Annotation of embedaddon/pcre/doc/html/pcretest.html, revision 1.1
1.1 ! misho 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>
! 8: Return to the <a href="index.html">PCRE index page</a>.
! 9: </p>
! 10: <p>
! 11: This page is part of the PCRE HTML documentation. It was generated automatically
! 12: from the original man page. If there is any nonsense in it, please consult the
! 13: 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">COMMAND LINE OPTIONS</a>
! 18: <li><a name="TOC3" href="#SEC3">DESCRIPTION</a>
! 19: <li><a name="TOC4" href="#SEC4">PATTERN MODIFIERS</a>
! 20: <li><a name="TOC5" href="#SEC5">DATA LINES</a>
! 21: <li><a name="TOC6" href="#SEC6">THE ALTERNATIVE MATCHING FUNCTION</a>
! 22: <li><a name="TOC7" href="#SEC7">DEFAULT OUTPUT FROM PCRETEST</a>
! 23: <li><a name="TOC8" href="#SEC8">OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION</a>
! 24: <li><a name="TOC9" href="#SEC9">RESTARTING AFTER A PARTIAL MATCH</a>
! 25: <li><a name="TOC10" href="#SEC10">CALLOUTS</a>
! 26: <li><a name="TOC11" href="#SEC11">NON-PRINTING CHARACTERS</a>
! 27: <li><a name="TOC12" href="#SEC12">SAVING AND RELOADING COMPILED PATTERNS</a>
! 28: <li><a name="TOC13" href="#SEC13">SEE ALSO</a>
! 29: <li><a name="TOC14" href="#SEC14">AUTHOR</a>
! 30: <li><a name="TOC15" href="#SEC15">REVISION</a>
! 31: </ul>
! 32: <br><a name="SEC1" href="#TOC1">SYNOPSIS</a><br>
! 33: <P>
! 34: <b>pcretest [options] [input file [output file]]</b>
! 35: <br>
! 36: <br>
! 37: <b>pcretest</b> was written as a test program for the PCRE regular expression
! 38: library itself, but it can also be used for experimenting with regular
! 39: expressions. This document describes the features of the test program; for
! 40: details of the regular expressions themselves, see the
! 41: <a href="pcrepattern.html"><b>pcrepattern</b></a>
! 42: documentation. For details of the PCRE library function calls and their
! 43: options, see the
! 44: <a href="pcreapi.html"><b>pcreapi</b></a>
! 45: documentation. The input for <b>pcretest</b> is a sequence of regular expression
! 46: patterns and strings to be matched, as described below. The output shows the
! 47: result of each match. Options on the command line and the patterns control PCRE
! 48: options and exactly what is output.
! 49: </P>
! 50: <br><a name="SEC2" href="#TOC1">COMMAND LINE OPTIONS</a><br>
! 51: <P>
! 52: <b>-b</b>
! 53: Behave as if each pattern has the <b>/B</b> (show byte code) modifier; the
! 54: internal form is output after compilation.
! 55: </P>
! 56: <P>
! 57: <b>-C</b>
! 58: Output the version number of the PCRE library, and all available information
! 59: about the optional features that are included, and then exit.
! 60: </P>
! 61: <P>
! 62: <b>-d</b>
! 63: Behave as if each pattern has the <b>/D</b> (debug) modifier; the internal
! 64: form and information about the compiled pattern is output after compilation;
! 65: <b>-d</b> is equivalent to <b>-b -i</b>.
! 66: </P>
! 67: <P>
! 68: <b>-dfa</b>
! 69: Behave as if each data line contains the \D escape sequence; this causes the
! 70: alternative matching function, <b>pcre_dfa_exec()</b>, to be used instead of the
! 71: standard <b>pcre_exec()</b> function (more detail is given below).
! 72: </P>
! 73: <P>
! 74: <b>-help</b>
! 75: Output a brief summary these options and then exit.
! 76: </P>
! 77: <P>
! 78: <b>-i</b>
! 79: Behave as if each pattern has the <b>/I</b> modifier; information about the
! 80: compiled pattern is given after compilation.
! 81: </P>
! 82: <P>
! 83: <b>-M</b>
! 84: Behave as if each data line contains the \M escape sequence; this causes
! 85: PCRE to discover the minimum MATCH_LIMIT and MATCH_LIMIT_RECURSION settings by
! 86: calling <b>pcre_exec()</b> repeatedly with different limits.
! 87: </P>
! 88: <P>
! 89: <b>-m</b>
! 90: Output the size of each compiled pattern after it has been compiled. This is
! 91: equivalent to adding <b>/M</b> to each regular expression.
! 92: </P>
! 93: <P>
! 94: <b>-o</b> <i>osize</i>
! 95: Set the number of elements in the output vector that is used when calling
! 96: <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b> to be <i>osize</i>. The default value
! 97: is 45, which is enough for 14 capturing subexpressions for <b>pcre_exec()</b> or
! 98: 22 different matches for <b>pcre_dfa_exec()</b>. The vector size can be
! 99: changed for individual matching calls by including \O in the data line (see
! 100: below).
! 101: </P>
! 102: <P>
! 103: <b>-p</b>
! 104: Behave as if each pattern has the <b>/P</b> modifier; the POSIX wrapper API is
! 105: used to call PCRE. None of the other options has any effect when <b>-p</b> is
! 106: set.
! 107: </P>
! 108: <P>
! 109: <b>-q</b>
! 110: Do not output the version number of <b>pcretest</b> at the start of execution.
! 111: </P>
! 112: <P>
! 113: <b>-S</b> <i>size</i>
! 114: On Unix-like systems, set the size of the run-time stack to <i>size</i>
! 115: megabytes.
