1083 lines
47 KiB
HTML
1083 lines
47 KiB
HTML
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<html>
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<head>
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<title>pcretest specification</title>
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</head>
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<body bgcolor="#FFFFFF" text="#00005A" link="#0066FF" alink="#3399FF" vlink="#2222BB">
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<h1>pcretest man page</h1>
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<p>
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Return to the <a href="index.html">PCRE index page</a>.
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</p>
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<p>
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This page is part of the PCRE HTML documentation. It was generated automatically
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from the original man page. If there is any nonsense in it, please consult the
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man page, in case the conversion went wrong.
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<br>
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<ul>
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<li><a name="TOC1" href="#SEC1">SYNOPSIS</a>
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<li><a name="TOC2" href="#SEC2">PCRE's 8-BIT, 16-BIT AND 32-BIT LIBRARIES</a>
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<li><a name="TOC3" href="#SEC3">COMMAND LINE OPTIONS</a>
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<li><a name="TOC4" href="#SEC4">DESCRIPTION</a>
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<li><a name="TOC5" href="#SEC5">PATTERN MODIFIERS</a>
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<li><a name="TOC6" href="#SEC6">DATA LINES</a>
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<li><a name="TOC7" href="#SEC7">THE ALTERNATIVE MATCHING FUNCTION</a>
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<li><a name="TOC8" href="#SEC8">DEFAULT OUTPUT FROM PCRETEST</a>
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<li><a name="TOC9" href="#SEC9">OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION</a>
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<li><a name="TOC10" href="#SEC10">RESTARTING AFTER A PARTIAL MATCH</a>
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<li><a name="TOC11" href="#SEC11">CALLOUTS</a>
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<li><a name="TOC12" href="#SEC12">NON-PRINTING CHARACTERS</a>
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<li><a name="TOC13" href="#SEC13">SAVING AND RELOADING COMPILED PATTERNS</a>
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<li><a name="TOC14" href="#SEC14">SEE ALSO</a>
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<li><a name="TOC15" href="#SEC15">AUTHOR</a>
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<li><a name="TOC16" href="#SEC16">REVISION</a>
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</ul>
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<br><a name="SEC1" href="#TOC1">SYNOPSIS</a><br>
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<P>
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<b>pcretest [options] [input file [output file]]</b>
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<br>
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<br>
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<b>pcretest</b> was written as a test program for the PCRE regular expression
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library itself, but it can also be used for experimenting with regular
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expressions. This document describes the features of the test program; for
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details of the regular expressions themselves, see the
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<a href="pcrepattern.html"><b>pcrepattern</b></a>
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documentation. For details of the PCRE library function calls and their
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options, see the
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<a href="pcreapi.html"><b>pcreapi</b></a>
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,
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<a href="pcre16.html"><b>pcre16</b></a>
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and
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<a href="pcre32.html"><b>pcre32</b></a>
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documentation.
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</P>
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<P>
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The input for <b>pcretest</b> is a sequence of regular expression patterns and
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strings to be matched, as described below. The output shows the result of each
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match. Options on the command line and the patterns control PCRE options and
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exactly what is output.
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</P>
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<P>
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As PCRE has evolved, it has acquired many different features, and as a result,
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<b>pcretest</b> now has rather a lot of obscure options for testing every
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possible feature. Some of these options are specifically designed for use in
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conjunction with the test script and data files that are distributed as part of
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PCRE, and are unlikely to be of use otherwise. They are all documented here,
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but without much justification.
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</P>
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<br><a name="SEC2" href="#TOC1">PCRE's 8-BIT, 16-BIT AND 32-BIT LIBRARIES</a><br>
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<P>
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From release 8.30, two separate PCRE libraries can be built. The original one
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supports 8-bit character strings, whereas the newer 16-bit library supports
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character strings encoded in 16-bit units. From release 8.32, a third
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library can be built, supporting character strings encoded in 32-bit units.
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The <b>pcretest</b> program can be
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used to test all three libraries. However, it is itself still an 8-bit program,
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reading 8-bit input and writing 8-bit output. When testing the 16-bit or 32-bit
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library, the patterns and data strings are converted to 16- or 32-bit format
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before being passed to the PCRE library functions. Results are converted to
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8-bit for output.
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</P>
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<P>
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References to functions and structures of the form <b>pcre[16|32]_xx</b> below
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mean "<b>pcre_xx</b> when using the 8-bit library or <b>pcre16_xx</b> when using
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the 16-bit library".
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</P>
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<br><a name="SEC3" href="#TOC1">COMMAND LINE OPTIONS</a><br>
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<P>
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<b>-8</b>
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If both the 8-bit library has been built, this option causes the 8-bit library
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to be used (which is the default); if the 8-bit library has not been built,
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this option causes an error.
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</P>
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<P>
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<b>-16</b>
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If both the 8-bit or the 32-bit, and the 16-bit libraries have been built, this
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option causes the 16-bit library to be used. If only the 16-bit library has been
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built, this is the default (so has no effect). If only the 8-bit or the 32-bit
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library has been built, this option causes an error.
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</P>
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<P>
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<b>-32</b>
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If both the 8-bit or the 16-bit, and the 32-bit libraries have been built, this
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option causes the 32-bit library to be used. If only the 32-bit library has been
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built, this is the default (so has no effect). If only the 8-bit or the 16-bit
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library has been built, this option causes an error.
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</P>
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<P>
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<b>-b</b>
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Behave as if each pattern has the <b>/B</b> (show byte code) modifier; the
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internal form is output after compilation.
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</P>
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<P>
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<b>-C</b>
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Output the version number of the PCRE library, and all available information
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about the optional features that are included, and then exit. All other options
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are ignored.
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</P>
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<P>
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<b>-C</b> <i>option</i>
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Output information about a specific build-time option, then exit. This
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functionality is intended for use in scripts such as <b>RunTest</b>. The
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following options output the value indicated:
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<pre>
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ebcdic-nl the code for LF (= NL) in an EBCDIC environment:
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0x15 or 0x25
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0 if used in an ASCII environment
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linksize the internal link size (2, 3, or 4)
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newline the default newline setting:
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CR, LF, CRLF, ANYCRLF, or ANY
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</pre>
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The following options output 1 for true or zero for false:
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<pre>
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ebcdic compiled for an EBCDIC environment
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jit just-in-time support is available
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pcre16 the 16-bit library was built
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pcre32 the 32-bit library was built
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pcre8 the 8-bit library was built
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ucp Unicode property support is available
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utf UTF-8 and/or UTF-16 and/or UTF-32 support is available
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</PRE>
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</P>
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<P>
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<b>-d</b>
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Behave as if each pattern has the <b>/D</b> (debug) modifier; the internal
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form and information about the compiled pattern is output after compilation;
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<b>-d</b> is equivalent to <b>-b -i</b>.
