1<html> 2<head> 3<title>pcretest specification</title> 4</head> 5<body bgcolor="#FFFFFF" text="#00005A" link="#0066FF" alink="#3399FF" vlink="#2222BB"> 6<h1>pcretest man page</h1> 7<p> 8Return to the <a href="index.html">PCRE index page</a>. 9</p> 10<p> 11This page is part of the PCRE HTML documentation. It was generated automatically 12from the original man page. If there is any nonsense in it, please consult the 13man 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">PCRE's 8-BIT and 16-BIT LIBRARIES</a> 18<li><a name="TOC3" href="#SEC3">COMMAND LINE OPTIONS</a> 19<li><a name="TOC4" href="#SEC4">DESCRIPTION</a> 20<li><a name="TOC5" href="#SEC5">PATTERN MODIFIERS</a> 21<li><a name="TOC6" href="#SEC6">DATA LINES</a> 22<li><a name="TOC7" href="#SEC7">THE ALTERNATIVE MATCHING FUNCTION</a> 23<li><a name="TOC8" href="#SEC8">DEFAULT OUTPUT FROM PCRETEST</a> 24<li><a name="TOC9" href="#SEC9">OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION</a> 25<li><a name="TOC10" href="#SEC10">RESTARTING AFTER A PARTIAL MATCH</a> 26<li><a name="TOC11" href="#SEC11">CALLOUTS</a> 27<li><a name="TOC12" href="#SEC12">NON-PRINTING CHARACTERS</a> 28<li><a name="TOC13" href="#SEC13">SAVING AND RELOADING COMPILED PATTERNS</a> 29<li><a name="TOC14" href="#SEC14">SEE ALSO</a> 30<li><a name="TOC15" href="#SEC15">AUTHOR</a> 31<li><a name="TOC16" href="#SEC16">REVISION</a> 32</ul> 33<br><a name="SEC1" href="#TOC1">SYNOPSIS</a><br> 34<P> 35<b>pcretest [options] [input file [output file]]</b> 36<br> 37<br> 38<b>pcretest</b> was written as a test program for the PCRE regular expression 39library itself, but it can also be used for experimenting with regular 40expressions. This document describes the features of the test program; for 41details of the regular expressions themselves, see the 42<a href="pcrepattern.html"><b>pcrepattern</b></a> 43documentation. For details of the PCRE library function calls and their 44options, see the 45<a href="pcreapi.html"><b>pcreapi</b></a> 46and 47<a href="pcre16.html"><b>pcre16</b></a> 48documentation. The input for <b>pcretest</b> is a sequence of regular expression 49patterns and strings to be matched, as described below. The output shows the 50result of each match. Options on the command line and the patterns control PCRE 51options and exactly what is output. 52</P> 53<br><a name="SEC2" href="#TOC1">PCRE's 8-BIT and 16-BIT LIBRARIES</a><br> 54<P> 55From release 8.30, two separate PCRE libraries can be built. The original one 56supports 8-bit character strings, whereas the newer 16-bit library supports 57character strings encoded in 16-bit units. The <b>pcretest</b> program can be 58used to test both libraries. However, it is itself still an 8-bit program, 59reading 8-bit input and writing 8-bit output. When testing the 16-bit library, 60the patterns and data strings are converted to 16-bit format before being 61passed to the PCRE library functions. Results are converted to 8-bit for 62output. 63</P> 64<P> 65References to functions and structures of the form <b>pcre[16]_xx</b> below 66mean "<b>pcre_xx</b> when using the 8-bit library or <b>pcre16_xx</b> when using 67the 16-bit library". 68</P> 69<br><a name="SEC3" href="#TOC1">COMMAND LINE OPTIONS</a><br> 70<P> 71<b>-16</b> 72If both the 8-bit and the 16-bit libraries have been built, this option causes 73the 16-bit library to be used. If only the 16-bit library has been built, this 74is the default (so has no effect). If only the 8-bit library has been built, 75this option causes an error. 76</P> 77<P> 78<b>-b</b> 79Behave as if each pattern has the <b>/B</b> (show byte code) modifier; the 80internal form is output after compilation. 81</P> 82<P> 83<b>-C</b> 84Output the version number of the PCRE library, and all available information 85about the optional features that are included, and then exit. All other options 86are ignored. 87</P> 88<P> 89<b>-C</b> <i>option</i> 90Output information about a specific build-time option, then exit. This 91functionality is intended for use in scripts such as <b>RunTest</b>. The 92following options output the value indicated: 93<pre> 94 linksize the internal link size (2, 3, or 4) 95 newline the default newline setting: 96 CR, LF, CRLF, ANYCRLF, or ANY 97</pre> 98The following options output 1 for true or zero for false: 99<pre> 100 jit just-in-time support is available 101 pcre16 the 16-bit library was built 102 pcre8 the 8-bit library was built 103 ucp Unicode property support is available 104 utf UTF-8 and/or UTF-16 support is available 105</PRE> 106</P> 107<P> 108<b>-d</b> 109Behave as if each pattern has the <b>/D</b> (debug) modifier; the internal 110form and information about the compiled pattern is output after compilation; 111<b>-d</b> is equivalent to <b>-b -i</b>. 112</P> 113<P> 114<b>-dfa</b> 115Behave as if each data line contains the \D escape sequence; this causes the 116alternative matching function, <b>pcre[16]_dfa_exec()</b>, to be used instead of 117the standard <b>pcre[16]_exec()</b> function (more detail is given below). 118</P> 119<P> 120<b>-help</b> 121Output a brief summary these options and then exit. 122</P> 123<P> 124<b>-i</b> 125Behave as if each pattern has the <b>/I</b> modifier; information about the 126compiled pattern is given after compilation. 127</P> 128<P> 129<b>-M</b> 130Behave as if each data line contains the \M escape sequence; this causes 131PCRE to discover the minimum MATCH_LIMIT and MATCH_LIMIT_RECURSION settings by 132calling <b>pcre[16]_exec()</b> repeatedly with different limits. 