! 116: </P>
! 117: <P>
! 118: <b>-s</b> or <b>-s+</b>
! 119: Behave as if each pattern has the <b>/S</b> modifier; in other words, force each
! 120: pattern to be studied. If <b>-s+</b> is used, the PCRE_STUDY_JIT_COMPILE flag is
! 121: passed to <b>pcre_study()</b>, causing just-in-time optimization to be set up if
! 122: it is available. If the <b>/I</b> or <b>/D</b> option is present on a pattern
! 123: (requesting output about the compiled pattern), information about the result of
! 124: studying is not included when studying is caused only by <b>-s</b> and neither
! 125: <b>-i</b> nor <b>-d</b> is present on the command line. This behaviour means that
! 126: the output from tests that are run with and without <b>-s</b> should be
! 127: identical, except when options that output information about the actual running
! 128: of a match are set. The <b>-M</b>, <b>-t</b>, and <b>-tm</b> options, which give
! 129: information about resources used, are likely to produce different output with
! 130: and without <b>-s</b>. Output may also differ if the <b>/C</b> option is present
! 131: on an individual pattern. This uses callouts to trace the the matching process,
! 132: and this may be different between studied and non-studied patterns. If the
! 133: pattern contains (*MARK) items there may also be differences, for the same
! 134: reason. The <b>-s</b> command line option can be overridden for specific
! 135: patterns that should never be studied (see the <b>/S</b> pattern modifier
! 136: below).
! 137: </P>
! 138: <P>
! 139: <b>-t</b>
! 140: Run each compile, study, and match many times with a timer, and output
! 141: resulting time per compile or match (in milliseconds). Do not set <b>-m</b> with
! 142: <b>-t</b>, because you will then get the size output a zillion times, and the
! 143: timing will be distorted. You can control the number of iterations that are
! 144: used for timing by following <b>-t</b> with a number (as a separate item on the
! 145: command line). For example, "-t 1000" would iterate 1000 times. The default is
! 146: to iterate 500000 times.
! 147: </P>
! 148: <P>
! 149: <b>-tm</b>
! 150: This is like <b>-t</b> except that it times only the matching phase, not the
! 151: compile or study phases.
! 152: </P>
! 153: <br><a name="SEC3" href="#TOC1">DESCRIPTION</a><br>
! 154: <P>
! 155: If <b>pcretest</b> is given two filename arguments, it reads from the first and
! 156: writes to the second. If it is given only one filename argument, it reads from
! 157: that file and writes to stdout. Otherwise, it reads from stdin and writes to
! 158: stdout, and prompts for each line of input, using "re>" to prompt for regular
! 159: expressions, and "data>" to prompt for data lines.
! 160: </P>
! 161: <P>
! 162: When <b>pcretest</b> is built, a configuration option can specify that it should
! 163: be linked with the <b>libreadline</b> library. When this is done, if the input
! 164: is from a terminal, it is read using the <b>readline()</b> function. This
! 165: provides line-editing and history facilities. The output from the <b>-help</b>
! 166: option states whether or not <b>readline()</b> will be used.
! 167: </P>
! 168: <P>
! 169: The program handles any number of sets of input on a single input file. Each
! 170: set starts with a regular expression, and continues with any number of data
! 171: lines to be matched against the pattern.
! 172: </P>
! 173: <P>
! 174: Each data line is matched separately and independently. If you want to do
! 175: multi-line matches, you have to use the \n escape sequence (or \r or \r\n,
! 176: etc., depending on the newline setting) in a single line of input to encode the
! 177: newline sequences. There is no limit on the length of data lines; the input
! 178: buffer is automatically extended if it is too small.
! 179: </P>
! 180: <P>
! 181: An empty line signals the end of the data lines, at which point a new regular
! 182: expression is read. The regular expressions are given enclosed in any
! 183: non-alphanumeric delimiters other than backslash, for example:
! 184: <pre>
! 185: /(a|bc)x+yz/
! 186: </pre>
! 187: White space before the initial delimiter is ignored. A regular expression may
! 188: be continued over several input lines, in which case the newline characters are
! 189: included within it. It is possible to include the delimiter within the pattern
! 190: by escaping it, for example
! 191: <pre>
! 192: /abc\/def/
! 193: </pre>
! 194: If you do so, the escape and the delimiter form part of the pattern, but since
! 195: delimiters are always non-alphanumeric, this does not affect its interpretation.
! 196: If the terminating delimiter is immediately followed by a backslash, for
! 197: example,
! 198: <pre>
! 199: /abc/\
! 200: </pre>
! 201: then a backslash is added to the end of the pattern. This is done to provide a
! 202: way of testing the error condition that arises if a pattern finishes with a
! 203: backslash, because
! 204: <pre>
! 205: /abc\/
! 206: </pre>
! 207: is interpreted as the first line of a pattern that starts with "abc/", causing
! 208: pcretest to read the next line as a continuation of the regular expression.
! 209: </P>
! 210: <br><a name="SEC4" href="#TOC1">PATTERN MODIFIERS</a><br>
! 211: <P>
! 212: A pattern may be followed by any number of modifiers, which are mostly single
! 213: characters. Following Perl usage, these are referred to below as, for example,
! 214: "the <b>/i</b> modifier", even though the delimiter of the pattern need not
! 215: always be a slash, and no slash is used when writing modifiers. White space may
! 216: appear between the final pattern delimiter and the first modifier, and between
! 217: the modifiers themselves.
