Annotation of embedaddon/pcre/doc/pcretest.1, revision 1.1
1.1 ! misho 1: .TH PCRETEST 1
! 2: .SH NAME
! 3: pcretest - a program for testing Perl-compatible regular expressions.
! 4: .SH SYNOPSIS
! 5: .rs
! 6: .sp
! 7: .B pcretest "[options] [input file [output file]]"
! 8: .sp
! 9: \fBpcretest\fP was written as a test program for the PCRE regular expression
! 10: library itself, but it can also be used for experimenting with regular
! 11: expressions. This document describes the features of the test program; for
! 12: details of the regular expressions themselves, see the
! 13: .\" HREF
! 14: \fBpcrepattern\fP
! 15: .\"
! 16: documentation. For details of the PCRE library function calls and their
! 17: options, see the
! 18: .\" HREF
! 19: \fBpcreapi\fP
! 20: .\"
! 21: documentation. The input for \fBpcretest\fP is a sequence of regular expression
! 22: patterns and strings to be matched, as described below. The output shows the
! 23: result of each match. Options on the command line and the patterns control PCRE
! 24: options and exactly what is output.
! 25: .
! 26: .
! 27: .SH COMMAND LINE OPTIONS
! 28: .rs
! 29: .TP 10
! 30: \fB-b\fP
! 31: Behave as if each pattern has the \fB/B\fP (show byte code) modifier; the
! 32: internal form is output after compilation.
! 33: .TP 10
! 34: \fB-C\fP
! 35: Output the version number of the PCRE library, and all available information
! 36: about the optional features that are included, and then exit.
! 37: .TP 10
! 38: \fB-d\fP
! 39: Behave as if each pattern has the \fB/D\fP (debug) modifier; the internal
! 40: form and information about the compiled pattern is output after compilation;
! 41: \fB-d\fP is equivalent to \fB-b -i\fP.
! 42: .TP 10
! 43: \fB-dfa\fP
! 44: Behave as if each data line contains the \eD escape sequence; this causes the
! 45: alternative matching function, \fBpcre_dfa_exec()\fP, to be used instead of the
! 46: standard \fBpcre_exec()\fP function (more detail is given below).
! 47: .TP 10
! 48: \fB-help\fP
! 49: Output a brief summary these options and then exit.
! 50: .TP 10
! 51: \fB-i\fP
! 52: Behave as if each pattern has the \fB/I\fP modifier; information about the
! 53: compiled pattern is given after compilation.
! 54: .TP 10
! 55: \fB-M\fP
! 56: Behave as if each data line contains the \eM escape sequence; this causes
! 57: PCRE to discover the minimum MATCH_LIMIT and MATCH_LIMIT_RECURSION settings by
! 58: calling \fBpcre_exec()\fP repeatedly with different limits.
! 59: .TP 10
! 60: \fB-m\fP
! 61: Output the size of each compiled pattern after it has been compiled. This is
! 62: equivalent to adding \fB/M\fP to each regular expression.
! 63: .TP 10
! 64: \fB-o\fP \fIosize\fP
! 65: Set the number of elements in the output vector that is used when calling
! 66: \fBpcre_exec()\fP or \fBpcre_dfa_exec()\fP to be \fIosize\fP. The default value
! 67: is 45, which is enough for 14 capturing subexpressions for \fBpcre_exec()\fP or
! 68: 22 different matches for \fBpcre_dfa_exec()\fP. The vector size can be
! 69: changed for individual matching calls by including \eO in the data line (see
! 70: below).
! 71: .TP 10
! 72: \fB-p\fP
! 73: Behave as if each pattern has the \fB/P\fP modifier; the POSIX wrapper API is
! 74: used to call PCRE. None of the other options has any effect when \fB-p\fP is
! 75: set.
! 76: .TP 10
! 77: \fB-q\fP
! 78: Do not output the version number of \fBpcretest\fP at the start of execution.
! 79: .TP 10
! 80: \fB-S\fP \fIsize\fP
! 81: On Unix-like systems, set the size of the run-time stack to \fIsize\fP
! 82: megabytes.
! 83: .TP 10
! 84: \fB-s\fP or \fB-s+\fP
! 85: Behave as if each pattern has the \fB/S\fP modifier; in other words, force each
! 86: pattern to be studied. If \fB-s+\fP is used, the PCRE_STUDY_JIT_COMPILE flag is
! 87: passed to \fBpcre_study()\fP, causing just-in-time optimization to be set up if
! 88: it is available. If the \fB/I\fP or \fB/D\fP option is present on a pattern
! 89: (requesting output about the compiled pattern), information about the result of
! 90: studying is not included when studying is caused only by \fB-s\fP and neither
! 91: \fB-i\fP nor \fB-d\fP is present on the command line. This behaviour means that
! 92: the output from tests that are run with and without \fB-s\fP should be
! 93: identical, except when options that output information about the actual running
! 94: of a match are set. The \fB-M\fP, \fB-t\fP, and \fB-tm\fP options, which give
! 95: information about resources used, are likely to produce different output with
! 96: and without \fB-s\fP. Output may also differ if the \fB/C\fP option is present
! 97: on an individual pattern. This uses callouts to trace the the matching process,
! 98: and this may be different between studied and non-studied patterns. If the
! 99: pattern contains (*MARK) items there may also be differences, for the same
! 100: reason. The \fB-s\fP command line option can be overridden for specific
! 101: patterns that should never be studied (see the \fB/S\fP pattern modifier
! 102: below).