133</P> 134<P> 135<b>-m</b> 136Output the size of each compiled pattern after it has been compiled. This is 137equivalent to adding <b>/M</b> to each regular expression. The size is given in 138bytes for both libraries. 139</P> 140<P> 141<b>-o</b> <i>osize</i> 142Set the number of elements in the output vector that is used when calling 143<b>pcre[16]_exec()</b> or <b>pcre[16]_dfa_exec()</b> to be <i>osize</i>. The 144default value is 45, which is enough for 14 capturing subexpressions for 145<b>pcre[16]_exec()</b> or 22 different matches for <b>pcre[16]_dfa_exec()</b>. 146The vector size can be changed for individual matching calls by including \O 147in the data line (see below). 148</P> 149<P> 150<b>-p</b> 151Behave as if each pattern has the <b>/P</b> modifier; the POSIX wrapper API is 152used to call PCRE. None of the other options has any effect when <b>-p</b> is 153set. This option can be used only with the 8-bit library. 154</P> 155<P> 156<b>-q</b> 157Do not output the version number of <b>pcretest</b> at the start of execution. 158</P> 159<P> 160<b>-S</b> <i>size</i> 161On Unix-like systems, set the size of the run-time stack to <i>size</i> 162megabytes. 163</P> 164<P> 165<b>-s</b> or <b>-s+</b> 166Behave as if each pattern has the <b>/S</b> modifier; in other words, force each 167pattern to be studied. If <b>-s+</b> is used, all the JIT compile options are 168passed to <b>pcre[16]_study()</b>, causing just-in-time optimization to be set 169up if it is available, for both full and partial matching. Specific JIT compile 170options can be selected by following <b>-s+</b> with a digit in the range 1 to 1717, which selects the JIT compile modes as follows: 172<pre> 173 1 normal match only 174 2 soft partial match only 175 3 normal match and soft partial match 176 4 hard partial match only 177 6 soft and hard partial match 178 7 all three modes (default) 179</pre> 180If <b>-s++</b> is used instead of <b>-s+</b> (with or without a following digit), 181the text "(JIT)" is added to the first output line after a match or no match 182when JIT-compiled code was actually used. 183</P> 184<P> 185If the <b>/I</b> or <b>/D</b> option is present on a pattern (requesting output 186about the compiled pattern), information about the result of studying is not 187included when studying is caused only by <b>-s</b> and neither <b>-i</b> nor 188<b>-d</b> is present on the command line. This behaviour means that the output 189from tests that are run with and without <b>-s</b> should be identical, except 190when options that output information about the actual running of a match are 191set. 192<br> 193<br> 194The <b>-M</b>, <b>-t</b>, and <b>-tm</b> options, which give information about 195resources used, are likely to produce different output with and without 196<b>-s</b>. Output may also differ if the <b>/C</b> option is present on an 197individual pattern. This uses callouts to trace the the matching process, and 198this may be different between studied and non-studied patterns. If the pattern 199contains (*MARK) items there may also be differences, for the same reason. The 200<b>-s</b> command line option can be overridden for specific patterns that 201should never be studied (see the <b>/S</b> pattern modifier below). 202</P> 203<P> 204<b>-t</b> 205Run each compile, study, and match many times with a timer, and output 206resulting time per compile or match (in milliseconds). Do not set <b>-m</b> with 207<b>-t</b>, because you will then get the size output a zillion times, and the 208timing will be distorted. You can control the number of iterations that are 209used for timing by following <b>-t</b> with a number (as a separate item on the 210command line). For example, "-t 1000" would iterate 1000 times. The default is 211to iterate 500000 times. 212</P> 213<P> 214<b>-tm</b> 215This is like <b>-t</b> except that it times only the matching phase, not the 216compile or study phases. 217</P> 218<br><a name="SEC4" href="#TOC1">DESCRIPTION</a><br> 219<P> 220If <b>pcretest</b> is given two filename arguments, it reads from the first and 221writes to the second. If it is given only one filename argument, it reads from 222that file and writes to stdout. Otherwise, it reads from stdin and writes to 223stdout, and prompts for each line of input, using "re>" to prompt for regular 224expressions, and "data>" to prompt for data lines. 225</P> 226<P> 227When <b>pcretest</b> is built, a configuration option can specify that it should 228be linked with the <b>libreadline</b> library. When this is done, if the input 229is from a terminal, it is read using the <b>readline()</b> function. This 230provides line-editing and history facilities. The output from the <b>-help</b> 231option states whether or not <b>readline()</b> will be used. 232</P> 233<P> 234The program handles any number of sets of input on a single input file. Each 235set starts with a regular expression, and continues with any number of data 236lines to be matched against the pattern. 237</P> 238<P> 239Each data line is matched separately and independently. If you want to do 240multi-line matches, you have to use the \n escape sequence (or \r or \r\n, 241etc., depending on the newline setting) in a single line of input to encode the 242newline sequences. There is no limit on the length of data lines; the input 243buffer is automatically extended if it is too small. 