! 218: </P>
! 219: <P>
! 220: The <b>/i</b>, <b>/m</b>, <b>/s</b>, and <b>/x</b> modifiers set the PCRE_CASELESS,
! 221: PCRE_MULTILINE, PCRE_DOTALL, or PCRE_EXTENDED options, respectively, when
! 222: <b>pcre_compile()</b> is called. These four modifier letters have the same
! 223: effect as they do in Perl. For example:
! 224: <pre>
! 225: /caseless/i
! 226: </pre>
! 227: The following table shows additional modifiers for setting PCRE compile-time
! 228: options that do not correspond to anything in Perl:
! 229: <pre>
! 230: <b>/8</b> PCRE_UTF8
! 231: <b>/?</b> PCRE_NO_UTF8_CHECK
! 232: <b>/A</b> PCRE_ANCHORED
! 233: <b>/C</b> PCRE_AUTO_CALLOUT
! 234: <b>/E</b> PCRE_DOLLAR_ENDONLY
! 235: <b>/f</b> PCRE_FIRSTLINE
! 236: <b>/J</b> PCRE_DUPNAMES
! 237: <b>/N</b> PCRE_NO_AUTO_CAPTURE
! 238: <b>/U</b> PCRE_UNGREEDY
! 239: <b>/W</b> PCRE_UCP
! 240: <b>/X</b> PCRE_EXTRA
! 241: <b>/Y</b> PCRE_NO_START_OPTIMIZE
! 242: <b>/<JS></b> PCRE_JAVASCRIPT_COMPAT
! 243: <b>/<cr></b> PCRE_NEWLINE_CR
! 244: <b>/<lf></b> PCRE_NEWLINE_LF
! 245: <b>/<crlf></b> PCRE_NEWLINE_CRLF
! 246: <b>/<anycrlf></b> PCRE_NEWLINE_ANYCRLF
! 247: <b>/<any></b> PCRE_NEWLINE_ANY
! 248: <b>/<bsr_anycrlf></b> PCRE_BSR_ANYCRLF
! 249: <b>/<bsr_unicode></b> PCRE_BSR_UNICODE
! 250: </pre>
! 251: The modifiers that are enclosed in angle brackets are literal strings as shown,
! 252: including the angle brackets, but the letters within can be in either case.
! 253: This example sets multiline matching with CRLF as the line ending sequence:
! 254: <pre>
! 255: /^abc/m<CRLF>
! 256: </pre>
! 257: As well as turning on the PCRE_UTF8 option, the <b>/8</b> modifier also causes
! 258: any non-printing characters in output strings to be printed using the
! 259: \x{hh...} notation if they are valid UTF-8 sequences. Full details of the PCRE
! 260: options are given in the
! 261: <a href="pcreapi.html"><b>pcreapi</b></a>
! 262: documentation.
! 263: </P>
! 264: <br><b>
! 265: Finding all matches in a string
! 266: </b><br>
! 267: <P>
! 268: Searching for all possible matches within each subject string can be requested
! 269: by the <b>/g</b> or <b>/G</b> modifier. After finding a match, PCRE is called
! 270: again to search the remainder of the subject string. The difference between
! 271: <b>/g</b> and <b>/G</b> is that the former uses the <i>startoffset</i> argument to
! 272: <b>pcre_exec()</b> to start searching at a new point within the entire string
! 273: (which is in effect what Perl does), whereas the latter passes over a shortened
! 274: substring. This makes a difference to the matching process if the pattern
! 275: begins with a lookbehind assertion (including \b or \B).
! 276: </P>
! 277: <P>
! 278: If any call to <b>pcre_exec()</b> in a <b>/g</b> or <b>/G</b> sequence matches an
! 279: empty string, the next call is done with the PCRE_NOTEMPTY_ATSTART and
! 280: PCRE_ANCHORED flags set in order to search for another, non-empty, match at the
! 281: same point. If this second match fails, the start offset is advanced, and the
! 282: normal match is retried. This imitates the way Perl handles such cases when
! 283: using the <b>/g</b> modifier or the <b>split()</b> function. Normally, the start
! 284: offset is advanced by one character, but if the newline convention recognizes
! 285: CRLF as a newline, and the current character is CR followed by LF, an advance
! 286: of two is used.
! 287: </P>
! 288: <br><b>
! 289: Other modifiers
! 290: </b><br>
! 291: <P>
! 292: There are yet more modifiers for controlling the way <b>pcretest</b>
! 293: operates.
! 294: </P>
! 295: <P>
! 296: The <b>/+</b> modifier requests that as well as outputting the substring that
! 297: matched the entire pattern, <b>pcretest</b> should in addition output the
! 298: remainder of the subject string. This is useful for tests where the subject
! 299: contains multiple copies of the same substring. If the <b>+</b> modifier appears
! 300: twice, the same action is taken for captured substrings. In each case the
! 301: remainder is output on the following line with a plus character following the
! 302: capture number. Note that this modifier must not immediately follow the /S
! 303: modifier because /S+ has another meaning.
! 304: </P>
! 305: <P>
! 306: The <b>/=</b> modifier requests that the values of all potential captured
! 307: parentheses be output after a match by <b>pcre_exec()</b>. By default, only
! 308: those up to the highest one actually used in the match are output
! 309: (corresponding to the return code from <b>pcre_exec()</b>). Values in the
! 310: offsets vector corresponding to higher numbers should be set to -1, and these
! 311: are output as "<unset>". This modifier gives a way of checking that this is
! 312: happening.
! 313: </P>
! 314: <P>
! 315: The <b>/B</b> modifier is a debugging feature. It requests that <b>pcretest</b>
! 316: output a representation of the compiled byte code after compilation. Normally
! 317: this information contains length and offset values; however, if <b>/Z</b> is
! 318: also present, this data is replaced by spaces. This is a special feature for
! 319: use in the automatic test scripts; it ensures that the same output is generated
! 320: for different internal link sizes.
