1 <html> 2 <head> 3 <title>pcre2test specification</title> 4 </head> 5 <body bgcolor="#FFFFFF" text="#00005A" link="#0066FF" alink="#3399FF" vlink="#2222BB"> 6 <h1>pcre2test man page</h1> 7 <p> 8 Return to the <a href="index.html">PCRE2 index page</a>. 9 </p> 10 <p> 11 This page is part of the PCRE2 HTML documentation. It was generated 12 automatically from the original man page. If there is any nonsense in it, 13 please consult the man page, in case the conversion went wrong. 14 <br> 15 <ul> 16 <li><a name="TOC1" href="#SEC1">SYNOPSIS</a> 17 <li><a name="TOC2" href="#SEC2">PCRE2's 8-BIT, 16-BIT AND 32-BIT LIBRARIES</a> 18 <li><a name="TOC3" href="#SEC3">INPUT ENCODING</a> 19 <li><a name="TOC4" href="#SEC4">COMMAND LINE OPTIONS</a> 20 <li><a name="TOC5" href="#SEC5">DESCRIPTION</a> 21 <li><a name="TOC6" href="#SEC6">COMMAND LINES</a> 22 <li><a name="TOC7" href="#SEC7">MODIFIER SYNTAX</a> 23 <li><a name="TOC8" href="#SEC8">PATTERN SYNTAX</a> 24 <li><a name="TOC9" href="#SEC9">SUBJECT LINE SYNTAX</a> 25 <li><a name="TOC10" href="#SEC10">PATTERN MODIFIERS</a> 26 <li><a name="TOC11" href="#SEC11">SUBJECT MODIFIERS</a> 27 <li><a name="TOC12" href="#SEC12">THE ALTERNATIVE MATCHING FUNCTION</a> 28 <li><a name="TOC13" href="#SEC13">DEFAULT OUTPUT FROM pcre2test</a> 29 <li><a name="TOC14" href="#SEC14">OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION</a> 30 <li><a name="TOC15" href="#SEC15">RESTARTING AFTER A PARTIAL MATCH</a> 31 <li><a name="TOC16" href="#SEC16">CALLOUTS</a> 32 <li><a name="TOC17" href="#SEC17">NON-PRINTING CHARACTERS</a> 33 <li><a name="TOC18" href="#SEC18">SAVING AND RESTORING COMPILED PATTERNS</a> 34 <li><a name="TOC19" href="#SEC19">SEE ALSO</a> 35 <li><a name="TOC20" href="#SEC20">AUTHOR</a> 36 <li><a name="TOC21" href="#SEC21">REVISION</a> 37 </ul> 38 <br><a name="SEC1" href="#TOC1">SYNOPSIS</a><br> 39 <P> 40 <b>pcre2test [options] [input file [output file]]</b> 41 <br> 42 <br> 43 <b>pcre2test</b> is a test program for the PCRE2 regular expression libraries, 44 but it can also be used for experimenting with regular expressions. This 45 document describes the features of the test program; for details of the regular 46 expressions themselves, see the 47 <a href="pcre2pattern.html"><b>pcre2pattern</b></a> 48 documentation. For details of the PCRE2 library function calls and their 49 options, see the 50 <a href="pcre2api.html"><b>pcre2api</b></a> 51 documentation. 52 </P> 53 <P> 54 The input for <b>pcre2test</b> is a sequence of regular expression patterns and 55 subject strings to be matched. There are also command lines for setting 56 defaults and controlling some special actions. The output shows the result of 57 each match attempt. Modifiers on external or internal command lines, the 58 patterns, and the subject lines specify PCRE2 function options, control how the 59 subject is processed, and what output is produced. 60 </P> 61 <P> 62 As the original fairly simple PCRE library evolved, it acquired many different 63 features, and as a result, the original <b>pcretest</b> program ended up with a 64 lot of options in a messy, arcane syntax for testing all the features. The 65 move to the new PCRE2 API provided an opportunity to re-implement the test 66 program as <b>pcre2test</b>, with a cleaner modifier syntax. Nevertheless, there 67 are still many obscure modifiers, some of which are specifically designed for 68 use in conjunction with the test script and data files that are distributed as 69 part of PCRE2. All the modifiers are documented here, some without much 70 justification, but many of them are unlikely to be of use except when testing 71 the libraries. 72 </P> 73 <br><a name="SEC2" href="#TOC1">PCRE2's 8-BIT, 16-BIT AND 32-BIT LIBRARIES</a><br> 74 <P> 75 Different versions of the PCRE2 library can be built to support character 76 strings that are encoded in 8-bit, 16-bit, or 32-bit code units. One, two, or 77 all three of these libraries may be simultaneously installed. The 78 <b>pcre2test</b> program can be used to test all the libraries. However, its own 79 input and output are always in 8-bit format. When testing the 16-bit or 32-bit 80 libraries, patterns and subject strings are converted to 16-bit or 32-bit 81 format before being passed to the library functions. Results are converted back 82 to 8-bit code units for output. 83 </P> 84 <P> 85 In the rest of this document, the names of library functions and structures 86 are given in generic form, for example, <b>pcre_compile()</b>. The actual 87 names used in the libraries have a suffix _8, _16, or _32, as appropriate. 88 <a name="inputencoding"></a></P> 89 <br><a name="SEC3" href="#TOC1">INPUT ENCODING</a><br> 90 <P> 91 Input to <b>pcre2test</b> is processed line by line, either by calling the C 92 library's <b>fgets()</b> function, or via the <b>libreadline</b> library. In some 93 Windows environments character 26 (hex 1A) causes an immediate end of file, and 94 no further data is read, so this character should be avoided unless you really 95 want that action. 96 </P> 97 <P> 98 The input is processed using using C's string functions, so must not 99 contain binary zeros, even though in Unix-like environments, <b>fgets()</b> 100 treats any bytes other than newline as data characters. An error is generated 101 if a binary zero is encountered. By default subject lines are processed for 102 backslash escapes, which makes it possible to include any data value in strings 103 that are passed to the library for matching. For patterns, there is a facility 104 for specifying some or all of the 8-bit input characters as hexadecimal pairs, 105 which makes it possible to include binary zeros. 106 </P> 107 <br><b> 108 Input for the 16-bit and 32-bit libraries 109 </b><br> 110 <P> 111 When testing the 16-bit or 32-bit libraries, there is a need to be able to 112 generate character code points greater than 255 in the strings that are passed 113 to the library. For subject lines, backslash escapes can be used. In addition, 114 when the <b>utf</b> modifier (see 115 <a href="#optionmodifiers">"Setting compilation options"</a> 116 below) is set, the pattern and any following subject lines are interpreted as 117 UTF-8 strings and translated to UTF-16 or UTF-32 as appropriate. 118 </P> 119 <P> 120 For non-UTF testing of wide characters, the <b>utf8_input</b> modifier can be 121 used. This is mutually exclusive with <b>utf</b>, and is allowed only in 16-bit 122 or 32-bit mode. It causes the pattern and following subject lines to be treated 123 as UTF-8 according to the original definition (RFC 2279), which allows for 124 character values up to 0x7fffffff. Each character is placed in one 16-bit or 125 32-bit code unit (in the 16-bit case, values greater than 0xffff cause an error 126 to occur). 127 </P> 128 <P> 129 UTF-8 (in its original definition) is not capable of encoding values greater 130 than 0x7fffffff, but such values can be handled by the 32-bit library. When 131 testing this library in non-UTF mode with <b>utf8_input</b> set, if any 132 character is preceded by the byte 0xff (which is an invalid byte in UTF-8) 133 0x80000000 is added to the character's value. This is the only way of passing 134 such code points in a pattern string. For subject strings, using an escape 135 sequence is preferable. 136 </P> 137 <br><a name="SEC4" href="#TOC1">COMMAND LINE OPTIONS</a><br> 138 <P> 139 <b>-8</b> 140 If the 8-bit library has been built, this option causes it to be used (this is 141 the default). If the 8-bit library has not been built, this option causes an 142 error. 143 </P> 144 <P> 145 <b>-16</b> 146 If the 16-bit library has been built, this option causes it to be used. If only 147 the 16-bit library has been built, this is the default. If the 16-bit library 148 has not been built, this option causes an error. 149 </P> 150 <P> 151 <b>-32</b> 152 If the 32-bit library has been built, this option causes it to be used. If only 153 the 32-bit library has been built, this is the default. If the 32-bit library 154 has not been built, this option causes an error. 155 </P> 156 <P> 157 <b>-ac</b> 158 Behave as if each pattern has the <b>auto_callout</b> modifier, that is, insert 159 automatic callouts into every pattern that is compiled. 160 </P> 161 <P> 162 <b>-AC</b> 163 As for <b>-ac</b>, but in addition behave as if each subject line has the 164 <b>callout_extra</b> modifier, that is, show additional information from 165 callouts. 166 </P> 167 <P> 168 <b>-b</b> 169 Behave as if each pattern has the <b>fullbincode</b> modifier; the full 170 internal binary form of the pattern is output after compilation. 171 </P> 172 <P> 173 <b>-C</b> 174 Output the version number of the PCRE2 library, and all available information 175 about the optional features that are included, and then exit with zero exit 176 code. All other options are ignored. If both -C and -LM are present, whichever 177 is first is recognized. 178 </P> 179 <P> 180 <b>-C</b> <i>option</i> 181 Output information about a specific build-time option, then exit. This 182 functionality is intended for use in scripts such as <b>RunTest</b>. The 183 following options output the value and set the exit code as indicated: 184 <pre> 185 ebcdic-nl the code for LF (= NL) in an EBCDIC environment: 186 0x15 or 0x25 187 0 if used in an ASCII environment 188 exit code is always 0 189 linksize the configured internal link size (2, 3, or 4) 190 exit code is set to the link size 191 newline the default newline setting: 192 CR, LF, CRLF, ANYCRLF, ANY, or NUL 193 exit code is always 0 194 bsr the default setting for what \R matches: 195 ANYCRLF or ANY 196 exit code is always 0 197 </pre> 198 The following options output 1 for true or 0 for false, and set the exit code 199 to the same value: 200 <pre> 201 backslash-C \C is supported (not locked out) 202 ebcdic compiled for an EBCDIC environment 203 jit just-in-time support is available 204 pcre2-16 the 16-bit library was built 205 pcre2-32 the 32-bit library was built 206 pcre2-8 the 8-bit library was built 207 unicode Unicode support is available 208 </pre> 209 If an unknown option is given, an error message is output; the exit code is 0. 210 </P> 211 <P> 212 <b>-d</b> 213 Behave as if each pattern has the <b>debug</b> modifier; the internal 214 form and information about the compiled pattern is output after compilation; 215 <b>-d</b> is equivalent to <b>-b -i</b>. 216 </P> 217 <P> 218 <b>-dfa</b> 219 Behave as if each subject line has the <b>dfa</b> modifier; matching is done 220 using the <b>pcre2_dfa_match()</b> function instead of the default 221 <b>pcre2_match()</b>. 222 </P> 223 <P> 224 <b>-error</b> <i>number[,number,...]</i> 225 Call <b>pcre2_get_error_message()</b> for each of the error numbers in the 226 comma-separated list, display the resulting messages on the standard output, 227 then exit with zero exit code. The numbers may be positive or negative. This is 228 a convenience facility for PCRE2 maintainers. 229 </P> 230 <P> 231 <b>-help</b> 232 Output a brief summary these options and then exit. 233 </P> 234 <P> 235 <b>-i</b> 236 Behave as if each pattern has the <b>info</b> modifier; information about the 237 compiled pattern is given after compilation. 238 </P> 239 <P> 240 <b>-jit</b> 241 Behave as if each pattern line has the <b>jit</b> modifier; after successful 242 compilation, each pattern is passed to the just-in-time compiler, if available. 