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Branches: pcre, MAIN
CVS tags: v8_34, HEAD
pcre 8.34

    1: .TH PCRETEST 1 "12 November 2013" "PCRE 8.34"
    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: ,
   22: .\" HREF
   23: \fBpcre16\fP
   24: and
   25: .\" HREF
   26: \fBpcre32\fP
   27: .\"
   28: documentation.
   29: .P
   30: The input for \fBpcretest\fP is a sequence of regular expression patterns and
   31: strings to be matched, as described below. The output shows the result of each
   32: match. Options on the command line and the patterns control PCRE options and
   33: exactly what is output.
   34: .P
   35: As PCRE has evolved, it has acquired many different features, and as a result,
   36: \fBpcretest\fP now has rather a lot of obscure options for testing every
   37: possible feature. Some of these options are specifically designed for use in
   38: conjunction with the test script and data files that are distributed as part of
   39: PCRE, and are unlikely to be of use otherwise. They are all documented here,
   40: but without much justification.
   41: .
   42: .
   43: .SH "INPUT DATA FORMAT"
   44: .rs
   45: .sp
   46: Input to \fBpcretest\fP is processed line by line, either by calling the C
   47: library's \fBfgets()\fP function, or via the \fBlibreadline\fP library (see
   48: below). In Unix-like environments, \fBfgets()\fP treats any bytes other than
   49: newline as data characters. However, in some Windows environments character 26
   50: (hex 1A) causes an immediate end of file, and no further data is read. For
   51: maximum portability, therefore, it is safest to use only ASCII characters in
   52: \fBpcretest\fP input files.
   53: .
   54: .
   55: .SH "PCRE's 8-BIT, 16-BIT AND 32-BIT LIBRARIES"
   56: .rs
   57: .sp
   58: From release 8.30, two separate PCRE libraries can be built. The original one
   59: supports 8-bit character strings, whereas the newer 16-bit library supports
   60: character strings encoded in 16-bit units. From release 8.32, a third library
   61: can be built, supporting character strings encoded in 32-bit units. The
   62: \fBpcretest\fP program can be used to test all three libraries. However, it is
   63: itself still an 8-bit program, reading 8-bit input and writing 8-bit output.
   64: When testing the 16-bit or 32-bit library, the patterns and data strings are
   65: converted to 16- or 32-bit format before being passed to the PCRE library
   66: functions. Results are converted to 8-bit for output.
   67: .P
   68: References to functions and structures of the form \fBpcre[16|32]_xx\fP below
   69: mean "\fBpcre_xx\fP when using the 8-bit library, \fBpcre16_xx\fP when using
   70: the 16-bit library, or \fBpcre32_xx\fP when using the 32-bit library".
   71: .
   72: .
   73: .SH "COMMAND LINE OPTIONS"
   74: .rs
   75: .TP 10
   76: \fB-8\fP
   77: If both the 8-bit library has been built, this option causes the 8-bit library
   78: to be used (which is the default); if the 8-bit library has not been built,
   79: this option causes an error.
   80: .TP 10
   81: \fB-16\fP
   82: If both the 8-bit or the 32-bit, and the 16-bit libraries have been built, this
   83: option causes the 16-bit library to be used. If only the 16-bit library has been
   84: built, this is the default (so has no effect). If only the 8-bit or the 32-bit
   85: library has been built, this option causes an error.
   86: .TP 10
   87: \fB-32\fP
   88: If both the 8-bit or the 16-bit, and the 32-bit libraries have been built, this
   89: option causes the 32-bit library to be used. If only the 32-bit library has been
   90: built, this is the default (so has no effect). If only the 8-bit or the 16-bit
   91: library has been built, this option causes an error.
   92: .TP 10
   93: \fB-b\fP
   94: Behave as if each pattern has the \fB/B\fP (show byte code) modifier; the
   95: internal form is output after compilation.
   96: .TP 10
   97: \fB-C\fP
   98: Output the version number of the PCRE library, and all available information
   99: about the optional features that are included, and then exit with zero exit
  100: code. All other options are ignored.
  101: .TP 10
  102: \fB-C\fP \fIoption\fP
  103: Output information about a specific build-time option, then exit. This
  104: functionality is intended for use in scripts such as \fBRunTest\fP. The
  105: following options output the value and set the exit code as indicated:
  106: .sp
  107:   ebcdic-nl  the code for LF (= NL) in an EBCDIC environment:
  108:                0x15 or 0x25
  109:                0 if used in an ASCII environment
  110:                exit code is always 0
  111:   linksize   the configured internal link size (2, 3, or 4)
  112:                exit code is set to the link size
  113:   newline    the default newline setting:
  114:                CR, LF, CRLF, ANYCRLF, or ANY
  115:                exit code is always 0
  116: .sp
  117: The following options output 1 for true or 0 for false, and set the exit code
  118: to the same value:
  119: .sp
  120:   ebcdic     compiled for an EBCDIC environment
  121:   jit        just-in-time support is available
  122:   pcre16     the 16-bit library was built
  123:   pcre32     the 32-bit library was built
  124:   pcre8      the 8-bit library was built
  125:   ucp        Unicode property support is available
  126:   utf        UTF-8 and/or UTF-16 and/or UTF-32 support
  127:                is available
  128: .sp
  129: If an unknown option is given, an error message is output; the exit code is 0.
  130: .TP 10
  131: \fB-d\fP
  132: Behave as if each pattern has the \fB/D\fP (debug) modifier; the internal
  133: form and information about the compiled pattern is output after compilation;
  134: \fB-d\fP is equivalent to \fB-b -i\fP.
  135: .TP 10
  136: \fB-dfa\fP
  137: Behave as if each data line contains the \eD escape sequence; this causes the
  138: alternative matching function, \fBpcre[16|32]_dfa_exec()\fP, to be used instead
  139: of the standard \fBpcre[16|32]_exec()\fP function (more detail is given below).
  140: .TP 10
  141: \fB-help\fP
  142: Output a brief summary these options and then exit.
  143: .TP 10
  144: \fB-i\fP
  145: Behave as if each pattern has the \fB/I\fP modifier; information about the
  146: compiled pattern is given after compilation.
  147: .TP 10
  148: \fB-M\fP
  149: Behave as if each data line contains the \eM escape sequence; this causes
  150: PCRE to discover the minimum MATCH_LIMIT and MATCH_LIMIT_RECURSION settings by
  151: calling \fBpcre[16|32]_exec()\fP repeatedly with different limits.
  152: .TP 10
  153: \fB-m\fP
  154: Output the size of each compiled pattern after it has been compiled. This is
  155: equivalent to adding \fB/M\fP to each regular expression. The size is given in
  156: bytes for both libraries.
  157: .TP 10
  158: \fB-O\fP
  159: Behave as if each pattern has the \fB/O\fP modifier, that is disable
  160: auto-possessification for all patterns.
  161: .TP 10
  162: \fB-o\fP \fIosize\fP
  163: Set the number of elements in the output vector that is used when calling
  164: \fBpcre[16|32]_exec()\fP or \fBpcre[16|32]_dfa_exec()\fP to be \fIosize\fP. The
  165: default value is 45, which is enough for 14 capturing subexpressions for
  166: \fBpcre[16|32]_exec()\fP or 22 different matches for
  167: \fBpcre[16|32]_dfa_exec()\fP.