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</P>
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<P>
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<b>-dfa</b>
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Behave as if each data line contains the \D escape sequence; this causes the
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alternative matching function, <b>pcre[16|32]_dfa_exec()</b>, to be used instead
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of the standard <b>pcre[16|32]_exec()</b> function (more detail is given below).
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</P>
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<P>
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<b>-help</b>
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Output a brief summary these options and then exit.
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</P>
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<P>
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<b>-i</b>
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Behave as if each pattern has the <b>/I</b> modifier; information about the
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compiled pattern is given after compilation.
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</P>
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<P>
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<b>-M</b>
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Behave as if each data line contains the \M escape sequence; this causes
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PCRE to discover the minimum MATCH_LIMIT and MATCH_LIMIT_RECURSION settings by
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calling <b>pcre[16|32]_exec()</b> repeatedly with different limits.
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</P>
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<P>
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<b>-m</b>
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Output the size of each compiled pattern after it has been compiled. This is
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equivalent to adding <b>/M</b> to each regular expression. The size is given in
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bytes for both libraries.
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</P>
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<P>
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<b>-o</b> <i>osize</i>
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Set the number of elements in the output vector that is used when calling
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<b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b> to be <i>osize</i>. The
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default value is 45, which is enough for 14 capturing subexpressions for
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<b>pcre[16|32]_exec()</b> or 22 different matches for
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<b>pcre[16|32]_dfa_exec()</b>.
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The vector size can be changed for individual matching calls by including \O
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in the data line (see below).
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</P>
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<P>
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<b>-p</b>
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Behave as if each pattern has the <b>/P</b> modifier; the POSIX wrapper API is
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used to call PCRE. None of the other options has any effect when <b>-p</b> is
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set. This option can be used only with the 8-bit library.
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</P>
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<P>
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<b>-q</b>
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Do not output the version number of <b>pcretest</b> at the start of execution.
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</P>
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<P>
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<b>-S</b> <i>size</i>
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On Unix-like systems, set the size of the run-time stack to <i>size</i>
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megabytes.
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</P>
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<P>
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<b>-s</b> or <b>-s+</b>
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Behave as if each pattern has the <b>/S</b> modifier; in other words, force each
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pattern to be studied. If <b>-s+</b> is used, all the JIT compile options are
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passed to <b>pcre[16|32]_study()</b>, causing just-in-time optimization to be set
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up if it is available, for both full and partial matching. Specific JIT compile
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options can be selected by following <b>-s+</b> with a digit in the range 1 to
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7, which selects the JIT compile modes as follows:
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<pre>
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1 normal match only
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2 soft partial match only
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3 normal match and soft partial match
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4 hard partial match only
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6 soft and hard partial match
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7 all three modes (default)
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</pre>
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If <b>-s++</b> is used instead of <b>-s+</b> (with or without a following digit),
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the text "(JIT)" is added to the first output line after a match or no match
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when JIT-compiled code was actually used.
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<br>
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<br>
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Note that there are pattern options that can override <b>-s</b>, either
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specifying no studying at all, or suppressing JIT compilation.
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<br>
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<br>
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If the <b>/I</b> or <b>/D</b> option is present on a pattern (requesting output
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about the compiled pattern), information about the result of studying is not
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included when studying is caused only by <b>-s</b> and neither <b>-i</b> nor
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<b>-d</b> is present on the command line. This behaviour means that the output
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from tests that are run with and without <b>-s</b> should be identical, except
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when options that output information about the actual running of a match are
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set.
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<br>
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<br>
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The <b>-M</b>, <b>-t</b>, and <b>-tm</b> options, which give information about
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resources used, are likely to produce different output with and without
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<b>-s</b>. Output may also differ if the <b>/C</b> option is present on an
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individual pattern. This uses callouts to trace the the matching process, and
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this may be different between studied and non-studied patterns. If the pattern
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contains (*MARK) items there may also be differences, for the same reason. The
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<b>-s</b> command line option can be overridden for specific patterns that
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should never be studied (see the <b>/S</b> pattern modifier below).
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</P>
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<P>
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<b>-t</b>
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Run each compile, study, and match many times with a timer, and output
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resulting time per compile or match (in milliseconds). Do not set <b>-m</b> with
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<b>-t</b>, because you will then get the size output a zillion times, and the
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timing will be distorted. You can control the number of iterations that are
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used for timing by following <b>-t</b> with a number (as a separate item on the
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command line). For example, "-t 1000" would iterate 1000 times. The default is
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to iterate 500000 times.
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</P>
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<P>
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<b>-tm</b>
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This is like <b>-t</b> except that it times only the matching phase, not the
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compile or study phases.
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</P>
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<br><a name="SEC4" href="#TOC1">DESCRIPTION</a><br>
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<P>
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If <b>pcretest</b> is given two filename arguments, it reads from the first and
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writes to the second. If it is given only one filename argument, it reads from
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that file and writes to stdout. Otherwise, it reads from stdin and writes to
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stdout, and prompts for each line of input, using "re>" to prompt for regular
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expressions, and "data>" to prompt for data lines.
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</P>
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<P>
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When <b>pcretest</b> is built, a configuration option can specify that it should
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be linked with the <b>libreadline</b> library. When this is done, if the input
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is from a terminal, it is read using the <b>readline()</b> function. This
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provides line-editing and history facilities. The output from the <b>-help</b>
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option states whether or not <b>readline()</b> will be used.
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</P>
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<P>
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The program handles any number of sets of input on a single input file. Each
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set starts with a regular expression, and continues with any number of data
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lines to be matched against the pattern.
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</P>
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<P>
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Each data line is matched separately and independently. If you want to do
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multi-line matches, you have to use the \n escape sequence (or \r or \r\n,
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etc., depending on the newline setting) in a single line of input to encode the
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newline sequences. There is no limit on the length of data lines; the input
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buffer is automatically extended if it is too small.
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</P>
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<P>
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An empty line signals the end of the data lines, at which point a new regular
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expression is read. The regular expressions are given enclosed in any
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non-alphanumeric delimiters other than backslash, for example:
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<pre>
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/(a|bc)x+yz/
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</pre>
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White space before the initial delimiter is ignored. A regular expression may
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be continued over several input lines, in which case the newline characters are
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included within it. It is possible to include the delimiter within the pattern
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by escaping it, for example
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<pre>
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/abc\/def/
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</pre>
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If you do so, the escape and the delimiter form part of the pattern, but since
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delimiters are always non-alphanumeric, this does not affect its interpretation.
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If the terminating delimiter is immediately followed by a backslash, for
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example,
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<pre>
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/abc/\
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</pre>
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then a backslash is added to the end of the pattern. This is done to provide a
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way of testing the error condition that arises if a pattern finishes with a
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backslash, because
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<pre>
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/abc\/
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</pre>
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is interpreted as the first line of a pattern that starts with "abc/", causing
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pcretest to read the next line as a continuation of the regular expression.