243 </P> 244 <P> 245 <b>-jitverify</b> 246 Behave as if each pattern line has the <b>jitverify</b> modifier; after 247 successful compilation, each pattern is passed to the just-in-time compiler, if 248 available, and the use of JIT is verified. 249 </P> 250 <P> 251 <b>-LM</b> 252 List modifiers: write a list of available pattern and subject modifiers to the 253 standard output, then exit with zero exit code. All other options are ignored. 254 If both -C and -LM are present, whichever is first is recognized. 255 </P> 256 <P> 257 \fB-pattern\fB <i>modifier-list</i> 258 Behave as if each pattern line contains the given modifiers. 259 </P> 260 <P> 261 <b>-q</b> 262 Do not output the version number of <b>pcre2test</b> at the start of execution. 263 </P> 264 <P> 265 <b>-S</b> <i>size</i> 266 On Unix-like systems, set the size of the run-time stack to <i>size</i> 267 mebibytes (units of 1024*1024 bytes). 268 </P> 269 <P> 270 <b>-subject</b> <i>modifier-list</i> 271 Behave as if each subject line contains the given modifiers. 272 </P> 273 <P> 274 <b>-t</b> 275 Run each compile and match many times with a timer, and output the resulting 276 times per compile or match. When JIT is used, separate times are given for the 277 initial compile and the JIT compile. You can control the number of iterations 278 that are used for timing by following <b>-t</b> with a number (as a separate 279 item on the command line). For example, "-t 1000" iterates 1000 times. The 280 default is to iterate 500,000 times. 281 </P> 282 <P> 283 <b>-tm</b> 284 This is like <b>-t</b> except that it times only the matching phase, not the 285 compile phase. 286 </P> 287 <P> 288 <b>-T</b> <b>-TM</b> 289 These behave like <b>-t</b> and <b>-tm</b>, but in addition, at the end of a run, 290 the total times for all compiles and matches are output. 291 </P> 292 <P> 293 <b>-version</b> 294 Output the PCRE2 version number and then exit. 295 </P> 296 <br><a name="SEC5" href="#TOC1">DESCRIPTION</a><br> 297 <P> 298 If <b>pcre2test</b> is given two filename arguments, it reads from the first and 299 writes to the second. If the first name is "-", input is taken from the 300 standard input. If <b>pcre2test</b> is given only one argument, it reads from 301 that file and writes to stdout. Otherwise, it reads from stdin and writes to 302 stdout. 303 </P> 304 <P> 305 When <b>pcre2test</b> is built, a configuration option can specify that it 306 should be linked with the <b>libreadline</b> or <b>libedit</b> library. When this 307 is done, if the input is from a terminal, it is read using the <b>readline()</b> 308 function. This provides line-editing and history facilities. The output from 309 the <b>-help</b> option states whether or not <b>readline()</b> will be used. 310 </P> 311 <P> 312 The program handles any number of tests, each of which consists of a set of 313 input lines. Each set starts with a regular expression pattern, followed by any 314 number of subject lines to be matched against that pattern. In between sets of 315 test data, command lines that begin with # may appear. This file format, with 316 some restrictions, can also be processed by the <b>perltest.sh</b> script that 317 is distributed with PCRE2 as a means of checking that the behaviour of PCRE2 318 and Perl is the same. For a specification of <b>perltest.sh</b>, see the 319 comments near its beginning. 320 </P> 321 <P> 322 When the input is a terminal, <b>pcre2test</b> prompts for each line of input, 323 using "re>" to prompt for regular expression patterns, and "data>" to prompt 324 for subject lines. Command lines starting with # can be entered only in 325 response to the "re>" prompt. 326 </P> 327 <P> 328 Each subject line is matched separately and independently. If you want to do 329 multi-line matches, you have to use the \n escape sequence (or \r or \r\n, 330 etc., depending on the newline setting) in a single line of input to encode the 331 newline sequences. There is no limit on the length of subject lines; the input 332 buffer is automatically extended if it is too small. There are replication 333 features that makes it possible to generate long repetitive pattern or subject 334 lines without having to supply them explicitly. 335 </P> 336 <P> 337 An empty line or the end of the file signals the end of the subject lines for a 338 test, at which point a new pattern or command line is expected if there is 339 still input to be read. 340 </P> 341 <br><a name="SEC6" href="#TOC1">COMMAND LINES</a><br> 342 <P> 343 In between sets of test data, a line that begins with # is interpreted as a 344 command line. If the first character is followed by white space or an 345 exclamation mark, the line is treated as a comment, and ignored. Otherwise, the 346 following commands are recognized: 347 <pre> 348 #forbid_utf 349 </pre> 350 Subsequent patterns automatically have the PCRE2_NEVER_UTF and PCRE2_NEVER_UCP 351 options set, which locks out the use of the PCRE2_UTF and PCRE2_UCP options and 352 the use of (*UTF) and (*UCP) at the start of patterns. This command also forces 353 an error if a subsequent pattern contains any occurrences of \P, \p, or \X, 354 which are still supported when PCRE2_UTF is not set, but which require Unicode 355 property support to be included in the library. 356 </P> 357 <P> 358 This is a trigger guard that is used in test files to ensure that UTF or 359 Unicode property tests are not accidentally added to files that are used when 360 Unicode support is not included in the library. Setting PCRE2_NEVER_UTF and 361 PCRE2_NEVER_UCP as a default can also be obtained by the use of <b>#pattern</b>; 362 the difference is that <b>#forbid_utf</b> cannot be unset, and the automatic 363 options are not displayed in pattern information, to avoid cluttering up test 364 output. 365 <pre> 366 #load <filename> 367 </pre> 368 This command is used to load a set of precompiled patterns from a file, as 369 described in the section entitled "Saving and restoring compiled patterns" 370 <a href="#saverestore">below.</a> 371 <pre> 372 #newline_default [<newline-list>] 373 </pre> 374 When PCRE2 is built, a default newline convention can be specified. This 375 determines which characters and/or character pairs are recognized as indicating 376 a newline in a pattern or subject string. The default can be overridden when a 377 pattern is compiled. The standard test files contain tests of various newline 378 conventions, but the majority of the tests expect a single linefeed to be 379 recognized as a newline by default. Without special action the tests would fail 380 when PCRE2 is compiled with either CR or CRLF as the default newline. 381 </P> 382 <P> 383 The #newline_default command specifies a list of newline types that are 384 acceptable as the default. The types must be one of CR, LF, CRLF, ANYCRLF, 385 ANY, or NUL (in upper or lower case), for example: 386 <pre> 387 #newline_default LF Any anyCRLF 388 </pre> 389 If the default newline is in the list, this command has no effect. Otherwise, 390 except when testing the POSIX API, a <b>newline</b> modifier that specifies the 391 first newline convention in the list (LF in the above example) is added to any 392 pattern that does not already have a <b>newline</b> modifier. If the newline 393 list is empty, the feature is turned off. This command is present in a number 394 of the standard test input files. 395 </P> 396 <P> 397 When the POSIX API is being tested there is no way to override the default 398 newline convention, though it is possible to set the newline convention from 399 within the pattern. A warning is given if the <b>posix</b> or <b>posix_nosub</b> 400 modifier is used when <b>#newline_default</b> would set a default for the 401 non-POSIX API. 402 <pre> 403 #pattern <modifier-list> 404 </pre> 405 This command sets a default modifier list that applies to all subsequent 406 patterns. Modifiers on a pattern can change these settings. 407 <pre> 408 #perltest 409 </pre> 410 The appearance of this line causes all subsequent modifier settings to be 411 checked for compatibility with the <b>perltest.sh</b> script, which is used to 412 confirm that Perl gives the same results as PCRE2. Also, apart from comment 413 lines, #pattern commands, and #subject commands that set or unset "mark", no 414 command lines are permitted, because they and many of the modifiers are 415 specific to <b>pcre2test</b>, and should not be used in test files that are also 416 processed by <b>perltest.sh</b>. The <b>#perltest</b> command helps detect tests 417 that are accidentally put in the wrong file. 418 <pre> 419 #pop [<modifiers>] 420 #popcopy [<modifiers>] 421 </pre> 422 These commands are used to manipulate the stack of compiled patterns, as 423 described in the section entitled "Saving and restoring compiled patterns" 424 <a href="#saverestore">below.</a> 425 <pre> 426 #save <filename> 427 </pre> 428 This command is used to save a set of compiled patterns to a file, as described 429 in the section entitled "Saving and restoring compiled patterns" 430 <a href="#saverestore">below.</a> 431 <pre> 432 #subject <modifier-list> 433 </pre> 434 This command sets a default modifier list that applies to all subsequent 435 subject lines. Modifiers on a subject line can change these settings. 436 </P> 437 <br><a name="SEC7" href="#TOC1">MODIFIER SYNTAX</a><br> 438 <P> 439 Modifier lists are used with both pattern and subject lines. Items in a list 440 are separated by commas followed by optional white space. Trailing whitespace 441 in a modifier list is ignored. Some modifiers may be given for both patterns 442 and subject lines, whereas others are valid only for one or the other. Each 443 modifier has a long name, for example "anchored", and some of them must be 444 followed by an equals sign and a value, for example, "offset=12". Values cannot 445 contain comma characters, but may contain spaces. Modifiers that do not take 446 values may be preceded by a minus sign to turn off a previous setting. 447 </P> 448 <P> 449 A few of the more common modifiers can also be specified as single letters, for 450 example "i" for "caseless". In documentation, following the Perl convention, 451 these are written with a slash ("the /i modifier") for clarity. Abbreviated 452 modifiers must all be concatenated in the first item of a modifier list. If the 453 first item is not recognized as a long modifier name, it is interpreted as a 454 sequence of these abbreviations. For example: 455 <pre> 456 /abc/ig,newline=cr,jit=3 457 </pre> 458 This is a pattern line whose modifier list starts with two one-letter modifiers 459 (/i and /g). The lower-case abbreviated modifiers are the same as used in Perl. 460 </P> 461 <br><a name="SEC8" href="#TOC1">PATTERN SYNTAX</a><br> 462 <P> 463 A pattern line must start with one of the following characters (common symbols, 464 excluding pattern meta-characters): 465 <pre> 466 / ! " ' ` - = _ : ; , % & @ ~ 467 </pre> 468 This is interpreted as the pattern's delimiter. A regular expression may be 469 continued over several input lines, in which case the newline characters are 470 included within it. It is possible to include the delimiter within the pattern 471 by escaping it with a backslash, for example 472 <pre> 473 /abc\/def/ 474 </pre> 475 If you do this, the escape and the delimiter form part of the pattern, but 476 since the delimiters are all non-alphanumeric, this does not affect its 477 interpretation. If the terminating delimiter is immediately followed by a 478 backslash, for example, 479 <pre> 480 /abc/\ 481 </pre> 482 then a backslash is added to the end of the pattern. This is done to provide a 483 way of testing the error condition that arises if a pattern finishes with a 484 backslash, because 485 <pre> 486 /abc\/ 487 </pre> 488 is interpreted as the first line of a pattern that starts with "abc/", causing 489 pcre2test to read the next line as a continuation of the regular expression. 