  168: The vector size can be changed for individual matching calls by including \eO
  169: in the data line (see below).
  170: .TP 10
  171: \fB-p\fP
  172: Behave as if each pattern has the \fB/P\fP modifier; the POSIX wrapper API is
  173: used to call PCRE. None of the other options has any effect when \fB-p\fP is
  174: set. This option can be used only with the 8-bit library.
  175: .TP 10
  176: \fB-q\fP
  177: Do not output the version number of \fBpcretest\fP at the start of execution.
  178: .TP 10
  179: \fB-S\fP \fIsize\fP
  180: On Unix-like systems, set the size of the run-time stack to \fIsize\fP
  181: megabytes.
  182: .TP 10
  183: \fB-s\fP or \fB-s+\fP
  184: Behave as if each pattern has the \fB/S\fP modifier; in other words, force each
  185: pattern to be studied. If \fB-s+\fP is used, all the JIT compile options are
  186: passed to \fBpcre[16|32]_study()\fP, causing just-in-time optimization to be set
  187: up if it is available, for both full and partial matching. Specific JIT compile
  188: options can be selected by following \fB-s+\fP with a digit in the range 1 to
  189: 7, which selects the JIT compile modes as follows:
  190: .sp
  191:   1  normal match only
  192:   2  soft partial match only
  193:   3  normal match and soft partial match
  194:   4  hard partial match only
  195:   6  soft and hard partial match
  196:   7  all three modes (default)
  197: .sp
  198: If \fB-s++\fP is used instead of \fB-s+\fP (with or without a following digit),
  199: the text "(JIT)" is added to the first output line after a match or no match
  200: when JIT-compiled code was actually used.
  201: .sp
  202: Note that there are pattern options that can override \fB-s\fP, either
  203: specifying no studying at all, or suppressing JIT compilation.
  204: .sp
  205: If the \fB/I\fP or \fB/D\fP option is present on a pattern (requesting output
  206: about the compiled pattern), information about the result of studying is not
  207: included when studying is caused only by \fB-s\fP and neither \fB-i\fP nor
  208: \fB-d\fP is present on the command line. This behaviour means that the output
  209: from tests that are run with and without \fB-s\fP should be identical, except
  210: when options that output information about the actual running of a match are
  211: set.
  212: .sp
  213: The \fB-M\fP, \fB-t\fP, and \fB-tm\fP options, which give information about
  214: resources used, are likely to produce different output with and without
  215: \fB-s\fP. Output may also differ if the \fB/C\fP option is present on an
  216: individual pattern. This uses callouts to trace the the matching process, and
  217: this may be different between studied and non-studied patterns. If the pattern
  218: contains (*MARK) items there may also be differences, for the same reason. The
  219: \fB-s\fP command line option can be overridden for specific patterns that
  220: should never be studied (see the \fB/S\fP pattern modifier below).
  221: .TP 10
  222: \fB-t\fP
  223: Run each compile, study, and match many times with a timer, and output the
  224: resulting times per compile, study, or match (in milliseconds). Do not set
  225: \fB-m\fP with \fB-t\fP, because you will then get the size output a zillion
  226: times, and the timing will be distorted. You can control the number of
  227: iterations that are used for timing by following \fB-t\fP with a number (as a
  228: separate item on the command line). For example, "-t 1000" iterates 1000 times.
  229: The default is to iterate 500000 times.
  230: .TP 10
  231: \fB-tm\fP
  232: This is like \fB-t\fP except that it times only the matching phase, not the
  233: compile or study phases.
  234: .TP 10
  235: \fB-T\fP \fB-TM\fP
  236: These behave like \fB-t\fP and \fB-tm\fP, but in addition, at the end of a run,
  237: the total times for all compiles, studies, and matches are output.
  238: .
  239: .
  240: .SH DESCRIPTION
  241: .rs
  242: .sp
  243: If \fBpcretest\fP is given two filename arguments, it reads from the first and
  244: writes to the second. If it is given only one filename argument, it reads from
  245: that file and writes to stdout. Otherwise, it reads from stdin and writes to
  246: stdout, and prompts for each line of input, using "re>" to prompt for regular
  247: expressions, and "data>" to prompt for data lines.
  248: .P
  249: When \fBpcretest\fP is built, a configuration option can specify that it should
  250: be linked with the \fBlibreadline\fP library. When this is done, if the input
  251: is from a terminal, it is read using the \fBreadline()\fP function. This
  252: provides line-editing and history facilities. The output from the \fB-help\fP
  253: option states whether or not \fBreadline()\fP will be used.
  254: .P
  255: The program handles any number of sets of input on a single input file. Each
  256: set starts with a regular expression, and continues with any number of data
  257: lines to be matched against that pattern.
  258: .P
  259: Each data line is matched separately and independently. If you want to do
  260: multi-line matches, you have to use the \en escape sequence (or \er or \er\en,
  261: etc., depending on the newline setting) in a single line of input to encode the
  262: newline sequences. There is no limit on the length of data lines; the input
  263: buffer is automatically extended if it is too small.
  264: .P
  265: An empty line signals the end of the data lines, at which point a new regular
  266: expression is read. The regular expressions are given enclosed in any
  267: non-alphanumeric delimiters other than backslash, for example:
  268: .sp
  269:   /(a|bc)x+yz/
  270: .sp
  271: White space before the initial delimiter is ignored. A regular expression may
  272: be continued over several input lines, in which case the newline characters are
  273: included within it. It is possible to include the delimiter within the pattern
  274: by escaping it, for example
  275: .sp
  276:   /abc\e/def/
  277: .sp
  278: If you do so, the escape and the delimiter form part of the pattern, but since
  279: delimiters are always non-alphanumeric, this does not affect its interpretation.
  280: If the terminating delimiter is immediately followed by a backslash, for
  281: example,
  282: .sp
  283:   /abc/\e
  284: .sp
  285: then a backslash is added to the end of the pattern. This is done to provide a
  286: way of testing the error condition that arises if a pattern finishes with a
  287: backslash, because
  288: .sp
  289:   /abc\e/
  290: .sp
  291: is interpreted as the first line of a pattern that starts with "abc/", causing
  292: pcretest to read the next line as a continuation of the regular expression.
  293: .
  294: .
  295: .SH "PATTERN MODIFIERS"
  296: .rs
  297: .sp
  298: A pattern may be followed by any number of modifiers, which are mostly single
  299: characters, though some of these can be qualified by further characters.
  300: Following Perl usage, these are referred to below as, for example, "the
  301: \fB/i\fP modifier", even though the delimiter of the pattern need not always be
  302: a slash, and no slash is used when writing modifiers. White space may appear
  303: between the final pattern delimiter and the first modifier, and between the
  304: modifiers themselves. For reference, here is a complete list of modifiers. They
  305: fall into several groups that are described in detail in the following
  306: sections.
