Annotation of embedaddon/pcre/doc/pcretest.1, revision 1.1.1.5

1.1.1.5 ! misho       1: .TH PCRETEST 1 "12 November 2013" "PCRE 8.34"
1.1       misho       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: .\"
1.1.1.4   misho      21: ,
1.1.1.2   misho      22: .\" HREF
                     23: \fBpcre16\fP
1.1.1.4   misho      24: and
                     25: .\" HREF
                     26: \fBpcre32\fP
1.1.1.2   misho      27: .\"
1.1.1.4   misho      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.
1.1       misho      41: .
                     42: .
1.1.1.4   misho      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"
1.1.1.2   misho      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
1.1.1.4   misho      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".
1.1.1.2   misho      71: .
                     72: .
                     73: .SH "COMMAND LINE OPTIONS"
1.1       misho      74: .rs
                     75: .TP 10
1.1.1.4   misho      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,
1.1.1.2   misho      79: this option causes an error.
                     80: .TP 10
1.1.1.4   misho      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
1.1       misho      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
1.1.1.4   misho      99: about the optional features that are included, and then exit with zero exit
                    100: code. All other options are ignored.
1.1.1.2   misho     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
1.1.1.4   misho     105: following options output the value and set the exit code as indicated:
1.1.1.2   misho     106: .sp
1.1.1.4   misho     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
1.1.1.2   misho     113:   newline    the default newline setting:
                    114:                CR, LF, CRLF, ANYCRLF, or ANY
1.1.1.4   misho     115:                exit code is always 0
1.1.1.2   misho     116: .sp
1.1.1.4   misho     117: The following options output 1 for true or 0 for false, and set the exit code
                    118: to the same value:
1.1.1.2   misho     119: .sp
1.1.1.4   misho     120:   ebcdic     compiled for an EBCDIC environment
1.1.1.2   misho     121:   jit        just-in-time support is available
                    122:   pcre16     the 16-bit library was built
1.1.1.4   misho     123:   pcre32     the 32-bit library was built
1.1.1.2   misho     124:   pcre8      the 8-bit library was built
                    125:   ucp        Unicode property support is available
1.1.1.4   misho     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.
1.1       misho     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
1.1.1.4   misho     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).
1.1       misho     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
1.1.1.4   misho     151: calling \fBpcre[16|32]_exec()\fP repeatedly with different limits.
1.1       misho     152: .TP 10
                    153: \fB-m\fP
                    154: Output the size of each compiled pattern after it has been compiled. This is
1.1.1.2   misho     155: equivalent to adding \fB/M\fP to each regular expression. The size is given in
                    156: bytes for both libraries.
1.1       misho     157: .TP 10
1.1.1.5 ! misho     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
1.1       misho     162: \fB-o\fP \fIosize\fP
                    163: Set the number of elements in the output vector that is used when calling
1.1.1.4   misho     164: \fBpcre[16|32]_exec()\fP or \fBpcre[16|32]_dfa_exec()\fP to be \fIosize\fP. The
1.1.1.2   misho     165: default value is 45, which is enough for 14 capturing subexpressions for
1.1.1.4   misho     166: \fBpcre[16|32]_exec()\fP or 22 different matches for
                    167: \fBpcre[16|32]_dfa_exec()\fP.
1.1.1.2   misho     168: The vector size can be changed for individual matching calls by including \eO
                    169: in the data line (see below).
1.1       misho     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
1.1.1.2   misho     174: set. This option can be used only with the 8-bit library.
1.1       misho     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
1.1.1.3   misho     185: pattern to be studied. If \fB-s+\fP is used, all the JIT compile options are
1.1.1.4   misho     186: passed to \fBpcre[16|32]_study()\fP, causing just-in-time optimization to be set
1.1.1.3   misho     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.
1.1.1.4   misho     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
1.1.1.3   misho     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.
1.1.1.2   misho     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).
1.1       misho     221: .TP 10
                    222: \fB-t\fP
1.1.1.5 ! misho     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.
1.1       misho     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.
1.1.1.5 ! misho     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.
1.1       misho     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
1.1.1.5 ! misho     257: lines to be matched against that pattern.
1.1       misho     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
1.1.1.4   misho     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
1.1.1.5 ! misho     331:   \fB/O\fP              set PCRE_NO_AUTO_POSSESS
1.1.1.4   misho     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
1.1       misho     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
1.1.1.4   misho     359: \fBpcre[16|32]_compile()\fP is called. These four modifier letters have the same
1.1       misho     360: effect as they do in Perl. For example:
                    361: .sp
                    362:   /caseless/i
                    363: .sp
1.1.1.4   misho     364: .