490 </P> 491 <P> 492 A pattern can be followed by a modifier list (details below). 493 </P> 494 <br><a name="SEC9" href="#TOC1">SUBJECT LINE SYNTAX</a><br> 495 <P> 496 Before each subject line is passed to <b>pcre2_match()</b> or 497 <b>pcre2_dfa_match()</b>, leading and trailing white space is removed, and the 498 line is scanned for backslash escapes, unless the <b>subject_literal</b> 499 modifier was set for the pattern. The following provide a means of encoding 500 non-printing characters in a visible way: 501 <pre> 502 \a alarm (BEL, \x07) 503 \b backspace (\x08) 504 \e escape (\x27) 505 \f form feed (\x0c) 506 \n newline (\x0a) 507 \r carriage return (\x0d) 508 \t tab (\x09) 509 \v vertical tab (\x0b) 510 \nnn octal character (up to 3 octal digits); always 511 a byte unless > 255 in UTF-8 or 16-bit or 32-bit mode 512 \o{dd...} octal character (any number of octal digits} 513 \xhh hexadecimal byte (up to 2 hex digits) 514 \x{hh...} hexadecimal character (any number of hex digits) 515 </pre> 516 The use of \x{hh...} is not dependent on the use of the <b>utf</b> modifier on 517 the pattern. It is recognized always. There may be any number of hexadecimal 518 digits inside the braces; invalid values provoke error messages. 519 </P> 520 <P> 521 Note that \xhh specifies one byte rather than one character in UTF-8 mode; 522 this makes it possible to construct invalid UTF-8 sequences for testing 523 purposes. On the other hand, \x{hh} is interpreted as a UTF-8 character in 524 UTF-8 mode, generating more than one byte if the value is greater than 127. 525 When testing the 8-bit library not in UTF-8 mode, \x{hh} generates one byte 526 for values less than 256, and causes an error for greater values. 527 </P> 528 <P> 529 In UTF-16 mode, all 4-digit \x{hhhh} values are accepted. This makes it 530 possible to construct invalid UTF-16 sequences for testing purposes. 531 </P> 532 <P> 533 In UTF-32 mode, all 4- to 8-digit \x{...} values are accepted. This makes it 534 possible to construct invalid UTF-32 sequences for testing purposes. 535 </P> 536 <P> 537 There is a special backslash sequence that specifies replication of one or more 538 characters: 539 <pre> 540 \[<characters>]{<count>} 541 </pre> 542 This makes it possible to test long strings without having to provide them as 543 part of the file. For example: 544 <pre> 545 \[abc]{4} 546 </pre> 547 is converted to "abcabcabcabc". This feature does not support nesting. To 548 include a closing square bracket in the characters, code it as \x5D. 549 </P> 550 <P> 551 A backslash followed by an equals sign marks the end of the subject string and 552 the start of a modifier list. For example: 553 <pre> 554 abc\=notbol,notempty 555 </pre> 556 If the subject string is empty and \= is followed by whitespace, the line is 557 treated as a comment line, and is not used for matching. For example: 558 <pre> 559 \= This is a comment. 560 abc\= This is an invalid modifier list. 561 </pre> 562 A backslash followed by any other non-alphanumeric character just escapes that 563 character. A backslash followed by anything else causes an error. However, if 564 the very last character in the line is a backslash (and there is no modifier 565 list), it is ignored. This gives a way of passing an empty line as data, since 566 a real empty line terminates the data input. 567 </P> 568 <P> 569 If the <b>subject_literal</b> modifier is set for a pattern, all subject lines 570 that follow are treated as literals, with no special treatment of backslashes. 571 No replication is possible, and any subject modifiers must be set as defaults 572 by a <b>#subject</b> command. 573 </P> 574 <br><a name="SEC10" href="#TOC1">PATTERN MODIFIERS</a><br> 575 <P> 576 There are several types of modifier that can appear in pattern lines. Except 577 where noted below, they may also be used in <b>#pattern</b> commands. A 578 pattern's modifier list can add to or override default modifiers that were set 579 by a previous <b>#pattern</b> command. 580 <a name="optionmodifiers"></a></P> 581 <br><b> 582 Setting compilation options 583 </b><br> 584 <P> 585 The following modifiers set options for <b>pcre2_compile()</b>. Most of them set 586 bits in the options argument of that function, but those whose names start with 587 PCRE2_EXTRA are additional options that are set in the compile context. For the 588 main options, there are some single-letter abbreviations that are the same as 589 Perl options. There is special handling for /x: if a second x is present, 590 PCRE2_EXTENDED is converted into PCRE2_EXTENDED_MORE as in Perl. A third 591 appearance adds PCRE2_EXTENDED as well, though this makes no difference to the 592 way <b>pcre2_compile()</b> behaves. See 593 <a href="pcre2api.html"><b>pcre2api</b></a> 594 for a description of the effects of these options. 595 <pre> 596 allow_empty_class set PCRE2_ALLOW_EMPTY_CLASS 597 allow_surrogate_escapes set PCRE2_EXTRA_ALLOW_SURROGATE_ESCAPES 598 alt_bsux set PCRE2_ALT_BSUX 599 alt_circumflex set PCRE2_ALT_CIRCUMFLEX 600 alt_verbnames set PCRE2_ALT_VERBNAMES 601 anchored set PCRE2_ANCHORED 602 auto_callout set PCRE2_AUTO_CALLOUT 603 bad_escape_is_literal set PCRE2_EXTRA_BAD_ESCAPE_IS_LITERAL 604 /i caseless set PCRE2_CASELESS 605 dollar_endonly set PCRE2_DOLLAR_ENDONLY 606 /s dotall set PCRE2_DOTALL 607 dupnames set PCRE2_DUPNAMES 608 endanchored set PCRE2_ENDANCHORED 609 /x extended set PCRE2_EXTENDED 610 /xx extended_more set PCRE2_EXTENDED_MORE 611 firstline set PCRE2_FIRSTLINE 612 literal set PCRE2_LITERAL 613 match_line set PCRE2_EXTRA_MATCH_LINE 614 match_unset_backref set PCRE2_MATCH_UNSET_BACKREF 615 match_word set PCRE2_EXTRA_MATCH_WORD 616 /m multiline set PCRE2_MULTILINE 617 never_backslash_c set PCRE2_NEVER_BACKSLASH_C 618 never_ucp set PCRE2_NEVER_UCP 619 never_utf set PCRE2_NEVER_UTF 620 /n no_auto_capture set PCRE2_NO_AUTO_CAPTURE 621 no_auto_possess set PCRE2_NO_AUTO_POSSESS 622 no_dotstar_anchor set PCRE2_NO_DOTSTAR_ANCHOR 623 no_start_optimize set PCRE2_NO_START_OPTIMIZE 624 no_utf_check set PCRE2_NO_UTF_CHECK 625 ucp set PCRE2_UCP 626 ungreedy set PCRE2_UNGREEDY 627 use_offset_limit set PCRE2_USE_OFFSET_LIMIT 628 utf set PCRE2_UTF 629 </pre> 630 As well as turning on the PCRE2_UTF option, the <b>utf</b> modifier causes all 631 non-printing characters in output strings to be printed using the \x{hh...} 632 notation. Otherwise, those less than 0x100 are output in hex without the curly 633 brackets. Setting <b>utf</b> in 16-bit or 32-bit mode also causes pattern and 634 subject strings to be translated to UTF-16 or UTF-32, respectively, before 635 being passed to library functions. 636 <a name="controlmodifiers"></a></P> 637 <br><b> 638 Setting compilation controls 639 </b><br> 640 <P> 641 The following modifiers affect the compilation process or request information 642 about the pattern. There are single-letter abbreviations for some that are 643 heavily used in the test files. 644 <pre> 645 bsr=[anycrlf|unicode] specify \R handling 646 /B bincode show binary code without lengths 647 callout_info show callout information 648 convert=<options> request foreign pattern conversion 649 convert_glob_escape=c set glob escape character 650 convert_glob_separator=c set glob separator character 651 convert_length set convert buffer length 652 debug same as info,fullbincode 653 framesize show matching frame size 654 fullbincode show binary code with lengths 655 /I info show info about compiled pattern 656 hex unquoted characters are hexadecimal 657 jit[=<number>] use JIT 658 jitfast use JIT fast path 659 jitverify verify JIT use 660 locale=<name> use this locale 661 max_pattern_length=<n> set the maximum pattern length 662 memory show memory used 663 newline=<type> set newline type 664 null_context compile with a NULL context 665 parens_nest_limit=<n> set maximum parentheses depth 666 posix use the POSIX API 667 posix_nosub use the POSIX API with REG_NOSUB 668 push push compiled pattern onto the stack 669 pushcopy push a copy onto the stack 670 stackguard=<number> test the stackguard feature 671 subject_literal treat all subject lines as literal 672 tables=[0|1|2] select internal tables 673 use_length do not zero-terminate the pattern 674 utf8_input treat input as UTF-8 675 </pre> 676 The effects of these modifiers are described in the following sections. 677 </P> 678 <br><b> 679 Newline and \R handling 680 </b><br> 681 <P> 682 The <b>bsr</b> modifier specifies what \R in a pattern should match. If it is 683 set to "anycrlf", \R matches CR, LF, or CRLF only. If it is set to "unicode", 684 \R matches any Unicode newline sequence. The default can be specified when 685 PCRE2 is built; if it is not, the default is set to Unicode. 686 </P> 687 <P> 688 The <b>newline</b> modifier specifies which characters are to be interpreted as 689 newlines, both in the pattern and in subject lines. The type must be one of CR, 690 LF, CRLF, ANYCRLF, ANY, or NUL (in upper or lower case). 691 </P> 692 <br><b> 693 Information about a pattern 694 </b><br> 695 <P> 696 The <b>debug</b> modifier is a shorthand for <b>info,fullbincode</b>, requesting 697 all available information. 698 </P> 699 <P> 700 The <b>bincode</b> modifier causes a representation of the compiled code to be 701 output after compilation. This information does not contain length and offset 702 values, which ensures that the same output is generated for different internal 703 link sizes and different code unit widths. By using <b>bincode</b>, the same 704 regression tests can be used in different environments. 705 </P> 706 <P> 707 The <b>fullbincode</b> modifier, by contrast, <i>does</i> include length and 708 offset values. This is used in a few special tests that run only for specific 709 code unit widths and link sizes, and is also useful for one-off tests. 710 </P> 711 <P> 712 The <b>info</b> modifier requests information about the compiled pattern 713 (whether it is anchored, has a fixed first character, and so on). The 714 information is obtained from the <b>pcre2_pattern_info()</b> function. Here are 715 some typical examples: 716 <pre> 717 re> /(?i)(^a|^b)/m,info 718 Capturing subpattern count = 1 719 Compile options: multiline 720 Overall options: caseless multiline 721 First code unit at start or follows newline 722 Subject length lower bound = 1 723 724 re> /(?i)abc/info 725 Capturing subpattern count = 0 726 Compile options: <none> 727 Overall options: caseless 728 First code unit = 'a' (caseless) 729 Last code unit = 'c' (caseless) 730 Subject length lower bound = 3 731 </pre> 732 "Compile options" are those specified by modifiers; "overall options" have 733 added options that are taken or deduced from the pattern. If both sets of 734 options are the same, just a single "options" line is output; if there are no 735 options, the line is omitted. "First code unit" is where any match must start; 736 if there is more than one they are listed as "starting code units". "Last code 737 unit" is the last literal code unit that must be present in any match. This is 738 not necessarily the last character. These lines are omitted if no starting or 739 ending code units are recorded. 