! 103: .TP 10
! 104: \fB-t\fP
! 105: Run each compile, study, and match many times with a timer, and output
! 106: resulting time per compile or match (in milliseconds). Do not set \fB-m\fP with
! 107: \fB-t\fP, because you will then get the size output a zillion times, and the
! 108: timing will be distorted. You can control the number of iterations that are
! 109: used for timing by following \fB-t\fP with a number (as a separate item on the
! 110: command line). For example, "-t 1000" would iterate 1000 times. The default is
! 111: to iterate 500000 times.
! 112: .TP 10
! 113: \fB-tm\fP
! 114: This is like \fB-t\fP except that it times only the matching phase, not the
! 115: compile or study phases.
! 116: .
! 117: .
! 118: .SH DESCRIPTION
! 119: .rs
! 120: .sp
! 121: If \fBpcretest\fP is given two filename arguments, it reads from the first and
! 122: writes to the second. If it is given only one filename argument, it reads from
! 123: that file and writes to stdout. Otherwise, it reads from stdin and writes to
! 124: stdout, and prompts for each line of input, using "re>" to prompt for regular
! 125: expressions, and "data>" to prompt for data lines.
! 126: .P
! 127: When \fBpcretest\fP is built, a configuration option can specify that it should
! 128: be linked with the \fBlibreadline\fP library. When this is done, if the input
! 129: is from a terminal, it is read using the \fBreadline()\fP function. This
! 130: provides line-editing and history facilities. The output from the \fB-help\fP
! 131: option states whether or not \fBreadline()\fP will be used.
! 132: .P
! 133: The program handles any number of sets of input on a single input file. Each
! 134: set starts with a regular expression, and continues with any number of data
! 135: lines to be matched against the pattern.
! 136: .P
! 137: Each data line is matched separately and independently. If you want to do
! 138: multi-line matches, you have to use the \en escape sequence (or \er or \er\en,
! 139: etc., depending on the newline setting) in a single line of input to encode the
! 140: newline sequences. There is no limit on the length of data lines; the input
! 141: buffer is automatically extended if it is too small.
! 142: .P
! 143: An empty line signals the end of the data lines, at which point a new regular
! 144: expression is read. The regular expressions are given enclosed in any
! 145: non-alphanumeric delimiters other than backslash, for example:
! 146: .sp
! 147: /(a|bc)x+yz/
! 148: .sp
! 149: White space before the initial delimiter is ignored. A regular expression may
! 150: be continued over several input lines, in which case the newline characters are
! 151: included within it. It is possible to include the delimiter within the pattern
! 152: by escaping it, for example
! 153: .sp
! 154: /abc\e/def/
! 155: .sp
! 156: If you do so, the escape and the delimiter form part of the pattern, but since
! 157: delimiters are always non-alphanumeric, this does not affect its interpretation.
! 158: If the terminating delimiter is immediately followed by a backslash, for
! 159: example,
! 160: .sp
! 161: /abc/\e
! 162: .sp
! 163: then a backslash is added to the end of the pattern. This is done to provide a
! 164: way of testing the error condition that arises if a pattern finishes with a
! 165: backslash, because
! 166: .sp
! 167: /abc\e/
! 168: .sp
! 169: is interpreted as the first line of a pattern that starts with "abc/", causing
! 170: pcretest to read the next line as a continuation of the regular expression.
! 171: .
! 172: .
! 173: .SH "PATTERN MODIFIERS"
! 174: .rs
! 175: .sp
! 176: A pattern may be followed by any number of modifiers, which are mostly single
! 177: characters. Following Perl usage, these are referred to below as, for example,
! 178: "the \fB/i\fP modifier", even though the delimiter of the pattern need not
! 179: always be a slash, and no slash is used when writing modifiers. White space may
! 180: appear between the final pattern delimiter and the first modifier, and between
! 181: the modifiers themselves.
! 182: .P
! 183: The \fB/i\fP, \fB/m\fP, \fB/s\fP, and \fB/x\fP modifiers set the PCRE_CASELESS,
! 184: PCRE_MULTILINE, PCRE_DOTALL, or PCRE_EXTENDED options, respectively, when
! 185: \fBpcre_compile()\fP is called. These four modifier letters have the same
! 186: effect as they do in Perl. For example:
! 187: .sp
! 188: /caseless/i
! 189: .sp
! 190: The following table shows additional modifiers for setting PCRE compile-time
! 191: options that do not correspond to anything in Perl:
! 192: .sp
! 193: \fB/8\fP PCRE_UTF8
! 194: \fB/?\fP PCRE_NO_UTF8_CHECK
! 195: \fB/A\fP PCRE_ANCHORED
! 196: \fB/C\fP PCRE_AUTO_CALLOUT
! 197: \fB/E\fP PCRE_DOLLAR_ENDONLY
! 198: \fB/f\fP PCRE_FIRSTLINE
! 199: \fB/J\fP PCRE_DUPNAMES
! 200: \fB/N\fP PCRE_NO_AUTO_CAPTURE
! 201: \fB/U\fP PCRE_UNGREEDY
! 202: \fB/W\fP PCRE_UCP
! 203: \fB/X\fP PCRE_EXTRA
! 204: \fB/Y\fP PCRE_NO_START_OPTIMIZE
! 205: \fB/<JS>\fP PCRE_JAVASCRIPT_COMPAT
! 206: \fB/<cr>\fP PCRE_NEWLINE_CR
! 207: \fB/<lf>\fP PCRE_NEWLINE_LF
! 208: \fB/<crlf>\fP PCRE_NEWLINE_CRLF
! 209: \fB/<anycrlf>\fP PCRE_NEWLINE_ANYCRLF
! 210: \fB/<any>\fP PCRE_NEWLINE_ANY
! 211: \fB/<bsr_anycrlf>\fP PCRE_BSR_ANYCRLF
! 212: \fB/<bsr_unicode>\fP PCRE_BSR_UNICODE
! 213: .sp
! 214: The modifiers that are enclosed in angle brackets are literal strings as shown,
! 215: including the angle brackets, but the letters within can be in either case.
