diff options
| -rw-r--r-- | ChangeLog | 12 | ||||
| -rw-r--r-- | awk.h | 2 | ||||
| -rw-r--r-- | awkgram.c | 2 | ||||
| -rw-r--r-- | awkgram.y | 2 | ||||
| -rw-r--r-- | doc/ChangeLog | 5 | ||||
| -rw-r--r-- | doc/gawk.info | 914 | ||||
| -rw-r--r-- | doc/gawk.texi | 63 | ||||
| -rw-r--r-- | doc/gawktexi.in | 63 | ||||
| -rw-r--r-- | main.c | 9 | ||||
| -rw-r--r-- | node.c | 2 |
10 files changed, 642 insertions, 432 deletions
@@ -1,5 +1,17 @@ 2018-07-31 Arnold D. Robbins <arnold@skeeve.com> + Handle newlines in -v and fix \-<newline>. Thanks to + Samy Mahmoudi <samy.mahmoudi@gmail.com> for the report. + + * awk.h [ELIDE_BACK_NL]: New constant. + * awkgram.y (yylex): Disallow any physical newlines in a string + even if escaped, in POSIX mode. + * main.c (arg_assign): In POSIX mode disallow physical newline + in a -v value. Otherwise call make_str_node() with ELIDE_BACK_NL. + * node.c (make_str_node): Handle ELIDE_BACK_NL. + +2018-07-31 Arnold D. Robbins <arnold@skeeve.com> + * array.c (cmp_strings): Preserve value of lmin so it can be passed to memcmp() if IGNORECASE comparison failed. Thanks to M. Rashid Zamani <rashid.z@gmail.com> for the report. @@ -1328,8 +1328,10 @@ DEREF(NODE *r) #define make_string(s, l) make_str_node((s), (l), 0) +// Flags for making string nodes #define SCAN 1 #define ALREADY_MALLOCED 2 +#define ELIDE_BACK_NL 4 #define cant_happen() r_fatal("internal error line %d, file: %s", \ __LINE__, __FILE__) @@ -6272,6 +6272,8 @@ retry: if (c == '\r') /* allow MS-DOS files. bleah */ c = nextc(true); if (c == '\n') { + if (do_posix) + fatal(_("POSIX does not allow physical newlines in string values")); sourceline++; continue; } @@ -3852,6 +3852,8 @@ retry: if (c == '\r') /* allow MS-DOS files. bleah */ c = nextc(true); if (c == '\n') { + if (do_posix) + fatal(_("POSIX does not allow physical newlines in string values")); sourceline++; continue; } diff --git a/doc/ChangeLog b/doc/ChangeLog index 51f19120..0821be14 100644 --- a/doc/ChangeLog +++ b/doc/ChangeLog @@ -1,5 +1,10 @@ 2018-07-31 Arnold D. Robbins <arnold@skeeve.com> + * gawktexi.in (Scalar Constants): Document what happens with + physical newlines in strings, escaped and otherwise. + +2018-07-31 Arnold D. Robbins <arnold@skeeve.com> + * gawktexi.in (Two-way I/O): Fix some typos. * gawkworkflow.texi (Configuring git): Correct some command usages. Thanks to Antonio Columbo for the fix. diff --git a/doc/gawk.info b/doc/gawk.info index bc245e3e..b4f59c53 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -7669,6 +7669,55 @@ can be of any length, and they can contain any of the possible eight-bit ASCII characters, including ASCII NUL (character code zero). Other 'awk' implementations may have difficulty with some character codes. + Some languages allow you to continue long strings across multiple +lines by ending the line with a backslash. For example in C: + + #include <stdio.h> + + int main() + { + printf "hello, \ + world\n"); + return 0; + } + +In such a case, the C compiler removes both the backslash and the +newline, producing a string as if it had been typed '"hello, world\n"'. +This is useful when a single string needs to contain a large amount of +text. + + The POSIX standard says explicitly that newlines are not allowed +inside string constants. And indeed, all 'awk' implementations report +an error if you try to do so. For example: + + $ gawk 'BEGIN { print "hello, + > world" }' + -| gawk: cmd. line:1: BEGIN print "hello, + -| gawk: cmd. line:1: ^ unterminated string + -| gawk: cmd. line:1: BEGIN print "hello, + -| gawk: cmd. line:1: ^ syntax error + + Although POSIX doesn't define what happens if you use an escaped +newline, as in the previous C example, all known versions of 'awk' allow +you to do so. Unfortunately, what each one does with such a string +varies. (d.c.) 'gawk', 'mawk', and the OpenSolaris POSIX 'awk' (*note +Other Versions::) elide the backslash and newline, as in C: + + $ gawk 'BEGIN { print "hello, \ + > world" }' + -| hello, world + + Brian Kernighan's 'awk' and Busybox 'awk' remove the backslash but +leave the newline intact, as part of the string: + + $ nawk 'BEGIN { print "hello, \ + > world" }' + -| hello, + -| world + + In POSIX mode (*note Options::), 'gawk' does not allow escaped +newlines. Otherwise, it behaves as just described. + ---------- Footnotes ---------- (1) The internal representation of all numbers, including integers, @@ -33879,6 +33928,7 @@ Index * dark corner, regexp constants, as arguments to user-defined functions: Standard Regexp Constants. (line 43) * dark corner, split() function: String Functions. (line 364) +* dark corner, string continuation: Scalar Constants. (line 53) * dark corner, strings, storing: gawk split records. (line 82) * dark corner, value of ARGV[0]: Auto-set. (line 39) * dark corner, ^, in FS: Regexp Field Splitting. @@ -34096,6 +34146,7 @@ Index * differences in awk and gawk, split() function: String Functions. (line 351) * differences in awk and gawk, strings: Scalar Constants. (line 20) +* differences in awk and gawk, strings <1>: Scalar Constants. (line 53) * differences in awk and gawk, strings, storing: gawk split records. (line 76) * differences in awk and gawk, SYMTAB variable: Auto-set. (line 331) @@ -35810,6 +35861,7 @@ Index * string-matching operators: Regexp Usage. (line 19) * string-translation functions: I18N Functions. (line 6) * strings splitting, example: String Functions. (line 337) +* strings, continuation across lines: Scalar Constants. (line 53) * strings, converting: Strings And Numbers. (line 6) * strings, converting <1>: Bitwise Functions. (line 109) * strings, converting letter case: String Functions. (line 526) @@ -36246,436 +36298,436 @@ Node: Expressions332646 Node: Values333834 Node: Constants334512 Node: Scalar Constants335203 -Ref: Scalar Constants-Footnote-1336067 -Node: Nondecimal-numbers336317 -Node: Regexp Constants339318 -Node: Using Constant Regexps339844 -Node: Standard Regexp Constants340466 -Node: Strong Regexp Constants343654 -Node: Variables346612 -Node: Using Variables347269 -Node: Assignment Options349179 -Node: Conversion351052 -Node: Strings And Numbers351576 -Ref: Strings And Numbers-Footnote-1354639 -Node: Locale influences conversions354748 -Ref: table-locale-affects357506 -Node: All Operators358124 -Node: Arithmetic Ops358753 -Node: Concatenation361259 -Ref: Concatenation-Footnote-1364106 -Node: Assignment Ops364213 -Ref: table-assign-ops369204 -Node: Increment Ops370517 -Node: Truth Values and Conditions373977 -Node: Truth Values375051 -Node: Typing and Comparison376099 -Node: Variable Typing376919 -Ref: Variable Typing-Footnote-1383382 -Ref: Variable Typing-Footnote-2383454 -Node: Comparison Operators383531 -Ref: table-relational-ops383950 -Node: POSIX String Comparison387445 -Ref: POSIX String Comparison-Footnote-1389140 -Ref: POSIX String Comparison-Footnote-2389279 -Node: Boolean Ops389363 -Ref: Boolean Ops-Footnote-1393845 -Node: Conditional Exp393937 -Node: Function Calls395673 -Node: Precedence399550 -Node: Locales403209 -Node: Expressions Summary404841 -Node: Patterns and Actions407414 -Node: Pattern Overview408534 -Node: Regexp Patterns410211 -Node: Expression Patterns410753 -Node: Ranges414534 -Node: BEGIN/END417642 -Node: Using BEGIN/END418403 -Ref: Using BEGIN/END-Footnote-1421139 -Node: I/O And BEGIN/END421245 -Node: BEGINFILE/ENDFILE423559 -Node: Empty426472 -Node: Using Shell Variables426789 -Node: Action Overview429063 -Node: Statements431388 -Node: If Statement433236 -Node: While Statement434731 -Node: Do Statement436759 -Node: For Statement437907 -Node: Switch Statement441078 -Node: Break Statement443464 -Node: Continue Statement445556 -Node: Next Statement447383 -Node: Nextfile Statement449766 -Node: Exit Statement452418 -Node: Built-in Variables454821 -Node: User-modified455954 -Node: Auto-set463721 -Ref: Auto-set-Footnote-1480023 -Ref: Auto-set-Footnote-2480229 -Node: ARGC and ARGV480285 -Node: Pattern Action Summary484498 -Node: Arrays486928 -Node: Array Basics488257 -Node: Array Intro489101 -Ref: figure-array-elements491076 -Ref: Array Intro-Footnote-1493780 -Node: Reference to Elements493908 -Node: Assigning Elements496372 -Node: Array Example496863 -Node: Scanning an Array498622 -Node: Controlling Scanning501644 -Ref: Controlling Scanning-Footnote-1507043 -Node: Numeric Array Subscripts507359 -Node: Uninitialized Subscripts509543 -Node: Delete511162 -Ref: Delete-Footnote-1513914 -Node: Multidimensional513971 -Node: Multiscanning517066 -Node: Arrays of Arrays518657 -Node: Arrays Summary523424 -Node: Functions525517 -Node: Built-in526555 -Node: Calling Built-in527636 -Node: Numeric Functions529632 -Ref: Numeric Functions-Footnote-1533660 -Ref: Numeric Functions-Footnote-2534017 -Ref: Numeric Functions-Footnote-3534065 -Node: String Functions534337 -Ref: String Functions-Footnote-1558046 -Ref: String Functions-Footnote-2558174 -Ref: String Functions-Footnote-3558422 -Node: Gory Details558509 -Ref: table-sub-escapes560300 -Ref: table-sub-proposed561819 -Ref: table-posix-sub563182 -Ref: table-gensub-escapes564723 -Ref: Gory Details-Footnote-1565546 -Node: I/O Functions565700 -Ref: table-system-return-values572168 -Ref: I/O Functions-Footnote-1574148 -Ref: I/O Functions-Footnote-2574296 -Node: Time Functions574416 -Ref: Time Functions-Footnote-1585087 -Ref: Time Functions-Footnote-2585155 -Ref: Time Functions-Footnote-3585313 -Ref: Time Functions-Footnote-4585424 -Ref: Time Functions-Footnote-5585536 -Ref: Time Functions-Footnote-6585763 -Node: Bitwise Functions586029 -Ref: table-bitwise-ops586623 -Ref: Bitwise Functions-Footnote-1592686 -Ref: Bitwise Functions-Footnote-2592859 -Node: Type Functions593050 -Node: I18N Functions595801 -Node: User-defined597452 -Node: Definition Syntax598257 -Ref: Definition Syntax-Footnote-1603944 -Node: Function Example604015 -Ref: Function Example-Footnote-1606937 -Node: Function Caveats606959 -Node: Calling A Function607477 -Node: Variable Scope608435 -Node: Pass