  307: .sp
  308:   \fB/8\fP              set UTF mode
  309:   \fB/9\fP              set PCRE_NEVER_UTF (locks out UTF mode)
  310:   \fB/?\fP              disable UTF validity check
  311:   \fB/+\fP              show remainder of subject after match
  312:   \fB/=\fP              show all captures (not just those that are set)
  313: .sp
  314:   \fB/A\fP              set PCRE_ANCHORED
  315:   \fB/B\fP              show compiled code
  316:   \fB/C\fP              set PCRE_AUTO_CALLOUT
  317:   \fB/D\fP              same as \fB/B\fP plus \fB/I\fP
  318:   \fB/E\fP              set PCRE_DOLLAR_ENDONLY
  319:   \fB/F\fP              flip byte order in compiled pattern
  320:   \fB/f\fP              set PCRE_FIRSTLINE
  321:   \fB/G\fP              find all matches (shorten string)
  322:   \fB/g\fP              find all matches (use startoffset)
  323:   \fB/I\fP              show information about pattern
  324:   \fB/i\fP              set PCRE_CASELESS
  325:   \fB/J\fP              set PCRE_DUPNAMES
  326:   \fB/K\fP              show backtracking control names
  327:   \fB/L\fP              set locale
  328:   \fB/M\fP              show compiled memory size
  329:   \fB/m\fP              set PCRE_MULTILINE
  330:   \fB/N\fP              set PCRE_NO_AUTO_CAPTURE
  331:   \fB/O\fP              set PCRE_NO_AUTO_POSSESS
  332:   \fB/P\fP              use the POSIX wrapper
  333:   \fB/S\fP              study the pattern after compilation
  334:   \fB/s\fP              set PCRE_DOTALL
  335:   \fB/T\fP              select character tables
  336:   \fB/U\fP              set PCRE_UNGREEDY
  337:   \fB/W\fP              set PCRE_UCP
  338:   \fB/X\fP              set PCRE_EXTRA
  339:   \fB/x\fP              set PCRE_EXTENDED
  340:   \fB/Y\fP              set PCRE_NO_START_OPTIMIZE
  341:   \fB/Z\fP              don't show lengths in \fB/B\fP output
  342: .sp
  343:   \fB/<any>\fP          set PCRE_NEWLINE_ANY
  344:   \fB/<anycrlf>\fP      set PCRE_NEWLINE_ANYCRLF
  345:   \fB/<cr>\fP           set PCRE_NEWLINE_CR
  346:   \fB/<crlf>\fP         set PCRE_NEWLINE_CRLF
  347:   \fB/<lf>\fP           set PCRE_NEWLINE_LF
  348:   \fB/<bsr_anycrlf>\fP  set PCRE_BSR_ANYCRLF
  349:   \fB/<bsr_unicode>\fP  set PCRE_BSR_UNICODE
  350:   \fB/<JS>\fP           set PCRE_JAVASCRIPT_COMPAT
  351: .sp
  352: .
  353: .
  354: .SS "Perl-compatible modifiers"
  355: .rs
  356: .sp
  357: The \fB/i\fP, \fB/m\fP, \fB/s\fP, and \fB/x\fP modifiers set the PCRE_CASELESS,
  358: PCRE_MULTILINE, PCRE_DOTALL, or PCRE_EXTENDED options, respectively, when
  359: \fBpcre[16|32]_compile()\fP is called. These four modifier letters have the same
  360: effect as they do in Perl. For example:
  361: .sp
  362:   /caseless/i
  363: .sp
  364: .
  365: .
  366: .SS "Modifiers for other PCRE options"
  367: .rs
  368: .sp
  369: The following table shows additional modifiers for setting PCRE compile-time
  370: options that do not correspond to anything in Perl:
  371: .sp
  372:   \fB/8\fP              PCRE_UTF8           ) when using the 8-bit
  373:   \fB/?\fP              PCRE_NO_UTF8_CHECK  )   library
  374: .sp
  375:   \fB/8\fP              PCRE_UTF16          ) when using the 16-bit
  376:   \fB/?\fP              PCRE_NO_UTF16_CHECK )   library
  377: .sp
  378:   \fB/8\fP              PCRE_UTF32          ) when using the 32-bit
  379:   \fB/?\fP              PCRE_NO_UTF32_CHECK )   library
  380: .sp
  381:   \fB/9\fP              PCRE_NEVER_UTF
  382:   \fB/A\fP              PCRE_ANCHORED
  383:   \fB/C\fP              PCRE_AUTO_CALLOUT
  384:   \fB/E\fP              PCRE_DOLLAR_ENDONLY
  385:   \fB/f\fP              PCRE_FIRSTLINE
  386:   \fB/J\fP              PCRE_DUPNAMES
  387:   \fB/N\fP              PCRE_NO_AUTO_CAPTURE
  388:   \fB/O\fP              PCRE_NO_AUTO_POSSESS
  389:   \fB/U\fP              PCRE_UNGREEDY
  390:   \fB/W\fP              PCRE_UCP
  391:   \fB/X\fP              PCRE_EXTRA
  392:   \fB/Y\fP              PCRE_NO_START_OPTIMIZE
  393:   \fB/<any>\fP          PCRE_NEWLINE_ANY
  394:   \fB/<anycrlf>\fP      PCRE_NEWLINE_ANYCRLF
  395:   \fB/<cr>\fP           PCRE_NEWLINE_CR
  396:   \fB/<crlf>\fP         PCRE_NEWLINE_CRLF
  397:   \fB/<lf>\fP           PCRE_NEWLINE_LF
  398:   \fB/<bsr_anycrlf>\fP  PCRE_BSR_ANYCRLF
  399:   \fB/<bsr_unicode>\fP  PCRE_BSR_UNICODE
  400:   \fB/<JS>\fP           PCRE_JAVASCRIPT_COMPAT
  401: .sp
  402: The modifiers that are enclosed in angle brackets are literal strings as shown,
  403: including the angle brackets, but the letters within can be in either case.
  404: This example sets multiline matching with CRLF as the line ending sequence:
  405: .sp
  406:   /^abc/m<CRLF>
  407: .sp
  408: As well as turning on the PCRE_UTF8/16/32 option, the \fB/8\fP modifier causes
  409: all non-printing characters in output strings to be printed using the
  410: \ex{hh...} notation. Otherwise, those less than 0x100 are output in hex without
  411: the curly brackets.
  412: .P
  413: Full details of the PCRE options are given in the
  414: .\" HREF
  415: \fBpcreapi\fP
  416: .\"
  417: documentation.
  418: .
  419: .
  420: .SS "Finding all matches in a string"
  421: .rs
  422: .sp
  423: Searching for all possible matches within each subject string can be requested
  424: by the \fB/g\fP or \fB/G\fP modifier. After finding a match, PCRE is called
  425: again to search the remainder of the subject string. The difference between
  426: \fB/g\fP and \fB/G\fP is that the former uses the \fIstartoffset\fP argument to
  427: \fBpcre[16|32]_exec()\fP to start searching at a new point within the entire
  428: string (which is in effect what Perl does), whereas the latter passes over a
  429: shortened substring. This makes a difference to the matching process if the
  430: pattern begins with a lookbehind assertion (including \eb or \eB).