! 321: </P>
! 322: <P>
! 323: The <b>/D</b> modifier is a PCRE debugging feature, and is equivalent to
! 324: <b>/BI</b>, that is, both the <b>/B</b> and the <b>/I</b> modifiers.
! 325: </P>
! 326: <P>
! 327: The <b>/F</b> modifier causes <b>pcretest</b> to flip the byte order of the
! 328: fields in the compiled pattern that contain 2-byte and 4-byte numbers. This
! 329: facility is for testing the feature in PCRE that allows it to execute patterns
! 330: that were compiled on a host with a different endianness. This feature is not
! 331: available when the POSIX interface to PCRE is being used, that is, when the
! 332: <b>/P</b> pattern modifier is specified. See also the section about saving and
! 333: reloading compiled patterns below.
! 334: </P>
! 335: <P>
! 336: The <b>/I</b> modifier requests that <b>pcretest</b> output information about the
! 337: compiled pattern (whether it is anchored, has a fixed first character, and
! 338: so on). It does this by calling <b>pcre_fullinfo()</b> after compiling a
! 339: pattern. If the pattern is studied, the results of that are also output.
! 340: </P>
! 341: <P>
! 342: The <b>/K</b> modifier requests <b>pcretest</b> to show names from backtracking
! 343: control verbs that are returned from calls to <b>pcre_exec()</b>. It causes
! 344: <b>pcretest</b> to create a <b>pcre_extra</b> block if one has not already been
! 345: created by a call to <b>pcre_study()</b>, and to set the PCRE_EXTRA_MARK flag
! 346: and the <b>mark</b> field within it, every time that <b>pcre_exec()</b> is
! 347: called. If the variable that the <b>mark</b> field points to is non-NULL for a
! 348: match, non-match, or partial match, <b>pcretest</b> prints the string to which
! 349: it points. For a match, this is shown on a line by itself, tagged with "MK:".
! 350: For a non-match it is added to the message.
! 351: </P>
! 352: <P>
! 353: The <b>/L</b> modifier must be followed directly by the name of a locale, for
! 354: example,
! 355: <pre>
! 356: /pattern/Lfr_FR
! 357: </pre>
! 358: For this reason, it must be the last modifier. The given locale is set,
! 359: <b>pcre_maketables()</b> is called to build a set of character tables for the
! 360: locale, and this is then passed to <b>pcre_compile()</b> when compiling the
! 361: regular expression. Without an <b>/L</b> (or <b>/T</b>) modifier, NULL is passed
! 362: as the tables pointer; that is, <b>/L</b> applies only to the expression on
! 363: which it appears.
! 364: </P>
! 365: <P>
! 366: The <b>/M</b> modifier causes the size of memory block used to hold the compiled
! 367: pattern to be output. This does not include the size of the <b>pcre</b> block;
! 368: it is just the actual compiled data. If the pattern is successfully studied
! 369: with the PCRE_STUDY_JIT_COMPILE option, the size of the JIT compiled code is
! 370: also output.
! 371: </P>
! 372: <P>
! 373: If the <b>/S</b> modifier appears once, it causes <b>pcre_study()</b> to be
! 374: called after the expression has been compiled, and the results used when the
! 375: expression is matched. If <b>/S</b> appears twice, it suppresses studying, even
! 376: if it was requested externally by the <b>-s</b> command line option. This makes
! 377: it possible to specify that certain patterns are always studied, and others are
! 378: never studied, independently of <b>-s</b>. This feature is used in the test
! 379: files in a few cases where the output is different when the pattern is studied.
! 380: </P>
! 381: <P>
! 382: If the <b>/S</b> modifier is immediately followed by a + character, the call to
! 383: <b>pcre_study()</b> is made with the PCRE_STUDY_JIT_COMPILE option, requesting
! 384: just-in-time optimization support if it is available. Note that there is also a
! 385: <b>/+</b> modifier; it must not be given immediately after <b>/S</b> because this
! 386: will be misinterpreted. If JIT studying is successful, it will automatically be
! 387: used when <b>pcre_exec()</b> is run, except when incompatible run-time options
! 388: are specified. These include the partial matching options; a complete list is
! 389: given in the
! 390: <a href="pcrejit.html"><b>pcrejit</b></a>
! 391: documentation. See also the <b>\J</b> escape sequence below for a way of
! 392: setting the size of the JIT stack.
! 393: </P>
! 394: <P>
! 395: The <b>/T</b> modifier must be followed by a single digit. It causes a specific
! 396: set of built-in character tables to be passed to <b>pcre_compile()</b>. It is
! 397: used in the standard PCRE tests to check behaviour with different character
! 398: tables. The digit specifies the tables as follows:
! 399: <pre>
! 400: 0 the default ASCII tables, as distributed in
! 401: pcre_chartables.c.dist
! 402: 1 a set of tables defining ISO 8859 characters
! 403: </pre>
! 404: In table 1, some characters whose codes are greater than 128 are identified as
! 405: letters, digits, spaces, etc.
! 406: </P>
! 407: <br><b>
! 408: Using the POSIX wrapper API
! 409: </b><br>
! 410: <P>
! 411: The <b>/P</b> modifier causes <b>pcretest</b> to call PCRE via the POSIX wrapper
! 412: API rather than its native API. When <b>/P</b> is set, the following modifiers
! 413: set options for the <b>regcomp()</b> function:
! 414: <pre>
! 415: /i REG_ICASE
! 416: /m REG_NEWLINE
! 417: /N REG_NOSUB
! 418: /s REG_DOTALL )
! 419: /U REG_UNGREEDY ) These options are not part of
! 420: /W REG_UCP ) the POSIX standard
! 421: /8 REG_UTF8 )
! 422: </pre>
! 423: The <b>/+</b> modifier works as described above. All other modifiers are
! 424: ignored.
