node: VMS Old Gawk849254 +Node: Bugs849728 +Node: Other Versions853580 +Node: Notes858861 +Node: Compatibility Mode859553 +Node: Additions860336 +Node: Accessing The Source861148 +Node: Adding Code862573 +Node: New Ports868540 +Node: Dynamic Extensions872653 +Node: Internals874029 +Node: Plugin License883132 +Node: Sample Library883766 +Node: Internal File Description884452 +Node: Internal File Ops888167 +Ref: Internal File Ops-Footnote-1892948 +Node: Using Internal File Ops893088 +Node: Future Extensions895465 +Node: Basic Concepts897969 +Node: Basic High Level898726 +Ref: Basic High Level-Footnote-1902761 +Node: Basic Data Typing902946 +Node: Floating Point Issues907471 +Node: String Conversion Precision908554 +Ref: String Conversion Precision-Footnote-1910254 +Node: Unexpected Results910363 +Node: POSIX Floating Point Problems912189 +Ref: POSIX Floating Point Problems-Footnote-1915894 +Node: Glossary915932 +Node: Copying940908 +Node: GNU Free Documentation License978465 +Node: Index1003602 End Tag Table |