244</P> 245<P> 246An empty line signals the end of the data lines, at which point a new regular 247expression is read. The regular expressions are given enclosed in any 248non-alphanumeric delimiters other than backslash, for example: 249<pre> 250 /(a|bc)x+yz/ 251</pre> 252White space before the initial delimiter is ignored. A regular expression may 253be continued over several input lines, in which case the newline characters are 254included within it. It is possible to include the delimiter within the pattern 255by escaping it, for example 256<pre> 257 /abc\/def/ 258</pre> 259If you do so, the escape and the delimiter form part of the pattern, but since 260delimiters are always non-alphanumeric, this does not affect its interpretation. 261If the terminating delimiter is immediately followed by a backslash, for 262example, 263<pre> 264 /abc/\ 265</pre> 266then a backslash is added to the end of the pattern. This is done to provide a 267way of testing the error condition that arises if a pattern finishes with a 268backslash, because 269<pre> 270 /abc\/ 271</pre> 272is interpreted as the first line of a pattern that starts with "abc/", causing 273pcretest to read the next line as a continuation of the regular expression. 274</P> 275<br><a name="SEC5" href="#TOC1">PATTERN MODIFIERS</a><br> 276<P> 277A pattern may be followed by any number of modifiers, which are mostly single 278characters. Following Perl usage, these are referred to below as, for example, 279"the <b>/i</b> modifier", even though the delimiter of the pattern need not 280always be a slash, and no slash is used when writing modifiers. White space may 281appear between the final pattern delimiter and the first modifier, and between 282the modifiers themselves. 283</P> 284<P> 285The <b>/i</b>, <b>/m</b>, <b>/s</b>, and <b>/x</b> modifiers set the PCRE_CASELESS, 286PCRE_MULTILINE, PCRE_DOTALL, or PCRE_EXTENDED options, respectively, when 287<b>pcre[16]_compile()</b> is called. These four modifier letters have the same 288effect as they do in Perl. For example: 289<pre> 290 /caseless/i 291</pre> 292The following table shows additional modifiers for setting PCRE compile-time 293options that do not correspond to anything in Perl: 294<pre> 295 <b>/8</b> PCRE_UTF8 ) when using the 8-bit 296 <b>/?</b> PCRE_NO_UTF8_CHECK ) library 297 298 <b>/8</b> PCRE_UTF16 ) when using the 16-bit 299 <b>/?</b> PCRE_NO_UTF16_CHECK ) library 300 301 <b>/A</b> PCRE_ANCHORED 302 <b>/C</b> PCRE_AUTO_CALLOUT 303 <b>/E</b> PCRE_DOLLAR_ENDONLY 304 <b>/f</b> PCRE_FIRSTLINE 305 <b>/J</b> PCRE_DUPNAMES 306 <b>/N</b> PCRE_NO_AUTO_CAPTURE 307 <b>/U</b> PCRE_UNGREEDY 308 <b>/W</b> PCRE_UCP 309 <b>/X</b> PCRE_EXTRA 310 <b>/Y</b> PCRE_NO_START_OPTIMIZE 311 <b>/<JS></b> PCRE_JAVASCRIPT_COMPAT 312 <b>/<cr></b> PCRE_NEWLINE_CR 313 <b>/<lf></b> PCRE_NEWLINE_LF 314 <b>/<crlf></b> PCRE_NEWLINE_CRLF 315 <b>/<anycrlf></b> PCRE_NEWLINE_ANYCRLF 316 <b>/<any></b> PCRE_NEWLINE_ANY 317 <b>/<bsr_anycrlf></b> PCRE_BSR_ANYCRLF 318 <b>/<bsr_unicode></b> PCRE_BSR_UNICODE 319</pre> 320The modifiers that are enclosed in angle brackets are literal strings as shown, 321including the angle brackets, but the letters within can be in either case. 322This example sets multiline matching with CRLF as the line ending sequence: 323<pre> 324 /^abc/m<CRLF> 325</pre> 326As well as turning on the PCRE_UTF8/16 option, the <b>/8</b> modifier causes 327all non-printing characters in output strings to be printed using the 328\x{hh...} notation. Otherwise, those less than 0x100 are output in hex without 329the curly brackets. 330</P> 331<P> 332Full details of the PCRE options are given in the 333<a href="pcreapi.html"><b>pcreapi</b></a> 334documentation. 335</P> 336<br><b> 337Finding all matches in a string 338</b><br> 339<P> 340Searching for all possible matches within each subject string can be requested 341by the <b>/g</b> or <b>/G</b> modifier. After finding a match, PCRE is called 342again to search the remainder of the subject string. The difference between 343<b>/g</b> and <b>/G</b> is that the former uses the <i>startoffset</i> argument to 344<b>pcre[16]_exec()</b> to start searching at a new point within the entire 345string (which is in effect what Perl does), whereas the latter passes over a 346shortened substring. This makes a difference to the matching process if the 347pattern begins with a lookbehind assertion (including \b or \B). 348</P> 349<P> 350If any call to <b>pcre[16]_exec()</b> in a <b>/g</b> or <b>/G</b> sequence matches 351an empty string, the next call is done with the PCRE_NOTEMPTY_ATSTART and 352PCRE_ANCHORED flags set in order to search for another, non-empty, match at the 353same point. If this second match fails, the start offset is advanced, and the 354normal match is retried. This imitates the way Perl handles such cases when 355using the <b>/g</b> modifier or the <b>split()</b> function. Normally, the start 356offset is advanced by one character, but if the newline convention recognizes 357CRLF as a newline, and the current character is CR followed by LF, an advance 358of two is used. 359</P> 360<br><b> 361Other modifiers 362</b><br> 363<P> 364There are yet more modifiers for controlling the way <b>pcretest</b> 365operates. 366</P> 367<P> 368The <b>/+</b> modifier requests that as well as outputting the substring that 369matched the entire pattern, <b>pcretest</b> should in addition output the 370remainder of the subject string. This is useful for tests where the subject 371contains multiple copies of the same substring. If the <b>+</b> modifier appears 372twice, the same action is taken for captured substrings. In each case the 373remainder is output on the following line with a plus character following the 374capture number. Note that this modifier must not immediately follow the /S 375modifier because /S+ and /S++ have other meanings. 