By Value/Reference611429 -Node: Return Statement614928 -Node: Dynamic Typing617907 -Node: Indirect Calls618837 -Ref: Indirect Calls-Footnote-1629089 -Node: Functions Summary629217 -Node: Library Functions631922 -Ref: Library Functions-Footnote-1635529 -Ref: Library Functions-Footnote-2635672 -Node: Library Names635843 -Ref: Library Names-Footnote-1639303 -Ref: Library Names-Footnote-2639526 -Node: General Functions639612 -Node: Strtonum Function640715 -Node: Assert Function643737 -Node: Round Function647063 -Node: Cliff Random Function648603 -Node: Ordinal Functions649619 -Ref: Ordinal Functions-Footnote-1652682 -Ref: Ordinal Functions-Footnote-2652934 -Node: Join Function653144 -Ref: Join Function-Footnote-1654914 -Node: Getlocaltime Function655114 -Node: Readfile Function658856 -Node: Shell Quoting660833 -Node: Data File Management662234 -Node: Filetrans Function662866 -Node: Rewind Function666962 -Node: File Checking668872 -Ref: File Checking-Footnote-1670206 -Node: Empty Files670407 -Node: Ignoring Assigns672386 -Node: Getopt Function673936 -Ref: Getopt Function-Footnote-1685405 -Node: Passwd Functions685605 -Ref: Passwd Functions-Footnote-1694444 -Node: Group Functions694532 -Ref: Group Functions-Footnote-1702430 -Node: Walking Arrays702637 -Node: Library Functions Summary705645 -Node: Library Exercises707051 -Node: Sample Programs707516 -Node: Running Examples708286 -Node: Clones709014 -Node: Cut Program710238 -Node: Egrep Program720167 -Ref: Egrep Program-Footnote-1727679 -Node: Id Program727789 -Node: Split Program731469 -Ref: Split Program-Footnote-1734927 -Node: Tee Program735056 -Node: Uniq Program737846 -Node: Wc Program745272 -Ref: Wc Program-Footnote-1749527 -Node: Miscellaneous Programs749621 -Node: Dupword Program750834 -Node: Alarm Program752864 -Node: Translate Program757719 -Ref: Translate Program-Footnote-1762284 -Node: Labels Program762554 -Ref: Labels Program-Footnote-1765905 -Node: Word Sorting765989 -Node: History Sorting770061 -Node: Extract Program771896 -Node: Simple Sed779950 -Node: Igawk Program783024 -Ref: Igawk Program-Footnote-1797355 -Ref: Igawk Program-Footnote-2797557 -Ref: Igawk Program-Footnote-3797679 -Node: Anagram Program797794 -Node: Signature Program800856 -Node: Programs Summary802103 -Node: Programs Exercises803317 -Ref: Programs Exercises-Footnote-1807446 -Node: Advanced Features807537 -Node: Nondecimal Data809527 -Node: Array Sorting811118 -Node: Controlling Array Traversal811818 -Ref: Controlling Array Traversal-Footnote-1820186 -Node: Array Sorting Functions820304 -Ref: Array Sorting Functions-Footnote-1825395 -Node: Two-way I/O825591 -Ref: Two-way I/O-Footnote-1833311 -Ref: Two-way I/O-Footnote-2833498 -Node: TCP/IP Networking833580 -Node: Profiling836698 -Ref: Profiling-Footnote-1845370 -Node: Advanced Features Summary845693 -Node: Internationalization847537 -Node: I18N and L10N849017 -Node: Explaining gettext849704 -Ref: Explaining gettext-Footnote-1855596 -Ref: Explaining gettext-Footnote-2855781 -Node: Programmer i18n855946 -Ref: Programmer i18n-Footnote-1860895 -Node: Translator i18n860944 -Node: String Extraction861738 -Ref: String Extraction-Footnote-1862870 -Node: Printf Ordering862956 -Ref: Printf Ordering-Footnote-1865742 -Node: I18N Portability865806 -Ref: I18N Portability-Footnote-1868262 -Node: I18N Example868325 -Ref: I18N Example-Footnote-1871131 -Node: Gawk I18N871204 -Node: I18N Summary871849 -Node: Debugger873190 -Node: Debugging874213 -Node: Debugging Concepts874654 -Node: Debugging Terms876463 -Node: Awk Debugging879038 -Node: Sample Debugging Session879944 -Node: Debugger Invocation880478 -Node: Finding The Bug881864 -Node: List of Debugger Commands888342 -Node: Breakpoint Control889675 -Node: Debugger Execution Control893369 -Node: Viewing And Changing Data896731 -Node: Execution Stack900105 -Node: Debugger Info901742 -Node: Miscellaneous Debugger Commands905813 -Node: Readline Support910875 -Node: Limitations911771 -Node: Debugging Summary913880 -Node: Arbitrary Precision Arithmetic915159 -Node: Computer Arithmetic916644 -Ref: table-numeric-ranges920410 -Ref: table-floating-point-ranges920903 -Ref: Computer Arithmetic-Footnote-1921561 -Node: Math Definitions921618 -Ref: table-ieee-formats924934 -Ref: Math Definitions-Footnote-1925537 -Node: MPFR features925642 -Node: FP Math Caution927360 -Ref: FP Math Caution-Footnote-1928432 -Node: Inexactness of computations928801 -Node: Inexact representation929761 -Node: Comparing FP Values931121 -Node: Errors accumulate932203 -Node: Getting Accuracy933636 -Node: Try To Round936346 -Node: Setting precision937245 -Ref: table-predefined-precision-strings937942 -Node: Setting the rounding mode939772 -Ref: table-gawk-rounding-modes940146 -Ref: Setting the rounding mode-Footnote-1944077 -Node: Arbitrary Precision Integers944256 -Ref: Arbitrary Precision Integers-Footnote-1947431 -Node: Checking for MPFR947580 -Node: POSIX Floating Point Problems949054 -Ref: POSIX Floating Point Problems-Footnote-1953339 -Node: Floating point summary953377 -Node: Dynamic Extensions955567 -Node: Extension Intro957120 -Node: Plugin License958386 -Node: Extension Mechanism Outline959183 -Ref: figure-load-extension959622 -Ref: figure-register-new-function961187 -Ref: figure-call-new-function962279 -Node: Extension API Description964341 -Node: Extension API Functions Introduction965983 -Node: General Data Types971523 -Ref: General Data Types-Footnote-1979884 -Node: Memory Allocation Functions980183 -Ref: Memory Allocation Functions-Footnote-1984393 -Node: Constructor Functions984492 -Node: Registration Functions988078 -Node: Extension Functions988763 -Node: Exit Callback Functions993978 -Node: Extension Version String995228 -Node: Input Parsers995891 -Node: Output Wrappers1008612 -Node: Two-way processors1013124 -Node: Printing Messages1015389 -Ref: Printing Messages-Footnote-11016560 -Node: Updating ERRNO1016713 -Node: Requesting Values1017452 -Ref: table-value-types-returned1018189 -Node: Accessing Parameters1019125 -Node: Symbol Table Access1020360 -Node: Symbol table by name1020872 -Node: Symbol table by cookie1022661 -Ref: Symbol table by cookie-Footnote-11026846 -Node: Cached values1026910 -Ref: Cached values-Footnote-11030446 -Node: Array Manipulation1030599 -Ref: Array Manipulation-Footnote-11031690 -Node: Array Data Types1031727 -Ref: Array Data Types-Footnote-11034385 -Node: Array Functions1034477 -Node: Flattening Arrays1038975 -Node: Creating Arrays1045951 -Node: Redirection API1050718 -Node: Extension API Variables1053551 -Node: Extension Versioning1054262 -Ref: gawk-api-version1054691 -Node: Extension GMP/MPFR Versioning1056422 -Node: Extension API Informational Variables1058050 -Node: Extension API Boilerplate1059123 -Node: Changes from API V11063097 -Node: Finding Extensions1064669 -Node: Extension Example1065228 -Node: Internal File Description1066026 -Node: Internal File Ops1070106 -Ref: Internal File Ops-Footnote-11081456 -Node: Using Internal File Ops1081596 -Ref: Using Internal File Ops-Footnote-11083979 -Node: Extension Samples1084253 -Node: Extension Sample File Functions1085782 -Node: Extension Sample Fnmatch1093431 -Node: Extension Sample Fork1094918 -Node: Extension Sample Inplace1096136 -Node: Extension Sample Ord1099353 -Node: Extension Sample Readdir1100189 -Ref: table-readdir-file-types1101078 -Node: Extension Sample Revout1101883 -Node: Extension Sample Rev2way1102472 -Node: Extension Sample Read write array1103212 -Node: Extension Sample Readfile1105154 -Node: Extension Sample Time1106249 -Node: Extension Sample API Tests1107597 -Node: gawkextlib1108089 -Node: Extension summary1111007 -Node: Extension Exercises1114709 -Node: Language History1116207 -Node: V7/SVR3.11117863 -Node: SVR41120015 -Node: POSIX1121449 -Node: BTL1122829 -Node: POSIX/GNU1123558 -Node: Feature History1129336 -Node: Common Extensions1145195 -Node: Ranges and Locales1146478 -Ref: Ranges and Locales-Footnote-11151094 -Ref: Ranges and Locales-Footnote-21151121 -Ref: Ranges and Locales-Footnote-31151356 -Node: Contributors1151577 -Node: History summary1157522 -Node: Installation1158902 -Node: Gawk Distribution1159846 -Node: Getting1160330 -Node: Extracting1161293 -Node: Distribution contents1162931 -Node: Unix Installation1169411 -Node: Quick Installation1170093 -Node: Shell Startup Files1172507 -Node: Additional Configuration Options1173596 -Node: Configuration Philosophy1175889 -Node: Non-Unix Installation1178258 -Node: PC Installation1178718 -Node: PC Binary Installation1179556 -Node: PC Compiling1179991 -Node: PC Using1181108 -Node: Cygwin1184323 -Node: MSYS1185422 -Node: VMS Installation1185923 -Node: VMS Compilation1186714 -Ref: VMS Compilation-Footnote-11187943 -Node: VMS Dynamic Extensions1188001 -Node: VMS Installation Details1189686 -Node: VMS Running1191939 -Node: VMS GNV1196218 -Node: VMS Old Gawk1196953 -Node: Bugs1197424 -Node: Bug address1198087 -Node: Usenet1200879 -Node: Maintainers1201656 -Node: Other Versions1202917 -Node: Installation summary1209679 -Node: Notes1210881 -Node: Compatibility Mode1211746 -Node: Additions1212528 -Node: Accessing The Source1213453 -Node: Adding Code1214890 -Node: New Ports1221109 -Node: Derived Files1225597 -Ref: Derived Files-Footnote-11231243 -Ref: Derived Files-Footnote-21231278 -Ref: Derived Files-Footnote-31231876 -Node: Future Extensions1231990 -Node: Implementation Limitations1232648 -Node: Extension Design1233831 -Node: Old Extension Problems1234985 -Ref: Old Extension Problems-Footnote-11236503 -Node: Extension New Mechanism Goals1236560 -Ref: Extension New Mechanism Goals-Footnote-11239924 -Node: Extension Other Design Decisions1240113 -Node: Extension Future Growth1242226 -Node: Old Extension Mechanism1243062 -Node: Notes summary1244825 -Node: Basic Concepts1246007 -Node: Basic High Level1246688 -Ref: figure-general-flow1246970 -Ref: figure-process-flow1247655 -Ref: Basic High Level-Footnote-11250956 -Node: Basic Data Typing1251141 -Node: Glossary1254469 -Node: Copying1286307 -Node: GNU Free Documentation License1323850 -Node: Index1348970 +Ref: Scalar Constants-Footnote-1337726 +Node: Nondecimal-numbers337976 +Node: Regexp Constants340977 +Node: Using Constant Regexps341503 +Node: Standard Regexp Constants342125 +Node: Strong Regexp Constants345313 +Node: Variables348271 +Node: Using Variables348928 +Node: Assignment Options350838 +Node: Conversion352711 +Node: Strings And Numbers353235 +Ref: Strings And Numbers-Footnote-1356298 +Node: Locale influences conversions356407 +Ref: table-locale-affects359165 +Node: All Operators359783 +Node: Arithmetic Ops360412 +Node: Concatenation362918 +Ref: Concatenation-Footnote-1365765 +Node: Assignment Ops365872 +Ref: table-assign-ops370863 +Node: Increment Ops372176 +Node: Truth Values and Conditions375636 +Node: Truth Values376710 +Node: Typing and Comparison377758 +Node: Variable Typing378578 +Ref: Variable Typing-Footnote-1385041 +Ref: Variable Typing-Footnote-2385113 +Node: Comparison Operators385190 +Ref: table-relational-ops385609 +Node: POSIX String Comparison389104 +Ref: POSIX String Comparison-Footnote-1390799 +Ref: POSIX String Comparison-Footnote-2390938 +Node: Boolean Ops391022 +Ref: Boolean Ops-Footnote-1395504 +Node: Conditional Exp395596 +Node: Function Calls397332 +Node: Precedence401209 +Node: Locales404868 +Node: Expressions Summary406500 +Node: Patterns and Actions409073 +Node: Pattern Overview410193 +Node: Regexp Patterns411870 +Node: Expression Patterns412412 +Node: Ranges416193 +Node: BEGIN/END419301 +Node: Using BEGIN/END420062 +Ref: Using BEGIN/END-Footnote-1422798 +Node: I/O And BEGIN/END422904 +Node: BEGINFILE/ENDFILE425218 +Node: Empty428131 +Node: Using Shell Variables428448 +Node: Action Overview430722 +Node: Statements433047 +Node: If Statement434895 +Node: While Statement436390 +Node: Do Statement438418 +Node: For Statement439566 +Node: Switch Statement442737 +Node: Break Statement445123 +Node: Continue Statement447215 +Node: Next Statement449042 +Node: Nextfile Statement451425 +Node: Exit Statement454077 +Node: Built-in Variables456480 +Node: User-modified457613 +Node: Auto-set465380 +Ref: Auto-set-Footnote-1481682 +Ref: Auto-set-Footnote-2481888 +Node: ARGC and ARGV481944 +Node: Pattern Action Summary486157 +Node: Arrays488587 +Node: Array Basics489916 +Node: Array Intro490760 +Ref: figure-array-elements492735 +Ref: Array Intro-Footnote-1495439 +Node: Reference to Elements495567 +Node: Assigning Elements498031 +Node: Array Example498522 +Node: Scanning an Array500281 +Node: Controlling Scanning503303 +Ref: Controlling Scanning-Footnote-1508702 +Node: Numeric Array Subscripts509018 +Node: Uninitialized Subscripts511202 +Node: Delete512821 +Ref: Delete-Footnote-1515573 +Node: Multidimensional515630 +Node: Multiscanning518725 +Node: Arrays of Arrays520316 +Node: Arrays Summary525083 +Node: Functions527176 +Node: Built-in528214 +Node: Calling Built-in529295 +Node: Numeric Functions531291 +Ref: Numeric Functions-Footnote-1535319 +Ref: Numeric Functions-Footnote-2535676 +Ref: Numeric Functions-Footnote-3535724 +Node: String Functions535996 +Ref: String Functions-Footnote-1559705 +Ref: String Functions-Footnote-2559833 +Ref: String Functions-Footnote-3560081 +Node: Gory Details560168 +Ref: table-sub-escapes561959 +Ref: table-sub-proposed563478 +Ref: table-posix-sub564841 +Ref: table-gensub-escapes566382 +Ref: Gory Details-Footnote-1567205 +Node: I/O Functions567359 +Ref: table-system-return-values573827 +Ref: I/O Functions-Footnote-1575807 +Ref: I/O Functions-Footnote-2575955 +Node: Time Functions576075 +Ref: Time Functions-Footnote-1586746 +Ref: Time Functions-Footnote-2586814 +Ref: Time Functions-Footnote-3586972 +Ref: Time Functions-Footnote-4587083 +Ref: Time Functions-Footnote-5587195 +Ref: Time Functions-Footnote-6587422 +Node: Bitwise Functions587688 +Ref: table-bitwise-ops588282 +Ref: Bitwise Functions-Footnote-1594345 +Ref: Bitwise Functions-Footnote-2594518 +Node: Type Functions594709 +Node: I18N Functions597460 +Node: User-defined599111 +Node: Definition Syntax599916 +Ref: Definition Syntax-Footnote-1605603 +Node: Function Example605674 +Ref: Function Example-Footnote-1608596 +Node: Function Caveats608618 +Node: Calling A Function609136 +Node: Variable Scope610094 +Node: Pass By Value/Reference613088 +Node: Return Statement616587 +Node: Dynamic Typing619566 +Node: Indirect Calls620496 +Ref: Indirect Calls-Footnote-1630748 +Node: Functions Summary630876 +Node: Library Functions633581 +Ref: Library Functions-Footnote-1637188 +Ref: Library Functions-Footnote-2637331 +Node: Library Names637502 +Ref: Library Names-Footnote-1640962 +Ref: Library Names-Footnote-2641185 +Node: General Functions641271 +Node: Strtonum Function642374 +Node: Assert Function645396 +Node: Round Function648722 +Node: Cliff Random Function650262 +Node: Ordinal Functions651278 +Ref: Ordinal Functions-Footnote-1654341 +Ref: Ordinal Functions-Footnote-2654593 +Node: Join Function654803 +Ref: Join Function-Footnote-1656573 +Node: Getlocaltime Function656773 +Node: Readfile Function660515 +Node: Shell Quoting662492 +Node: Data File Management663893 +Node: Filetrans Function664525 +Node: Rewind Function668621 +Node: File Checking670531 +Ref: File Checking-Footnote-1671865 +Node: Empty Files672066 +Node: Ignoring Assigns674045 +Node: Getopt Function675595 +Ref: Getopt Function-Footnote-1687064 +Node: Passwd Functions687264 +Ref: Passwd Functions-Footnote-1696103 +Node: Group Functions696191 +Ref: Group Functions-Footnote-1704089 +Node: Walking Arrays704296 +Node: Library Functions Summary707304 +Node: Library Exercises708710 +Node: Sample Programs709175 +Node: Running Examples709945 +Node: Clones710673 +Node: Cut Program711897 +Node: Egrep Program721826 +Ref: Egrep Program-Footnote-1729338 +Node: Id Program729448 +Node: Split Program733128 +Ref: Split Program-Footnote-1736586 +Node: Tee Program736715 +Node: Uniq Program739505 +Node: Wc Program746931 +Ref: Wc Program-Footnote-1751186 +Node: Miscellaneous Programs751280 +Node: Dupword Program752493 +Node: Alarm Program754523 +Node: Translate Program759378 +Ref: Translate Program-Footnote-1763943 +Node: Labels Program764213 +Ref: Labels Program-Footnote-1767564 +Node: Word Sorting767648 +Node: History Sorting771720 +Node: Extract Program773555 +Node: Simple Sed781609 +Node: Igawk Program784683 +Ref: Igawk Program-Footnote-1799014 +Ref: Igawk Program-Footnote-2799216 +Ref: Igawk Program-Footnote-3799338 +Node: Anagram Program799453 +Node: Signature Program802515 +Node: Programs Summary803762 +Node: Programs Exercises804976 +Ref: Programs Exercises-Footnote-1809105 +Node: Advanced Features809196 +Node: Nondecimal Data811186 +Node: Array Sorting812777 +Node: Controlling Array Traversal813477 +Ref: Controlling Array Traversal-Footnote-1821845 +Node: Array Sorting Functions821963 +Ref: Array Sorting Functions-Footnote-1827054 +Node: Two-way I/O827250 +Ref: Two-way I/O-Footnote-1834970 +Ref: Two-way I/O-Footnote-2835157 +Node: TCP/IP Networking835239 +Node: Profiling838357 +Ref: Profiling-Footnote-1847029 +Node: Advanced Features Summary847352 +Node: Internationalization849196 +Node: I18N and L10N850676 +Node: Explaining gettext851363 +Ref: Explaining gettext-Footnote-1857255 +Ref: Explaining gettext-Footnote-2857440 +Node: Programmer i18n857605 +Ref: Programmer i18n-Footnote-1862554 +Node: Translator i18n862603 +Node: String Extraction863397 +Ref: String Extraction-Footnote-1864529 +Node: Printf Ordering864615 +Ref: Printf Ordering-Footnote-1867401 +Node: I18N Portability867465 +Ref: I18N Portability-Footnote-1869921 +Node: I18N Example869984 +Ref: I18N Example-Footnote-1872790 +Node: Gawk I18N872863 +Node: I18N Summary873508 +Node: Debugger874849 +Node: Debugging875872 +Node: Debugging Concepts876313 +Node: Debugging Terms878122 +Node: Awk Debugging880697 +Node: Sample Debugging Session881603 +Node: Debugger Invocation882137 +Node: Finding The Bug883523 +Node: List of Debugger Commands890001 +Node: Breakpoint Control891334 +Node: Debugger Execution Control895028 +Node: Viewing And Changing Data898390 +Node: Execution Stack901764 +Node: Debugger Info903401 +Node: Miscellaneous Debugger Commands907472 +Node: Readline Support912534 +Node: Limitations913430 +Node: Debugging Summary915539 +Node: Arbitrary Precision Arithmetic916818 +Node: Computer Arithmetic918303 +Ref: table-numeric-ranges922069 +Ref: table-floating-point-ranges922562 +Ref: Computer Arithmetic-Footnote-1923220 +Node: Math Definitions923277 +Ref: table-ieee-formats926593 +Ref: Math Definitions-Footnote-1927196 +Node: MPFR features927301 +Node: FP Math Caution929019 +Ref: FP Math Caution-Footnote-1930091 +Node: Inexactness of computations930460 +Node: Inexact representation931420 +Node: Comparing FP Values932780 +Node: Errors accumulate933862 +Node: Getting Accuracy935295 +Node: Try To Round938005 +Node: Setting precision938904 +Ref: table-predefined-precision-strings939601 +Node: Setting the rounding mode941431 +Ref: table-gawk-rounding-modes941805 +Ref: Setting the rounding mode-Footnote-1945736 +Node: Arbitrary Precision Integers945915 +Ref: Arbitrary Precision Integers-Footnote-1949090 +Node: Checking for MPFR949239 +Node: POSIX Floating Point Problems950713 +Ref: POSIX Floating Point Problems-Footnote-1954998 +Node: Floating point summary955036 +Node: Dynamic Extensions957226 +Node: Extension Intro958779 +Node: Plugin License960045 +Node: Extension Mechanism Outline960842 +Ref: figure-load-extension961281 +Ref: figure-register-new-function962846 +Ref: figure-call-new-function963938 +Node: Extension API Description966000 +Node: Extension API Functions Introduction967642 +Node: General Data Types973182 +Ref: General Data Types-Footnote-1981543 +Node: Memory Allocation Functions981842 +Ref: Memory Allocation Functions-Footnote-1986052 +Node: Constructor Functions986151 +Node: Registration Functions989737 +Node: Extension Functions990422 +Node: Exit Callback Functions995637 +Node: Extension Version String996887 +Node: Input Parsers997550 +Node: Output Wrappers1010271 +Node: Two-way processors1014783 +Node: Printing Messages1017048 +Ref: Printing Messages-Footnote-11018219 +Node: Updating ERRNO1018372 +Node: Requesting Values1019111 +Ref: table-value-types-returned1019848 +Node: Accessing Parameters1020784 +Node: Symbol Table Access1022019 +Node: Symbol table by name1022531 +Node: Symbol table by cookie1024320 +Ref: Symbol table by cookie-Footnote-11028505 +Node: Cached values1028569 +Ref: Cached values-Footnote-11032105 +Node: Array Manipulation1032258 +Ref: Array Manipulation-Footnote-11033349 +Node: Array Data Types1033386 +Ref: Array Data Types-Footnote-11036044 +Node: Array Functions1036136 +Node: Flattening Arrays1040634 +Node: Creating Arrays1047610 +Node: Redirection API1052377 +Node: Extension API Variables1055210 +Node: Extension Versioning1055921 +Ref: gawk-api-version1056350 +Node: Extension GMP/MPFR Versioning1058081 +Node: Extension API Informational Variables1059709 +Node: Extension API Boilerplate1060782 +Node: Changes from API V11064756 +Node: Finding Extensions1066328 +Node: Extension Example1066887 +Node: Internal File Description1067685 +Node: Internal File Ops1071765 +Ref: Internal File Ops-Footnote-11083115 +Node: Using Internal File Ops1083255 +Ref: Using Internal File Ops-Footnote-11085638 +Node: Extension Samples1085912 +Node: Extension Sample File Functions1087441 +Node: Extension Sample Fnmatch1095090 +Node: Extension Sample Fork1096577 +Node: Extension Sample Inplace1097795 +Node: Extension Sample Ord1101012 +Node: Extension Sample Readdir1101848 +Ref: table-readdir-file-types1102737 +Node: Extension Sample Revout1103542 +Node: Extension Sample Rev2way1104131 +Node: Extension Sample Read write array1104871 +Node: Extension Sample Readfile1106813 +Node: Extension Sample Time1107908 +Node: Extension Sample API Tests1109256 +Node: gawkextlib1109748 +Node: Extension summary1112666 +Node: Extension Exercises1116368 +Node: Language History1117866 +Node: V7/SVR3.11119522 +Node: SVR41121674 +Node: POSIX1123108 +Node: BTL1124488 +Node: POSIX/GNU1125217 +Node: Feature History1130995 +Node: Common Extensions1146854 +Node: Ranges and Locales1148137 +Ref: Ranges and Locales-Footnote-11152753 +Ref: Ranges and Locales-Footnote-21152780 +Ref: Ranges and Locales-Footnote-31153015 +Node: Contributors1153236 +Node: History summary1159181 +Node: Installation1160561 +Node: Gawk Distribution1161505 +Node: Getting1161989 +Node: Extracting1162952 +Node: Distribution contents1164590 +Node: Unix Installation1171070 +Node: Quick Installation1171752 +Node: Shell Startup Files1174166 +Node: Additional Configuration Options1175255 +Node: Configuration Philosophy1177548 +Node: Non-Unix Installation1179917 +Node: PC Installation1180377 +Node: PC Binary Installation1181215 +Node: PC Compiling1181650 +Node: PC Using1182767 +Node: Cygwin1185982 +Node: MSYS1187081 +Node: VMS Installation1187582 +Node: VMS Compilation1188373 +Ref: VMS Compilation-Footnote-11189602 +Node: VMS Dynamic Extensions1189660 +Node: VMS Installation Details1191345 +Node: VMS Running1193598 +Node: VMS GNV1197877 +Node: VMS Old Gawk1198612 +Node: Bugs1199083 +Node: Bug address1199746 +Node: Usenet1202538 +Node: Maintainers1203315 +Node: Other Versions1204576 +Node: Installation summary1211338 +Node: Notes1212540 +Node: Compatibility Mode1213405 +Node: Additions1214187 +Node: Accessing The Source1215112 +Node: Adding Code1216549 +Node: New Ports1222768 +Node: Derived Files1227256 +Ref: Derived Files-Footnote-11232902 +Ref: Derived Files-Footnote-21232937 +Ref: Derived Files-Footnote-31233535 +Node: Future Extensions1233649 +Node: Implementation Limitations1234307 +Node: Extension Design1235490 +Node: Old Extension Problems1236644 +Ref: Old Extension Problems-Footnote-11238162 +Node: Extension New Mechanism Goals1238219 +Ref: Extension New Mechanism Goals-Footnote-11241583 +Node: Extension Other Design Decisions1241772 +Node: Extension Future Growth1243885 +Node: Old Extension Mechanism1244721 +Node: Notes summary1246484 +Node: Basic Concepts1247666 +Node: Basic High Level1248347 +Ref: figure-general-flow1248629 +Ref: figure-process-flow1249314 +Ref: Basic High Level-Footnote-11252615 +Node: Basic Data Typing1252800 +Node: Glossary1256128 +Node: Copying1287966 +Node: GNU Free Documentation License1325509 +Node: Index1350629 End Tag Table diff --git a/doc/gawk.texi b/doc/gawk.texi index 6db3a2af..68ba82dd 100644 --- a/doc/gawk.texi +++ b/doc/gawk.texi @@ -11025,6 +11025,69 @@ eight-bit ASCII characters, including ASCII @sc{nul} (character code zero). Other @command{awk} implementations may have difficulty with some character codes. +Some languages allow you to continue long strings across +multiple lines by ending the line with a backslash. For example in C: + +@example +#include <stdio.h> + +int main() +@{ + printf "hello, \ +world\n"); + return 0; +@} +@end example + +@noindent +In such a case, the C compiler removes both the backslash and the newline, +producing a string