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</P>
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|
<br><a name="SEC5" href="#TOC1">PATTERN MODIFIERS</a><br>
|
||
|
|
<P>
|
||
|
|
A pattern may be followed by any number of modifiers, which are mostly single
|
||
|
|
characters, though some of these can be qualified by further characters.
|
||
|
|
Following Perl usage, these are referred to below as, for example, "the
|
||
|
|
<b>/i</b> modifier", even though the delimiter of the pattern need not always be
|
||
|
|
a slash, and no slash is used when writing modifiers. White space may appear
|
||
|
|
between the final pattern delimiter and the first modifier, and between the
|
||
|
|
modifiers themselves. For reference, here is a complete list of modifiers. They
|
||
|
|
fall into several groups that are described in detail in the following
|
||
|
|
sections.
|
||
|
|
<pre>
|
||
|
|
<b>/8</b> set UTF mode
|
||
|
|
<b>/?</b> disable UTF validity check
|
||
|
|
<b>/+</b> show remainder of subject after match
|
||
|
|
<b>/=</b> show all captures (not just those that are set)
|
||
|
|
|
||
|
|
<b>/A</b> set PCRE_ANCHORED
|
||
|
|
<b>/B</b> show compiled code
|
||
|
|
<b>/C</b> set PCRE_AUTO_CALLOUT
|
||
|
|
<b>/D</b> same as <b>/B</b> plus <b>/I</b>
|
||
|
|
<b>/E</b> set PCRE_DOLLAR_ENDONLY
|
||
|
|
<b>/F</b> flip byte order in compiled pattern
|
||
|
|
<b>/f</b> set PCRE_FIRSTLINE
|
||
|
|
<b>/G</b> find all matches (shorten string)
|
||
|
|
<b>/g</b> find all matches (use startoffset)
|
||
|
|
<b>/I</b> show information about pattern
|
||
|
|
<b>/i</b> set PCRE_CASELESS
|
||
|
|
<b>/J</b> set PCRE_DUPNAMES
|
||
|
|
<b>/K</b> show backtracking control names
|
||
|
|
<b>/L</b> set locale
|
||
|
|
<b>/M</b> show compiled memory size
|
||
|
|
<b>/m</b> set PCRE_MULTILINE
|
||
|
|
<b>/N</b> set PCRE_NO_AUTO_CAPTURE
|
||
|
|
<b>/P</b> use the POSIX wrapper
|
||
|
|
<b>/S</b> study the pattern after compilation
|
||
|
|
<b>/s</b> set PCRE_DOTALL
|
||
|
|
<b>/T</b> select character tables
|
||
|
|
<b>/U</b> set PCRE_UNGREEDY
|
||
|
|
<b>/W</b> set PCRE_UCP
|
||
|
|
<b>/X</b> set PCRE_EXTRA
|
||
|
|
<b>/x</b> set PCRE_EXTENDED
|
||
|
|
<b>/Y</b> set PCRE_NO_START_OPTIMIZE
|
||
|
|
<b>/Z</b> don't show lengths in <b>/B</b> output
|
||
|
|
|
||
|
|
<b>/<any></b> set PCRE_NEWLINE_ANY
|
||
|
|
<b>/<anycrlf></b> set PCRE_NEWLINE_ANYCRLF
|
||
|
|
<b>/<cr></b> set PCRE_NEWLINE_CR
|
||
|
|
<b>/<crlf></b> set PCRE_NEWLINE_CRLF
|
||
|
|
<b>/<lf></b> set PCRE_NEWLINE_LF
|
||
|
|
<b>/<bsr_anycrlf></b> set PCRE_BSR_ANYCRLF
|
||
|
|
<b>/<bsr_unicode></b> set PCRE_BSR_UNICODE
|
||
|
|
<b>/<JS></b> set PCRE_JAVASCRIPT_COMPAT
|
||
|
|
|
||
|
|
</PRE>
|
||
|
|
</P>
|
||
|
|
<br><b>
|
||
|
|
Perl-compatible modifiers
|
||
|
|
</b><br>
|
||
|
|
<P>
|
||
|
|
The <b>/i</b>, <b>/m</b>, <b>/s</b>, and <b>/x</b> modifiers set the PCRE_CASELESS,
|
||
|
|
PCRE_MULTILINE, PCRE_DOTALL, or PCRE_EXTENDED options, respectively, when
|
||
|
|
<b>pcre[16|32]_compile()</b> is called. These four modifier letters have the same
|
||
|
|
effect as they do in Perl. For example:
|
||
|
|
<pre>
|
||
|
|
/caseless/i
|
||
|
|
|
||
|
|
</PRE>
|
||
|
|
</P>
|
||
|
|
<br><b>
|
||
|
|
Modifiers for other PCRE options
|
||
|
|
</b><br>
|
||
|
|
<P>
|
||
|
|
The following table shows additional modifiers for setting PCRE compile-time
|
||
|
|
options that do not correspond to anything in Perl:
|
||
|
|
<pre>
|
||
|
|
<b>/8</b> PCRE_UTF8 ) when using the 8-bit
|
||
|
|
<b>/?</b> PCRE_NO_UTF8_CHECK ) library
|
||
|
|
|
||
|
|
<b>/8</b> PCRE_UTF16 ) when using the 16-bit
|
||
|
|
<b>/?</b> PCRE_NO_UTF16_CHECK ) library
|
||
|
|
|
||
|
|
<b>/8</b> PCRE_UTF32 ) when using the 32-bit
|
||
|
|
<b>/?</b> PCRE_NO_UTF32_CHECK ) library
|
||
|
|
|
||
|
|
<b>/A</b> PCRE_ANCHORED
|
||
|
|
<b>/C</b> PCRE_AUTO_CALLOUT
|
||
|
|
<b>/E</b> PCRE_DOLLAR_ENDONLY
|
||
|
|
<b>/f</b> PCRE_FIRSTLINE
|
||
|
|
<b>/J</b> PCRE_DUPNAMES
|
||
|
|
<b>/N</b> PCRE_NO_AUTO_CAPTURE
|
||
|
|
<b>/U</b> PCRE_UNGREEDY
|
||
|
|
<b>/W</b> PCRE_UCP
|
||
|
|
<b>/X</b> PCRE_EXTRA
|
||
|
|
<b>/Y</b> PCRE_NO_START_OPTIMIZE
|
||
|
|
<b>/<any></b> PCRE_NEWLINE_ANY
|
||
|
|
<b>/<anycrlf></b> PCRE_NEWLINE_ANYCRLF
|
||
|
|
<b>/<cr></b> PCRE_NEWLINE_CR
|
||
|
|
<b>/<crlf></b> PCRE_NEWLINE_CRLF
|
||
|
|
<b>/<lf></b> PCRE_NEWLINE_LF
|
||
|
|
<b>/<bsr_anycrlf></b> PCRE_BSR_ANYCRLF
|
||
|
|
<b>/<bsr_unicode></b> PCRE_BSR_UNICODE
|
||
|
|
<b>/<JS></b> PCRE_JAVASCRIPT_COMPAT
|
||
|
|
</pre>
|
||
|
|
The modifiers that are enclosed in angle brackets are literal strings as shown,
|
||
|
|
including the angle brackets, but the letters within can be in either case.