! 216: This example sets multiline matching with CRLF as the line ending sequence:
! 217: .sp
! 218: /^abc/m<CRLF>
! 219: .sp
! 220: As well as turning on the PCRE_UTF8 option, the \fB/8\fP modifier also causes
! 221: any non-printing characters in output strings to be printed using the
! 222: \ex{hh...} notation if they are valid UTF-8 sequences. Full details of the PCRE
! 223: options are given in the
! 224: .\" HREF
! 225: \fBpcreapi\fP
! 226: .\"
! 227: documentation.
! 228: .
! 229: .
! 230: .SS "Finding all matches in a string"
! 231: .rs
! 232: .sp
! 233: Searching for all possible matches within each subject string can be requested
! 234: by the \fB/g\fP or \fB/G\fP modifier. After finding a match, PCRE is called
! 235: again to search the remainder of the subject string. The difference between
! 236: \fB/g\fP and \fB/G\fP is that the former uses the \fIstartoffset\fP argument to
! 237: \fBpcre_exec()\fP to start searching at a new point within the entire string
! 238: (which is in effect what Perl does), whereas the latter passes over a shortened
! 239: substring. This makes a difference to the matching process if the pattern
! 240: begins with a lookbehind assertion (including \eb or \eB).
! 241: .P
! 242: If any call to \fBpcre_exec()\fP in a \fB/g\fP or \fB/G\fP sequence matches an
! 243: empty string, the next call is done with the PCRE_NOTEMPTY_ATSTART and
! 244: PCRE_ANCHORED flags set in order to search for another, non-empty, match at the
! 245: same point. If this second match fails, the start offset is advanced, and the
! 246: normal match is retried. This imitates the way Perl handles such cases when
! 247: using the \fB/g\fP modifier or the \fBsplit()\fP function. Normally, the start
! 248: offset is advanced by one character, but if the newline convention recognizes
! 249: CRLF as a newline, and the current character is CR followed by LF, an advance
! 250: of two is used.
! 251: .
! 252: .
! 253: .SS "Other modifiers"
! 254: .rs
! 255: .sp
! 256: There are yet more modifiers for controlling the way \fBpcretest\fP
! 257: operates.
! 258: .P
! 259: The \fB/+\fP modifier requests that as well as outputting the substring that
! 260: matched the entire pattern, \fBpcretest\fP should in addition output the
! 261: remainder of the subject string. This is useful for tests where the subject
! 262: contains multiple copies of the same substring. If the \fB+\fP modifier appears
! 263: twice, the same action is taken for captured substrings. In each case the
! 264: remainder is output on the following line with a plus character following the
! 265: capture number. Note that this modifier must not immediately follow the /S
! 266: modifier because /S+ has another meaning.
! 267: .P
! 268: The \fB/=\fP modifier requests that the values of all potential captured
! 269: parentheses be output after a match by \fBpcre_exec()\fP. By default, only
! 270: those up to the highest one actually used in the match are output
! 271: (corresponding to the return code from \fBpcre_exec()\fP). Values in the
! 272: offsets vector corresponding to higher numbers should be set to -1, and these
! 273: are output as "<unset>". This modifier gives a way of checking that this is
! 274: happening.
! 275: .P
! 276: The \fB/B\fP modifier is a debugging feature. It requests that \fBpcretest\fP
! 277: output a representation of the compiled byte code after compilation. Normally
! 278: this information contains length and offset values; however, if \fB/Z\fP is
! 279: also present, this data is replaced by spaces. This is a special feature for
! 280: use in the automatic test scripts; it ensures that the same output is generated
! 281: for different internal link sizes.
! 282: .P
! 283: The \fB/D\fP modifier is a PCRE debugging feature, and is equivalent to
! 284: \fB/BI\fP, that is, both the \fB/B\fP and the \fB/I\fP modifiers.
! 285: .P
! 286: The \fB/F\fP modifier causes \fBpcretest\fP to flip the byte order of the
! 287: fields in the compiled pattern that contain 2-byte and 4-byte numbers. This
! 288: facility is for testing the feature in PCRE that allows it to execute patterns
! 289: that were compiled on a host with a different endianness. This feature is not
! 290: available when the POSIX interface to PCRE is being used, that is, when the
! 291: \fB/P\fP pattern modifier is specified. See also the section about saving and
! 292: reloading compiled patterns below.
! 293: .P
! 294: The \fB/I\fP modifier requests that \fBpcretest\fP output information about the
! 295: compiled pattern (whether it is anchored, has a fixed first character, and
! 296: so on). It does this by calling \fBpcre_fullinfo()\fP after compiling a
! 297: pattern. If the pattern is studied, the results of that are also output.
! 298: .P
! 299: The \fB/K\fP modifier requests \fBpcretest\fP to show names from backtracking
! 300: control verbs that are returned from calls to \fBpcre_exec()\fP. It causes
! 301: \fBpcretest\fP to create a \fBpcre_extra\fP block if one has not already been
! 302: created by a call to \fBpcre_study()\fP, and to set the PCRE_EXTRA_MARK flag
! 303: and the \fBmark\fP field within it, every time that \fBpcre_exec()\fP is
! 304: called. If the variable that the \fBmark\fP field points to is non-NULL for a
! 305: match, non-match, or partial match, \fBpcretest\fP prints the string to which
! 306: it points. For a match, this is shown on a line by itself, tagged with "MK:".