740 </P> 741 <P> 742 The <b>framesize</b> modifier shows the size, in bytes, of the storage frames 743 used by <b>pcre2_match()</b> for handling backtracking. The size depends on the 744 number of capturing parentheses in the pattern. 745 </P> 746 <P> 747 The <b>callout_info</b> modifier requests information about all the callouts in 748 the pattern. A list of them is output at the end of any other information that 749 is requested. For each callout, either its number or string is given, followed 750 by the item that follows it in the pattern. 751 </P> 752 <br><b> 753 Passing a NULL context 754 </b><br> 755 <P> 756 Normally, <b>pcre2test</b> passes a context block to <b>pcre2_compile()</b>. If 757 the <b>null_context</b> modifier is set, however, NULL is passed. This is for 758 testing that <b>pcre2_compile()</b> behaves correctly in this case (it uses 759 default values). 760 </P> 761 <br><b> 762 Specifying pattern characters in hexadecimal 763 </b><br> 764 <P> 765 The <b>hex</b> modifier specifies that the characters of the pattern, except for 766 substrings enclosed in single or double quotes, are to be interpreted as pairs 767 of hexadecimal digits. This feature is provided as a way of creating patterns 768 that contain binary zeros and other non-printing characters. White space is 769 permitted between pairs of digits. For example, this pattern contains three 770 characters: 771 <pre> 772 /ab 32 59/hex 773 </pre> 774 Parts of such a pattern are taken literally if quoted. This pattern contains 775 nine characters, only two of which are specified in hexadecimal: 776 <pre> 777 /ab "literal" 32/hex 778 </pre> 779 Either single or double quotes may be used. There is no way of including 780 the delimiter within a substring. The <b>hex</b> and <b>expand</b> modifiers are 781 mutually exclusive. 782 </P> 783 <br><b> 784 Specifying the pattern's length 785 </b><br> 786 <P> 787 By default, patterns are passed to the compiling functions as zero-terminated 788 strings but can be passed by length instead of being zero-terminated. The 789 <b>use_length</b> modifier causes this to happen. Using a length happens 790 automatically (whether or not <b>use_length</b> is set) when <b>hex</b> is set, 791 because patterns specified in hexadecimal may contain binary zeros. 792 </P> 793 <P> 794 If <b>hex</b> or <b>use_length</b> is used with the POSIX wrapper API (see 795 <a href="#posixwrapper">"Using the POSIX wrapper API"</a> 796 below), the REG_PEND extension is used to pass the pattern's length. 797 </P> 798 <br><b> 799 Specifying wide characters in 16-bit and 32-bit modes 800 </b><br> 801 <P> 802 In 16-bit and 32-bit modes, all input is automatically treated as UTF-8 and 803 translated to UTF-16 or UTF-32 when the <b>utf</b> modifier is set. For testing 804 the 16-bit and 32-bit libraries in non-UTF mode, the <b>utf8_input</b> modifier 805 can be used. It is mutually exclusive with <b>utf</b>. Input lines are 806 interpreted as UTF-8 as a means of specifying wide characters. More details are 807 given in 808 <a href="#inputencoding">"Input encoding"</a> 809 above. 810 </P> 811 <br><b> 812 Generating long repetitive patterns 813 </b><br> 814 <P> 815 Some tests use long patterns that are very repetitive. Instead of creating a 816 very long input line for such a pattern, you can use a special repetition 817 feature, similar to the one described for subject lines above. If the 818 <b>expand</b> modifier is present on a pattern, parts of the pattern that have 819 the form 820 <pre> 821 \[<characters>]{<count>} 822 </pre> 823 are expanded before the pattern is passed to <b>pcre2_compile()</b>. For 824 example, \[AB]{6000} is expanded to "ABAB..." 6000 times. This construction 825 cannot be nested. An initial "\[" sequence is recognized only if "]{" followed 826 by decimal digits and "}" is found later in the pattern. If not, the characters 827 remain in the pattern unaltered. The <b>expand</b> and <b>hex</b> modifiers are 828 mutually exclusive. 829 </P> 830 <P> 831 If part of an expanded pattern looks like an expansion, but is really part of 832 the actual pattern, unwanted expansion can be avoided by giving two values in 833 the quantifier. For example, \[AB]{6000,6000} is not recognized as an 834 expansion item. 835 </P> 836 <P> 837 If the <b>info</b> modifier is set on an expanded pattern, the result of the 838 expansion is included in the information that is output. 839 </P> 840 <br><b> 841 JIT compilation 842 </b><br> 843 <P> 844 Just-in-time (JIT) compiling is a heavyweight optimization that can greatly 845 speed up pattern matching. See the 846 <a href="pcre2jit.html"><b>pcre2jit</b></a> 847 documentation for details. JIT compiling happens, optionally, after a pattern 848 has been successfully compiled into an internal form. The JIT compiler converts 849 this to optimized machine code. It needs to know whether the match-time options 850 PCRE2_PARTIAL_HARD and PCRE2_PARTIAL_SOFT are going to be used, because 851 different code is generated for the different cases. See the <b>partial</b> 852 modifier in "Subject Modifiers" 853 <a href="#subjectmodifiers">below</a> 854 for details of how these options are specified for each match attempt. 855 </P> 856 <P> 857 JIT compilation is requested by the <b>jit</b> pattern modifier, which may 858 optionally be followed by an equals sign and a number in the range 0 to 7. 859 The three bits that make up the number specify which of the three JIT operating 860 modes are to be compiled: 861 <pre> 862 1 compile JIT code for non-partial matching 863 2 compile JIT code for soft partial matching 864 4 compile JIT code for hard partial matching 865 </pre> 866 The possible values for the <b>jit</b> modifier are therefore: 867 <pre> 868 0 disable JIT 869 1 normal matching only 870 2 soft partial matching only 871 3 normal and soft partial matching 872 4 hard partial matching only 873 6 soft and hard partial matching only 874 7 all three modes 875 </pre> 876 If no number is given, 7 is assumed. The phrase "partial matching" means a call 877 to <b>pcre2_match()</b> with either the PCRE2_PARTIAL_SOFT or the 878 PCRE2_PARTIAL_HARD option set. Note that such a call may return a complete 879 match; the options enable the possibility of a partial match, but do not 880 require it. Note also that if you request JIT compilation only for partial 881 matching (for example, jit=2) but do not set the <b>partial</b> modifier on a 882 subject line, that match will not use JIT code because none was compiled for 883 non-partial matching. 884 </P> 885 <P> 886 If JIT compilation is successful, the compiled JIT code will automatically be 887 used when an appropriate type of match is run, except when incompatible 888 run-time options are specified. For more details, see the 889 <a href="pcre2jit.html"><b>pcre2jit</b></a> 890 documentation. See also the <b>jitstack</b> modifier below for a way of 891 setting the size of the JIT stack. 892 </P> 893 <P> 894 If the <b>jitfast</b> modifier is specified, matching is done using the JIT 895 "fast path" interface, <b>pcre2_jit_match()</b>, which skips some of the sanity 896 checks that are done by <b>pcre2_match()</b>, and of course does not work when 897 JIT is not supported. If <b>jitfast</b> is specified without <b>jit</b>, jit=7 is 898 assumed. 899 </P> 900 <P> 901 If the <b>jitverify</b> modifier is specified, information about the compiled 902 pattern shows whether JIT compilation was or was not successful. If 903 <b>jitverify</b> is specified without <b>jit</b>, jit=7 is assumed. If JIT 904 compilation is successful when <b>jitverify</b> is set, the text "(JIT)" is 905 added to the first output line after a match or non match when JIT-compiled 906 code was actually used in the match. 907 </P> 908 <br><b> 909 Setting a locale 910 </b><br> 911 <P> 912 The <b>locale</b> modifier must specify the name of a locale, for example: 913 <pre> 914 /pattern/locale=fr_FR 915 </pre> 916 The given locale is set, <b>pcre2_maketables()</b> is called to build a set of 917 character tables for the locale, and this is then passed to 918 <b>pcre2_compile()</b> when compiling the regular expression. The same tables 919 are used when matching the following subject lines. The <b>locale</b> modifier 920 applies only to the pattern on which it appears, but can be given in a 921 <b>#pattern</b> command if a default is needed. Setting a locale and alternate 922 character tables are mutually exclusive. 923 </P> 924 <br><b> 925 Showing pattern memory 926 </b><br> 927 <P> 928 The <b>memory</b> modifier causes the size in bytes of the memory used to hold 929 the compiled pattern to be output. This does not include the size of the 930 <b>pcre2_code</b> block; it is just the actual compiled data. If the pattern is 931 subsequently passed to the JIT compiler, the size of the JIT compiled code is 932 also output. Here is an example: 933 <pre> 934 re> /a(b)c/jit,memory 935 Memory allocation (code space): 21 936 Memory allocation (JIT code): 1910 937 938 </PRE> 939 </P> 940 <br><b> 941 Limiting nested parentheses 942 </b><br> 943 <P> 944 The <b>parens_nest_limit</b> modifier sets a limit on the depth of nested 945 parentheses in a pattern. Breaching the limit causes a compilation error. 946 The default for the library is set when PCRE2 is built, but <b>pcre2test</b> 947 sets its own default of 220, which is required for running the standard test 948 suite. 949 </P> 950 <br><b> 951 Limiting the pattern length 952 </b><br> 953 <P> 954 The <b>max_pattern_length</b> modifier sets a limit, in code units, to the 955 length of pattern that <b>pcre2_compile()</b> will accept. Breaching the limit 956 causes a compilation error. The default is the largest number a PCRE2_SIZE 957 variable can hold (essentially unlimited). 958 <a name="posixwrapper"></a></P> 959 <br><b> 960 Using the POSIX wrapper API 961 </b><br> 962 <P> 963 The <b>posix</b> and <b>posix_nosub</b> modifiers cause <b>pcre2test</b> to call 964 PCRE2 via the POSIX wrapper API rather than its native API. When 965 <b>posix_nosub</b> is used, the POSIX option REG_NOSUB is passed to 966 <b>regcomp()</b>. The POSIX wrapper supports only the 8-bit library. Note that 967 it does not imply POSIX matching semantics; for more detail see the 968 <a href="pcre2posix.html"><b>pcre2posix</b></a> 969 documentation. The following pattern modifiers set options for the 970 <b>regcomp()</b> function: 971 <pre> 972 caseless REG_ICASE 973 multiline REG_NEWLINE 974 dotall REG_DOTALL ) 975 ungreedy REG_UNGREEDY ) These options are not part of 976 ucp REG_UCP ) the POSIX standard 977 utf REG_UTF8 ) 978 </pre> 979 The <b>regerror_buffsize</b> modifier specifies a size for the error buffer that 980 is passed to <b>regerror()</b> in the event of a compilation error. For example: 981 <pre> 982 /abc/posix,regerror_buffsize=20 983 </pre> 984 This provides a means of testing the behaviour of <b>regerror()</b> when the 985 buffer is too small for the error message. If this modifier has not been set, a 986 large buffer is used. 987 </P> 988 <P> 989 The <b>aftertext</b> and <b>allaftertext</b> subject modifiers work as described 990 below. All other modifiers are either ignored, with a warning message, or cause 991 an error. 