376</P> 377<P> 378The <b>/=</b> modifier requests that the values of all potential captured 379parentheses be output after a match. By default, only those up to the highest 380one actually used in the match are output (corresponding to the return code 381from <b>pcre[16]_exec()</b>). Values in the offsets vector corresponding to 382higher numbers should be set to -1, and these are output as "<unset>". This 383modifier gives a way of checking that this is happening. 384</P> 385<P> 386The <b>/B</b> modifier is a debugging feature. It requests that <b>pcretest</b> 387output a representation of the compiled code after compilation. Normally this 388information contains length and offset values; however, if <b>/Z</b> is also 389present, this data is replaced by spaces. This is a special feature for use in 390the automatic test scripts; it ensures that the same output is generated for 391different internal link sizes. 392</P> 393<P> 394The <b>/D</b> modifier is a PCRE debugging feature, and is equivalent to 395<b>/BI</b>, that is, both the <b>/B</b> and the <b>/I</b> modifiers. 396</P> 397<P> 398The <b>/F</b> modifier causes <b>pcretest</b> to flip the byte order of the 3992-byte and 4-byte fields in the compiled pattern. This facility is for testing 400the feature in PCRE that allows it to execute patterns that were compiled on a 401host with a different endianness. This feature is not available when the POSIX 402interface to PCRE is being used, that is, when the <b>/P</b> pattern modifier is 403specified. See also the section about saving and reloading compiled patterns 404below. 405</P> 406<P> 407The <b>/I</b> modifier requests that <b>pcretest</b> output information about the 408compiled pattern (whether it is anchored, has a fixed first character, and 409so on). It does this by calling <b>pcre[16]_fullinfo()</b> after compiling a 410pattern. If the pattern is studied, the results of that are also output. 411</P> 412<P> 413The <b>/K</b> modifier requests <b>pcretest</b> to show names from backtracking 414control verbs that are returned from calls to <b>pcre[16]_exec()</b>. It causes 415<b>pcretest</b> to create a <b>pcre[16]_extra</b> block if one has not already 416been created by a call to <b>pcre[16]_study()</b>, and to set the 417PCRE_EXTRA_MARK flag and the <b>mark</b> field within it, every time that 418<b>pcre[16]_exec()</b> is called. If the variable that the <b>mark</b> field 419points to is non-NULL for a match, non-match, or partial match, <b>pcretest</b> 420prints the string to which it points. For a match, this is shown on a line by 421itself, tagged with "MK:". For a non-match it is added to the message. 422</P> 423<P> 424The <b>/L</b> modifier must be followed directly by the name of a locale, for 425example, 426<pre> 427 /pattern/Lfr_FR 428</pre> 429For this reason, it must be the last modifier. The given locale is set, 430<b>pcre[16]_maketables()</b> is called to build a set of character tables for 431the locale, and this is then passed to <b>pcre[16]_compile()</b> when compiling 432the regular expression. Without an <b>/L</b> (or <b>/T</b>) modifier, NULL is 433passed as the tables pointer; that is, <b>/L</b> applies only to the expression 434on which it appears. 435</P> 436<P> 437The <b>/M</b> modifier causes the size in bytes of the memory block used to hold 438the compiled pattern to be output. This does not include the size of the 439<b>pcre[16]</b> block; it is just the actual compiled data. If the pattern is 440successfully studied with the PCRE_STUDY_JIT_COMPILE option, the size of the 441JIT compiled code is also output. 442</P> 443<P> 444If the <b>/S</b> modifier appears once, it causes <b>pcre[16]_study()</b> to be 445called after the expression has been compiled, and the results used when the 446expression is matched. If <b>/S</b> appears twice, it suppresses studying, even 447if it was requested externally by the <b>-s</b> command line option. This makes 448it possible to specify that certain patterns are always studied, and others are 449never studied, independently of <b>-s</b>. This feature is used in the test 450files in a few cases where the output is different when the pattern is studied. 451</P> 452<P> 453If the <b>/S</b> modifier is immediately followed by a + character, the call to 454<b>pcre[16]_study()</b> is made with all the JIT study options, requesting 455just-in-time optimization support if it is available, for both normal and 456partial matching. If you want to restrict the JIT compiling modes, you can 457follow <b>/S+</b> with a digit in the range 1 to 7: 458<pre> 459 1 normal match only 460 2 soft partial match only 461 3 normal match and soft partial match 462 4 hard partial match only 463 6 soft and hard partial match 464 7 all three modes (default) 465</pre> 466If <b>/S++</b> is used instead of <b>/S+</b> (with or without a following digit), 467the text "(JIT)" is added to the first output line after a match or no match 468when JIT-compiled code was actually used. 469</P> 470<P> 471Note that there is also an independent <b>/+</b> modifier; it must not be given 472immediately after <b>/S</b> or <b>/S+</b> because this will be misinterpreted. 473</P> 474<P> 475If JIT studying is successful, the compiled JIT code will automatically be used 476when <b>pcre[16]_exec()</b> is run, except when incompatible run-time options 477are specified. For more details, see the 478<a href="pcrejit.html"><b>pcrejit</b></a> 479documentation. See also the <b>\J</b> escape sequence below for a way of 480setting the size of the JIT stack. 