  431: .P
  432: If any call to \fBpcre[16|32]_exec()\fP in a \fB/g\fP or \fB/G\fP sequence matches
  433: an empty string, the next call is done with the PCRE_NOTEMPTY_ATSTART and
  434: PCRE_ANCHORED flags set in order to search for another, non-empty, match at the
  435: same point. If this second match fails, the start offset is advanced, and the
  436: normal match is retried. This imitates the way Perl handles such cases when
  437: using the \fB/g\fP modifier or the \fBsplit()\fP function. Normally, the start
  438: offset is advanced by one character, but if the newline convention recognizes
  439: CRLF as a newline, and the current character is CR followed by LF, an advance
  440: of two is used.
  441: .
  442: .
  443: .SS "Other modifiers"
  444: .rs
  445: .sp
  446: There are yet more modifiers for controlling the way \fBpcretest\fP
  447: operates.
  448: .P
  449: The \fB/+\fP modifier requests that as well as outputting the substring that
  450: matched the entire pattern, \fBpcretest\fP should in addition output the
  451: remainder of the subject string. This is useful for tests where the subject
  452: contains multiple copies of the same substring. If the \fB+\fP modifier appears
  453: twice, the same action is taken for captured substrings. In each case the
  454: remainder is output on the following line with a plus character following the
  455: capture number. Note that this modifier must not immediately follow the /S
  456: modifier because /S+ and /S++ have other meanings.
  457: .P
  458: The \fB/=\fP modifier requests that the values of all potential captured
  459: parentheses be output after a match. By default, only those up to the highest
  460: one actually used in the match are output (corresponding to the return code
  461: from \fBpcre[16|32]_exec()\fP). Values in the offsets vector corresponding to
  462: higher numbers should be set to -1, and these are output as "<unset>". This
  463: modifier gives a way of checking that this is happening.
  464: .P
  465: The \fB/B\fP modifier is a debugging feature. It requests that \fBpcretest\fP
  466: output a representation of the compiled code after compilation. Normally this
  467: information contains length and offset values; however, if \fB/Z\fP is also
  468: present, this data is replaced by spaces. This is a special feature for use in
  469: the automatic test scripts; it ensures that the same output is generated for
  470: different internal link sizes.
  471: .P
  472: The \fB/D\fP modifier is a PCRE debugging feature, and is equivalent to
  473: \fB/BI\fP, that is, both the \fB/B\fP and the \fB/I\fP modifiers.
  474: .P
  475: The \fB/F\fP modifier causes \fBpcretest\fP to flip the byte order of the
  476: 2-byte and 4-byte fields in the compiled pattern. This facility is for testing
  477: the feature in PCRE that allows it to execute patterns that were compiled on a
  478: host with a different endianness. This feature is not available when the POSIX
  479: interface to PCRE is being used, that is, when the \fB/P\fP pattern modifier is
  480: specified. See also the section about saving and reloading compiled patterns
  481: below.
  482: .P
  483: The \fB/I\fP modifier requests that \fBpcretest\fP output information about the
  484: compiled pattern (whether it is anchored, has a fixed first character, and
  485: so on). It does this by calling \fBpcre[16|32]_fullinfo()\fP after compiling a
  486: pattern. If the pattern is studied, the results of that are also output.
  487: .P
  488: The \fB/K\fP modifier requests \fBpcretest\fP to show names from backtracking
  489: control verbs that are returned from calls to \fBpcre[16|32]_exec()\fP. It causes
  490: \fBpcretest\fP to create a \fBpcre[16|32]_extra\fP block if one has not already
  491: been created by a call to \fBpcre[16|32]_study()\fP, and to set the
  492: PCRE_EXTRA_MARK flag and the \fBmark\fP field within it, every time that
  493: \fBpcre[16|32]_exec()\fP is called. If the variable that the \fBmark\fP field
  494: points to is non-NULL for a match, non-match, or partial match, \fBpcretest\fP
  495: prints the string to which it points. For a match, this is shown on a line by
  496: itself, tagged with "MK:". For a non-match it is added to the message.
  497: .P
  498: The \fB/L\fP modifier must be followed directly by the name of a locale, for
  499: example,
  500: .sp
  501:   /pattern/Lfr_FR
  502: .sp
  503: For this reason, it must be the last modifier. The given locale is set,
  504: \fBpcre[16|32]_maketables()\fP is called to build a set of character tables for
  505: the locale, and this is then passed to \fBpcre[16|32]_compile()\fP when compiling
  506: the regular expression. Without an \fB/L\fP (or \fB/T\fP) modifier, NULL is
  507: passed as the tables pointer; that is, \fB/L\fP applies only to the expression
  508: on which it appears.
  509: .P
  510: The \fB/M\fP modifier causes the size in bytes of the memory block used to hold
  511: the compiled pattern to be output. This does not include the size of the
  512: \fBpcre[16|32]\fP block; it is just the actual compiled data. If the pattern is
  513: successfully studied with the PCRE_STUDY_JIT_COMPILE option, the size of the
  514: JIT compiled code is also output.
  515: .P
  516: The \fB/S\fP modifier causes \fBpcre[16|32]_study()\fP to be called after the
  517: expression has been compiled, and the results used when the expression is
  518: matched. There are a number of qualifying characters that may follow \fB/S\fP.
  519: They may appear in any order.
  520: .P
  521: If \fB/S\fP is followed by an exclamation mark, \fBpcre[16|32]_study()\fP is
  522: called with the PCRE_STUDY_EXTRA_NEEDED option, causing it always to return a
  523: \fBpcre_extra\fP block, even when studying discovers no useful information.
  524: .P
  525: If \fB/S\fP is followed by a second S character, it suppresses studying, even
  526: if it was requested externally by the \fB-s\fP command line option. This makes
  527: it possible to specify that certain patterns are always studied, and others are
  528: never studied, independently of \fB-s\fP. This feature is used in the test
  529: files in a few cases where the output is different when the pattern is studied.
  530: .P
  531: If the \fB/S\fP modifier is followed by a + character, the call to
  532: \fBpcre[16|32]_study()\fP is made with all the JIT study options, requesting
  533: just-in-time optimization support if it is available, for both normal and
  534: partial matching. If you want to restrict the JIT compiling modes, you can
  535: follow \fB/S+\fP with a digit in the range 1 to 7:
  536: .sp
  537:   1  normal match only
  538:   2  soft partial match only
  539:   3  normal match and soft partial match
  540:   4  hard partial match only
  541:   6  soft and hard partial match
  542:   7  all three modes (default)
  543: .sp
  544: If \fB/S++\fP is used instead of \fB/S+\fP (with or without a following digit),
  545: the text "(JIT)" is added to the first output line after a match or no match
  546: when JIT-compiled code was actually used.
  547: .P
  548: Note that there is also an independent \fB/+\fP modifier; it must not be given
  549: immediately after \fB/S\fP or \fB/S+\fP because this will be misinterpreted.