|
||
|
|
This example sets multiline matching with CRLF as the line ending sequence:
|
||
|
|
<pre>
|
||
|
|
/^abc/m<CRLF>
|
||
|
|
</pre>
|
||
|
|
As well as turning on the PCRE_UTF8/16/32 option, the <b>/8</b> modifier causes
|
||
|
|
all non-printing characters in output strings to be printed using the
|
||
|
|
\x{hh...} notation. Otherwise, those less than 0x100 are output in hex without
|
||
|
|
the curly brackets.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
Full details of the PCRE options are given in the
|
||
|
|
<a href="pcreapi.html"><b>pcreapi</b></a>
|
||
|
|
documentation.
|
||
|
|
</P>
|
||
|
|
<br><b>
|
||
|
|
Finding all matches in a string
|
||
|
|
</b><br>
|
||
|
|
<P>
|
||
|
|
Searching for all possible matches within each subject string can be requested
|
||
|
|
by the <b>/g</b> or <b>/G</b> modifier. After finding a match, PCRE is called
|
||
|
|
again to search the remainder of the subject string. The difference between
|
||
|
|
<b>/g</b> and <b>/G</b> is that the former uses the <i>startoffset</i> argument to
|
||
|
|
<b>pcre[16|32]_exec()</b> to start searching at a new point within the entire
|
||
|
|
string (which is in effect what Perl does), whereas the latter passes over a
|
||
|
|
shortened substring. This makes a difference to the matching process if the
|
||
|
|
pattern begins with a lookbehind assertion (including \b or \B).
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
If any call to <b>pcre[16|32]_exec()</b> in a <b>/g</b> or <b>/G</b> sequence matches
|
||
|
|
an empty string, the next call is done with the PCRE_NOTEMPTY_ATSTART and
|
||
|
|
PCRE_ANCHORED flags set in order to search for another, non-empty, match at the
|
||
|
|
same point. If this second match fails, the start offset is advanced, and the
|
||
|
|
normal match is retried. This imitates the way Perl handles such cases when
|
||
|
|
using the <b>/g</b> modifier or the <b>split()</b> function. Normally, the start
|
||
|
|
offset is advanced by one character, but if the newline convention recognizes
|
||
|
|
CRLF as a newline, and the current character is CR followed by LF, an advance
|
||
|
|
of two is used.
|
||
|
|
</P>
|
||
|
|
<br><b>
|
||
|
|
Other modifiers
|
||
|
|
</b><br>
|
||
|
|
<P>
|
||
|
|
There are yet more modifiers for controlling the way <b>pcretest</b>
|
||
|
|
operates.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
The <b>/+</b> modifier requests that as well as outputting the substring that
|
||
|
|
matched the entire pattern, <b>pcretest</b> should in addition output the
|
||
|
|
remainder of the subject string. This is useful for tests where the subject
|
||
|
|
contains multiple copies of the same substring. If the <b>+</b> modifier appears
|
||
|
|
twice, the same action is taken for captured substrings. In each case the
|
||
|
|
remainder is output on the following line with a plus character following the
|
||
|
|
capture number. Note that this modifier must not immediately follow the /S
|
||
|
|
modifier because /S+ and /S++ have other meanings.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
The <b>/=</b> modifier requests that the values of all potential captured
|
||
|
|
parentheses be output after a match. By default, only those up to the highest
|
||
|
|
one actually used in the match are output (corresponding to the return code
|
||
|
|
from <b>pcre[16|32]_exec()</b>). Values in the offsets vector corresponding to
|
||
|
|
higher numbers should be set to -1, and these are output as "<unset>". This
|
||
|
|
modifier gives a way of checking that this is happening.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
The <b>/B</b> modifier is a debugging feature. It requests that <b>pcretest</b>
|
||
|
|
output a representation of the compiled code after compilation. Normally this
|
||
|
|
information contains length and offset values; however, if <b>/Z</b> is also
|
||
|
|
present, this data is replaced by spaces. This is a special feature for use in
|
||
|
|
the automatic test scripts; it ensures that the same output is generated for
|
||
|
|
different internal link sizes.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
The <b>/D</b> modifier is a PCRE debugging feature, and is equivalent to
|
||
|
|
<b>/BI</b>, that is, both the <b>/B</b> and the <b>/I</b> modifiers.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
The <b>/F</b> modifier causes <b>pcretest</b> to flip the byte order of the
|
||
|
|
2-byte and 4-byte fields in the compiled pattern. This facility is for testing
|
||
|
|
the feature in PCRE that allows it to execute patterns that were compiled on a
|
||
|
|
host with a different endianness. This feature is not available when the POSIX
|
||
|
|
interface to PCRE is being used, that is, when the <b>/P</b> pattern modifier is
|
||
|
|
specified. See also the section about saving and reloading compiled patterns
|
||
|
|
below.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
The <b>/I</b> modifier requests that <b>pcretest</b> output information about the
|
||
|
|
compiled pattern (whether it is anchored, has a fixed first character, and
|
||
|
|
so on). It does this by calling <b>pcre[16|32]_fullinfo()</b> after compiling a
|
||
|
|
pattern. If the pattern is studied, the results of that are also output.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
The <b>/K</b> modifier requests <b>pcretest</b> to show names from backtracking
|
||
|
|
control verbs that are returned from calls to <b>pcre[16|32]_exec()</b>. It causes
|
||
|
|
<b>pcretest</b> to create a <b>pcre[16|32]_extra</b> block if one has not already
|
||
|
|
been created by a call to <b>pcre[16|32]_study()</b>, and to set the
|
||
|
|
PCRE_EXTRA_MARK flag and the <b>mark</b> field within it, every time that
|
||
|
|
<b>pcre[16|32]_exec()</b> is called. If the variable that the <b>mark</b> field
|
||
|
|
points to is non-NULL for a match, non-match, or partial match, <b>pcretest</b>
|
||
|
|
prints the string to which it points. For a match, this is shown on a line by
|
||
|
|
itself, tagged with "MK:". For a non-match it is added to the message.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
The <b>/L</b> modifier must be followed directly by the name of a locale, for
|
||
|
|
example,
|
||
|
|
<pre>
|
||
|
|
/pattern/Lfr_FR
|
||
|
|
</pre>
|
||
|
|
For this reason, it must be the last modifier. The given locale is set,
|
||
|
|
<b>pcre[16|32]_maketables()</b> is called to build a set of character tables for
|
||
|
|
the locale, and this is then passed to <b>pcre[16|32]_compile()</b> when compiling
|
||
|
|
the regular expression. Without an <b>/L</b> (or <b>/T</b>) modifier, NULL is
|
||
|
|
passed as the tables pointer; that is, <b>/L</b> applies only to the expression
|
||
|
|
on which it appears.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
The <b>/M</b> modifier causes the size in bytes of the memory block used to hold
|
||
|
|
the compiled pattern to be output. This does not include the size of the
|
||
|
|
<b>pcre[16|32]</b> block; it is just the actual compiled data. If the pattern is
|
||
|
|
successfully studied with the PCRE_STUDY_JIT_COMPILE option, the size of the
|
||
|
|
JIT compiled code is also output.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
The <b>/S</b> modifier causes <b>pcre[16|32]_study()</b> to be called after the
|
||
|
|
expression has been compiled, and the results used when the expression is
|
||
|
|
matched. There are a number of qualifying characters that may follow <b>/S</b>.