! 307: For a non-match it is added to the message.
! 308: .P
! 309: The \fB/L\fP modifier must be followed directly by the name of a locale, for
! 310: example,
! 311: .sp
! 312: /pattern/Lfr_FR
! 313: .sp
! 314: For this reason, it must be the last modifier. The given locale is set,
! 315: \fBpcre_maketables()\fP is called to build a set of character tables for the
! 316: locale, and this is then passed to \fBpcre_compile()\fP when compiling the
! 317: regular expression. Without an \fB/L\fP (or \fB/T\fP) modifier, NULL is passed
! 318: as the tables pointer; that is, \fB/L\fP applies only to the expression on
! 319: which it appears.
! 320: .P
! 321: The \fB/M\fP modifier causes the size of memory block used to hold the compiled
! 322: pattern to be output. This does not include the size of the \fBpcre\fP block;
! 323: it is just the actual compiled data. If the pattern is successfully studied
! 324: with the PCRE_STUDY_JIT_COMPILE option, the size of the JIT compiled code is
! 325: also output.
! 326: .P
! 327: If the \fB/S\fP modifier appears once, it causes \fBpcre_study()\fP to be
! 328: called after the expression has been compiled, and the results used when the
! 329: expression is matched. If \fB/S\fP appears twice, it suppresses studying, even
! 330: if it was requested externally by the \fB-s\fP command line option. This makes
! 331: it possible to specify that certain patterns are always studied, and others are
! 332: never studied, independently of \fB-s\fP. This feature is used in the test
! 333: files in a few cases where the output is different when the pattern is studied.
! 334: .P
! 335: If the \fB/S\fP modifier is immediately followed by a + character, the call to
! 336: \fBpcre_study()\fP is made with the PCRE_STUDY_JIT_COMPILE option, requesting
! 337: just-in-time optimization support if it is available. Note that there is also a
! 338: \fB/+\fP modifier; it must not be given immediately after \fB/S\fP because this
! 339: will be misinterpreted. If JIT studying is successful, it will automatically be
! 340: used when \fBpcre_exec()\fP is run, except when incompatible run-time options
! 341: are specified. These include the partial matching options; a complete list is
! 342: given in the
! 343: .\" HREF
! 344: \fBpcrejit\fP
! 345: .\"
! 346: documentation. See also the \fB\eJ\fP escape sequence below for a way of
! 347: setting the size of the JIT stack.
! 348: .P
! 349: The \fB/T\fP modifier must be followed by a single digit. It causes a specific
! 350: set of built-in character tables to be passed to \fBpcre_compile()\fP. It is
! 351: used in the standard PCRE tests to check behaviour with different character
! 352: tables. The digit specifies the tables as follows:
! 353: .sp
! 354: 0 the default ASCII tables, as distributed in
! 355: pcre_chartables.c.dist
! 356: 1 a set of tables defining ISO 8859 characters
! 357: .sp
! 358: In table 1, some characters whose codes are greater than 128 are identified as
! 359: letters, digits, spaces, etc.
! 360: .
! 361: .
! 362: .SS "Using the POSIX wrapper API"
! 363: .rs
! 364: .sp
! 365: The \fB/P\fP modifier causes \fBpcretest\fP to call PCRE via the POSIX wrapper
! 366: API rather than its native API. When \fB/P\fP is set, the following modifiers
! 367: set options for the \fBregcomp()\fP function:
! 368: .sp
! 369: /i REG_ICASE
! 370: /m REG_NEWLINE
! 371: /N REG_NOSUB
! 372: /s REG_DOTALL )
! 373: /U REG_UNGREEDY ) These options are not part of
! 374: /W REG_UCP ) the POSIX standard
! 375: /8 REG_UTF8 )
! 376: .sp
! 377: The \fB/+\fP modifier works as described above. All other modifiers are
! 378: ignored.
! 379: .
! 380: .
! 381: .SH "DATA LINES"
! 382: .rs
! 383: .sp
! 384: Before each data line is passed to \fBpcre_exec()\fP, leading and trailing
! 385: white space is removed, and it is then scanned for \e escapes. Some of these
! 386: are pretty esoteric features, intended for checking out some of the more
! 387: complicated features of PCRE. If you are just testing "ordinary" regular
! 388: expressions, you probably don't need any of these. The following escapes are
! 389: recognized:
! 390: .sp
! 391: \ea alarm (BEL, \ex07)
! 392: \eb backspace (\ex08)
! 393: \ee escape (\ex27)
! 394: \ef form feed (\ex0c)
! 395: \en newline (\ex0a)
! 396: .\" JOIN
! 397: \eqdd set the PCRE_MATCH_LIMIT limit to dd
! 398: (any number of digits)
! 399: \er carriage return (\ex0d)
! 400: \et tab (\ex09)
! 401: \ev vertical tab (\ex0b)
! 402: \ennn octal character (up to 3 octal digits)
! 403: always a byte unless > 255 in UTF-8 mode
! 404: \exhh hexadecimal byte (up to 2 hex digits)
! 405: .\" JOIN
! 406: \ex{hh...} hexadecimal character, any number of digits
! 407: in UTF-8 mode
! 408: .\" JOIN