                    365: .
                    366: .SS "Modifiers for other PCRE options"
                    367: .rs
                    368: .sp
1.1       misho     369: The following table shows additional modifiers for setting PCRE compile-time
                    370: options that do not correspond to anything in Perl:
                    371: .sp
1.1.1.2   misho     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
1.1.1.4   misho     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
1.1       misho     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
1.1.1.5 ! misho     388:   \fB/O\fP              PCRE_NO_AUTO_POSSESS
1.1       misho     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
1.1.1.4   misho     393:   \fB/<any>\fP          PCRE_NEWLINE_ANY
                    394:   \fB/<anycrlf>\fP      PCRE_NEWLINE_ANYCRLF
1.1       misho     395:   \fB/<cr>\fP           PCRE_NEWLINE_CR
                    396:   \fB/<crlf>\fP         PCRE_NEWLINE_CRLF
1.1.1.4   misho     397:   \fB/<lf>\fP           PCRE_NEWLINE_LF
1.1       misho     398:   \fB/<bsr_anycrlf>\fP  PCRE_BSR_ANYCRLF
                    399:   \fB/<bsr_unicode>\fP  PCRE_BSR_UNICODE
1.1.1.4   misho     400:   \fB/<JS>\fP           PCRE_JAVASCRIPT_COMPAT
1.1       misho     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
1.1.1.4   misho     408: As well as turning on the PCRE_UTF8/16/32 option, the \fB/8\fP modifier causes
1.1.1.2   misho     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
1.1       misho     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
1.1.1.4   misho     427: \fBpcre[16|32]_exec()\fP to start searching at a new point within the entire
1.1.1.2   misho     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).
1.1       misho     431: .P
1.1.1.4   misho     432: If any call to \fBpcre[16|32]_exec()\fP in a \fB/g\fP or \fB/G\fP sequence matches
1.1.1.2   misho     433: an empty string, the next call is done with the PCRE_NOTEMPTY_ATSTART and
1.1       misho     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
1.1.1.3   misho     456: modifier because /S+ and /S++ have other meanings.
1.1       misho     457: .P
                    458: The \fB/=\fP modifier requests that the values of all potential captured
1.1.1.2   misho     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
1.1.1.4   misho     461: from \fBpcre[16|32]_exec()\fP). Values in the offsets vector corresponding to
1.1.1.2   misho     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.
1.1       misho     464: .P
                    465: The \fB/B\fP modifier is a debugging feature. It requests that \fBpcretest\fP
1.1.1.2   misho     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.
1.1       misho     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
1.1.1.2   misho     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.
1.1       misho     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
1.1.1.4   misho     485: so on). It does this by calling \fBpcre[16|32]_fullinfo()\fP after compiling a
1.1       misho     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
1.1.1.4   misho     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
1.1.1.2   misho     492: PCRE_EXTRA_MARK flag and the \fBmark\fP field within it, every time that
1.1.1.4   misho     493: \fBpcre[16|32]_exec()\fP is called. If the variable that the \fBmark\fP field
1.1.1.2   misho     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.
1.1       misho     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,
1.1.1.4   misho     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
1.1.1.2   misho     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
1.1.1.4   misho     512: \fBpcre[16|32]\fP block; it is just the actual compiled data. If the pattern is
1.1.1.2   misho     513: successfully studied with the PCRE_STUDY_JIT_COMPILE option, the size of the
                    514: JIT compiled code is also output.
1.1       misho     515: .P
1.1.1.4   misho     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
1.1.1.5 ! misho     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
1.1.1.4   misho     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
1.1       misho     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
1.1.1.4   misho     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
1.1.1.3   misho     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
1.1.1.4   misho     552: when \fBpcre[16|32]_exec()\fP is run, except when incompatible run-time options
1.1.1.3   misho     553: are specified. For more details, see the
1.1       misho     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
1.1.1.4   misho     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
1.1       misho     565: The \fB/T\fP modifier must be followed by a single digit. It causes a specific
1.1.1.4   misho     566: set of built-in character tables to be passed to \fBpcre[16|32]_compile()\fP. It
1.1.1.2   misho     567: is used in the standard PCRE tests to check behaviour with different character
1.1       misho     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
1.1.1.2   misho     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:
1.1       misho     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: .