  550: .P
  551: If JIT studying is successful, the compiled JIT code will automatically be used
  552: when \fBpcre[16|32]_exec()\fP is run, except when incompatible run-time options
  553: are specified. For more details, see the
  554: .\" HREF
  555: \fBpcrejit\fP
  556: .\"
  557: documentation. See also the \fB\eJ\fP escape sequence below for a way of
  558: setting the size of the JIT stack.
  559: .P
  560: Finally, if \fB/S\fP is followed by a minus character, JIT compilation is
  561: suppressed, even if it was requested externally by the \fB-s\fP command line
  562: option. This makes it possible to specify that JIT is never to be used for
  563: certain patterns.
  564: .P
  565: The \fB/T\fP modifier must be followed by a single digit. It causes a specific
  566: set of built-in character tables to be passed to \fBpcre[16|32]_compile()\fP. It
  567: is used in the standard PCRE tests to check behaviour with different character
  568: tables. The digit specifies the tables as follows:
  569: .sp
  570:   0   the default ASCII tables, as distributed in
  571:         pcre_chartables.c.dist
  572:   1   a set of tables defining ISO 8859 characters
  573: .sp
  574: In table 1, some characters whose codes are greater than 128 are identified as
  575: letters, digits, spaces, etc.
  576: .
  577: .
  578: .SS "Using the POSIX wrapper API"
  579: .rs
  580: .sp
  581: The \fB/P\fP modifier causes \fBpcretest\fP to call PCRE via the POSIX wrapper
  582: API rather than its native API. This supports only the 8-bit library. When
  583: \fB/P\fP is set, the following modifiers set options for the \fBregcomp()\fP
  584: function:
  585: .sp
  586:   /i    REG_ICASE
  587:   /m    REG_NEWLINE
  588:   /N    REG_NOSUB
  589:   /s    REG_DOTALL     )
  590:   /U    REG_UNGREEDY   ) These options are not part of
  591:   /W    REG_UCP        )   the POSIX standard
  592:   /8    REG_UTF8       )
  593: .sp
  594: The \fB/+\fP modifier works as described above. All other modifiers are
  595: ignored.
  596: .
  597: .
  598: .SS "Locking out certain modifiers"
  599: .rs
  600: .sp
  601: PCRE can be compiled with or without support for certain features such as
  602: UTF-8/16/32 or Unicode properties. Accordingly, the standard tests are split up
  603: into a number of different files that are selected for running depending on
  604: which features are available. When updating the tests, it is all too easy to
  605: put a new test into the wrong file by mistake; for example, to put a test that
  606: requires UTF support into a file that is used when it is not available. To help
  607: detect such mistakes as early as possible, there is a facility for locking out
  608: specific modifiers. If an input line for \fBpcretest\fP starts with the string
  609: "< forbid " the following sequence of characters is taken as a list of
  610: forbidden modifiers. For example, in the test files that must not use UTF or
  611: Unicode property support, this line appears:
  612: .sp
  613:   < forbid 8W
  614: .sp
  615: This locks out the /8 and /W modifiers. An immediate error is given if they are
  616: subsequently encountered. If the character string contains < but not >, all the
  617: multi-character modifiers that begin with < are locked out. Otherwise, such
  618: modifiers must be explicitly listed, for example:
  619: .sp
  620:   < forbid <JS><cr>
  621: .sp
  622: There must be a single space between < and "forbid" for this feature to be
  623: recognised. If there is not, the line is interpreted either as a request to
  624: re-load a pre-compiled pattern (see "SAVING AND RELOADING COMPILED PATTERNS"
  625: below) or, if there is a another < character, as a pattern that uses < as its
  626: delimiter.
  627: .
  628: .
  629: .SH "DATA LINES"
  630: .rs
  631: .sp
  632: Before each data line is passed to \fBpcre[16|32]_exec()\fP, leading and trailing
  633: white space is removed, and it is then scanned for \e escapes. Some of these
  634: are pretty esoteric features, intended for checking out some of the more
  635: complicated features of PCRE. If you are just testing "ordinary" regular
  636: expressions, you probably don't need any of these. The following escapes are
  637: recognized:
  638: .sp
  639:   \ea         alarm (BEL, \ex07)
  640:   \eb         backspace (\ex08)
  641:   \ee         escape (\ex27)
  642:   \ef         form feed (\ex0c)
  643:   \en         newline (\ex0a)
  644: .\" JOIN
  645:   \eqdd       set the PCRE_MATCH_LIMIT limit to dd
  646:                (any number of digits)
  647:   \er         carriage return (\ex0d)
  648:   \et         tab (\ex09)
  649:   \ev         vertical tab (\ex0b)
  650:   \ennn       octal character (up to 3 octal digits); always
  651:                a byte unless > 255 in UTF-8 or 16-bit or 32-bit mode
  652:   \eo{dd...}  octal character (any number of octal digits}
  653:   \exhh       hexadecimal byte (up to 2 hex digits)
  654:   \ex{hh...}  hexadecimal character (any number of hex digits)
  655: .\" JOIN
  656:   \eA         pass the PCRE_ANCHORED option to \fBpcre[16|32]_exec()\fP
  657:                or \fBpcre[16|32]_dfa_exec()\fP
  658: .\" JOIN
  659:   \eB         pass the PCRE_NOTBOL option to \fBpcre[16|32]_exec()\fP
  660:                or \fBpcre[16|32]_dfa_exec()\fP
  661: .\" JOIN
  662:   \eCdd       call pcre[16|32]_copy_substring() for substring dd
  663:                after a successful match (number less than 32)
  664: .\" JOIN
  665:   \eCname     call pcre[16|32]_copy_named_substring() for substring
  666:                "name" after a successful match (name termin-
  667:                ated by next non alphanumeric character)
  668: .\" JOIN
  669:   \eC+        show the current captured substrings at callout
  670:                time
  671:   \eC-        do not supply a callout function
  672: .\" JOIN
  673:   \eC!n       return 1 instead of 0 when callout number n is
  674:                reached
  675: .\" JOIN
  676:   \eC!n!m     return 1 instead of 0 when callout number n is
  677:                reached for the nth time
  678: .\" JOIN
  679:   \eC*n       pass the number n (may be negative) as callout
  680:                data; this is used as the callout return value
  681:   \eD         use the \fBpcre[16|32]_dfa_exec()\fP match function
  682:   \eF         only shortest match for \fBpcre[16|32]_dfa_exec()\fP
  683: .\" JOIN
  684:   \eGdd       call pcre[16|32]_get_substring() for substring dd
  685:                after a successful match (number less than 32)
  686: .\" JOIN
  687:   \eGname     call pcre[16|32]_get_named_substring() for substring
  688:                "name" after a successful match (name termin-
  689:                ated by next non-alphanumeric character)
  690: .\" JOIN