! 409: \eA pass the PCRE_ANCHORED option to \fBpcre_exec()\fP
! 410: or \fBpcre_dfa_exec()\fP
! 411: .\" JOIN
! 412: \eB pass the PCRE_NOTBOL option to \fBpcre_exec()\fP
! 413: or \fBpcre_dfa_exec()\fP
! 414: .\" JOIN
! 415: \eCdd call pcre_copy_substring() for substring dd
! 416: after a successful match (number less than 32)
! 417: .\" JOIN
! 418: \eCname call pcre_copy_named_substring() for substring
! 419: "name" after a successful match (name termin-
! 420: ated by next non alphanumeric character)
! 421: .\" JOIN
! 422: \eC+ show the current captured substrings at callout
! 423: time
! 424: \eC- do not supply a callout function
! 425: .\" JOIN
! 426: \eC!n return 1 instead of 0 when callout number n is
! 427: reached
! 428: .\" JOIN
! 429: \eC!n!m return 1 instead of 0 when callout number n is
! 430: reached for the nth time
! 431: .\" JOIN
! 432: \eC*n pass the number n (may be negative) as callout
! 433: data; this is used as the callout return value
! 434: \eD use the \fBpcre_dfa_exec()\fP match function
! 435: \eF only shortest match for \fBpcre_dfa_exec()\fP
! 436: .\" JOIN
! 437: \eGdd call pcre_get_substring() for substring dd
! 438: after a successful match (number less than 32)
! 439: .\" JOIN
! 440: \eGname call pcre_get_named_substring() for substring
! 441: "name" after a successful match (name termin-
! 442: ated by next non-alphanumeric character)
! 443: .\" JOIN
! 444: \eJdd set up a JIT stack of dd kilobytes maximum (any
! 445: number of digits)
! 446: .\" JOIN
! 447: \eL call pcre_get_substringlist() after a
! 448: successful match
! 449: .\" JOIN
! 450: \eM discover the minimum MATCH_LIMIT and
! 451: MATCH_LIMIT_RECURSION settings
! 452: .\" JOIN
! 453: \eN pass the PCRE_NOTEMPTY option to \fBpcre_exec()\fP
! 454: or \fBpcre_dfa_exec()\fP; if used twice, pass the
! 455: PCRE_NOTEMPTY_ATSTART option
! 456: .\" JOIN
! 457: \eOdd set the size of the output vector passed to
! 458: \fBpcre_exec()\fP to dd (any number of digits)
! 459: .\" JOIN
! 460: \eP pass the PCRE_PARTIAL_SOFT option to \fBpcre_exec()\fP
! 461: or \fBpcre_dfa_exec()\fP; if used twice, pass the
! 462: PCRE_PARTIAL_HARD option
! 463: .\" JOIN
! 464: \eQdd set the PCRE_MATCH_LIMIT_RECURSION limit to dd
! 465: (any number of digits)
! 466: \eR pass the PCRE_DFA_RESTART option to \fBpcre_dfa_exec()\fP
! 467: \eS output details of memory get/free calls during matching
! 468: .\" JOIN
! 469: \eY pass the PCRE_NO_START_OPTIMIZE option to \fBpcre_exec()\fP
! 470: or \fBpcre_dfa_exec()\fP
! 471: .\" JOIN
! 472: \eZ pass the PCRE_NOTEOL option to \fBpcre_exec()\fP
! 473: or \fBpcre_dfa_exec()\fP
! 474: .\" JOIN
! 475: \e? pass the PCRE_NO_UTF8_CHECK option to
! 476: \fBpcre_exec()\fP or \fBpcre_dfa_exec()\fP
! 477: .\" JOIN
! 478: \e>dd start the match at offset dd (optional "-"; then
! 479: any number of digits); this sets the \fIstartoffset\fP
! 480: argument for \fBpcre_exec()\fP or \fBpcre_dfa_exec()\fP
! 481: .\" JOIN
! 482: \e<cr> pass the PCRE_NEWLINE_CR option to \fBpcre_exec()\fP
! 483: or \fBpcre_dfa_exec()\fP
! 484: .\" JOIN
! 485: \e<lf> pass the PCRE_NEWLINE_LF option to \fBpcre_exec()\fP
! 486: or \fBpcre_dfa_exec()\fP
! 487: .\" JOIN
! 488: \e<crlf> pass the PCRE_NEWLINE_CRLF option to \fBpcre_exec()\fP
! 489: or \fBpcre_dfa_exec()\fP
! 490: .\" JOIN
! 491: \e<anycrlf> pass the PCRE_NEWLINE_ANYCRLF option to \fBpcre_exec()\fP
! 492: or \fBpcre_dfa_exec()\fP
! 493: .\" JOIN
! 494: \e<any> pass the PCRE_NEWLINE_ANY option to \fBpcre_exec()\fP
! 495: or \fBpcre_dfa_exec()\fP
! 496: .sp
! 497: Note that \exhh always specifies one byte, even in UTF-8 mode; this makes it
! 498: possible to construct invalid UTF-8 sequences for testing purposes. On the
! 499: other hand, \ex{hh} is interpreted as a UTF-8 character in UTF-8 mode,
! 500: generating more than one byte if the value is greater than 127. When not in
! 501: UTF-8 mode, it generates one byte for values less than 256, and causes an error
! 502: for greater values.
! 503: .P
! 504: The escapes that specify line ending sequences are literal strings, exactly as
! 505: shown. No more than one newline setting should be present in any data line.
! 506: .P
! 507: A backslash followed by anything else just escapes the anything else. If
! 508: the very last character is a backslash, it is ignored. This gives a way of
! 509: passing an empty line as data, since a real empty line terminates the data
! 510: input.
! 511: .P
! 512: The \fB\eJ\fP escape provides a way of setting the maximum stack size that is
! 513: used by the just-in-time optimization code. It is ignored if JIT optimization
! 514: is not being used. Providing a stack that is larger than the default 32K is
! 515: necessary only for very complicated patterns.