992 </P> 993 <P> 994 The pattern is passed to <b>regcomp()</b> as a zero-terminated string by 995 default, but if the <b>use_length</b> or <b>hex</b> modifiers are set, the 996 REG_PEND extension is used to pass it by length. 997 </P> 998 <br><b> 999 Testing the stack guard feature 1000 </b><br> 1001 <P> 1002 The <b>stackguard</b> modifier is used to test the use of 1003 <b>pcre2_set_compile_recursion_guard()</b>, a function that is provided to 1004 enable stack availability to be checked during compilation (see the 1005 <a href="pcre2api.html"><b>pcre2api</b></a> 1006 documentation for details). If the number specified by the modifier is greater 1007 than zero, <b>pcre2_set_compile_recursion_guard()</b> is called to set up 1008 callback from <b>pcre2_compile()</b> to a local function. The argument it 1009 receives is the current nesting parenthesis depth; if this is greater than the 1010 value given by the modifier, non-zero is returned, causing the compilation to 1011 be aborted. 1012 </P> 1013 <br><b> 1014 Using alternative character tables 1015 </b><br> 1016 <P> 1017 The value specified for the <b>tables</b> modifier must be one of the digits 0, 1018 1, or 2. It causes a specific set of built-in character tables to be passed to 1019 <b>pcre2_compile()</b>. This is used in the PCRE2 tests to check behaviour with 1020 different character tables. The digit specifies the tables as follows: 1021 <pre> 1022 0 do not pass any special character tables 1023 1 the default ASCII tables, as distributed in 1024 pcre2_chartables.c.dist 1025 2 a set of tables defining ISO 8859 characters 1026 </pre> 1027 In table 2, some characters whose codes are greater than 128 are identified as 1028 letters, digits, spaces, etc. Setting alternate character tables and a locale 1029 are mutually exclusive. 1030 </P> 1031 <br><b> 1032 Setting certain match controls 1033 </b><br> 1034 <P> 1035 The following modifiers are really subject modifiers, and are described under 1036 "Subject Modifiers" below. However, they may be included in a pattern's 1037 modifier list, in which case they are applied to every subject line that is 1038 processed with that pattern. These modifiers do not affect the compilation 1039 process. 1040 <pre> 1041 aftertext show text after match 1042 allaftertext show text after captures 1043 allcaptures show all captures 1044 allusedtext show all consulted text 1045 altglobal alternative global matching 1046 /g global global matching 1047 jitstack=<n> set size of JIT stack 1048 mark show mark values 1049 replace=<string> specify a replacement string 1050 startchar show starting character when relevant 1051 substitute_extended use PCRE2_SUBSTITUTE_EXTENDED 1052 substitute_overflow_length use PCRE2_SUBSTITUTE_OVERFLOW_LENGTH 1053 substitute_unknown_unset use PCRE2_SUBSTITUTE_UNKNOWN_UNSET 1054 substitute_unset_empty use PCRE2_SUBSTITUTE_UNSET_EMPTY 1055 </pre> 1056 These modifiers may not appear in a <b>#pattern</b> command. If you want them as 1057 defaults, set them in a <b>#subject</b> command. 1058 </P> 1059 <br><b> 1060 Specifying literal subject lines 1061 </b><br> 1062 <P> 1063 If the <b>subject_literal</b> modifier is present on a pattern, all the subject 1064 lines that it matches are taken as literal strings, with no interpretation of 1065 backslashes. It is not possible to set subject modifiers on such lines, but any 1066 that are set as defaults by a <b>#subject</b> command are recognized. 1067 </P> 1068 <br><b> 1069 Saving a compiled pattern 1070 </b><br> 1071 <P> 1072 When a pattern with the <b>push</b> modifier is successfully compiled, it is 1073 pushed onto a stack of compiled patterns, and <b>pcre2test</b> expects the next 1074 line to contain a new pattern (or a command) instead of a subject line. This 1075 facility is used when saving compiled patterns to a file, as described in the 1076 section entitled "Saving and restoring compiled patterns" 1077 <a href="#saverestore">below.</a> 1078 If <b>pushcopy</b> is used instead of <b>push</b>, a copy of the compiled 1079 pattern is stacked, leaving the original as current, ready to match the 1080 following input lines. This provides a way of testing the 1081 <b>pcre2_code_copy()</b> function. 1082 The <b>push</b> and <b>pushcopy </b> modifiers are incompatible with compilation 1083 modifiers such as <b>global</b> that act at match time. Any that are specified 1084 are ignored (for the stacked copy), with a warning message, except for 1085 <b>replace</b>, which causes an error. Note that <b>jitverify</b>, which is 1086 allowed, does not carry through to any subsequent matching that uses a stacked 1087 pattern. 1088 </P> 1089 <br><b> 1090 Testing foreign pattern conversion 1091 </b><br> 1092 <P> 1093 The experimental foreign pattern conversion functions in PCRE2 can be tested by 1094 setting the <b>convert</b> modifier. Its argument is a colon-separated list of 1095 options, which set the equivalent option for the <b>pcre2_pattern_convert()</b> 1096 function: 1097 <pre> 1098 glob PCRE2_CONVERT_GLOB 1099 glob_no_starstar PCRE2_CONVERT_GLOB_NO_STARSTAR 1100 glob_no_wild_separator PCRE2_CONVERT_GLOB_NO_WILD_SEPARATOR 1101 posix_basic PCRE2_CONVERT_POSIX_BASIC 1102 posix_extended PCRE2_CONVERT_POSIX_EXTENDED 1103 unset Unset all options 1104 </pre> 1105 The "unset" value is useful for turning off a default that has been set by a 1106 <b>#pattern</b> command. When one of these options is set, the input pattern is 1107 passed to <b>pcre2_pattern_convert()</b>. If the conversion is successful, the 1108 result is reflected in the output and then passed to <b>pcre2_compile()</b>. The 1109 normal <b>utf</b> and <b>no_utf_check</b> options, if set, cause the 1110 PCRE2_CONVERT_UTF and PCRE2_CONVERT_NO_UTF_CHECK options to be passed to 1111 <b>pcre2_pattern_convert()</b>. 1112 </P> 1113 <P> 1114 By default, the conversion function is allowed to allocate a buffer for its 1115 output. However, if the <b>convert_length</b> modifier is set to a value greater 1116 than zero, <b>pcre2test</b> passes a buffer of the given length. This makes it 1117 possible to test the length check. 1118 </P> 1119 <P> 1120 The <b>convert_glob_escape</b> and <b>convert_glob_separator</b> modifiers can be 1121 used to specify the escape and separator characters for glob processing, 1122 overriding the defaults, which are operating-system dependent. 1123 <a name="subjectmodifiers"></a></P> 1124 <br><a name="SEC11" href="#TOC1">SUBJECT MODIFIERS</a><br> 1125 <P> 1126 The modifiers that can appear in subject lines and the <b>#subject</b> 1127 command are of two types. 1128 </P> 1129 <br><b> 1130 Setting match options 1131 </b><br> 1132 <P> 1133 The following modifiers set options for <b>pcre2_match()</b> or 1134 <b>pcre2_dfa_match()</b>. See 1135 <a href="pcreapi.html"><b>pcreapi</b></a> 1136 for a description of their effects. 1137 <pre> 1138 anchored set PCRE2_ANCHORED 1139 endanchored set PCRE2_ENDANCHORED 1140 dfa_restart set PCRE2_DFA_RESTART 1141 dfa_shortest set PCRE2_DFA_SHORTEST 1142 no_jit set PCRE2_NO_JIT 1143 no_utf_check set PCRE2_NO_UTF_CHECK 1144 notbol set PCRE2_NOTBOL 1145 notempty set PCRE2_NOTEMPTY 1146 notempty_atstart set PCRE2_NOTEMPTY_ATSTART 1147 noteol set PCRE2_NOTEOL 1148 partial_hard (or ph) set PCRE2_PARTIAL_HARD 1149 partial_soft (or ps) set PCRE2_PARTIAL_SOFT 1150 </pre> 1151 The partial matching modifiers are provided with abbreviations because they 1152 appear frequently in tests. 1153 </P> 1154 <P> 1155 If the <b>posix</b> or <b>posix_nosub</b> modifier was present on the pattern, 1156 causing the POSIX wrapper API to be used, the only option-setting modifiers 1157 that have any effect are <b>notbol</b>, <b>notempty</b>, and <b>noteol</b>, 1158 causing REG_NOTBOL, REG_NOTEMPTY, and REG_NOTEOL, respectively, to be passed to 1159 <b>regexec()</b>. The other modifiers are ignored, with a warning message. 1160 </P> 1161 <P> 1162 There is one additional modifier that can be used with the POSIX wrapper. It is 1163 ignored (with a warning) if used for non-POSIX matching. 1164 <pre> 1165 posix_startend=<n>[:<m>] 1166 </pre> 1167 This causes the subject string to be passed to <b>regexec()</b> using the 1168 REG_STARTEND option, which uses offsets to specify which part of the string is 1169 searched. If only one number is given, the end offset is passed as the end of 1170 the subject string. For more detail of REG_STARTEND, see the 1171 <a href="pcre2posix.html"><b>pcre2posix</b></a> 1172 documentation. If the subject string contains binary zeros (coded as escapes 1173 such as \x{00} because <b>pcre2test</b> does not support actual binary zeros in 1174 its input), you must use <b>posix_startend</b> to specify its length. 1175 </P> 1176 <br><b> 1177 Setting match controls 1178 </b><br> 1179 <P> 1180 The following modifiers affect the matching process or request additional 1181 information. Some of them may also be specified on a pattern line (see above), 1182 in which case they apply to every subject line that is matched against that 1183 pattern. 1184 <pre> 1185 aftertext show text after match 1186 allaftertext show text after captures 1187 allcaptures show all captures 1188 allusedtext show all consulted text (non-JIT only) 1189 altglobal alternative global matching 1190 callout_capture show captures at callout time 1191 callout_data=<n> set a value to pass via callouts 1192 callout_error=<n>[:<m>] control callout error 1193 callout_extra show extra callout information 1194 callout_fail=<n>[:<m>] control callout failure 1195 callout_no_where do not show position of a callout 1196 callout_none do not supply a callout function 1197 copy=<number or name> copy captured substring 1198 depth_limit=<n> set a depth limit 1199 dfa use <b>pcre2_dfa_match()</b> 1200 find_limits find match and depth limits 1201 get=<number or name> extract captured substring 1202 getall extract all captured substrings 1203 /g global global matching 1204 heap_limit=<n> set a limit on heap memory (Kbytes) 1205 jitstack=<n> set size of JIT stack 1206 mark show mark values 1207 match_limit=<n> set a match limit 1208 memory show heap memory usage 1209 null_context match with a NULL context 1210 offset=<n> set starting offset 1211 offset_limit=<n> set offset limit 1212 ovector=<n> set size of output vector 1213 recursion_limit=<n> obsolete synonym for depth_limit 1214 replace=<string> specify a replacement string 1215 startchar show startchar when relevant 1216 startoffset=<n> same as offset=<n> 1217 substitute_extedded use PCRE2_SUBSTITUTE_EXTENDED 1218 substitute_overflow_length use PCRE2_SUBSTITUTE_OVERFLOW_LENGTH 1219 substitute_unknown_unset use PCRE2_SUBSTITUTE_UNKNOWN_UNSET 1220 substitute_unset_empty use PCRE2_SUBSTITUTE_UNSET_EMPTY 1221 zero_terminate pass the subject as zero-terminated 1222 </pre> 1223 The effects of these modifiers are described in the following sections. When 1224 matching via the POSIX wrapper API, the <b>aftertext</b>, <b>allaftertext</b>, 1225 and <b>ovector</b> subject modifiers work as described below. All other 1226 modifiers are either ignored, with a warning message, or cause an error. 1227 </P> 1228 <br><b> 1229 Showing more text 1230 </b><br> 1231 <P> 1232 The <b>aftertext</b> modifier requests that as well as outputting the part of 1233 the subject string that matched the entire pattern, <b>pcre2test</b> should in 1234 addition output the remainder of the subject string. This is useful for tests 1235 where the subject contains multiple copies of the same substring. The 1236 <b>allaftertext</b> modifier requests the same action for captured substrings as 1237 well as the main matched substring. In each case the remainder is output on the 1238 following line with a plus character following the capture number. 