|
||
|
|
They may appear in any order.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
If <b>S</b> is followed by an exclamation mark, <b>pcre[16|32]_study()</b> is called
|
||
|
|
with the PCRE_STUDY_EXTRA_NEEDED option, causing it always to return a
|
||
|
|
<b>pcre_extra</b> block, even when studying discovers no useful information.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
If <b>/S</b> is followed by a second S character, it suppresses studying, even
|
||
|
|
if it was requested externally by the <b>-s</b> command line option. This makes
|
||
|
|
it possible to specify that certain patterns are always studied, and others are
|
||
|
|
never studied, independently of <b>-s</b>. This feature is used in the test
|
||
|
|
files in a few cases where the output is different when the pattern is studied.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
If the <b>/S</b> modifier is followed by a + character, the call to
|
||
|
|
<b>pcre[16|32]_study()</b> is made with all the JIT study options, requesting
|
||
|
|
just-in-time optimization support if it is available, for both normal and
|
||
|
|
partial matching. If you want to restrict the JIT compiling modes, you can
|
||
|
|
follow <b>/S+</b> with a digit in the range 1 to 7:
|
||
|
|
<pre>
|
||
|
|
1 normal match only
|
||
|
|
2 soft partial match only
|
||
|
|
3 normal match and soft partial match
|
||
|
|
4 hard partial match only
|
||
|
|
6 soft and hard partial match
|
||
|
|
7 all three modes (default)
|
||
|
|
</pre>
|
||
|
|
If <b>/S++</b> is used instead of <b>/S+</b> (with or without a following digit),
|
||
|
|
the text "(JIT)" is added to the first output line after a match or no match
|
||
|
|
when JIT-compiled code was actually used.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
Note that there is also an independent <b>/+</b> modifier; it must not be given
|
||
|
|
immediately after <b>/S</b> or <b>/S+</b> because this will be misinterpreted.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
If JIT studying is successful, the compiled JIT code will automatically be used
|
||
|
|
when <b>pcre[16|32]_exec()</b> is run, except when incompatible run-time options
|
||
|
|
are specified. For more details, see the
|
||
|
|
<a href="pcrejit.html"><b>pcrejit</b></a>
|
||
|
|
documentation. See also the <b>\J</b> escape sequence below for a way of
|
||
|
|
setting the size of the JIT stack.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
Finally, if <b>/S</b> is followed by a minus character, JIT compilation is
|
||
|
|
suppressed, even if it was requested externally by the <b>-s</b> command line
|
||
|
|
option. This makes it possible to specify that JIT is never to be used for
|
||
|
|
certain patterns.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
The <b>/T</b> modifier must be followed by a single digit. It causes a specific
|
||
|
|
set of built-in character tables to be passed to <b>pcre[16|32]_compile()</b>. It
|
||
|
|
is used in the standard PCRE tests to check behaviour with different character
|
||
|
|
tables. The digit specifies the tables as follows:
|
||
|
|
<pre>
|
||
|
|
0 the default ASCII tables, as distributed in
|
||
|
|
pcre_chartables.c.dist
|
||
|
|
1 a set of tables defining ISO 8859 characters
|
||
|
|
</pre>
|
||
|
|
In table 1, some characters whose codes are greater than 128 are identified as
|
||
|
|
letters, digits, spaces, etc.
|
||
|
|
</P>
|
||
|
|
<br><b>
|
||
|
|
Using the POSIX wrapper API
|
||
|
|
</b><br>
|
||
|
|
<P>
|
||
|
|
The <b>/P</b> modifier causes <b>pcretest</b> to call PCRE via the POSIX wrapper
|
||
|
|
API rather than its native API. This supports only the 8-bit library. When
|
||
|
|
<b>/P</b> is set, the following modifiers set options for the <b>regcomp()</b>
|
||
|
|
function:
|
||
|
|
<pre>
|
||
|
|
/i REG_ICASE
|
||
|
|
/m REG_NEWLINE
|
||
|
|
/N REG_NOSUB
|
||
|
|
/s REG_DOTALL )
|
||
|
|
/U REG_UNGREEDY ) These options are not part of
|
||
|
|
/W REG_UCP ) the POSIX standard
|
||
|
|
/8 REG_UTF8 )
|
||
|
|
</pre>
|
||
|
|
The <b>/+</b> modifier works as described above. All other modifiers are
|
||
|
|
ignored.