! 425: </P>
! 426: <br><a name="SEC5" href="#TOC1">DATA LINES</a><br>
! 427: <P>
! 428: Before each data line is passed to <b>pcre_exec()</b>, leading and trailing
! 429: white space is removed, and it is then scanned for \ escapes. Some of these
! 430: are pretty esoteric features, intended for checking out some of the more
! 431: complicated features of PCRE. If you are just testing "ordinary" regular
! 432: expressions, you probably don't need any of these. The following escapes are
! 433: recognized:
! 434: <pre>
! 435: \a alarm (BEL, \x07)
! 436: \b backspace (\x08)
! 437: \e escape (\x27)
! 438: \f form feed (\x0c)
! 439: \n newline (\x0a)
! 440: \qdd set the PCRE_MATCH_LIMIT limit to dd (any number of digits)
! 441: \r carriage return (\x0d)
! 442: \t tab (\x09)
! 443: \v vertical tab (\x0b)
! 444: \nnn octal character (up to 3 octal digits)
! 445: always a byte unless > 255 in UTF-8 mode
! 446: \xhh hexadecimal byte (up to 2 hex digits)
! 447: \x{hh...} hexadecimal character, any number of digits in UTF-8 mode
! 448: \A pass the PCRE_ANCHORED option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>
! 449: \B pass the PCRE_NOTBOL option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>
! 450: \Cdd call pcre_copy_substring() for substring dd after a successful match (number less than 32)
! 451: \Cname call pcre_copy_named_substring() for substring "name" after a successful match (name termin-
! 452: ated by next non alphanumeric character)
! 453: \C+ show the current captured substrings at callout time
! 454: \C- do not supply a callout function
! 455: \C!n return 1 instead of 0 when callout number n is reached
! 456: \C!n!m return 1 instead of 0 when callout number n is reached for the nth time
! 457: \C*n pass the number n (may be negative) as callout data; this is used as the callout return value
! 458: \D use the <b>pcre_dfa_exec()</b> match function
! 459: \F only shortest match for <b>pcre_dfa_exec()</b>
! 460: \Gdd call pcre_get_substring() for substring dd after a successful match (number less than 32)
! 461: \Gname call pcre_get_named_substring() for substring "name" after a successful match (name termin-
! 462: ated by next non-alphanumeric character)
! 463: \Jdd set up a JIT stack of dd kilobytes maximum (any number of digits)
! 464: \L call pcre_get_substringlist() after a successful match
! 465: \M discover the minimum MATCH_LIMIT and MATCH_LIMIT_RECURSION settings
! 466: \N pass the PCRE_NOTEMPTY option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>; if used twice, pass the
! 467: PCRE_NOTEMPTY_ATSTART option
! 468: \Odd set the size of the output vector passed to <b>pcre_exec()</b> to dd (any number of digits)
! 469: \P pass the PCRE_PARTIAL_SOFT option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>; if used twice, pass the
! 470: PCRE_PARTIAL_HARD option
! 471: \Qdd set the PCRE_MATCH_LIMIT_RECURSION limit to dd (any number of digits)
! 472: \R pass the PCRE_DFA_RESTART option to <b>pcre_dfa_exec()</b>
! 473: \S output details of memory get/free calls during matching
! 474: \Y pass the PCRE_NO_START_OPTIMIZE option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>
! 475: \Z pass the PCRE_NOTEOL option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>
! 476: \? pass the PCRE_NO_UTF8_CHECK option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>
! 477: \>dd start the match at offset dd (optional "-"; then any number of digits); this sets the <i>startoffset</i>
! 478: argument for <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>
! 479: \<cr> pass the PCRE_NEWLINE_CR option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>
! 480: \<lf> pass the PCRE_NEWLINE_LF option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>
! 481: \<crlf> pass the PCRE_NEWLINE_CRLF option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>
! 482: \<anycrlf> pass the PCRE_NEWLINE_ANYCRLF option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>
! 483: \<any> pass the PCRE_NEWLINE_ANY option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>
! 484: </pre>
! 485: Note that \xhh always specifies one byte, even in UTF-8 mode; this makes it
! 486: possible to construct invalid UTF-8 sequences for testing purposes. On the
! 487: other hand, \x{hh} is interpreted as a UTF-8 character in UTF-8 mode,
! 488: generating more than one byte if the value is greater than 127. When not in
! 489: UTF-8 mode, it generates one byte for values less than 256, and causes an error
! 490: for greater values.
! 491: </P>
! 492: <P>
! 493: The escapes that specify line ending sequences are literal strings, exactly as
! 494: shown. No more than one newline setting should be present in any data line.
! 495: </P>
! 496: <P>
! 497: A backslash followed by anything else just escapes the anything else. If
! 498: the very last character is a backslash, it is ignored. This gives a way of
! 499: passing an empty line as data, since a real empty line terminates the data
! 500: input.
! 501: </P>
! 502: <P>
! 503: The <b>\J</b> escape provides a way of setting the maximum stack size that is
! 504: used by the just-in-time optimization code. It is ignored if JIT optimization
! 505: is not being used. Providing a stack that is larger than the default 32K is
! 506: necessary only for very complicated patterns.
! 507: </P>
! 508: <P>
! 509: If \M is present, <b>pcretest</b> calls <b>pcre_exec()</b> several times, with
! 510: different values in the <i>match_limit</i> and <i>match_limit_recursion</i>
! 511: fields of the <b>pcre_extra</b> data structure, until it finds the minimum
! 512: numbers for each parameter that allow <b>pcre_exec()</b> to complete without
! 513: error. Because this is testing a specific feature of the normal interpretive
! 514: <b>pcre_exec()</b> execution, the use of any JIT optimization that might have
! 515: been set up by the <b>/S+</b> qualifier of <b>-s+</b> option is disabled.