1239 </P> 1240 <P> 1241 The <b>allusedtext</b> modifier requests that all the text that was consulted 1242 during a successful pattern match by the interpreter should be shown. This 1243 feature is not supported for JIT matching, and if requested with JIT it is 1244 ignored (with a warning message). Setting this modifier affects the output if 1245 there is a lookbehind at the start of a match, or a lookahead at the end, or if 1246 \K is used in the pattern. Characters that precede or follow the start and end 1247 of the actual match are indicated in the output by '<' or '>' characters 1248 underneath them. Here is an example: 1249 <pre> 1250 re> /(?<=pqr)abc(?=xyz)/ 1251 data> 123pqrabcxyz456\=allusedtext 1252 0: pqrabcxyz 1253 <<< >>> 1254 </pre> 1255 This shows that the matched string is "abc", with the preceding and following 1256 strings "pqr" and "xyz" having been consulted during the match (when processing 1257 the assertions). 1258 </P> 1259 <P> 1260 The <b>startchar</b> modifier requests that the starting character for the match 1261 be indicated, if it is different to the start of the matched string. The only 1262 time when this occurs is when \K has been processed as part of the match. In 1263 this situation, the output for the matched string is displayed from the 1264 starting character instead of from the match point, with circumflex characters 1265 under the earlier characters. For example: 1266 <pre> 1267 re> /abc\Kxyz/ 1268 data> abcxyz\=startchar 1269 0: abcxyz 1270 ^^^ 1271 </pre> 1272 Unlike <b>allusedtext</b>, the <b>startchar</b> modifier can be used with JIT. 1273 However, these two modifiers are mutually exclusive. 1274 </P> 1275 <br><b> 1276 Showing the value of all capture groups 1277 </b><br> 1278 <P> 1279 The <b>allcaptures</b> modifier requests that the values of all potential 1280 captured parentheses be output after a match. By default, only those up to the 1281 highest one actually used in the match are output (corresponding to the return 1282 code from <b>pcre2_match()</b>). Groups that did not take part in the match 1283 are output as "<unset>". This modifier is not relevant for DFA matching (which 1284 does no capturing); it is ignored, with a warning message, if present. 1285 </P> 1286 <br><b> 1287 Testing callouts 1288 </b><br> 1289 <P> 1290 A callout function is supplied when <b>pcre2test</b> calls the library matching 1291 functions, unless <b>callout_none</b> is specified. Its behaviour can be 1292 controlled by various modifiers listed above whose names begin with 1293 <b>callout_</b>. Details are given in the section entitled "Callouts" 1294 <a href="#callouts">below.</a> 1295 </P> 1296 <br><b> 1297 Finding all matches in a string 1298 </b><br> 1299 <P> 1300 Searching for all possible matches within a subject can be requested by the 1301 <b>global</b> or <b>altglobal</b> modifier. After finding a match, the matching 1302 function is called again to search the remainder of the subject. The difference 1303 between <b>global</b> and <b>altglobal</b> is that the former uses the 1304 <i>start_offset</i> argument to <b>pcre2_match()</b> or <b>pcre2_dfa_match()</b> 1305 to start searching at a new point within the entire string (which is what Perl 1306 does), whereas the latter passes over a shortened subject. This makes a 1307 difference to the matching process if the pattern begins with a lookbehind 1308 assertion (including \b or \B). 1309 </P> 1310 <P> 1311 If an empty string is matched, the next match is done with the 1312 PCRE2_NOTEMPTY_ATSTART and PCRE2_ANCHORED flags set, in order to search for 1313 another, non-empty, match at the same point in the subject. If this match 1314 fails, the start offset is advanced, and the normal match is retried. This 1315 imitates the way Perl handles such cases when using the <b>/g</b> modifier or 1316 the <b>split()</b> function. Normally, the start offset is advanced by one 1317 character, but if the newline convention recognizes CRLF as a newline, and the 1318 current character is CR followed by LF, an advance of two characters occurs. 1319 </P> 1320 <br><b> 1321 Testing substring extraction functions 1322 </b><br> 1323 <P> 1324 The <b>copy</b> and <b>get</b> modifiers can be used to test the 1325 <b>pcre2_substring_copy_xxx()</b> and <b>pcre2_substring_get_xxx()</b> functions. 1326 They can be given more than once, and each can specify a group name or number, 1327 for example: 1328 <pre> 1329 abcd\=copy=1,copy=3,get=G1 1330 </pre> 1331 If the <b>#subject</b> command is used to set default copy and/or get lists, 1332 these can be unset by specifying a negative number to cancel all numbered 1333 groups and an empty name to cancel all named groups. 1334 </P> 1335 <P> 1336 The <b>getall</b> modifier tests <b>pcre2_substring_list_get()</b>, which 1337 extracts all captured substrings. 1338 </P> 1339 <P> 1340 If the subject line is successfully matched, the substrings extracted by the 1341 convenience functions are output with C, G, or L after the string number 1342 instead of a colon. This is in addition to the normal full list. The string 1343 length (that is, the return from the extraction function) is given in 1344 parentheses after each substring, followed by the name when the extraction was 1345 by name. 1346 </P> 1347 <br><b> 1348 Testing the substitution function 1349 </b><br> 1350 <P> 1351 If the <b>replace</b> modifier is set, the <b>pcre2_substitute()</b> function is 1352 called instead of one of the matching functions. Note that replacement strings 1353 cannot contain commas, because a comma signifies the end of a modifier. This is 1354 not thought to be an issue in a test program. 1355 </P> 1356 <P> 1357 Unlike subject strings, <b>pcre2test</b> does not process replacement strings 1358 for escape sequences. In UTF mode, a replacement string is checked to see if it 1359 is a valid UTF-8 string. If so, it is correctly converted to a UTF string of 1360 the appropriate code unit width. If it is not a valid UTF-8 string, the 1361 individual code units are copied directly. This provides a means of passing an 1362 invalid UTF-8 string for testing purposes. 1363 </P> 1364 <P> 1365 The following modifiers set options (in additional to the normal match options) 1366 for <b>pcre2_substitute()</b>: 1367 <pre> 1368 global PCRE2_SUBSTITUTE_GLOBAL 1369 substitute_extended PCRE2_SUBSTITUTE_EXTENDED 1370 substitute_overflow_length PCRE2_SUBSTITUTE_OVERFLOW_LENGTH 1371 substitute_unknown_unset PCRE2_SUBSTITUTE_UNKNOWN_UNSET 1372 substitute_unset_empty PCRE2_SUBSTITUTE_UNSET_EMPTY 1373 1374 </PRE> 1375 </P> 1376 <P> 1377 After a successful substitution, the modified string is output, preceded by the 1378 number of replacements. This may be zero if there were no matches. Here is a 1379 simple example of a substitution test: 1380 <pre> 1381 /abc/replace=xxx 1382 =abc=abc= 1383 1: =xxx=abc= 1384 =abc=abc=\=global 1385 2: =xxx=xxx= 1386 </pre> 1387 Subject and replacement strings should be kept relatively short (fewer than 256 1388 characters) for substitution tests, as fixed-size buffers are used. To make it 1389 easy to test for buffer overflow, if the replacement string starts with a 1390 number in square brackets, that number is passed to <b>pcre2_substitute()</b> as 1391 the size of the output buffer, with the replacement string starting at the next 1392 character. Here is an example that tests the edge case: 1393 <pre> 1394 /abc/ 1395 123abc123\=replace=[10]XYZ 1396 1: 123XYZ123 1397 123abc123\=replace=[9]XYZ 1398 Failed: error -47: no more memory 1399 </pre> 1400 The default action of <b>pcre2_substitute()</b> is to return 1401 PCRE2_ERROR_NOMEMORY when the output buffer is too small. However, if the 1402 PCRE2_SUBSTITUTE_OVERFLOW_LENGTH option is set (by using the 1403 <b>substitute_overflow_length</b> modifier), <b>pcre2_substitute()</b> continues 1404 to go through the motions of matching and substituting, in order to compute the 1405 size of buffer that is required. When this happens, <b>pcre2test</b> shows the 1406 required buffer length (which includes space for the trailing zero) as part of 1407 the error message. For example: 1408 <pre> 1409 /abc/substitute_overflow_length 1410 123abc123\=replace=[9]XYZ 1411 Failed: error -47: no more memory: 10 code units are needed 1412 </pre> 1413 A replacement string is ignored with POSIX and DFA matching. Specifying partial 1414 matching provokes an error return ("bad option value") from 1415 <b>pcre2_substitute()</b>. 1416 </P> 1417 <br><b> 1418 Setting the JIT stack size 1419 </b><br> 1420 <P> 1421 The <b>jitstack</b> modifier provides a way of setting the maximum stack size 1422 that is used by the just-in-time optimization code. It is ignored if JIT 1423 optimization is not being used. The value is a number of kibibytes (units of 1424 1024 bytes). Setting zero reverts to the default of 32KiB. Providing a stack 1425 that is larger than the default is necessary only for very complicated 1426 patterns. If <b>jitstack</b> is set non-zero on a subject line it overrides any 1427 value that was set on the pattern. 1428 </P> 1429 <br><b> 1430 Setting heap, match, and depth limits 1431 </b><br> 1432 <P> 1433 The <b>heap_limit</b>, <b>match_limit</b>, and <b>depth_limit</b> modifiers set 1434 the appropriate limits in the match context. These values are ignored when the 1435 <b>find_limits</b> modifier is specified. 1436 </P> 1437 <br><b> 1438 Finding minimum limits 1439 </b><br> 1440 <P> 1441 If the <b>find_limits</b> modifier is present on a subject line, <b>pcre2test</b> 1442 calls the relevant matching function several times, setting different values in 1443 the match context via <b>pcre2_set_heap_limit()</b>, 1444 <b>pcre2_set_match_limit()</b>, or <b>pcre2_set_depth_limit()</b> until it finds 1445 the minimum values for each parameter that allows the match to complete without 1446 error. If JIT is being used, only the match limit is relevant. 1447 </P> 1448 <P> 1449 When using this modifier, the pattern should not contain any limit settings 1450 such as (*LIMIT_MATCH=...) within it. If such a setting is present and is 1451 lower than the minimum matching value, the minimum value cannot be found 1452 because <b>pcre2_set_match_limit()</b> etc. are only able to reduce the value of 1453 an in-pattern limit; they cannot increase it. 1454 </P> 1455 <P> 1456 For non-DFA matching, the minimum <i>depth_limit</i> number is a measure of how 1457 much nested backtracking happens (that is, how deeply the pattern's tree is 1458 searched). In the case of DFA matching, <i>depth_limit</i> controls the depth of 1459 recursive calls of the internal function that is used for handling pattern 1460 recursion, lookaround assertions, and atomic groups. 1461 </P> 1462 <P> 1463 For non-DFA matching, the <i>match_limit</i> number is a measure of the amount 1464 of backtracking that takes place, and learning the minimum value can be 1465 instructive. For most simple matches, the number is quite small, but for 1466 patterns with very large numbers of matching possibilities, it can become large 1467 very quickly with increasing length of subject string. In the case of DFA 1468 matching, <i>match_limit</i> controls the total number of calls, both recursive 1469 and non-recursive, to the internal matching function, thus controlling the 1470 overall amount of computing resource that is used. 1471 </P> 1472 <P> 1473 For both kinds of matching, the <i>heap_limit</i> number, which is in kibibytes 1474 (units of 1024 bytes), limits the amount of heap memory used for matching. A 1475 value of zero disables the use of any heap memory; many simple pattern matches 1476 can be done without using the heap, so zero is not an unreasonable setting. 