! 516: .P
! 517: If \eM is present, \fBpcretest\fP calls \fBpcre_exec()\fP several times, with
! 518: different values in the \fImatch_limit\fP and \fImatch_limit_recursion\fP
! 519: fields of the \fBpcre_extra\fP data structure, until it finds the minimum
! 520: numbers for each parameter that allow \fBpcre_exec()\fP to complete without
! 521: error. Because this is testing a specific feature of the normal interpretive
! 522: \fBpcre_exec()\fP execution, the use of any JIT optimization that might have
! 523: been set up by the \fB/S+\fP qualifier of \fB-s+\fP option is disabled.
! 524: .P
! 525: The \fImatch_limit\fP number is a measure of the amount of backtracking
! 526: that takes place, and checking it out can be instructive. For most simple
! 527: matches, the number is quite small, but for patterns with very large numbers of
! 528: matching possibilities, it can become large very quickly with increasing length
! 529: of subject string. The \fImatch_limit_recursion\fP number is a measure of how
! 530: much stack (or, if PCRE is compiled with NO_RECURSE, how much heap) memory is
! 531: needed to complete the match attempt.
! 532: .P
! 533: When \eO is used, the value specified may be higher or lower than the size set
! 534: by the \fB-O\fP command line option (or defaulted to 45); \eO applies only to
! 535: the call of \fBpcre_exec()\fP for the line in which it appears.
! 536: .P
! 537: If the \fB/P\fP modifier was present on the pattern, causing the POSIX wrapper
! 538: API to be used, the only option-setting sequences that have any effect are \eB,
! 539: \eN, and \eZ, causing REG_NOTBOL, REG_NOTEMPTY, and REG_NOTEOL, respectively,
! 540: to be passed to \fBregexec()\fP.
! 541: .P
! 542: The use of \ex{hh...} to represent UTF-8 characters is not dependent on the use
! 543: of the \fB/8\fP modifier on the pattern. It is recognized always. There may be
! 544: any number of hexadecimal digits inside the braces. The result is from one to
! 545: six bytes, encoded according to the original UTF-8 rules of RFC 2279. This
! 546: allows for values in the range 0 to 0x7FFFFFFF. Note that not all of those are
! 547: valid Unicode code points, or indeed valid UTF-8 characters according to the
! 548: later rules in RFC 3629.
! 549: .
! 550: .
! 551: .SH "THE ALTERNATIVE MATCHING FUNCTION"
! 552: .rs
! 553: .sp
! 554: By default, \fBpcretest\fP uses the standard PCRE matching function,
! 555: \fBpcre_exec()\fP to match each data line. From release 6.0, PCRE supports an
! 556: alternative matching function, \fBpcre_dfa_test()\fP, which operates in a
! 557: different way, and has some restrictions. The differences between the two
! 558: functions are described in the
! 559: .\" HREF
! 560: \fBpcrematching\fP
! 561: .\"
! 562: documentation.
! 563: .P
! 564: If a data line contains the \eD escape sequence, or if the command line
! 565: contains the \fB-dfa\fP option, the alternative matching function is called.
! 566: This function finds all possible matches at a given point. If, however, the \eF
! 567: escape sequence is present in the data line, it stops after the first match is
! 568: found. This is always the shortest possible match.
! 569: .
! 570: .
! 571: .SH "DEFAULT OUTPUT FROM PCRETEST"
! 572: .rs
! 573: .sp
! 574: This section describes the output when the normal matching function,
! 575: \fBpcre_exec()\fP, is being used.
! 576: .P
! 577: When a match succeeds, \fBpcretest\fP outputs the list of captured substrings
! 578: that \fBpcre_exec()\fP returns, starting with number 0 for the string that
! 579: matched the whole pattern. Otherwise, it outputs "No match" when the return is
! 580: PCRE_ERROR_NOMATCH, and "Partial match:" followed by the partially matching
! 581: substring when \fBpcre_exec()\fP returns PCRE_ERROR_PARTIAL. (Note that this is
! 582: the entire substring that was inspected during the partial match; it may
! 583: include characters before the actual match start if a lookbehind assertion,
! 584: \eK, \eb, or \eB was involved.) For any other return, \fBpcretest\fP outputs
! 585: the PCRE negative error number and a short descriptive phrase. If the error is
! 586: a failed UTF-8 string check, the byte offset of the start of the failing
! 587: character and the reason code are also output, provided that the size of the
! 588: output vector is at least two. Here is an example of an interactive
! 589: \fBpcretest\fP run.
! 590: .sp
! 591: $ pcretest
! 592: PCRE version 8.13 2011-04-30
! 593: .sp
! 594: re> /^abc(\ed+)/
! 595: data> abc123
! 596: 0: abc123
! 597: 1: 123
! 598: data> xyz
! 599: No match
! 600: .sp
! 601: Unset capturing substrings that are not followed by one that is set are not
! 602: returned by \fBpcre_exec()\fP, and are not shown by \fBpcretest\fP. In the
! 603: following example, there are two capturing substrings, but when the first data
! 604: line is matched, the second, unset substring is not shown. An "internal" unset
! 605: substring is shown as "<unset>", as for the second data line.