1.1.1.5 ! misho     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: .
1.1       misho     629: .SH "DATA LINES"
                    630: .rs
                    631: .sp
1.1.1.4   misho     632: Before each data line is passed to \fBpcre[16|32]_exec()\fP, leading and trailing
1.1       misho     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)
1.1.1.2   misho     650:   \ennn       octal character (up to 3 octal digits); always
1.1.1.4   misho     651:                a byte unless > 255 in UTF-8 or 16-bit or 32-bit mode
1.1.1.5 ! misho     652:   \eo{dd...}  octal character (any number of octal digits}
1.1       misho     653:   \exhh       hexadecimal byte (up to 2 hex digits)
1.1.1.2   misho     654:   \ex{hh...}  hexadecimal character (any number of hex digits)
1.1       misho     655: .\" JOIN
1.1.1.4   misho     656:   \eA         pass the PCRE_ANCHORED option to \fBpcre[16|32]_exec()\fP
                    657:                or \fBpcre[16|32]_dfa_exec()\fP
1.1       misho     658: .\" JOIN
1.1.1.4   misho     659:   \eB         pass the PCRE_NOTBOL option to \fBpcre[16|32]_exec()\fP
                    660:                or \fBpcre[16|32]_dfa_exec()\fP
1.1       misho     661: .\" JOIN
1.1.1.4   misho     662:   \eCdd       call pcre[16|32]_copy_substring() for substring dd
1.1       misho     663:                after a successful match (number less than 32)
                    664: .\" JOIN
1.1.1.4   misho     665:   \eCname     call pcre[16|32]_copy_named_substring() for substring
1.1       misho     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
1.1.1.4   misho     681:   \eD         use the \fBpcre[16|32]_dfa_exec()\fP match function
                    682:   \eF         only shortest match for \fBpcre[16|32]_dfa_exec()\fP
1.1       misho     683: .\" JOIN
1.1.1.4   misho     684:   \eGdd       call pcre[16|32]_get_substring() for substring dd
1.1       misho     685:                after a successful match (number less than 32)
                    686: .\" JOIN
1.1.1.4   misho     687:   \eGname     call pcre[16|32]_get_named_substring() for substring
1.1       misho     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
1.1.1.4   misho     694:   \eL         call pcre[16|32]_get_substringlist() after a
1.1       misho     695:                successful match
                    696: .\" JOIN
                    697:   \eM         discover the minimum MATCH_LIMIT and
                    698:                MATCH_LIMIT_RECURSION settings
                    699: .\" JOIN
1.1.1.4   misho     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
1.1       misho     702:                PCRE_NOTEMPTY_ATSTART option
                    703: .\" JOIN
                    704:   \eOdd       set the size of the output vector passed to
1.1.1.4   misho     705:                \fBpcre[16|32]_exec()\fP to dd (any number of digits)
1.1       misho     706: .\" JOIN
1.1.1.4   misho     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
1.1       misho     709:                PCRE_PARTIAL_HARD option
                    710: .\" JOIN
                    711:   \eQdd       set the PCRE_MATCH_LIMIT_RECURSION limit to dd
                    712:                (any number of digits)
1.1.1.4   misho     713:   \eR         pass the PCRE_DFA_RESTART option to \fBpcre[16|32]_dfa_exec()\fP
1.1       misho     714:   \eS         output details of memory get/free calls during matching
                    715: .\" JOIN
1.1.1.4   misho     716:   \eY         pass the PCRE_NO_START_OPTIMIZE option to \fBpcre[16|32]_exec()\fP
                    717:                or \fBpcre[16|32]_dfa_exec()\fP
1.1       misho     718: .\" JOIN
1.1.1.4   misho     719:   \eZ         pass the PCRE_NOTEOL option to \fBpcre[16|32]_exec()\fP
                    720:                or \fBpcre[16|32]_dfa_exec()\fP
1.1       misho     721: .\" JOIN
1.1.1.4   misho     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
1.1       misho     724: .\" JOIN
                    725:   \e>dd       start the match at offset dd (optional "-"; then
                    726:                any number of digits); this sets the \fIstartoffset\fP
1.1.1.4   misho     727:                argument for \fBpcre[16|32]_exec()\fP or \fBpcre[16|32]_dfa_exec()\fP
1.1       misho     728: .\" JOIN
1.1.1.4   misho     729:   \e<cr>      pass the PCRE_NEWLINE_CR option to \fBpcre[16|32]_exec()\fP
                    730:                or \fBpcre[16|32]_dfa_exec()\fP
1.1       misho     731: .\" JOIN
1.1.1.4   misho     732:   \e<lf>      pass the PCRE_NEWLINE_LF option to \fBpcre[16|32]_exec()\fP