481</P> 482<P> 483The <b>/T</b> modifier must be followed by a single digit. It causes a specific 484set of built-in character tables to be passed to <b>pcre[16]_compile()</b>. It 485is used in the standard PCRE tests to check behaviour with different character 486tables. The digit specifies the tables as follows: 487<pre> 488 0 the default ASCII tables, as distributed in 489 pcre_chartables.c.dist 490 1 a set of tables defining ISO 8859 characters 491</pre> 492In table 1, some characters whose codes are greater than 128 are identified as 493letters, digits, spaces, etc. 494</P> 495<br><b> 496Using the POSIX wrapper API 497</b><br> 498<P> 499The <b>/P</b> modifier causes <b>pcretest</b> to call PCRE via the POSIX wrapper 500API rather than its native API. This supports only the 8-bit library. When 501<b>/P</b> is set, the following modifiers set options for the <b>regcomp()</b> 502function: 503<pre> 504 /i REG_ICASE 505 /m REG_NEWLINE 506 /N REG_NOSUB 507 /s REG_DOTALL ) 508 /U REG_UNGREEDY ) These options are not part of 509 /W REG_UCP ) the POSIX standard 510 /8 REG_UTF8 ) 511</pre> 512The <b>/+</b> modifier works as described above. All other modifiers are 513ignored. 514</P> 515<br><a name="SEC6" href="#TOC1">DATA LINES</a><br> 516<P> 517Before each data line is passed to <b>pcre[16]_exec()</b>, leading and trailing 518white space is removed, and it is then scanned for \ escapes. Some of these 519are pretty esoteric features, intended for checking out some of the more 520complicated features of PCRE. If you are just testing "ordinary" regular 521expressions, you probably don't need any of these. The following escapes are 522recognized: 523<pre> 524 \a alarm (BEL, \x07) 525 \b backspace (\x08) 526 \e escape (\x27) 527 \f form feed (\x0c) 528 \n newline (\x0a) 529 \qdd set the PCRE_MATCH_LIMIT limit to dd (any number of digits) 530 \r carriage return (\x0d) 531 \t tab (\x09) 532 \v vertical tab (\x0b) 533 \nnn octal character (up to 3 octal digits); always 534 a byte unless > 255 in UTF-8 or 16-bit mode 535 \xhh hexadecimal byte (up to 2 hex digits) 536 \x{hh...} hexadecimal character (any number of hex digits) 537 \A pass the PCRE_ANCHORED option to <b>pcre[16]_exec()</b> or <b>pcre[16]_dfa_exec()</b> 538 \B pass the PCRE_NOTBOL option to <b>pcre[16]_exec()</b> or <b>pcre[16]_dfa_exec()</b> 539 \Cdd call pcre[16]_copy_substring() for substring dd after a successful match (number less than 32) 540 \Cname call pcre[16]_copy_named_substring() for substring "name" after a successful match (name termin- 541 ated by next non alphanumeric character) 542 \C+ show the current captured substrings at callout time 543 \C- do not supply a callout function 544 \C!n return 1 instead of 0 when callout number n is reached 545 \C!n!m return 1 instead of 0 when callout number n is reached for the nth time 546 \C*n pass the number n (may be negative) as callout data; this is used as the callout return value 547 \D use the <b>pcre[16]_dfa_exec()</b> match function 548 \F only shortest match for <b>pcre[16]_dfa_exec()</b> 549 \Gdd call pcre[16]_get_substring() for substring dd after a successful match (number less than 32) 550 \Gname call pcre[16]_get_named_substring() for substring "name" after a successful match (name termin- 551 ated by next non-alphanumeric character) 552 \Jdd set up a JIT stack of dd kilobytes maximum (any number of digits) 553 \L call pcre[16]_get_substringlist() after a successful match 554 \M discover the minimum MATCH_LIMIT and MATCH_LIMIT_RECURSION settings 555 \N pass the PCRE_NOTEMPTY option to <b>pcre[16]_exec()</b> or <b>pcre[16]_dfa_exec()</b>; if used twice, pass the 556 PCRE_NOTEMPTY_ATSTART option 557 \Odd set the size of the output vector passed to <b>pcre[16]_exec()</b> to dd (any number of digits) 558 \P pass the PCRE_PARTIAL_SOFT option to <b>pcre[16]_exec()</b> or <b>pcre[16]_dfa_exec()</b>; if used twice, pass the 559 PCRE_PARTIAL_HARD option 560 \Qdd set the PCRE_MATCH_LIMIT_RECURSION limit to dd (any number of digits) 561 \R pass the PCRE_DFA_RESTART option to <b>pcre[16]_dfa_exec()</b> 562 \S output details of memory get/free calls during matching 563 \Y pass the PCRE_NO_START_OPTIMIZE option to <b>pcre[16]_exec()</b> or <b>pcre[16]_dfa_exec()</b> 564 \Z pass the PCRE_NOTEOL option to <b>pcre[16]_exec()</b> or <b>pcre[16]_dfa_exec()</b> 565 \? pass the PCRE_NO_UTF[8|16]_CHECK option to <b>pcre[16]_exec()</b> or <b>pcre[16]_dfa_exec()</b> 566 \>dd start the match at offset dd (optional "-"; then any number of digits); this sets the <i>startoffset</i> 567 argument for <b>pcre[16]_exec()</b> or <b>pcre[16]_dfa_exec()</b> 568 \<cr> pass the PCRE_NEWLINE_CR option to <b>pcre[16]_exec()</b> or <b>pcre[16]_dfa_exec()</b> 569 \<lf> pass the PCRE_NEWLINE_LF option to <b>pcre[16]_exec()</b> or <b>pcre[16]_dfa_exec()</b> 570 \<crlf> pass the PCRE_NEWLINE_CRLF option to <b>pcre[16]_exec()</b> or <b>pcre[16]_dfa_exec()</b> 571 \<anycrlf> pass the PCRE_NEWLINE_ANYCRLF option to <b>pcre[16]_exec()</b> or <b>pcre[16]_dfa_exec()</b> 572 \<any> pass the PCRE_NEWLINE_ANY option to <b>pcre[16]_exec()</b> or <b>pcre[16]_dfa_exec()</b> 573</pre> 574The use of \x{hh...} is not dependent on the use of the <b>/8</b> modifier on 575the pattern. It is recognized always. There may be any number of hexadecimal 576digits inside the braces; invalid values provoke error messages. 