! 516: </P>
! 517: <P>
! 518: The <i>match_limit</i> number is a measure of the amount of backtracking
! 519: that takes place, and checking it out can be instructive. For most simple
! 520: matches, the number is quite small, but for patterns with very large numbers of
! 521: matching possibilities, it can become large very quickly with increasing length
! 522: of subject string. The <i>match_limit_recursion</i> number is a measure of how
! 523: much stack (or, if PCRE is compiled with NO_RECURSE, how much heap) memory is
! 524: needed to complete the match attempt.
! 525: </P>
! 526: <P>
! 527: When \O is used, the value specified may be higher or lower than the size set
! 528: by the <b>-O</b> command line option (or defaulted to 45); \O applies only to
! 529: the call of <b>pcre_exec()</b> for the line in which it appears.
! 530: </P>
! 531: <P>
! 532: If the <b>/P</b> modifier was present on the pattern, causing the POSIX wrapper
! 533: API to be used, the only option-setting sequences that have any effect are \B,
! 534: \N, and \Z, causing REG_NOTBOL, REG_NOTEMPTY, and REG_NOTEOL, respectively,
! 535: to be passed to <b>regexec()</b>.
! 536: </P>
! 537: <P>
! 538: The use of \x{hh...} to represent UTF-8 characters is not dependent on the use
! 539: of the <b>/8</b> modifier on the pattern. It is recognized always. There may be
! 540: any number of hexadecimal digits inside the braces. The result is from one to
! 541: six bytes, encoded according to the original UTF-8 rules of RFC 2279. This
! 542: allows for values in the range 0 to 0x7FFFFFFF. Note that not all of those are
! 543: valid Unicode code points, or indeed valid UTF-8 characters according to the
! 544: later rules in RFC 3629.
! 545: </P>
! 546: <br><a name="SEC6" href="#TOC1">THE ALTERNATIVE MATCHING FUNCTION</a><br>
! 547: <P>
! 548: By default, <b>pcretest</b> uses the standard PCRE matching function,
! 549: <b>pcre_exec()</b> to match each data line. From release 6.0, PCRE supports an
! 550: alternative matching function, <b>pcre_dfa_test()</b>, which operates in a
! 551: different way, and has some restrictions. The differences between the two
! 552: functions are described in the
! 553: <a href="pcrematching.html"><b>pcrematching</b></a>
! 554: documentation.
! 555: </P>
! 556: <P>
! 557: If a data line contains the \D escape sequence, or if the command line
! 558: contains the <b>-dfa</b> option, the alternative matching function is called.
! 559: This function finds all possible matches at a given point. If, however, the \F
! 560: escape sequence is present in the data line, it stops after the first match is
! 561: found. This is always the shortest possible match.
! 562: </P>
! 563: <br><a name="SEC7" href="#TOC1">DEFAULT OUTPUT FROM PCRETEST</a><br>
! 564: <P>
! 565: This section describes the output when the normal matching function,
! 566: <b>pcre_exec()</b>, is being used.
! 567: </P>
! 568: <P>
! 569: When a match succeeds, <b>pcretest</b> outputs the list of captured substrings
! 570: that <b>pcre_exec()</b> returns, starting with number 0 for the string that
! 571: matched the whole pattern. Otherwise, it outputs "No match" when the return is
! 572: PCRE_ERROR_NOMATCH, and "Partial match:" followed by the partially matching
! 573: substring when <b>pcre_exec()</b> returns PCRE_ERROR_PARTIAL. (Note that this is
! 574: the entire substring that was inspected during the partial match; it may
! 575: include characters before the actual match start if a lookbehind assertion,
! 576: \K, \b, or \B was involved.) For any other return, <b>pcretest</b> outputs
! 577: the PCRE negative error number and a short descriptive phrase. If the error is
! 578: a failed UTF-8 string check, the byte offset of the start of the failing
! 579: character and the reason code are also output, provided that the size of the
! 580: output vector is at least two. Here is an example of an interactive
! 581: <b>pcretest</b> run.
! 582: <pre>
! 583: $ pcretest
! 584: PCRE version 8.13 2011-04-30
! 585:
! 586: re> /^abc(\d+)/
! 587: data> abc123
! 588: 0: abc123
! 589: 1: 123
! 590: data> xyz
! 591: No match
! 592: </pre>
! 593: Unset capturing substrings that are not followed by one that is set are not
! 594: returned by <b>pcre_exec()</b>, and are not shown by <b>pcretest</b>. In the
! 595: following example, there are two capturing substrings, but when the first data
! 596: line is matched, the second, unset substring is not shown. An "internal" unset
! 597: substring is shown as "<unset>", as for the second data line.