as if it had been typed @samp{"hello, world\n"}. +This is useful when a single string needs to contain a large amount of text. + +The POSIX standard says explicitly that newlines are not allowed inside string +constants. And indeed, all @command{awk} implementations report an error +if you try to do so. For example: + +@example +$ @kbd{gawk 'BEGIN @{ print "hello, } +> @kbd{world" @}'} +@print{} gawk: cmd. line:1: BEGIN { print "hello, +@print{} gawk: cmd. line:1: ^ unterminated string +@print{} gawk: cmd. line:1: BEGIN { print "hello, +@print{} gawk: cmd. line:1: ^ syntax error +@end example + +@cindex dark corner, string continuation +@cindex strings, continuation across lines +@cindex differences in @command{awk} and @command{gawk}, strings +Although POSIX doesn't define what happens if you use an escaped +newline, as in the previous C example, all known versions of +@command{awk} allow you to do so. Unfortunately, what each one +does with such a string varies. @value{DARKCORNER} @command{gawk}, +@command{mawk}, and the OpenSolaris POSIX @command{awk} +(@pxref{Other Versions}) elide the backslash and newline, as in C: + +@example +$ @kbd{gawk 'BEGIN @{ print "hello, \} +> @kbd{world" @}'} +@print{} hello, world +@end example + +Brian Kernighan's @command{awk} and Busybox @command{awk} +remove the backslash but leave the newline +intact, as part of the string: + +@example +$ @kbd{nawk 'BEGIN @{ print "hello, \} +> @kbd{world" @}'} +@print{} hello, +@print{} world +@end example + +In POSIX mode (@pxref{Options}), @command{gawk} does not +allow escaped newlines. Otherwise, it behaves as +just described. + @node Nondecimal-numbers @subsubsection Octal and Hexadecimal Numbers @cindex octal numbers diff --git a/doc/gawktexi.in b/doc/gawktexi.in index 2a2fdd4b..3ba511ba 100644 --- a/doc/gawktexi.in +++ b/doc/gawktexi.in @@ -10511,6 +10511,69 @@ eight-bit ASCII characters, including ASCII @sc{nul} (character code zero). Other @command{awk} implementations may have difficulty with some character codes. +Some languages allow you to continue long strings across +multiple lines by ending the line with a backslash. For example in C: + +@example +#include <stdio.h> + +int main() +@{ + printf "hello, \ +world\n"); + return 0; +@} +@end example + +@noindent +In such a case, the C compiler removes both the backslash and the newline, +producing a string as if it had been typed @samp{"hello, world\n"}. +This is useful when a single string needs to contain a large amount of text. + +The POSIX standard says explicitly that newlines are not allowed inside string +constants. And indeed, all @command{awk} implementations report an error +if you try to do so. For example: + +@example +$ @kbd{gawk 'BEGIN @{ print "hello, } +> @kbd{world" @}'} +@print{} gawk: cmd. line:1: BEGIN { print "hello, +@print{} gawk: cmd. line:1: ^ unterminated string +@print{} gawk: cmd. line:1: BEGIN { print "hello, +@print{} gawk: cmd. line:1: ^ syntax error +@end example + +@cindex dark corner, string continuation +@cindex strings, continuation across lines +@cindex differences in @command{awk} and @command{gawk}, strings +Although POSIX doesn't define what happens if you use an escaped +newline, as in the previous C example, all known versions of +@command{awk} allow you to do so. Unfortunately, what each one +does with such a string varies. @value{DARKCORNER} @command{gawk}, +@command{mawk}, and the OpenSolaris POSIX @command{awk} +(@pxref{Other Versions}) elide the backslash and newline, as in C: + +@example +$ @kbd{gawk 'BEGIN @{ print "hello, \} +> @kbd{world" @}'} +@print{} hello, world +@end example + +Brian Kernighan's @command{awk} and Busybox @command{awk} +remove the backslash but leave the newline +intact, as part of the string: + +@example +$ @kbd{nawk 'BEGIN @{ print "hello, \} +> @kbd{world" @}'} +@print{} hello, +@print{} world +@end example + +In POSIX mode (@pxref{Options}), @command{gawk} does not +allow escaped newlines. Otherwise, it behaves as +just described. + @node Nondecimal-numbers @subsubsection Octal and Hexadecimal Numbers @cindex octal numbers @@ -1165,11 +1165,18 @@ arg_assign(char *arg, bool initing) fatal(_("cannot use function `%s' as variable name"), arg); } + // POSIX disallows any newlines inside strings + // The scanner handles that for program files. + // We have to check here for strings passed to -v. + if (do_posix && strchr(cp, '\n') != NULL) + fatal(_("POSIX does not allow physical newlines in string values")); + /* * BWK awk expands escapes inside assignments. * This makes sense, so we do it too. + * In addition, remove \-<newline> as in scanning. */ - it = make_str_node(cp, strlen(cp), SCAN); + it = make_str_node(cp, strlen(cp), SCAN | ELIDE_BACK_NL); it->flags |= USER_INPUT; #ifdef LC_NUMERIC /* @@ -451,6 +451,8 @@ make_str_node(const char *s, size_t len, int flags) if (c < 0) { if (do_lint) lintwarn(_("backslash at end of string")); + if ((flags & ELIDE_BACK_NL) != 0) + continue; c = '\\'; } *ptm++ = c; |