577</P> 578<P> 579Note that \xhh specifies one byte rather than one character in UTF-8 mode; 580this makes it possible to construct invalid UTF-8 sequences for testing 581purposes. On the other hand, \x{hh} is interpreted as a UTF-8 character in 582UTF-8 mode, generating more than one byte if the value is greater than 127. 583When testing the 8-bit library not in UTF-8 mode, \x{hh} generates one byte 584for values less than 256, and causes an error for greater values. 585</P> 586<P> 587In UTF-16 mode, all 4-digit \x{hhhh} values are accepted. This makes it 588possible to construct invalid UTF-16 sequences for testing purposes. 589</P> 590<P> 591The escapes that specify line ending sequences are literal strings, exactly as 592shown. No more than one newline setting should be present in any data line. 593</P> 594<P> 595A backslash followed by anything else just escapes the anything else. If 596the very last character is a backslash, it is ignored. This gives a way of 597passing an empty line as data, since a real empty line terminates the data 598input. 599</P> 600<P> 601The <b>\J</b> escape provides a way of setting the maximum stack size that is 602used by the just-in-time optimization code. It is ignored if JIT optimization 603is not being used. Providing a stack that is larger than the default 32K is 604necessary only for very complicated patterns. 605</P> 606<P> 607If \M is present, <b>pcretest</b> calls <b>pcre[16]_exec()</b> several times, 608with different values in the <i>match_limit</i> and <i>match_limit_recursion</i> 609fields of the <b>pcre[16]_extra</b> data structure, until it finds the minimum 610numbers for each parameter that allow <b>pcre[16]_exec()</b> to complete without 611error. Because this is testing a specific feature of the normal interpretive 612<b>pcre[16]_exec()</b> execution, the use of any JIT optimization that might 613have been set up by the <b>/S+</b> qualifier of <b>-s+</b> option is disabled. 614</P> 615<P> 616The <i>match_limit</i> number is a measure of the amount of backtracking 617that takes place, and checking it out can be instructive. For most simple 618matches, the number is quite small, but for patterns with very large numbers of 619matching possibilities, it can become large very quickly with increasing length 620of subject string. The <i>match_limit_recursion</i> number is a measure of how 621much stack (or, if PCRE is compiled with NO_RECURSE, how much heap) memory is 622needed to complete the match attempt. 623</P> 624<P> 625When \O is used, the value specified may be higher or lower than the size set 626by the <b>-O</b> command line option (or defaulted to 45); \O applies only to 627the call of <b>pcre[16]_exec()</b> for the line in which it appears. 628</P> 629<P> 630If the <b>/P</b> modifier was present on the pattern, causing the POSIX wrapper 631API to be used, the only option-setting sequences that have any effect are \B, 632\N, and \Z, causing REG_NOTBOL, REG_NOTEMPTY, and REG_NOTEOL, respectively, 633to be passed to <b>regexec()</b>. 634</P> 635<br><a name="SEC7" href="#TOC1">THE ALTERNATIVE MATCHING FUNCTION</a><br> 636<P> 637By default, <b>pcretest</b> uses the standard PCRE matching function, 638<b>pcre[16]_exec()</b> to match each data line. PCRE also supports an 639alternative matching function, <b>pcre[16]_dfa_test()</b>, which operates in a 640different way, and has some restrictions. The differences between the two 641functions are described in the 642<a href="pcrematching.html"><b>pcrematching</b></a> 643documentation. 644</P> 645<P> 646If a data line contains the \D escape sequence, or if the command line 647contains the <b>-dfa</b> option, the alternative matching function is used. 648This function finds all possible matches at a given point. If, however, the \F 649escape sequence is present in the data line, it stops after the first match is 650found. This is always the shortest possible match. 651</P> 652<br><a name="SEC8" href="#TOC1">DEFAULT OUTPUT FROM PCRETEST</a><br> 653<P> 654This section describes the output when the normal matching function, 655<b>pcre[16]_exec()</b>, is being used. 656</P> 657<P> 658When a match succeeds, <b>pcretest</b> outputs the list of captured substrings 659that <b>pcre[16]_exec()</b> returns, starting with number 0 for the string that 660matched the whole pattern. Otherwise, it outputs "No match" when the return is 661PCRE_ERROR_NOMATCH, and "Partial match:" followed by the partially matching 662substring when <b>pcre[16]_exec()</b> returns PCRE_ERROR_PARTIAL. (Note that 663this is the entire substring that was inspected during the partial match; it 664may include characters before the actual match start if a lookbehind assertion, 665\K, \b, or \B was involved.) For any other return, <b>pcretest</b> outputs 666the PCRE negative error number and a short descriptive phrase. If the error is 667a failed UTF string check, the offset of the start of the failing character and 668the reason code are also output, provided that the size of the output vector is 669at least two. Here is an example of an interactive <b>pcretest</b> run. 670<pre> 671 $ pcretest 672 PCRE version 8.13 2011-04-30 673 674 re> /^abc(\d+)/ 675 data> abc123 676 0: abc123 677 1: 123 678 data> xyz 679 No match 680</pre> 681Unset capturing substrings that are not followed by one that is set are not 682returned by <b>pcre[16]_exec()</b>, and are not shown by <b>pcretest</b>. In the 683following example, there are two capturing substrings, but when the first data 684line is matched, the second, unset substring is not shown. An "internal" unset 685substring is shown as "<unset>", as for the second data line. 686<pre> 687 re> /(a)|(b)/ 688 data> a 689 0: a 690 1: a 691 data> b 692 0: b 693 1: <unset> 694 2: b 695</pre> 696If the strings contain any non-printing characters, they are output as \xhh 697escapes if the value is less than 256 and UTF mode is not set. Otherwise they 698are output as \x{hh...