! 606: .sp
! 607: re> /(a)|(b)/
! 608: data> a
! 609: 0: a
! 610: 1: a
! 611: data> b
! 612: 0: b
! 613: 1: <unset>
! 614: 2: b
! 615: .sp
! 616: If the strings contain any non-printing characters, they are output as \e0x
! 617: escapes, or as \ex{...} escapes if the \fB/8\fP modifier was present on the
! 618: pattern. See below for the definition of non-printing characters. If the
! 619: pattern has the \fB/+\fP modifier, the output for substring 0 is followed by
! 620: the the rest of the subject string, identified by "0+" like this:
! 621: .sp
! 622: re> /cat/+
! 623: data> cataract
! 624: 0: cat
! 625: 0+ aract
! 626: .sp
! 627: If the pattern has the \fB/g\fP or \fB/G\fP modifier, the results of successive
! 628: matching attempts are output in sequence, like this:
! 629: .sp
! 630: re> /\eBi(\ew\ew)/g
! 631: data> Mississippi
! 632: 0: iss
! 633: 1: ss
! 634: 0: iss
! 635: 1: ss
! 636: 0: ipp
! 637: 1: pp
! 638: .sp
! 639: "No match" is output only if the first match attempt fails. Here is an example
! 640: of a failure message (the offset 4 that is specified by \e>4 is past the end of
! 641: the subject string):
! 642: .sp
! 643: re> /xyz/
! 644: data> xyz\e>4
! 645: Error -24 (bad offset value)
! 646: .P
! 647: If any of the sequences \fB\eC\fP, \fB\eG\fP, or \fB\eL\fP are present in a
! 648: data line that is successfully matched, the substrings extracted by the
! 649: convenience functions are output with C, G, or L after the string number
! 650: instead of a colon. This is in addition to the normal full list. The string
! 651: length (that is, the return from the extraction function) is given in
! 652: parentheses after each string for \fB\eC\fP and \fB\eG\fP.
! 653: .P
! 654: Note that whereas patterns can be continued over several lines (a plain ">"
! 655: prompt is used for continuations), data lines may not. However newlines can be
! 656: included in data by means of the \en escape (or \er, \er\en, etc., depending on
! 657: the newline sequence setting).
! 658: .
! 659: .
! 660: .
! 661: .SH "OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION"
! 662: .rs
! 663: .sp
! 664: When the alternative matching function, \fBpcre_dfa_exec()\fP, is used (by
! 665: means of the \eD escape sequence or the \fB-dfa\fP command line option), the
! 666: output consists of a list of all the matches that start at the first point in
! 667: the subject where there is at least one match. For example:
! 668: .sp
! 669: re> /(tang|tangerine|tan)/
! 670: data> yellow tangerine\eD
! 671: 0: tangerine
! 672: 1: tang
! 673: 2: tan
! 674: .sp
! 675: (Using the normal matching function on this data finds only "tang".) The
! 676: longest matching string is always given first (and numbered zero). After a
! 677: PCRE_ERROR_PARTIAL return, the output is "Partial match:", followed by the
! 678: partially matching substring. (Note that this is the entire substring that was
! 679: inspected during the partial match; it may include characters before the actual
! 680: match start if a lookbehind assertion, \eK, \eb, or \eB was involved.)
! 681: .P
! 682: If \fB/g\fP is present on the pattern, the search for further matches resumes
! 683: at the end of the longest match. For example:
! 684: .sp
! 685: re> /(tang|tangerine|tan)/g
! 686: data> yellow tangerine and tangy sultana\eD
! 687: 0: tangerine
! 688: 1: tang
! 689: 2: tan
! 690: 0: tang
! 691: 1: tan
! 692: 0: tan
! 693: .sp
! 694: Since the matching function does not support substring capture, the escape
! 695: sequences that are concerned with captured substrings are not relevant.
! 696: .
! 697: .
! 698: .SH "RESTARTING AFTER A PARTIAL MATCH"
! 699: .rs
! 700: .sp
! 701: When the alternative matching function has given the PCRE_ERROR_PARTIAL return,
! 702: indicating that the subject partially matched the pattern, you can restart the
! 703: match with additional subject data by means of the \eR escape sequence. For
! 704: example:
! 705: .sp
! 706: re> /^\ed?\ed(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\ed\ed$/
! 707: data> 23ja\eP\eD
! 708: Partial match: 23ja
! 709: data> n05\eR\eD
! 710: 0: n05
! 711: .sp
! 712: For further information about partial matching, see the
! 713: .\" HREF
! 714: \fBpcrepartial\fP
! 715: .\"
! 716: documentation.
! 717: .
! 718: .
! 719: .SH CALLOUTS
! 720: .rs
! 721: .sp
! 722: If the pattern contains any callout requests, \fBpcretest\fP's callout function
! 723: is called during matching. This works with both matching functions. By default,
! 724: the called function displays the callout number, the start and current
! 725: positions in the text at the callout time, and the next pattern item to be
! 726: tested. For example, the output
! 727: .sp
! 728: --->pqrabcdef
! 729: 0 ^ ^ \ed
! 730: .sp
! 731: indicates that callout number 0 occurred for a match attempt starting at the
! 732: fourth character of the subject string, when the pointer was at the seventh
! 733: character of the data, and when the next pattern item was \ed. Just one
! 734: circumflex is output if the start and current positions are the same.
! 735: .P
! 736: Callouts numbered 255 are assumed to be automatic callouts, inserted as a
! 737: result of the \fB/C\fP pattern modifier. In this case, instead of showing the
! 738: callout number, the offset in the pattern, preceded by a plus, is output. For
! 739: example:
! 740: .sp
! 741: re> /\ed?[A-E]\e*/C
! 742: data> E*
! 743: --->E*
! 744: +0 ^ \ed?