  691:   \eJdd       set up a JIT stack of dd kilobytes maximum (any
  692:                number of digits)
  693: .\" JOIN
  694:   \eL         call pcre[16|32]_get_substringlist() after a
  695:                successful match
  696: .\" JOIN
  697:   \eM         discover the minimum MATCH_LIMIT and
  698:                MATCH_LIMIT_RECURSION settings
  699: .\" JOIN
  700:   \eN         pass the PCRE_NOTEMPTY option to \fBpcre[16|32]_exec()\fP
  701:                or \fBpcre[16|32]_dfa_exec()\fP; if used twice, pass the
  702:                PCRE_NOTEMPTY_ATSTART option
  703: .\" JOIN
  704:   \eOdd       set the size of the output vector passed to
  705:                \fBpcre[16|32]_exec()\fP to dd (any number of digits)
  706: .\" JOIN
  707:   \eP         pass the PCRE_PARTIAL_SOFT option to \fBpcre[16|32]_exec()\fP
  708:                or \fBpcre[16|32]_dfa_exec()\fP; if used twice, pass the
  709:                PCRE_PARTIAL_HARD option
  710: .\" JOIN
  711:   \eQdd       set the PCRE_MATCH_LIMIT_RECURSION limit to dd
  712:                (any number of digits)
  713:   \eR         pass the PCRE_DFA_RESTART option to \fBpcre[16|32]_dfa_exec()\fP
  714:   \eS         output details of memory get/free calls during matching
  715: .\" JOIN
  716:   \eY         pass the PCRE_NO_START_OPTIMIZE option to \fBpcre[16|32]_exec()\fP
  717:                or \fBpcre[16|32]_dfa_exec()\fP
  718: .\" JOIN
  719:   \eZ         pass the PCRE_NOTEOL option to \fBpcre[16|32]_exec()\fP
  720:                or \fBpcre[16|32]_dfa_exec()\fP
  721: .\" JOIN
  722:   \e?         pass the PCRE_NO_UTF[8|16|32]_CHECK option to
  723:                \fBpcre[16|32]_exec()\fP or \fBpcre[16|32]_dfa_exec()\fP
  724: .\" JOIN
  725:   \e>dd       start the match at offset dd (optional "-"; then
  726:                any number of digits); this sets the \fIstartoffset\fP
  727:                argument for \fBpcre[16|32]_exec()\fP or \fBpcre[16|32]_dfa_exec()\fP
  728: .\" JOIN
  729:   \e<cr>      pass the PCRE_NEWLINE_CR option to \fBpcre[16|32]_exec()\fP
  730:                or \fBpcre[16|32]_dfa_exec()\fP
  731: .\" JOIN
  732:   \e<lf>      pass the PCRE_NEWLINE_LF option to \fBpcre[16|32]_exec()\fP
  733:                or \fBpcre[16|32]_dfa_exec()\fP
  734: .\" JOIN
  735:   \e<crlf>    pass the PCRE_NEWLINE_CRLF option to \fBpcre[16|32]_exec()\fP
  736:                or \fBpcre[16|32]_dfa_exec()\fP
  737: .\" JOIN
  738:   \e<anycrlf> pass the PCRE_NEWLINE_ANYCRLF option to \fBpcre[16|32]_exec()\fP
  739:                or \fBpcre[16|32]_dfa_exec()\fP
  740: .\" JOIN
  741:   \e<any>     pass the PCRE_NEWLINE_ANY option to \fBpcre[16|32]_exec()\fP
  742:                or \fBpcre[16|32]_dfa_exec()\fP
  743: .sp
  744: The use of \ex{hh...} is not dependent on the use of the \fB/8\fP modifier on
  745: the pattern. It is recognized always. There may be any number of hexadecimal
  746: digits inside the braces; invalid values provoke error messages.
  747: .P
  748: Note that \exhh specifies one byte rather than one character in UTF-8 mode;
  749: this makes it possible to construct invalid UTF-8 sequences for testing
  750: purposes. On the other hand, \ex{hh} is interpreted as a UTF-8 character in
  751: UTF-8 mode, generating more than one byte if the value is greater than 127.
  752: When testing the 8-bit library not in UTF-8 mode, \ex{hh} generates one byte
  753: for values less than 256, and causes an error for greater values.
  754: .P
  755: In UTF-16 mode, all 4-digit \ex{hhhh} values are accepted. This makes it
  756: possible to construct invalid UTF-16 sequences for testing purposes.
  757: .P
  758: In UTF-32 mode, all 4- to 8-digit \ex{...} values are accepted. This makes it
  759: possible to construct invalid UTF-32 sequences for testing purposes.
  760: .P
  761: The escapes that specify line ending sequences are literal strings, exactly as
  762: shown. No more than one newline setting should be present in any data line.
  763: .P
  764: A backslash followed by anything else just escapes the anything else. If
  765: the very last character is a backslash, it is ignored. This gives a way of
  766: passing an empty line as data, since a real empty line terminates the data
  767: input.
  768: .P
  769: The \fB\eJ\fP escape provides a way of setting the maximum stack size that is
  770: used by the just-in-time optimization code. It is ignored if JIT optimization
  771: is not being used. Providing a stack that is larger than the default 32K is
  772: necessary only for very complicated patterns.
  773: .P
  774: If \eM is present, \fBpcretest\fP calls \fBpcre[16|32]_exec()\fP several times,
  775: with different values in the \fImatch_limit\fP and \fImatch_limit_recursion\fP
  776: fields of the \fBpcre[16|32]_extra\fP data structure, until it finds the minimum
  777: numbers for each parameter that allow \fBpcre[16|32]_exec()\fP to complete without
  778: error. Because this is testing a specific feature of the normal interpretive
  779: \fBpcre[16|32]_exec()\fP execution, the use of any JIT optimization that might
  780: have been set up by the \fB/S+\fP qualifier of \fB-s+\fP option is disabled.
  781: .P
  782: The \fImatch_limit\fP number is a measure of the amount of backtracking
  783: that takes place, and checking it out can be instructive. For most simple
  784: matches, the number is quite small, but for patterns with very large numbers of
  785: matching possibilities, it can become large very quickly with increasing length
  786: of subject string. The \fImatch_limit_recursion\fP number is a measure of how
  787: much stack (or, if PCRE is compiled with NO_RECURSE, how much heap) memory is
  788: needed to complete the match attempt.
  789: .P
  790: When \eO is used, the value specified may be higher or lower than the size set
  791: by the \fB-O\fP command line option (or defaulted to 45); \eO applies only to
  792: the call of \fBpcre[16|32]_exec()\fP for the line in which it appears.
  793: .P
  794: If the \fB/P\fP modifier was present on the pattern, causing the POSIX wrapper
  795: API to be used, the only option-setting sequences that have any effect are \eB,
  796: \eN, and \eZ, causing REG_NOTBOL, REG_NOTEMPTY, and REG_NOTEOL, respectively,
  797: to be passed to \fBregexec()\fP.
  798: .
  799: .
  800: .SH "THE ALTERNATIVE MATCHING FUNCTION"
  801: .rs
  802: .sp
  803: By default, \fBpcretest\fP uses the standard PCRE matching function,
  804: \fBpcre[16|32]_exec()\fP to match each data line. PCRE also supports an
  805: alternative matching function, \fBpcre[16|32]_dfa_test()\fP, which operates in a
  806: different way, and has some restrictions. The differences between the two
  807: functions are described in the
  808: .\" HREF
  809: \fBpcrematching\fP
  810: .\"
  811: documentation.