} escapes. See below for the definition of non-printing 699characters. If the pattern has the <b>/+</b> modifier, the output for substring 7000 is followed by the the rest of the subject string, identified by "0+" like 701this: 702<pre> 703 re> /cat/+ 704 data> cataract 705 0: cat 706 0+ aract 707</pre> 708If the pattern has the <b>/g</b> or <b>/G</b> modifier, the results of successive 709matching attempts are output in sequence, like this: 710<pre> 711 re> /\Bi(\w\w)/g 712 data> Mississippi 713 0: iss 714 1: ss 715 0: iss 716 1: ss 717 0: ipp 718 1: pp 719</pre> 720"No match" is output only if the first match attempt fails. Here is an example 721of a failure message (the offset 4 that is specified by \>4 is past the end of 722the subject string): 723<pre> 724 re> /xyz/ 725 data> xyz\>4 726 Error -24 (bad offset value) 727</PRE> 728</P> 729<P> 730If any of the sequences <b>\C</b>, <b>\G</b>, or <b>\L</b> are present in a 731data line that is successfully matched, the substrings extracted by the 732convenience functions are output with C, G, or L after the string number 733instead of a colon. This is in addition to the normal full list. The string 734length (that is, the return from the extraction function) is given in 735parentheses after each string for <b>\C</b> and <b>\G</b>. 736</P> 737<P> 738Note that whereas patterns can be continued over several lines (a plain ">" 739prompt is used for continuations), data lines may not. However newlines can be 740included in data by means of the \n escape (or \r, \r\n, etc., depending on 741the newline sequence setting). 742</P> 743<br><a name="SEC9" href="#TOC1">OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION</a><br> 744<P> 745When the alternative matching function, <b>pcre[16]_dfa_exec()</b>, is used (by 746means of the \D escape sequence or the <b>-dfa</b> command line option), the 747output consists of a list of all the matches that start at the first point in 748the subject where there is at least one match. For example: 749<pre> 750 re> /(tang|tangerine|tan)/ 751 data> yellow tangerine\D 752 0: tangerine 753 1: tang 754 2: tan 755</pre> 756(Using the normal matching function on this data finds only "tang".) The 757longest matching string is always given first (and numbered zero). After a 758PCRE_ERROR_PARTIAL return, the output is "Partial match:", followed by the 759partially matching substring. (Note that this is the entire substring that was 760inspected during the partial match; it may include characters before the actual 761match start if a lookbehind assertion, \K, \b, or \B was involved.) 762</P> 763<P> 764If <b>/g</b> is present on the pattern, the search for further matches resumes 765at the end of the longest match. For example: 766<pre> 767 re> /(tang|tangerine|tan)/g 768 data> yellow tangerine and tangy sultana\D 769 0: tangerine 770 1: tang 771 2: tan 772 0: tang 773 1: tan 774 0: tan 775</pre> 776Since the matching function does not support substring capture, the escape 777sequences that are concerned with captured substrings are not relevant. 778</P> 779<br><a name="SEC10" href="#TOC1">RESTARTING AFTER A PARTIAL MATCH</a><br> 780<P> 781When the alternative matching function has given the PCRE_ERROR_PARTIAL return, 782indicating that the subject partially matched the pattern, you can restart the 783match with additional subject data by means of the \R escape sequence. For 784example: 785<pre> 786 re> /^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$/ 787 data> 23ja\P\D 788 Partial match: 23ja 789 data> n05\R\D 790 0: n05 791</pre> 792For further information about partial matching, see the 793<a href="pcrepartial.html"><b>pcrepartial</b></a> 794documentation. 795</P> 796<br><a name="SEC11" href="#TOC1">CALLOUTS</a><br> 797<P> 798If the pattern contains any callout requests, <b>pcretest</b>'s callout function 799is called during matching. This works with both matching functions. By default, 800the called function displays the callout number, the start and current 801positions in the text at the callout time, and the next pattern item to be 802tested. For example: 803<pre> 804 --->pqrabcdef 805 0 ^ ^ \d 806</pre> 807This output indicates that callout number 0 occurred for a match attempt 808starting at the fourth character of the subject string, when the pointer was at 809the seventh character of the data, and when the next pattern item was \d. Just 810one circumflex is output if the start and current positions are the same. 811</P> 812<P> 813Callouts numbered 255 are assumed to be automatic callouts, inserted as a 814result of the <b>/C</b> pattern modifier. In this case, instead of showing the 815callout number, the offset in the pattern, preceded by a plus, is output. For 816example: 817<pre> 818 re> /\d?[A-E]\*/C 819 data> E* 820 --->E* 821 +0 ^ \d? 822 +3 ^ [A-E] 823 +8 ^^ \* 824 +10 ^ ^ 825 0: E* 826</pre> 827If a pattern contains (*MARK) items, an additional line is output whenever 828a change of latest mark is passed to the callout function. For example: 829<pre> 830 re> /a(*MARK:X)bc/C 831 data> abc 832 --->abc 833 +0 ^ a 834 +1 ^^ (*MARK:X) 835 +10 ^^ b 836 Latest Mark: X 837 +11 ^ ^ c 838 +12 ^ ^ 839 0: abc 840</pre> 841The mark changes between matching "a" and "b", but stays the same for the rest 842of the match, so nothing more is output. If, as a result of backtracking, the 843mark reverts to being unset, the text "<unset>" is output. 