! 745: +3 ^ [A-E]
! 746: +8 ^^ \e*
! 747: +10 ^ ^
! 748: 0: E*
! 749: .sp
! 750: If a pattern contains (*MARK) items, an additional line is output whenever
! 751: a change of latest mark is passed to the callout function. For example:
! 752: .sp
! 753: re> /a(*MARK:X)bc/C
! 754: data> abc
! 755: --->abc
! 756: +0 ^ a
! 757: +1 ^^ (*MARK:X)
! 758: +10 ^^ b
! 759: Latest Mark: X
! 760: +11 ^ ^ c
! 761: +12 ^ ^
! 762: 0: abc
! 763: .sp
! 764: The mark changes between matching "a" and "b", but stays the same for the rest
! 765: of the match, so nothing more is output. If, as a result of backtracking, the
! 766: mark reverts to being unset, the text "<unset>" is output.
! 767: .P
! 768: The callout function in \fBpcretest\fP returns zero (carry on matching) by
! 769: default, but you can use a \eC item in a data line (as described above) to
! 770: change this and other parameters of the callout.
! 771: .P
! 772: Inserting callouts can be helpful when using \fBpcretest\fP to check
! 773: complicated regular expressions. For further information about callouts, see
! 774: the
! 775: .\" HREF
! 776: \fBpcrecallout\fP
! 777: .\"
! 778: documentation.
! 779: .
! 780: .
! 781: .
! 782: .SH "NON-PRINTING CHARACTERS"
! 783: .rs
! 784: .sp
! 785: When \fBpcretest\fP is outputting text in the compiled version of a pattern,
! 786: bytes other than 32-126 are always treated as non-printing characters are are
! 787: therefore shown as hex escapes.
! 788: .P
! 789: When \fBpcretest\fP is outputting text that is a matched part of a subject
! 790: string, it behaves in the same way, unless a different locale has been set for
! 791: the pattern (using the \fB/L\fP modifier). In this case, the \fBisprint()\fP
! 792: function to distinguish printing and non-printing characters.
! 793: .
! 794: .
! 795: .
! 796: .SH "SAVING AND RELOADING COMPILED PATTERNS"
! 797: .rs
! 798: .sp
! 799: The facilities described in this section are not available when the POSIX
! 800: interface to PCRE is being used, that is, when the \fB/P\fP pattern modifier is
! 801: specified.
! 802: .P
! 803: When the POSIX interface is not in use, you can cause \fBpcretest\fP to write a
! 804: compiled pattern to a file, by following the modifiers with > and a file name.
! 805: For example:
! 806: .sp
! 807: /pattern/im >/some/file
! 808: .sp
! 809: See the
! 810: .\" HREF
! 811: \fBpcreprecompile\fP
! 812: .\"
! 813: documentation for a discussion about saving and re-using compiled patterns.
! 814: Note that if the pattern was successfully studied with JIT optimization, the
! 815: JIT data cannot be saved.
! 816: .P
! 817: The data that is written is binary. The first eight bytes are the length of the
! 818: compiled pattern data followed by the length of the optional study data, each
! 819: written as four bytes in big-endian order (most significant byte first). If
! 820: there is no study data (either the pattern was not studied, or studying did not
! 821: return any data), the second length is zero. The lengths are followed by an
! 822: exact copy of the compiled pattern. If there is additional study data, this
! 823: (excluding any JIT data) follows immediately after the compiled pattern. After
! 824: writing the file, \fBpcretest\fP expects to read a new pattern.
! 825: .P
! 826: A saved pattern can be reloaded into \fBpcretest\fP by specifying < and a file
! 827: name instead of a pattern. The name of the file must not contain a < character,
! 828: as otherwise \fBpcretest\fP will interpret the line as a pattern delimited by <
! 829: characters.
! 830: For example:
! 831: .sp
! 832: re> </some/file
! 833: Compiled pattern loaded from /some/file
! 834: No study data
! 835: .sp
! 836: If the pattern was previously studied with the JIT optimization, the JIT
! 837: information cannot be saved and restored, and so is lost. When the pattern has
! 838: been loaded, \fBpcretest\fP proceeds to read data lines in the usual way.
! 839: .P
! 840: You can copy a file written by \fBpcretest\fP to a different host and reload it
! 841: there, even if the new host has opposite endianness to the one on which the
! 842: pattern was compiled. For example, you can compile on an i86 machine and run on
! 843: a SPARC machine.
! 844: .P
! 845: File names for saving and reloading can be absolute or relative, but note that
! 846: the shell facility of expanding a file name that starts with a tilde (~) is not
! 847: available.
! 848: .P
! 849: The ability to save and reload files in \fBpcretest\fP is intended for testing
! 850: and experimentation. It is not intended for production use because only a
! 851: single pattern can be written to a file. Furthermore, there is no facility for
! 852: supplying custom character tables for use with a reloaded pattern. If the
! 853: original pattern was compiled with custom tables, an attempt to match a subject
! 854: string using a reloaded pattern is likely to cause \fBpcretest\fP to crash.
! 855: Finally, if you attempt to load a file that is not in the correct format, the
! 856: result is undefined.
! 857: .
! 858: .
! 859: .SH "SEE ALSO"
! 860: .rs
! 861: .sp
! 862: \fBpcre\fP(3), \fBpcreapi\fP(3), \fBpcrecallout\fP(3), \fBpcrejit\fP,
! 863: \fBpcrematching\fP(3), \fBpcrepartial\fP(d), \fBpcrepattern\fP(3),
! 864: \fBpcreprecompile\fP(3).
! 865: .
! 866: .
! 867: .SH AUTHOR
! 868: .rs
! 869: .sp
! 870: .nf
! 871: Philip Hazel
! 872: University Computing Service
! 873: Cambridge CB2 3QH, England.
! 874: .fi
! 875: .
! 876: .
! 877: .SH REVISION
! 878: .rs
! 879: .sp
! 880: .nf
! 881: Last updated: 02 December 2011
! 882: Copyright (c) 1997-2011 University of Cambridge.
! 883: .fi
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