  812: .P
  813: If a data line contains the \eD escape sequence, or if the command line
  814: contains the \fB-dfa\fP option, the alternative matching function is used.
  815: This function finds all possible matches at a given point. If, however, the \eF
  816: escape sequence is present in the data line, it stops after the first match is
  817: found. This is always the shortest possible match.
  818: .
  819: .
  820: .SH "DEFAULT OUTPUT FROM PCRETEST"
  821: .rs
  822: .sp
  823: This section describes the output when the normal matching function,
  824: \fBpcre[16|32]_exec()\fP, is being used.
  825: .P
  826: When a match succeeds, \fBpcretest\fP outputs the list of captured substrings
  827: that \fBpcre[16|32]_exec()\fP returns, starting with number 0 for the string that
  828: matched the whole pattern. Otherwise, it outputs "No match" when the return is
  829: PCRE_ERROR_NOMATCH, and "Partial match:" followed by the partially matching
  830: substring when \fBpcre[16|32]_exec()\fP returns PCRE_ERROR_PARTIAL. (Note that
  831: this is the entire substring that was inspected during the partial match; it
  832: may include characters before the actual match start if a lookbehind assertion,
  833: \eK, \eb, or \eB was involved.) For any other return, \fBpcretest\fP outputs
  834: the PCRE negative error number and a short descriptive phrase. If the error is
  835: a failed UTF string check, the offset of the start of the failing character and
  836: the reason code are also output, provided that the size of the output vector is
  837: at least two. Here is an example of an interactive \fBpcretest\fP run.
  838: .sp
  839:   $ pcretest
  840:   PCRE version 8.13 2011-04-30
  841: .sp
  842:     re> /^abc(\ed+)/
  843:   data> abc123
  844:    0: abc123
  845:    1: 123
  846:   data> xyz
  847:   No match
  848: .sp
  849: Unset capturing substrings that are not followed by one that is set are not
  850: returned by \fBpcre[16|32]_exec()\fP, and are not shown by \fBpcretest\fP. In the
  851: following example, there are two capturing substrings, but when the first data
  852: line is matched, the second, unset substring is not shown. An "internal" unset
  853: substring is shown as "<unset>", as for the second data line.
  854: .sp
  855:     re> /(a)|(b)/
  856:   data> a
  857:    0: a
  858:    1: a
  859:   data> b
  860:    0: b
  861:    1: <unset>
  862:    2: b
  863: .sp
  864: If the strings contain any non-printing characters, they are output as \exhh
  865: escapes if the value is less than 256 and UTF mode is not set. Otherwise they
  866: are output as \ex{hh...} escapes. See below for the definition of non-printing
  867: characters. If the pattern has the \fB/+\fP modifier, the output for substring
  868: 0 is followed by the the rest of the subject string, identified by "0+" like
  869: this:
  870: .sp
  871:     re> /cat/+
  872:   data> cataract
  873:    0: cat
  874:    0+ aract
  875: .sp
  876: If the pattern has the \fB/g\fP or \fB/G\fP modifier, the results of successive
  877: matching attempts are output in sequence, like this:
  878: .sp
  879:     re> /\eBi(\ew\ew)/g
  880:   data> Mississippi
  881:    0: iss
  882:    1: ss
  883:    0: iss
  884:    1: ss
  885:    0: ipp
  886:    1: pp
  887: .sp
  888: "No match" is output only if the first match attempt fails. Here is an example
  889: of a failure message (the offset 4 that is specified by \e>4 is past the end of
  890: the subject string):
  891: .sp
  892:     re> /xyz/
  893:   data> xyz\e>4
  894:   Error -24 (bad offset value)
  895: .P
  896: If any of the sequences \fB\eC\fP, \fB\eG\fP, or \fB\eL\fP are present in a
  897: data line that is successfully matched, the substrings extracted by the
  898: convenience functions are output with C, G, or L after the string number
  899: instead of a colon. This is in addition to the normal full list. The string
  900: length (that is, the return from the extraction function) is given in
  901: parentheses after each string for \fB\eC\fP and \fB\eG\fP.
  902: .P
  903: Note that whereas patterns can be continued over several lines (a plain ">"
  904: prompt is used for continuations), data lines may not. However newlines can be
  905: included in data by means of the \en escape (or \er, \er\en, etc., depending on
  906: the newline sequence setting).
  907: .
  908: .
  909: .
  910: .SH "OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION"
  911: .rs
  912: .sp
  913: When the alternative matching function, \fBpcre[16|32]_dfa_exec()\fP, is used (by
  914: means of the \eD escape sequence or the \fB-dfa\fP command line option), the
  915: output consists of a list of all the matches that start at the first point in
  916: the subject where there is at least one match. For example:
  917: .sp
  918:     re> /(tang|tangerine|tan)/
  919:   data> yellow tangerine\eD
  920:    0: tangerine
  921:    1: tang
  922:    2: tan
  923: .sp
  924: (Using the normal matching function on this data finds only "tang".) The
  925: longest matching string is always given first (and numbered zero). After a
  926: PCRE_ERROR_PARTIAL return, the output is "Partial match:", followed by the
  927: partially matching substring. (Note that this is the entire substring that was
  928: inspected during the partial match; it may include characters before the actual
  929: match start if a lookbehind assertion, \eK, \eb, or \eB was involved.)
  930: .P
  931: If \fB/g\fP is present on the pattern, the search for further matches resumes
  932: at the end of the longest match. For example:
  933: .sp
  934:     re> /(tang|tangerine|tan)/g
  935:   data> yellow tangerine and tangy sultana\eD
  936:    0: tangerine
  937:    1: tang
  938:    2: tan
  939:    0: tang
  940:    1: tan
  941:    0: tan
  942: .sp
  943: Since the matching function does not support substring capture, the escape
  944: sequences that are concerned with captured substrings are not relevant.
  945: .
  946: .
  947: .SH "RESTARTING AFTER A PARTIAL MATCH"
  948: .rs
  949: .sp
  950: When the alternative matching function has given the PCRE_ERROR_PARTIAL return,
  951: indicating that the subject partially matched the pattern, you can restart the
  952: match with additional subject data by means of the \eR escape sequence. For
  953: example:
  954: .sp
  955:     re> /^\ed?\ed(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\ed\ed$/
  956:   data> 23ja\eP\eD
  957:   Partial match: 23ja
  958:   data> n05\eR\eD
  959:    0: n05
  960: .sp
  961: For further information about partial matching, see the
  962: .\" HREF
  963: \fBpcrepartial\fP
  964: .\"
  965: documentation.
  966: .
  967: .
  968: .SH CALLOUTS
  969: .rs
  970: .sp
  971: If the pattern contains any callout requests, \fBpcretest\fP's callout function
  972: is called during matching. This works with both matching functions. By default,
  973: the called function displays the callout number, the start and current
  974: positions in the text at the callout time, and the next pattern item to be
  975: tested. For example:
  976: .sp
  977:   --->pqrabcdef
  978:     0    ^  ^     \ed
  979: .sp
  980: This output indicates that callout number 0 occurred for a match attempt
  981: starting at the fourth character of the subject string, when the pointer was at
  982: the seventh character of the data, and when the next pattern item was \ed. Just
  983: one circumflex is output if the start and current positions are the same.