                    733:                or \fBpcre[16|32]_dfa_exec()\fP
1.1       misho     734: .\" JOIN
1.1.1.4   misho     735:   \e<crlf>    pass the PCRE_NEWLINE_CRLF option to \fBpcre[16|32]_exec()\fP
                    736:                or \fBpcre[16|32]_dfa_exec()\fP
1.1       misho     737: .\" JOIN
1.1.1.4   misho     738:   \e<anycrlf> pass the PCRE_NEWLINE_ANYCRLF option to \fBpcre[16|32]_exec()\fP
                    739:                or \fBpcre[16|32]_dfa_exec()\fP
1.1       misho     740: .\" JOIN
1.1.1.4   misho     741:   \e<any>     pass the PCRE_NEWLINE_ANY option to \fBpcre[16|32]_exec()\fP
                    742:                or \fBpcre[16|32]_dfa_exec()\fP
1.1       misho     743: .sp
1.1.1.2   misho     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.
1.1       misho     757: .P
1.1.1.4   misho     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
1.1       misho     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
1.1.1.4   misho     774: If \eM is present, \fBpcretest\fP calls \fBpcre[16|32]_exec()\fP several times,
1.1.1.2   misho     775: with different values in the \fImatch_limit\fP and \fImatch_limit_recursion\fP
1.1.1.4   misho     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
1.1       misho     778: error. Because this is testing a specific feature of the normal interpretive
1.1.1.4   misho     779: \fBpcre[16|32]_exec()\fP execution, the use of any JIT optimization that might
1.1.1.2   misho     780: have been set up by the \fB/S+\fP qualifier of \fB-s+\fP option is disabled.
1.1       misho     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
1.1.1.4   misho     792: the call of \fBpcre[16|32]_exec()\fP for the line in which it appears.
1.1       misho     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,
1.1.1.4   misho     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
1.1       misho     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
1.1.1.2   misho     814: contains the \fB-dfa\fP option, the alternative matching function is used.
1.1       misho     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,
1.1.1.4   misho     824: \fBpcre[16|32]_exec()\fP, is being used.
1.1       misho     825: .P
                    826: When a match succeeds, \fBpcretest\fP outputs the list of captured substrings
1.1.1.4   misho     827: that \fBpcre[16|32]_exec()\fP returns, starting with number 0 for the string that
1.1       misho     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
1.1.1.4   misho     830: substring when \fBpcre[16|32]_exec()\fP returns PCRE_ERROR_PARTIAL. (Note that
1.1.1.2   misho     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,
1.1       misho     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
1.1.1.2   misho     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.
1.1       misho     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
1.1.1.4   misho     850: returned by \fBpcre[16|32]_exec()\fP, and are not shown by \fBpcretest\fP. In the
1.1       misho     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
1.1.1.2   misho     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:
1.1       misho     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
1.1.1.4   misho     913: When the alternative matching function, \fBpcre[16|32]_dfa_exec()\fP, is used (by
1.1       misho     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
1.1.1.2   misho     975: tested. For example:
1.1       misho     976: .sp
                    977:   --->pqrabcdef
                    978:     0    ^  ^     \ed
                    979: .sp
1.1.1.2   misho     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.
1.1       misho     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
1.1.1.5 ! misho    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:
1.1       misho    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
1.1.1.2   misho    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.
1.1       misho    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
1.1.1.4   misho    1118: \fBpcre\fP(3), \fBpcre16\fP(3), \fBpcre32\fP(3), \fBpcreapi\fP(3),
                   1119: \fBpcrecallout\fP(3),
1.1.1.2   misho    1120: \fBpcrejit\fP, \fBpcrematching\fP(3), \fBpcrepartial\fP(d),
                   1121: \fBpcrepattern\fP(3), \fBpcreprecompile\fP(3).
1.1       misho    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
1.1.1.5 ! misho    1138: Last updated: 12 November 2013
1.1.1.4   misho    1139: Copyright (c) 1997-2013 University of Cambridge.
1.1       misho    1140: .fi

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