|
||
|
|
</P>
|
||
|
|
<br><a name="SEC6" href="#TOC1">DATA LINES</a><br>
|
||
|
|
<P>
|
||
|
|
Before each data line is passed to <b>pcre[16|32]_exec()</b>, leading and trailing
|
||
|
|
white space is removed, and it is then scanned for \ escapes. Some of these
|
||
|
|
are pretty esoteric features, intended for checking out some of the more
|
||
|
|
complicated features of PCRE. If you are just testing "ordinary" regular
|
||
|
|
expressions, you probably don't need any of these. The following escapes are
|
||
|
|
recognized:
|
||
|
|
<pre>
|
||
|
|
\a alarm (BEL, \x07)
|
||
|
|
\b backspace (\x08)
|
||
|
|
\e escape (\x27)
|
||
|
|
\f form feed (\x0c)
|
||
|
|
\n newline (\x0a)
|
||
|
|
\qdd set the PCRE_MATCH_LIMIT limit to dd (any number of digits)
|
||
|
|
\r carriage return (\x0d)
|
||
|
|
\t tab (\x09)
|
||
|
|
\v vertical tab (\x0b)
|
||
|
|
\nnn octal character (up to 3 octal digits); always
|
||
|
|
a byte unless > 255 in UTF-8 or 16-bit or 32-bit mode
|
||
|
|
\xhh hexadecimal byte (up to 2 hex digits)
|
||
|
|
\x{hh...} hexadecimal character (any number of hex digits)
|
||
|
|
\A pass the PCRE_ANCHORED option to <b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b>
|
||
|
|
\B pass the PCRE_NOTBOL option to <b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b>
|
||
|
|
\Cdd call pcre[16|32]_copy_substring() for substring dd after a successful match (number less than 32)
|
||
|
|
\Cname call pcre[16|32]_copy_named_substring() for substring "name" after a successful match (name termin-
|
||
|
|
ated by next non alphanumeric character)
|
||
|
|
\C+ show the current captured substrings at callout time
|
||
|
|
\C- do not supply a callout function
|
||
|
|
\C!n return 1 instead of 0 when callout number n is reached
|
||
|
|
\C!n!m return 1 instead of 0 when callout number n is reached for the nth time
|
||
|
|
\C*n pass the number n (may be negative) as callout data; this is used as the callout return value
|
||
|
|
\D use the <b>pcre[16|32]_dfa_exec()</b> match function
|
||
|
|
\F only shortest match for <b>pcre[16|32]_dfa_exec()</b>
|
||
|
|
\Gdd call pcre[16|32]_get_substring() for substring dd after a successful match (number less than 32)
|
||
|
|
\Gname call pcre[16|32]_get_named_substring() for substring "name" after a successful match (name termin-
|
||
|
|
ated by next non-alphanumeric character)
|
||
|
|
\Jdd set up a JIT stack of dd kilobytes maximum (any number of digits)
|
||
|
|
\L call pcre[16|32]_get_substringlist() after a successful match
|
||
|
|
\M discover the minimum MATCH_LIMIT and MATCH_LIMIT_RECURSION settings
|
||
|
|
\N pass the PCRE_NOTEMPTY option to <b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b>; if used twice, pass the
|
||
|
|
PCRE_NOTEMPTY_ATSTART option
|
||
|
|
\Odd set the size of the output vector passed to <b>pcre[16|32]_exec()</b> to dd (any number of digits)
|
||
|
|
\P pass the PCRE_PARTIAL_SOFT option to <b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b>; if used twice, pass the
|
||
|
|
PCRE_PARTIAL_HARD option
|
||
|
|
\Qdd set the PCRE_MATCH_LIMIT_RECURSION limit to dd (any number of digits)
|
||
|
|
\R pass the PCRE_DFA_RESTART option to <b>pcre[16|32]_dfa_exec()</b>
|
||
|
|
\S output details of memory get/free calls during matching
|
||
|
|
\Y pass the PCRE_NO_START_OPTIMIZE option to <b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b>
|
||
|
|
\Z pass the PCRE_NOTEOL option to <b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b>
|
||
|
|
\? pass the PCRE_NO_UTF[8|16|32]_CHECK option to <b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b>
|
||
|
|
\>dd start the match at offset dd (optional "-"; then any number of digits); this sets the <i>startoffset</i>
|
||
|
|
argument for <b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b>
|
||
|
|
\<cr> pass the PCRE_NEWLINE_CR option to <b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b>
|
||
|
|
\<lf> pass the PCRE_NEWLINE_LF option to <b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b>
|
||
|
|
\<crlf> pass the PCRE_NEWLINE_CRLF option to <b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b>
|
||
|
|
\<anycrlf> pass the PCRE_NEWLINE_ANYCRLF option to <b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b>
|
||
|
|
\<any> pass the PCRE_NEWLINE_ANY option to <b>pcre[16|32]_exec()</b> or <b>pcre[16|32]_dfa_exec()</b>
|
||
|
|
</pre>
|
||
|
|
The use of \x{hh...} is not dependent on the use of the <b>/8</b> modifier on
|
||
|
|
the pattern. It is recognized always. There may be any number of hexadecimal
|
||
|
|
digits inside the braces; invalid values provoke error messages.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
Note that \xhh specifies one byte rather than one character in UTF-8 mode;
|
||
|
|
this makes it possible to construct invalid UTF-8 sequences for testing
|
||
|
|
purposes. On the other hand, \x{hh} is interpreted as a UTF-8 character in
|
||
|
|
UTF-8 mode, generating more than one byte if the value is greater than 127.
|
||
|
|
When testing the 8-bit library not in UTF-8 mode, \x{hh} generates one byte
|
||
|
|
for values less than 256, and causes an error for greater values.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
In UTF-16 mode, all 4-digit \x{hhhh} values are accepted. This makes it
|
||
|
|
possible to construct invalid UTF-16 sequences for testing purposes.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
In UTF-32 mode, all 4- to 8-digit \x{...} values are accepted. This makes it
|
||
|
|
possible to construct invalid UTF-32 sequences for testing purposes.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
The escapes that specify line ending sequences are literal strings, exactly as
|
||
|
|
shown. No more than one newline setting should be present in any data line.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
A backslash followed by anything else just escapes the anything else. If
|
||
|
|
the very last character is a backslash, it is ignored. This gives a way of
|
||
|
|
passing an empty line as data, since a real empty line terminates the data
|
||
|
|
input.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
The <b>\J</b> escape provides a way of setting the maximum stack size that is
|
||
|
|
used by the just-in-time optimization code. It is ignored if JIT optimization
|
||
|
|
is not being used. Providing a stack that is larger than the default 32K is
|
||
|
|
necessary only for very complicated patterns.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
If \M is present, <b>pcretest</b> calls <b>pcre[16|32]_exec()</b> several times,
|
||
|
|
with different values in the <i>match_limit</i> and <i>match_limit_recursion</i>
|
||
|
|
fields of the <b>pcre[16|32]_extra</b> data structure, until it finds the minimum
|
||
|
|
numbers for each parameter that allow <b>pcre[16|32]_exec()</b> to complete without
|
||
|
|
error. Because this is testing a specific feature of the normal interpretive
|
||
|
|
<b>pcre[16|32]_exec()</b> execution, the use of any JIT optimization that might
|
||
|
|
have been set up by the <b>/S+</b> qualifier of <b>-s+</b> option is disabled.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
The <i>match_limit</i> number is a measure of the amount of backtracking
|
||
|
|
that takes place, and checking it out can be instructive. For most simple
|
||
|
|
matches, the number is quite small, but for patterns with very large numbers of
|
||
|
|
matching possibilities, it can become large very quickly with increasing length
|
||
|
|
of subject string. The <i>match_limit_recursion</i> number is a measure of how
|
||
|
|
much stack (or, if PCRE is compiled with NO_RECURSE, how much heap) memory is
|
||
|
|
needed to complete the match attempt.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
When \O is used, the value specified may be higher or lower than the size set
|
||
|
|
by the <b>-O</b> command line option (or defaulted to 45); \O applies only to
|
||
|
|
the call of <b>pcre[16|32]_exec()</b> for the line in which it appears.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
If the <b>/P</b> modifier was present on the pattern, causing the POSIX wrapper
|
||
|
|
API to be used, the only option-setting sequences that have any effect are \B,
|
||
|
|
\N, and \Z, causing REG_NOTBOL, REG_NOTEMPTY, and REG_NOTEOL, respectively,
|
||
|
|
to be passed to <b>regexec()</b>.