844</P> 845<P> 846The callout function in <b>pcretest</b> returns zero (carry on matching) by 847default, but you can use a \C item in a data line (as described above) to 848change this and other parameters of the callout. 849</P> 850<P> 851Inserting callouts can be helpful when using <b>pcretest</b> to check 852complicated regular expressions. For further information about callouts, see 853the 854<a href="pcrecallout.html"><b>pcrecallout</b></a> 855documentation. 856</P> 857<br><a name="SEC12" href="#TOC1">NON-PRINTING CHARACTERS</a><br> 858<P> 859When <b>pcretest</b> is outputting text in the compiled version of a pattern, 860bytes other than 32-126 are always treated as non-printing characters are are 861therefore shown as hex escapes. 862</P> 863<P> 864When <b>pcretest</b> is outputting text that is a matched part of a subject 865string, it behaves in the same way, unless a different locale has been set for 866the pattern (using the <b>/L</b> modifier). In this case, the <b>isprint()</b> 867function to distinguish printing and non-printing characters. 868</P> 869<br><a name="SEC13" href="#TOC1">SAVING AND RELOADING COMPILED PATTERNS</a><br> 870<P> 871The facilities described in this section are not available when the POSIX 872interface to PCRE is being used, that is, when the <b>/P</b> pattern modifier is 873specified. 874</P> 875<P> 876When the POSIX interface is not in use, you can cause <b>pcretest</b> to write a 877compiled pattern to a file, by following the modifiers with > and a file name. 878For example: 879<pre> 880 /pattern/im >/some/file 881</pre> 882See the 883<a href="pcreprecompile.html"><b>pcreprecompile</b></a> 884documentation for a discussion about saving and re-using compiled patterns. 885Note that if the pattern was successfully studied with JIT optimization, the 886JIT data cannot be saved. 887</P> 888<P> 889The data that is written is binary. The first eight bytes are the length of the 890compiled pattern data followed by the length of the optional study data, each 891written as four bytes in big-endian order (most significant byte first). If 892there is no study data (either the pattern was not studied, or studying did not 893return any data), the second length is zero. The lengths are followed by an 894exact copy of the compiled pattern. If there is additional study data, this 895(excluding any JIT data) follows immediately after the compiled pattern. After 896writing the file, <b>pcretest</b> expects to read a new pattern. 897</P> 898<P> 899A saved pattern can be reloaded into <b>pcretest</b> by specifying < and a file 900name instead of a pattern. The name of the file must not contain a < character, 901as otherwise <b>pcretest</b> will interpret the line as a pattern delimited by < 902characters. 903For example: 904<pre> 905 re> </some/file 906 Compiled pattern loaded from /some/file 907 No study data 908</pre> 909If the pattern was previously studied with the JIT optimization, the JIT 910information cannot be saved and restored, and so is lost. When the pattern has 911been loaded, <b>pcretest</b> proceeds to read data lines in the usual way. 912</P> 913<P> 914You can copy a file written by <b>pcretest</b> to a different host and reload it 915there, even if the new host has opposite endianness to the one on which the 916pattern was compiled. For example, you can compile on an i86 machine and run on 917a SPARC machine. When a pattern is reloaded on a host with different 918endianness, the confirmation message is changed to: 919<pre> 920 Compiled pattern (byte-inverted) loaded from /some/file 921</pre> 922The test suite contains some saved pre-compiled patterns with different 923endianness. These are reloaded using "<!" instead of just "<". This suppresses 924the "(byte-inverted)" text so that the output is the same on all hosts. It also 925forces debugging output once the pattern has been reloaded. 926</P> 927<P> 928File names for saving and reloading can be absolute or relative, but note that 929the shell facility of expanding a file name that starts with a tilde (~) is not 930available. 931</P> 932<P> 933The ability to save and reload files in <b>pcretest</b> is intended for testing 934and experimentation. It is not intended for production use because only a 935single pattern can be written to a file. Furthermore, there is no facility for 936supplying custom character tables for use with a reloaded pattern. If the 937original pattern was compiled with custom tables, an attempt to match a subject 938string using a reloaded pattern is likely to cause <b>pcretest</b> to crash. 939Finally, if you attempt to load a file that is not in the correct format, the 940result is undefined. 941</P> 942<br><a name="SEC14" href="#TOC1">SEE ALSO</a><br> 943<P> 944<b>pcre</b>(3), <b>pcre16</b>(3), <b>pcreapi</b>(3), <b>pcrecallout</b>(3), 945<b>pcrejit</b>, <b>pcrematching</b>(3), <b>pcrepartial</b>(d), 946<b>pcrepattern</b>(3), <b>pcreprecompile</b>(3). 947</P> 948<br><a name="SEC15" href="#TOC1">AUTHOR</a><br> 949<P> 950Philip Hazel 951<br> 952University Computing Service 953<br> 954Cambridge CB2 3QH, England. 955<br> 956</P> 957<br><a name="SEC16" href="#TOC1">REVISION</a><br> 958<P> 959Last updated: 21 February 2012 960<br> 961Copyright © 1997-2012 University of Cambridge. 962<br> 963<p> 964Return to the <a href="index.html">PCRE index page</a>. 965</p> 966