! 598: <pre>
! 599: re> /(a)|(b)/
! 600: data> a
! 601: 0: a
! 602: 1: a
! 603: data> b
! 604: 0: b
! 605: 1: <unset>
! 606: 2: b
! 607: </pre>
! 608: If the strings contain any non-printing characters, they are output as \0x
! 609: escapes, or as \x{...} escapes if the <b>/8</b> modifier was present on the
! 610: pattern. See below for the definition of non-printing characters. If the
! 611: pattern has the <b>/+</b> modifier, the output for substring 0 is followed by
! 612: the the rest of the subject string, identified by "0+" like this:
! 613: <pre>
! 614: re> /cat/+
! 615: data> cataract
! 616: 0: cat
! 617: 0+ aract
! 618: </pre>
! 619: If the pattern has the <b>/g</b> or <b>/G</b> modifier, the results of successive
! 620: matching attempts are output in sequence, like this:
! 621: <pre>
! 622: re> /\Bi(\w\w)/g
! 623: data> Mississippi
! 624: 0: iss
! 625: 1: ss
! 626: 0: iss
! 627: 1: ss
! 628: 0: ipp
! 629: 1: pp
! 630: </pre>
! 631: "No match" is output only if the first match attempt fails. Here is an example
! 632: of a failure message (the offset 4 that is specified by \>4 is past the end of
! 633: the subject string):
! 634: <pre>
! 635: re> /xyz/
! 636: data> xyz\>4
! 637: Error -24 (bad offset value)
! 638: </PRE>
! 639: </P>
! 640: <P>
! 641: If any of the sequences <b>\C</b>, <b>\G</b>, or <b>\L</b> are present in a
! 642: data line that is successfully matched, the substrings extracted by the
! 643: convenience functions are output with C, G, or L after the string number
! 644: instead of a colon. This is in addition to the normal full list. The string
! 645: length (that is, the return from the extraction function) is given in
! 646: parentheses after each string for <b>\C</b> and <b>\G</b>.
! 647: </P>
! 648: <P>
! 649: Note that whereas patterns can be continued over several lines (a plain ">"
! 650: prompt is used for continuations), data lines may not. However newlines can be
! 651: included in data by means of the \n escape (or \r, \r\n, etc., depending on
! 652: the newline sequence setting).
! 653: </P>
! 654: <br><a name="SEC8" href="#TOC1">OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION</a><br>
! 655: <P>
! 656: When the alternative matching function, <b>pcre_dfa_exec()</b>, is used (by
! 657: means of the \D escape sequence or the <b>-dfa</b> command line option), the
! 658: output consists of a list of all the matches that start at the first point in
! 659: the subject where there is at least one match. For example:
! 660: <pre>
! 661: re> /(tang|tangerine|tan)/
! 662: data> yellow tangerine\D
! 663: 0: tangerine
! 664: 1: tang
! 665: 2: tan
! 666: </pre>
! 667: (Using the normal matching function on this data finds only "tang".) The
! 668: longest matching string is always given first (and numbered zero). After a
! 669: PCRE_ERROR_PARTIAL return, the output is "Partial match:", followed by the
! 670: partially matching substring. (Note that this is the entire substring that was
! 671: inspected during the partial match; it may include characters before the actual
! 672: match start if a lookbehind assertion, \K, \b, or \B was involved.)
! 673: </P>
! 674: <P>
! 675: If <b>/g</b> is present on the pattern, the search for further matches resumes
! 676: at the end of the longest match. For example:
! 677: <pre>
! 678: re> /(tang|tangerine|tan)/g
! 679: data> yellow tangerine and tangy sultana\D
! 680: 0: tangerine
! 681: 1: tang
! 682: 2: tan
! 683: 0: tang
! 684: 1: tan
! 685: 0: tan
! 686: </pre>
! 687: Since the matching function does not support substring capture, the escape
! 688: sequences that are concerned with captured substrings are not relevant.
! 689: </P>
! 690: <br><a name="SEC9" href="#TOC1">RESTARTING AFTER A PARTIAL MATCH</a><br>
! 691: <P>
! 692: When the alternative matching function has given the PCRE_ERROR_PARTIAL return,
! 693: indicating that the subject partially matched the pattern, you can restart the
! 694: match with additional subject data by means of the \R escape sequence. For
! 695: example:
! 696: <pre>
! 697: re> /^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$/
! 698: data> 23ja\P\D
! 699: Partial match: 23ja
! 700: data> n05\R\D
! 701: 0: n05
! 702: </pre>
! 703: For further information about partial matching, see the
! 704: <a href="pcrepartial.html"><b>pcrepartial</b></a>
! 705: documentation.
! 706: </P>
! 707: <br><a name="SEC10" href="#TOC1">CALLOUTS</a><br>
! 708: <P>
! 709: If the pattern contains any callout requests, <b>pcretest</b>'s callout function
! 710: is called during matching. This works with both matching functions. By default,
! 711: the called function displays the callout number, the start and current
! 712: positions in the text at the callout time, and the next pattern item to be
! 713: tested. For example, the output
! 714: <pre>
! 715: --->pqrabcdef
! 716: 0 ^ ^ \d
! 717: </pre>
! 718: indicates that callout number 0 occurred for a match attempt starting at the
! 719: fourth character of the subject string, when the pointer was at the seventh
! 720: character of the data, and when the next pattern item was \d. Just one
! 721: circumflex is output if the start and current positions are the same.
! 722: </P>
! 723: <P>
! 724: Callouts numbered 255 are assumed to be automatic callouts, inserted as a
! 725: result of the <b>/C</b> pattern modifier. In this case, instead of showing the
! 726: callout number, the offset in the pattern, preceded by a plus, is output. For
! 727: example:
! 728: <pre>
! 729: re> /\d?[A-E]\*/C
! 730: data> E*
! 731: --->E*
! 732: +0 ^ \d?
! 733: +3 ^ [A-E]
! 734: +8 ^^ \*
! 735: +10 ^ ^
! 736: 0: E*
! 737: </pre>
! 738: If a pattern contains (*MARK) items, an additional line is output whenever
! 739: a change of latest mark is passed to the callout function. For example:
! 740: <pre>
! 741: re> /a(*MARK:X)bc/C
! 742: data> abc
! 743: --->abc
! 744: +0 ^ a
! 745: +1 ^^ (*MARK:X)
! 746: +10 ^^ b
! 747: Latest Mark: X
! 748: +11 ^ ^ c
! 749: +12 ^ ^
! 750: 0: abc
! 751: </pre>
! 752: The mark changes between matching "a" and "b", but stays the same for the rest
! 753: of the match, so nothing more is output. If, as a result of backtracking, the
! 754: mark reverts to being unset, the text "<unset>" is output.