|
||
|
|
</P>
|
||
|
|
<br><a name="SEC7" href="#TOC1">THE ALTERNATIVE MATCHING FUNCTION</a><br>
|
||
|
|
<P>
|
||
|
|
By default, <b>pcretest</b> uses the standard PCRE matching function,
|
||
|
|
<b>pcre[16|32]_exec()</b> to match each data line. PCRE also supports an
|
||
|
|
alternative matching function, <b>pcre[16|32]_dfa_test()</b>, which operates in a
|
||
|
|
different way, and has some restrictions. The differences between the two
|
||
|
|
functions are described in the
|
||
|
|
<a href="pcrematching.html"><b>pcrematching</b></a>
|
||
|
|
documentation.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
If a data line contains the \D escape sequence, or if the command line
|
||
|
|
contains the <b>-dfa</b> option, the alternative matching function is used.
|
||
|
|
This function finds all possible matches at a given point. If, however, the \F
|
||
|
|
escape sequence is present in the data line, it stops after the first match is
|
||
|
|
found. This is always the shortest possible match.
|
||
|
|
</P>
|
||
|
|
<br><a name="SEC8" href="#TOC1">DEFAULT OUTPUT FROM PCRETEST</a><br>
|
||
|
|
<P>
|
||
|
|
This section describes the output when the normal matching function,
|
||
|
|
<b>pcre[16|32]_exec()</b>, is being used.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
When a match succeeds, <b>pcretest</b> outputs the list of captured substrings
|
||
|
|
that <b>pcre[16|32]_exec()</b> returns, starting with number 0 for the string that
|
||
|
|
matched the whole pattern. Otherwise, it outputs "No match" when the return is
|
||
|
|
PCRE_ERROR_NOMATCH, and "Partial match:" followed by the partially matching
|
||
|
|
substring when <b>pcre[16|32]_exec()</b> returns PCRE_ERROR_PARTIAL. (Note that
|
||
|
|
this is the entire substring that was inspected during the partial match; it
|
||
|
|
may include characters before the actual match start if a lookbehind assertion,
|
||
|
|
\K, \b, or \B was involved.) For any other return, <b>pcretest</b> outputs
|
||
|
|
the PCRE negative error number and a short descriptive phrase. If the error is
|
||
|
|
a failed UTF string check, the offset of the start of the failing character and
|
||
|
|
the reason code are also output, provided that the size of the output vector is
|
||
|
|
at least two. Here is an example of an interactive <b>pcretest</b> run.
|
||
|
|
<pre>
|
||
|
|
$ pcretest
|
||
|
|
PCRE version 8.13 2011-04-30
|
||
|
|
|
||
|
|
re> /^abc(\d+)/
|
||
|
|
data> abc123
|
||
|
|
0: abc123
|
||
|
|
1: 123
|
||
|
|
data> xyz
|
||
|
|
No match
|
||
|
|
</pre>
|
||
|
|
Unset capturing substrings that are not followed by one that is set are not
|
||
|
|
returned by <b>pcre[16|32]_exec()</b>, and are not shown by <b>pcretest</b>. In the
|
||
|
|
following example, there are two capturing substrings, but when the first data
|
||
|
|
line is matched, the second, unset substring is not shown. An "internal" unset
|
||
|
|
substring is shown as "<unset>", as for the second data line.
|
||
|
|
<pre>
|
||
|
|
re> /(a)|(b)/
|
||
|
|
data> a
|
||
|
|
0: a
|
||
|
|
1: a
|
||
|
|
data> b
|
||
|
|
0: b
|
||
|
|
1: <unset>
|
||
|
|
2: b
|
||
|
|
</pre>
|
||
|
|
If the strings contain any non-printing characters, they are output as \xhh
|
||
|
|
escapes if the value is less than 256 and UTF mode is not set. Otherwise they
|
||
|
|
are output as \x{hh...} escapes. See below for the definition of non-printing
|
||
|
|
characters. If the pattern has the <b>/+</b> modifier, the output for substring
|
||
|
|
0 is followed by the the rest of the subject string, identified by "0+" like
|
||
|
|
this:
|
||
|
|
<pre>
|
||
|
|
re> /cat/+
|
||
|
|
data> cataract
|
||
|
|
0: cat
|
||
|
|
0+ aract
|
||
|
|
</pre>
|
||
|
|
If the pattern has the <b>/g</b> or <b>/G</b> modifier, the results of successive
|
||
|
|
matching attempts are output in sequence, like this:
|
||
|
|
<pre>
|
||
|
|
re> /\Bi(\w\w)/g
|
||
|
|
data> Mississippi
|
||
|
|
0: iss
|
||
|
|
1: ss
|
||
|
|
0: iss
|
||
|
|
1: ss
|
||
|
|
0: ipp
|
||
|
|
1: pp
|
||
|
|
</pre>
|
||
|
|
"No match" is output only if the first match attempt fails. Here is an example
|
||
|
|
of a failure message (the offset 4 that is specified by \>4 is past the end of
|
||
|
|
the subject string):
|
||
|
|
<pre>
|
||
|
|
re> /xyz/
|
||
|
|
data> xyz\>4
|
||
|
|
Error -24 (bad offset value)
|
||
|
|
</PRE>
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
If any of the sequences <b>\C</b>, <b>\G</b>, or <b>\L</b> are present in a
|
||
|
|
data line that is successfully matched, the substrings extracted by the
|
||
|
|
convenience functions are output with C, G, or L after the string number
|
||
|
|
instead of a colon. This is in addition to the normal full list. The string
|
||
|
|
length (that is, the return from the extraction function) is given in
|
||
|
|
parentheses after each string for <b>\C</b> and <b>\G</b>.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
Note that whereas patterns can be continued over several lines (a plain ">"
|
||
|
|
prompt is used for continuations), data lines may not. However newlines can be
|
||
|
|
included in data by means of the \n escape (or \r, \r\n, etc., depending on
|
||
|
|
the newline sequence setting).