  984: .P
  985: Callouts numbered 255 are assumed to be automatic callouts, inserted as a
  986: result of the \fB/C\fP pattern modifier. In this case, instead of showing the
  987: callout number, the offset in the pattern, preceded by a plus, is output. For
  988: example:
  989: .sp
  990:     re> /\ed?[A-E]\e*/C
  991:   data> E*
  992:   --->E*
  993:    +0 ^      \ed?
  994:    +3 ^      [A-E]
  995:    +8 ^^     \e*
  996:   +10 ^ ^
  997:    0: E*
  998: .sp
  999: If a pattern contains (*MARK) items, an additional line is output whenever
 1000: a change of latest mark is passed to the callout function. For example:
 1001: .sp
 1002:     re> /a(*MARK:X)bc/C
 1003:   data> abc
 1004:   --->abc
 1005:    +0 ^       a
 1006:    +1 ^^      (*MARK:X)
 1007:   +10 ^^      b
 1008:   Latest Mark: X
 1009:   +11 ^ ^     c
 1010:   +12 ^  ^
 1011:    0: abc
 1012: .sp
 1013: The mark changes between matching "a" and "b", but stays the same for the rest
 1014: of the match, so nothing more is output. If, as a result of backtracking, the
 1015: mark reverts to being unset, the text "<unset>" is output.
 1016: .P
 1017: The callout function in \fBpcretest\fP returns zero (carry on matching) by
 1018: default, but you can use a \eC item in a data line (as described above) to
 1019: change this and other parameters of the callout.
 1020: .P
 1021: Inserting callouts can be helpful when using \fBpcretest\fP to check
 1022: complicated regular expressions. For further information about callouts, see
 1023: the
 1024: .\" HREF
 1025: \fBpcrecallout\fP
 1026: .\"
 1027: documentation.
 1028: .
 1029: .
 1030: .
 1031: .SH "NON-PRINTING CHARACTERS"
 1032: .rs
 1033: .sp
 1034: When \fBpcretest\fP is outputting text in the compiled version of a pattern,
 1035: bytes other than 32-126 are always treated as non-printing characters are are
 1036: therefore shown as hex escapes.
 1037: .P
 1038: When \fBpcretest\fP is outputting text that is a matched part of a subject
 1039: string, it behaves in the same way, unless a different locale has been set for
 1040: the pattern (using the \fB/L\fP modifier). In this case, the \fBisprint()\fP
 1041: function to distinguish printing and non-printing characters.
 1042: .
 1043: .
 1044: .
 1045: .SH "SAVING AND RELOADING COMPILED PATTERNS"
 1046: .rs
 1047: .sp
 1048: The facilities described in this section are not available when the POSIX
 1049: interface to PCRE is being used, that is, when the \fB/P\fP pattern modifier is
 1050: specified.
 1051: .P
 1052: When the POSIX interface is not in use, you can cause \fBpcretest\fP to write a
 1053: compiled pattern to a file, by following the modifiers with > and a file name.
 1054: For example:
 1055: .sp
 1056:   /pattern/im >/some/file
 1057: .sp
 1058: See the
 1059: .\" HREF
 1060: \fBpcreprecompile\fP
 1061: .\"
 1062: documentation for a discussion about saving and re-using compiled patterns.
 1063: Note that if the pattern was successfully studied with JIT optimization, the
 1064: JIT data cannot be saved.
 1065: .P
 1066: The data that is written is binary. The first eight bytes are the length of the
 1067: compiled pattern data followed by the length of the optional study data, each
 1068: written as four bytes in big-endian order (most significant byte first). If
 1069: there is no study data (either the pattern was not studied, or studying did not
 1070: return any data), the second length is zero. The lengths are followed by an
 1071: exact copy of the compiled pattern. If there is additional study data, this
 1072: (excluding any JIT data) follows immediately after the compiled pattern. After
 1073: writing the file, \fBpcretest\fP expects to read a new pattern.
 1074: .P
 1075: A saved pattern can be reloaded into \fBpcretest\fP by specifying < and a file
 1076: name instead of a pattern. There must be no space between < and the file name,
 1077: which must not contain a < character, as otherwise \fBpcretest\fP will
 1078: interpret the line as a pattern delimited by < characters. For example:
 1079: .sp
 1080:    re> </some/file
 1081:   Compiled pattern loaded from /some/file
 1082:   No study data
 1083: .sp
 1084: If the pattern was previously studied with the JIT optimization, the JIT
 1085: information cannot be saved and restored, and so is lost. When the pattern has
 1086: been loaded, \fBpcretest\fP proceeds to read data lines in the usual way.
 1087: .P
 1088: You can copy a file written by \fBpcretest\fP to a different host and reload it
 1089: there, even if the new host has opposite endianness to the one on which the
 1090: pattern was compiled. For example, you can compile on an i86 machine and run on
 1091: a SPARC machine. When a pattern is reloaded on a host with different
 1092: endianness, the confirmation message is changed to:
 1093: .sp
 1094:   Compiled pattern (byte-inverted) loaded from /some/file
 1095: .sp
 1096: The test suite contains some saved pre-compiled patterns with different
 1097: endianness. These are reloaded using "<!" instead of just "<". This suppresses
 1098: the "(byte-inverted)" text so that the output is the same on all hosts. It also
 1099: forces debugging output once the pattern has been reloaded.
 1100: .P
 1101: File names for saving and reloading can be absolute or relative, but note that
 1102: the shell facility of expanding a file name that starts with a tilde (~) is not
 1103: available.
 1104: .P
 1105: The ability to save and reload files in \fBpcretest\fP is intended for testing
 1106: and experimentation. It is not intended for production use because only a
 1107: single pattern can be written to a file. Furthermore, there is no facility for
 1108: supplying custom character tables for use with a reloaded pattern. If the
 1109: original pattern was compiled with custom tables, an attempt to match a subject
 1110: string using a reloaded pattern is likely to cause \fBpcretest\fP to crash.
 1111: Finally, if you attempt to load a file that is not in the correct format, the
 1112: result is undefined.
 1113: .
 1114: .
 1115: .SH "SEE ALSO"
 1116: .rs
 1117: .sp
 1118: \fBpcre\fP(3), \fBpcre16\fP(3), \fBpcre32\fP(3), \fBpcreapi\fP(3),
 1119: \fBpcrecallout\fP(3),
 1120: \fBpcrejit\fP, \fBpcrematching\fP(3), \fBpcrepartial\fP(d),
 1121: \fBpcrepattern\fP(3), \fBpcreprecompile\fP(3).
 1122: .
 1123: .
 1124: .SH AUTHOR
 1125: .rs
 1126: .sp
 1127: .nf
 1128: Philip Hazel
 1129: University Computing Service
 1130: Cambridge CB2 3QH, England.
 1131: .fi
 1132: .
 1133: .
 1134: .SH REVISION
 1135: .rs
 1136: .sp
 1137: .nf
 1138: Last updated: 12 November 2013
 1139: Copyright (c) 1997-2013 University of Cambridge.
 1140: .fi

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