1477 </P> 1478 <br><b> 1479 Showing MARK names 1480 </b><br> 1481 <P> 1482 The <b>mark</b> modifier causes the names from backtracking control verbs that 1483 are returned from calls to <b>pcre2_match()</b> to be displayed. If a mark is 1484 returned for a match, non-match, or partial match, <b>pcre2test</b> shows it. 1485 For a match, it is on a line by itself, tagged with "MK:". Otherwise, it 1486 is added to the non-match message. 1487 </P> 1488 <br><b> 1489 Showing memory usage 1490 </b><br> 1491 <P> 1492 The <b>memory</b> modifier causes <b>pcre2test</b> to log the sizes of all heap 1493 memory allocation and freeing calls that occur during a call to 1494 <b>pcre2_match()</b> or <b>pcre2_dfa_match()</b>. These occur only when a match 1495 requires a bigger vector than the default for remembering backtracking points 1496 (<b>pcre2_match()</b>) or for internal workspace (<b>pcre2_dfa_match()</b>). In 1497 many cases there will be no heap memory used and therefore no additional 1498 output. No heap memory is allocated during matching with JIT, so in that case 1499 the <b>memory</b> modifier never has any effect. For this modifier to work, the 1500 <b>null_context</b> modifier must not be set on both the pattern and the 1501 subject, though it can be set on one or the other. 1502 </P> 1503 <br><b> 1504 Setting a starting offset 1505 </b><br> 1506 <P> 1507 The <b>offset</b> modifier sets an offset in the subject string at which 1508 matching starts. Its value is a number of code units, not characters. 1509 </P> 1510 <br><b> 1511 Setting an offset limit 1512 </b><br> 1513 <P> 1514 The <b>offset_limit</b> modifier sets a limit for unanchored matches. If a match 1515 cannot be found starting at or before this offset in the subject, a "no match" 1516 return is given. The data value is a number of code units, not characters. When 1517 this modifier is used, the <b>use_offset_limit</b> modifier must have been set 1518 for the pattern; if not, an error is generated. 1519 </P> 1520 <br><b> 1521 Setting the size of the output vector 1522 </b><br> 1523 <P> 1524 The <b>ovector</b> modifier applies only to the subject line in which it 1525 appears, though of course it can also be used to set a default in a 1526 <b>#subject</b> command. It specifies the number of pairs of offsets that are 1527 available for storing matching information. The default is 15. 1528 </P> 1529 <P> 1530 A value of zero is useful when testing the POSIX API because it causes 1531 <b>regexec()</b> to be called with a NULL capture vector. When not testing the 1532 POSIX API, a value of zero is used to cause 1533 <b>pcre2_match_data_create_from_pattern()</b> to be called, in order to create a 1534 match block of exactly the right size for the pattern. (It is not possible to 1535 create a match block with a zero-length ovector; there is always at least one 1536 pair of offsets.) 1537 </P> 1538 <br><b> 1539 Passing the subject as zero-terminated 1540 </b><br> 1541 <P> 1542 By default, the subject string is passed to a native API matching function with 1543 its correct length. In order to test the facility for passing a zero-terminated 1544 string, the <b>zero_terminate</b> modifier is provided. It causes the length to 1545 be passed as PCRE2_ZERO_TERMINATED. When matching via the POSIX interface, 1546 this modifier is ignored, with a warning. 1547 </P> 1548 <P> 1549 When testing <b>pcre2_substitute()</b>, this modifier also has the effect of 1550 passing the replacement string as zero-terminated. 1551 </P> 1552 <br><b> 1553 Passing a NULL context 1554 </b><br> 1555 <P> 1556 Normally, <b>pcre2test</b> passes a context block to <b>pcre2_match()</b>, 1557 <b>pcre2_dfa_match()</b> or <b>pcre2_jit_match()</b>. If the <b>null_context</b> 1558 modifier is set, however, NULL is passed. This is for testing that the matching 1559 functions behave correctly in this case (they use default values). This 1560 modifier cannot be used with the <b>find_limits</b> modifier or when testing the 1561 substitution function. 1562 </P> 1563 <br><a name="SEC12" href="#TOC1">THE ALTERNATIVE MATCHING FUNCTION</a><br> 1564 <P> 1565 By default, <b>pcre2test</b> uses the standard PCRE2 matching function, 1566 <b>pcre2_match()</b> to match each subject line. PCRE2 also supports an 1567 alternative matching function, <b>pcre2_dfa_match()</b>, which operates in a 1568 different way, and has some restrictions. The differences between the two 1569 functions are described in the 1570 <a href="pcre2matching.html"><b>pcre2matching</b></a> 1571 documentation. 1572 </P> 1573 <P> 1574 If the <b>dfa</b> modifier is set, the alternative matching function is used. 1575 This function finds all possible matches at a given point in the subject. If, 1576 however, the <b>dfa_shortest</b> modifier is set, processing stops after the 1577 first match is found. This is always the shortest possible match. 1578 </P> 1579 <br><a name="SEC13" href="#TOC1">DEFAULT OUTPUT FROM pcre2test</a><br> 1580 <P> 1581 This section describes the output when the normal matching function, 1582 <b>pcre2_match()</b>, is being used. 1583 </P> 1584 <P> 1585 When a match succeeds, <b>pcre2test</b> outputs the list of captured substrings, 1586 starting with number 0 for the string that matched the whole pattern. 1587 Otherwise, it outputs "No match" when the return is PCRE2_ERROR_NOMATCH, or 1588 "Partial match:" followed by the partially matching substring when the 1589 return is PCRE2_ERROR_PARTIAL. (Note that this is the 1590 entire substring that was inspected during the partial match; it may include 1591 characters before the actual match start if a lookbehind assertion, \K, \b, 1592 or \B was involved.) 1593 </P> 1594 <P> 1595 For any other return, <b>pcre2test</b> outputs the PCRE2 negative error number 1596 and a short descriptive phrase. If the error is a failed UTF string check, the 1597 code unit offset of the start of the failing character is also output. Here is 1598 an example of an interactive <b>pcre2test</b> run. 1599 <pre> 1600 $ pcre2test 1601 PCRE2 version 10.22 2016-07-29 1602 1603 re> /^abc(\d+)/ 1604 data> abc123 1605 0: abc123 1606 1: 123 1607 data> xyz 1608 No match 1609 </pre> 1610 Unset capturing substrings that are not followed by one that is set are not 1611 shown by <b>pcre2test</b> unless the <b>allcaptures</b> modifier is specified. In 1612 the following example, there are two capturing substrings, but when the first 1613 data line is matched, the second, unset substring is not shown. An "internal" 1614 unset substring is shown as "<unset>", as for the second data line. 1615 <pre> 1616 re> /(a)|(b)/ 1617 data> a 1618 0: a 1619 1: a 1620 data> b 1621 0: b 1622 1: <unset> 1623 2: b 1624 </pre> 1625 If the strings contain any non-printing characters, they are output as \xhh 1626 escapes if the value is less than 256 and UTF mode is not set. Otherwise they 1627 are output as \x{hh...} escapes. See below for the definition of non-printing 1628 characters. If the <b>aftertext</b> modifier is set, the output for substring 1629 0 is followed by the the rest of the subject string, identified by "0+" like 1630 this: 1631 <pre> 1632 re> /cat/aftertext 1633 data> cataract 1634 0: cat 1635 0+ aract 1636 </pre> 1637 If global matching is requested, the results of successive matching attempts 1638 are output in sequence, like this: 1639 <pre> 1640 re> /\Bi(\w\w)/g 1641 data> Mississippi 1642 0: iss 1643 1: ss 1644 0: iss 1645 1: ss 1646 0: ipp 1647 1: pp 1648 </pre> 1649 "No match" is output only if the first match attempt fails. Here is an example 1650 of a failure message (the offset 4 that is specified by the <b>offset</b> 1651 modifier is past the end of the subject string): 1652 <pre> 1653 re> /xyz/ 1654 data> xyz\=offset=4 1655 Error -24 (bad offset value) 1656 </PRE> 1657 </P> 1658 <P> 1659 Note that whereas patterns can be continued over several lines (a plain ">" 1660 prompt is used for continuations), subject lines may not. However newlines can 1661 be included in a subject by means of the \n escape (or \r, \r\n, etc., 1662 depending on the newline sequence setting). 1663 </P> 1664 <br><a name="SEC14" href="#TOC1">OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION</a><br> 1665 <P> 1666 When the alternative matching function, <b>pcre2_dfa_match()</b>, is used, the 1667 output consists of a list of all the matches that start at the first point in 1668 the subject where there is at least one match. For example: 1669 <pre> 1670 re> /(tang|tangerine|tan)/ 1671 data> yellow tangerine\=dfa 1672 0: tangerine 1673 1: tang 1674 2: tan 1675 </pre> 1676 Using the normal matching function on this data finds only "tang". The 1677 longest matching string is always given first (and numbered zero). After a 1678 PCRE2_ERROR_PARTIAL return, the output is "Partial match:", followed by the 1679 partially matching substring. Note that this is the entire substring that was 1680 inspected during the partial match; it may include characters before the actual 1681 match start if a lookbehind assertion, \b, or \B was involved. (\K is not 1682 supported for DFA matching.) 1683 </P> 1684 <P> 1685 If global matching is requested, the search for further matches resumes 1686 at the end of the longest match. For example: 1687 <pre> 1688 re> /(tang|tangerine|tan)/g 1689 data> yellow tangerine and tangy sultana\=dfa 1690 0: tangerine 1691 1: tang 1692 2: tan 1693 0: tang 1694 1: tan 1695 0: tan 1696 </pre> 1697 The alternative matching function does not support substring capture, so the 1698 modifiers that are concerned with captured substrings are not relevant. 1699 </P> 1700 <br><a name="SEC15" href="#TOC1">RESTARTING AFTER A PARTIAL MATCH</a><br> 1701 <P> 1702 When the alternative matching function has given the PCRE2_ERROR_PARTIAL 1703 return, indicating that the subject partially matched the pattern, you can 1704 restart the match with additional subject data by means of the 1705 <b>dfa_restart</b> modifier. For example: 1706 <pre> 1707 re> /^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$/ 1708 data> 23ja\=P,dfa 1709 Partial match: 23ja 1710 data> n05\=dfa,dfa_restart 1711 0: n05 1712 </pre> 1713 For further information about partial matching, see the 1714 <a href="pcre2partial.html"><b>pcre2partial</b></a> 1715 documentation. 1716 <a name="callouts"></a></P> 1717 <br><a name="SEC16" href="#TOC1">CALLOUTS</a><br> 1718 <P> 1719 If the pattern contains any callout requests, <b>pcre2test</b>'s callout 1720 function is called during matching unless <b>callout_none</b> is specified. This 1721 works with both matching functions, and with JIT, though there are some 1722 differences in behaviour. The output for callouts with numerical arguments and 1723 those with string arguments is slightly different. 