! 755: </P>
! 756: <P>
! 757: The callout function in <b>pcretest</b> returns zero (carry on matching) by
! 758: default, but you can use a \C item in a data line (as described above) to
! 759: change this and other parameters of the callout.
! 760: </P>
! 761: <P>
! 762: Inserting callouts can be helpful when using <b>pcretest</b> to check
! 763: complicated regular expressions. For further information about callouts, see
! 764: the
! 765: <a href="pcrecallout.html"><b>pcrecallout</b></a>
! 766: documentation.
! 767: </P>
! 768: <br><a name="SEC11" href="#TOC1">NON-PRINTING CHARACTERS</a><br>
! 769: <P>
! 770: When <b>pcretest</b> is outputting text in the compiled version of a pattern,
! 771: bytes other than 32-126 are always treated as non-printing characters are are
! 772: therefore shown as hex escapes.
! 773: </P>
! 774: <P>
! 775: When <b>pcretest</b> is outputting text that is a matched part of a subject
! 776: string, it behaves in the same way, unless a different locale has been set for
! 777: the pattern (using the <b>/L</b> modifier). In this case, the <b>isprint()</b>
! 778: function to distinguish printing and non-printing characters.
! 779: </P>
! 780: <br><a name="SEC12" href="#TOC1">SAVING AND RELOADING COMPILED PATTERNS</a><br>
! 781: <P>
! 782: The facilities described in this section are not available when the POSIX
! 783: interface to PCRE is being used, that is, when the <b>/P</b> pattern modifier is
! 784: specified.
! 785: </P>
! 786: <P>
! 787: When the POSIX interface is not in use, you can cause <b>pcretest</b> to write a
! 788: compiled pattern to a file, by following the modifiers with > and a file name.
! 789: For example:
! 790: <pre>
! 791: /pattern/im >/some/file
! 792: </pre>
! 793: See the
! 794: <a href="pcreprecompile.html"><b>pcreprecompile</b></a>
! 795: documentation for a discussion about saving and re-using compiled patterns.
! 796: Note that if the pattern was successfully studied with JIT optimization, the
! 797: JIT data cannot be saved.
! 798: </P>
! 799: <P>
! 800: The data that is written is binary. The first eight bytes are the length of the
! 801: compiled pattern data followed by the length of the optional study data, each
! 802: written as four bytes in big-endian order (most significant byte first). If
! 803: there is no study data (either the pattern was not studied, or studying did not
! 804: return any data), the second length is zero. The lengths are followed by an
! 805: exact copy of the compiled pattern. If there is additional study data, this
! 806: (excluding any JIT data) follows immediately after the compiled pattern. After
! 807: writing the file, <b>pcretest</b> expects to read a new pattern.
! 808: </P>
! 809: <P>
! 810: A saved pattern can be reloaded into <b>pcretest</b> by specifying < and a file
! 811: name instead of a pattern. The name of the file must not contain a < character,
! 812: as otherwise <b>pcretest</b> will interpret the line as a pattern delimited by <
! 813: characters.
! 814: For example:
! 815: <pre>
! 816: re> </some/file
! 817: Compiled pattern loaded from /some/file
! 818: No study data
! 819: </pre>
! 820: If the pattern was previously studied with the JIT optimization, the JIT
! 821: information cannot be saved and restored, and so is lost. When the pattern has
! 822: been loaded, <b>pcretest</b> proceeds to read data lines in the usual way.
! 823: </P>
! 824: <P>
! 825: You can copy a file written by <b>pcretest</b> to a different host and reload it
! 826: there, even if the new host has opposite endianness to the one on which the
! 827: pattern was compiled. For example, you can compile on an i86 machine and run on
! 828: a SPARC machine.
! 829: </P>
! 830: <P>
! 831: File names for saving and reloading can be absolute or relative, but note that
! 832: the shell facility of expanding a file name that starts with a tilde (~) is not
! 833: available.
! 834: </P>
! 835: <P>
! 836: The ability to save and reload files in <b>pcretest</b> is intended for testing
! 837: and experimentation. It is not intended for production use because only a
! 838: single pattern can be written to a file. Furthermore, there is no facility for
! 839: supplying custom character tables for use with a reloaded pattern. If the
! 840: original pattern was compiled with custom tables, an attempt to match a subject
! 841: string using a reloaded pattern is likely to cause <b>pcretest</b> to crash.
! 842: Finally, if you attempt to load a file that is not in the correct format, the
! 843: result is undefined.
! 844: </P>
! 845: <br><a name="SEC13" href="#TOC1">SEE ALSO</a><br>
! 846: <P>
! 847: <b>pcre</b>(3), <b>pcreapi</b>(3), <b>pcrecallout</b>(3), <b>pcrejit</b>,
! 848: <b>pcrematching</b>(3), <b>pcrepartial</b>(d), <b>pcrepattern</b>(3),
! 849: <b>pcreprecompile</b>(3).
! 850: </P>
! 851: <br><a name="SEC14" href="#TOC1">AUTHOR</a><br>
! 852: <P>
! 853: Philip Hazel
! 854: <br>
! 855: University Computing Service
! 856: <br>
! 857: Cambridge CB2 3QH, England.
! 858: <br>
! 859: </P>
! 860: <br><a name="SEC15" href="#TOC1">REVISION</a><br>
! 861: <P>
! 862: Last updated: 02 December 2011
! 863: <br>
! 864: Copyright © 1997-2011 University of Cambridge.
! 865: <br>
! 866: <p>
! 867: Return to the <a href="index.html">PCRE index page</a>.
! 868: </p>
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