1724 </P> 1725 <br><b> 1726 Callouts with numerical arguments 1727 </b><br> 1728 <P> 1729 By default, the callout function displays the callout number, the start and 1730 current positions in the subject text at the callout time, and the next pattern 1731 item to be tested. For example: 1732 <pre> 1733 --->pqrabcdef 1734 0 ^ ^ \d 1735 </pre> 1736 This output indicates that callout number 0 occurred for a match attempt 1737 starting at the fourth character of the subject string, when the pointer was at 1738 the seventh character, and when the next pattern item was \d. Just 1739 one circumflex is output if the start and current positions are the same, or if 1740 the current position precedes the start position, which can happen if the 1741 callout is in a lookbehind assertion. 1742 </P> 1743 <P> 1744 Callouts numbered 255 are assumed to be automatic callouts, inserted as a 1745 result of the <b>auto_callout</b> pattern modifier. In this case, instead of 1746 showing the callout number, the offset in the pattern, preceded by a plus, is 1747 output. For example: 1748 <pre> 1749 re> /\d?[A-E]\*/auto_callout 1750 data> E* 1751 --->E* 1752 +0 ^ \d? 1753 +3 ^ [A-E] 1754 +8 ^^ \* 1755 +10 ^ ^ 1756 0: E* 1757 </pre> 1758 If a pattern contains (*MARK) items, an additional line is output whenever 1759 a change of latest mark is passed to the callout function. For example: 1760 <pre> 1761 re> /a(*MARK:X)bc/auto_callout 1762 data> abc 1763 --->abc 1764 +0 ^ a 1765 +1 ^^ (*MARK:X) 1766 +10 ^^ b 1767 Latest Mark: X 1768 +11 ^ ^ c 1769 +12 ^ ^ 1770 0: abc 1771 </pre> 1772 The mark changes between matching "a" and "b", but stays the same for the rest 1773 of the match, so nothing more is output. If, as a result of backtracking, the 1774 mark reverts to being unset, the text "<unset>" is output. 1775 </P> 1776 <br><b> 1777 Callouts with string arguments 1778 </b><br> 1779 <P> 1780 The output for a callout with a string argument is similar, except that instead 1781 of outputting a callout number before the position indicators, the callout 1782 string and its offset in the pattern string are output before the reflection of 1783 the subject string, and the subject string is reflected for each callout. For 1784 example: 1785 <pre> 1786 re> /^ab(?C'first')cd(?C"second")ef/ 1787 data> abcdefg 1788 Callout (7): 'first' 1789 --->abcdefg 1790 ^ ^ c 1791 Callout (20): "second" 1792 --->abcdefg 1793 ^ ^ e 1794 0: abcdef 1795 1796 </PRE> 1797 </P> 1798 <br><b> 1799 Callout modifiers 1800 </b><br> 1801 <P> 1802 The callout function in <b>pcre2test</b> returns zero (carry on matching) by 1803 default, but you can use a <b>callout_fail</b> modifier in a subject line to 1804 change this and other parameters of the callout (see below). 1805 </P> 1806 <P> 1807 If the <b>callout_capture</b> modifier is set, the current captured groups are 1808 output when a callout occurs. This is useful only for non-DFA matching, as 1809 <b>pcre2_dfa_match()</b> does not support capturing, so no captures are ever 1810 shown. 1811 </P> 1812 <P> 1813 The normal callout output, showing the callout number or pattern offset (as 1814 described above) is suppressed if the <b>callout_no_where</b> modifier is set. 1815 </P> 1816 <P> 1817 When using the interpretive matching function <b>pcre2_match()</b> without JIT, 1818 setting the <b>callout_extra</b> modifier causes additional output from 1819 <b>pcre2test</b>'s callout function to be generated. For the first callout in a 1820 match attempt at a new starting position in the subject, "New match attempt" is 1821 output. If there has been a backtrack since the last callout (or start of 1822 matching if this is the first callout), "Backtrack" is output, followed by "No 1823 other matching paths" if the backtrack ended the previous match attempt. For 1824 example: 1825 <pre> 1826 re> /(a+)b/auto_callout,no_start_optimize,no_auto_possess 1827 data> aac\=callout_extra 1828 New match attempt 1829 --->aac 1830 +0 ^ ( 1831 +1 ^ a+ 1832 +3 ^ ^ ) 1833 +4 ^ ^ b 1834 Backtrack 1835 --->aac 1836 +3 ^^ ) 1837 +4 ^^ b 1838 Backtrack 1839 No other matching paths 1840 New match attempt 1841 --->aac 1842 +0 ^ ( 1843 +1 ^ a+ 1844 +3 ^^ ) 1845 +4 ^^ b 1846 Backtrack 1847 No other matching paths 1848 New match attempt 1849 --->aac 1850 +0 ^ ( 1851 +1 ^ a+ 1852 Backtrack 1853 No other matching paths 1854 New match attempt 1855 --->aac 1856 +0 ^ ( 1857 +1 ^ a+ 1858 No match 1859 </pre> 1860 Notice that various optimizations must be turned off if you want all possible 1861 matching paths to be scanned. If <b>no_start_optimize</b> is not used, there is 1862 an immediate "no match", without any callouts, because the starting 1863 optimization fails to find "b" in the subject, which it knows must be present 1864 for any match. If <b>no_auto_possess</b> is not used, the "a+" item is turned 1865 into "a++", which reduces the number of backtracks. 1866 </P> 1867 <P> 1868 The <b>callout_extra</b> modifier has no effect if used with the DFA matching 1869 function, or with JIT. 1870 </P> 1871 <br><b> 1872 Return values from callouts 1873 </b><br> 1874 <P> 1875 The default return from the callout function is zero, which allows matching to 1876 continue. The <b>callout_fail</b> modifier can be given one or two numbers. If 1877 there is only one number, 1 is returned instead of 0 (causing matching to 1878 backtrack) when a callout of that number is reached. If two numbers (<n>:<m>) 1879 are given, 1 is returned when callout <n> is reached and there have been at 1880 least <m> callouts. The <b>callout_error</b> modifier is similar, except that 1881 PCRE2_ERROR_CALLOUT is returned, causing the entire matching process to be 1882 aborted. If both these modifiers are set for the same callout number, 1883 <b>callout_error</b> takes precedence. Note that callouts with string arguments 1884 are always given the number zero. 1885 </P> 1886 <P> 1887 The <b>callout_data</b> modifier can be given an unsigned or a negative number. 1888 This is set as the "user data" that is passed to the matching function, and 1889 passed back when the callout function is invoked. Any value other than zero is 1890 used as a return from <b>pcre2test</b>'s callout function. 1891 </P> 1892 <P> 1893 Inserting callouts can be helpful when using <b>pcre2test</b> to check 1894 complicated regular expressions. For further information about callouts, see 1895 the 1896 <a href="pcre2callout.html"><b>pcre2callout</b></a> 1897 documentation. 1898 </P> 1899 <br><a name="SEC17" href="#TOC1">NON-PRINTING CHARACTERS</a><br> 1900 <P> 1901 When <b>pcre2test</b> is outputting text in the compiled version of a pattern, 1902 bytes other than 32-126 are always treated as non-printing characters and are 1903 therefore shown as hex escapes. 1904 </P> 1905 <P> 1906 When <b>pcre2test</b> is outputting text that is a matched part of a subject 1907 string, it behaves in the same way, unless a different locale has been set for 1908 the pattern (using the <b>locale</b> modifier). In this case, the 1909 <b>isprint()</b> function is used to distinguish printing and non-printing 1910 characters. 1911 <a name="saverestore"></a></P> 1912 <br><a name="SEC18" href="#TOC1">SAVING AND RESTORING COMPILED PATTERNS</a><br> 1913 <P> 1914 It is possible to save compiled patterns on disc or elsewhere, and reload them 1915 later, subject to a number of restrictions. JIT data cannot be saved. The host 1916 on which the patterns are reloaded must be running the same version of PCRE2, 1917 with the same code unit width, and must also have the same endianness, pointer 1918 width and PCRE2_SIZE type. Before compiled patterns can be saved they must be 1919 serialized, that is, converted to a stream of bytes. A single byte stream may 1920 contain any number of compiled patterns, but they must all use the same 1921 character tables. A single copy of the tables is included in the byte stream 1922 (its size is 1088 bytes). 1923 </P> 1924 <P> 1925 The functions whose names begin with <b>pcre2_serialize_</b> are used 1926 for serializing and de-serializing. They are described in the 1927 <a href="pcre2serialize.html"><b>pcre2serialize</b></a> 1928 documentation. In this section we describe the features of <b>pcre2test</b> that 1929 can be used to test these functions. 1930 </P> 1931 <P> 1932 Note that "serialization" in PCRE2 does not convert compiled patterns to an 1933 abstract format like Java or .NET. It just makes a reloadable byte code stream. 1934 Hence the restrictions on reloading mentioned above. 1935 </P> 1936 <P> 1937 In <b>pcre2test</b>, when a pattern with <b>push</b> modifier is successfully 1938 compiled, it is pushed onto a stack of compiled patterns, and <b>pcre2test</b> 1939 expects the next line to contain a new pattern (or command) instead of a 1940 subject line. By contrast, the <b>pushcopy</b> modifier causes a copy of the 1941 compiled pattern to be stacked, leaving the original available for immediate 1942 matching. By using <b>push</b> and/or <b>pushcopy</b>, a number of patterns can 1943 be compiled and retained. These modifiers are incompatible with <b>posix</b>, 1944 and control modifiers that act at match time are ignored (with a message) for 1945 the stacked patterns. The <b>jitverify</b> modifier applies only at compile 1946 time. 1947 </P> 1948 <P> 1949 The command 1950 <pre> 1951 #save <filename> 1952 </pre> 1953 causes all the stacked patterns to be serialized and the result written to the 1954 named file. Afterwards, all the stacked patterns are freed. The command 1955 <pre> 1956 #load <filename> 1957 </pre> 1958 reads the data in the file, and then arranges for it to be de-serialized, with 1959 the resulting compiled patterns added to the pattern stack. The pattern on the 1960 top of the stack can be retrieved by the #pop command, which must be followed 1961 by lines of subjects that are to be matched with the pattern, terminated as 1962 usual by an empty line or end of file. This command may be followed by a 1963 modifier list containing only 1964 <a href="#controlmodifiers">control modifiers</a> 1965 that act after a pattern has been compiled. In particular, <b>hex</b>, 1966 <b>posix</b>, <b>posix_nosub</b>, <b>push</b>, and <b>pushcopy</b> are not allowed, 1967 nor are any 1968 <a href="#optionmodifiers">option-setting modifiers.</a> 1969 The JIT modifiers are, however permitted. Here is an example that saves and 1970 reloads two patterns. 1971 <pre> 1972 /abc/push 1973 /xyz/push 1974 #save tempfile 1975 #load tempfile 1976 #pop info 1977 xyz 1978 1979 #pop jit,bincode 1980 abc 1981 </pre> 1982 If <b>jitverify</b> is used with #pop, it does not automatically imply 1983 <b>jit</b>, which is different behaviour from when it is used on a pattern. 1984 </P> 1985 <P> 1986 The #popcopy command is analagous to the <b>pushcopy</b> modifier in that it 1987 makes current a copy of the topmost stack pattern, leaving the original still 1988 on the stack. 1989 </P> 1990 <br><a name="SEC19" href="#TOC1">SEE ALSO</a><br> 1991 <P> 1992 <b>pcre2</b>(3), <b>pcre2api</b>(3), <b>pcre2callout</b>(3), 1993 <b>pcre2jit</b>, <b>pcre2matching</b>(3), <b>pcre2partial</b>(d), 1994 <b>pcre2pattern</b>(3), <b>pcre2serialize</b>(3). 1995 </P> 1996 <br><a name="SEC20" href="#TOC1">AUTHOR</a><br> 1997 <P> 1998 Philip Hazel 1999 <br> 2000 University Computing Service 2001 <br> 2002 Cambridge, England. 2003 <br> 2004 </P> 2005 <br><a name="SEC21" href="#TOC1">REVISION</a><br> 2006 <P> 2007 Last updated: 21 July 2018 2008 <br> 2009 Copyright © 1997-2018 University of Cambridge. 2010 <br> 2011 <p> 2012 Return to the <a href="index.html">PCRE2 index page</a>. 2013 </p> 2014