|
||
|
|
</P>
|
||
|
|
<br><a name="SEC9" href="#TOC1">OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION</a><br>
|
||
|
|
<P>
|
||
|
|
When the alternative matching function, <b>pcre[16|32]_dfa_exec()</b>, is used (by
|
||
|
|
means of the \D escape sequence or the <b>-dfa</b> command line option), the
|
||
|
|
output consists of a list of all the matches that start at the first point in
|
||
|
|
the subject where there is at least one match. For example:
|
||
|
|
<pre>
|
||
|
|
re> /(tang|tangerine|tan)/
|
||
|
|
data> yellow tangerine\D
|
||
|
|
0: tangerine
|
||
|
|
1: tang
|
||
|
|
2: tan
|
||
|
|
</pre>
|
||
|
|
(Using the normal matching function on this data finds only "tang".) The
|
||
|
|
longest matching string is always given first (and numbered zero). After a
|
||
|
|
PCRE_ERROR_PARTIAL return, the output is "Partial match:", followed by the
|
||
|
|
partially matching substring. (Note that this is the entire substring that was
|
||
|
|
inspected during the partial match; it may include characters before the actual
|
||
|
|
match start if a lookbehind assertion, \K, \b, or \B was involved.)
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
If <b>/g</b> is present on the pattern, the search for further matches resumes
|
||
|
|
at the end of the longest match. For example:
|
||
|
|
<pre>
|
||
|
|
re> /(tang|tangerine|tan)/g
|
||
|
|
data> yellow tangerine and tangy sultana\D
|
||
|
|
0: tangerine
|
||
|
|
1: tang
|
||
|
|
2: tan
|
||
|
|
0: tang
|
||
|
|
1: tan
|
||
|
|
0: tan
|
||
|
|
</pre>
|
||
|
|
Since the matching function does not support substring capture, the escape
|
||
|
|
sequences that are concerned with captured substrings are not relevant.
|
||
|
|
</P>
|
||
|
|
<br><a name="SEC10" href="#TOC1">RESTARTING AFTER A PARTIAL MATCH</a><br>
|
||
|
|
<P>
|
||
|
|
When the alternative matching function has given the PCRE_ERROR_PARTIAL return,
|
||
|
|
indicating that the subject partially matched the pattern, you can restart the
|
||
|
|
match with additional subject data by means of the \R escape sequence. For
|
||
|
|
example:
|
||
|
|
<pre>
|
||
|
|
re> /^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$/
|
||
|
|
data> 23ja\P\D
|
||
|
|
Partial match: 23ja
|
||
|
|
data> n05\R\D
|
||
|
|
0: n05
|
||
|
|
</pre>
|
||
|
|
For further information about partial matching, see the
|
||
|
|
<a href="pcrepartial.html"><b>pcrepartial</b></a>
|
||
|
|
documentation.
|
||
|
|
</P>
|
||
|
|
<br><a name="SEC11" href="#TOC1">CALLOUTS</a><br>
|
||
|
|
<P>
|
||
|
|
If the pattern contains any callout requests, <b>pcretest</b>'s callout function
|
||
|
|
is called during matching. This works with both matching functions. By default,
|
||
|
|
the called function displays the callout number, the start and current
|
||
|
|
positions in the text at the callout time, and the next pattern item to be
|
||
|
|
tested. For example:
|
||
|
|
<pre>
|
||
|
|
--->pqrabcdef
|
||
|
|
0 ^ ^ \d
|
||
|
|
</pre>
|
||
|
|
This output indicates that callout number 0 occurred for a match attempt
|
||
|
|
starting at the fourth character of the subject string, when the pointer was at
|
||
|
|
the seventh character of the data, and when the next pattern item was \d. Just
|
||
|
|
one circumflex is output if the start and current positions are the same.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
Callouts numbered 255 are assumed to be automatic callouts, inserted as a
|
||
|
|
result of the <b>/C</b> pattern modifier. In this case, instead of showing the
|
||
|
|
callout number, the offset in the pattern, preceded by a plus, is output. For
|
||
|
|
example:
|
||
|
|
<pre>
|
||
|
|
re> /\d?[A-E]\*/C
|
||
|
|
data> E*
|
||
|
|
--->E*
|
||
|
|
+0 ^ \d?
|
||
|
|
+3 ^ [A-E]
|
||
|
|
+8 ^^ \*
|
||
|
|
+10 ^ ^
|
||
|
|
0: E*
|
||
|
|
</pre>
|
||
|
|
If a pattern contains (*MARK) items, an additional line is output whenever
|
||
|
|
a change of latest mark is passed to the callout function. For example:
|
||
|
|
<pre>
|
||
|
|
re> /a(*MARK:X)bc/C
|
||
|
|
data> abc
|
||
|
|
--->abc
|
||
|
|
+0 ^ a
|
||
|
|
+1 ^^ (*MARK:X)
|
||
|
|
+10 ^^ b
|
||
|
|
Latest Mark: X
|
||
|
|
+11 ^ ^ c
|
||
|
|
+12 ^ ^
|
||
|
|
0: abc
|
||
|
|
</pre>
|
||
|
|
The mark changes between matching "a" and "b", but stays the same for the rest
|
||
|
|
of the match, so nothing more is output. If, as a result of backtracking, the
|
||
|
|
mark reverts to being unset, the text "<unset>" is output.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
The callout function in <b>pcretest</b> returns zero (carry on matching) by
|
||
|
|
default, but you can use a \C item in a data line (as described above) to
|
||
|
|
change this and other parameters of the callout.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
Inserting callouts can be helpful when using <b>pcretest</b> to check
|
||
|
|
complicated regular expressions. For further information about callouts, see
|
||
|
|
the
|
||
|
|
<a href="pcrecallout.html"><b>pcrecallout</b></a>
|
||
|
|
documentation.
|
||
|
|
</P>
|
||
|
|
<br><a name="SEC12" href="#TOC1">NON-PRINTING CHARACTERS</a><br>
|
||
|
|
<P>
|
||
|
|
When <b>pcretest</b> is outputting text in the compiled version of a pattern,
|
||
|
|
bytes other than 32-126 are always treated as non-printing characters are are
|
||
|
|
therefore shown as hex escapes.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
When <b>pcretest</b> is outputting text that is a matched part of a subject
|
||
|
|
string, it behaves in the same way, unless a different locale has been set for
|
||
|
|
the pattern (using the <b>/L</b> modifier). In this case, the <b>isprint()</b>
|
||
|
|
function to distinguish printing and non-printing characters.
|
||
|
|
</P>
|
||
|
|
<br><a name="SEC13" href="#TOC1">SAVING AND RELOADING COMPILED PATTERNS</a><br>
|
||
|
|
<P>
|
||
|
|
The facilities described in this section are not available when the POSIX
|
||
|
|
interface to PCRE is being used, that is, when the <b>/P</b> pattern modifier is
|
||
|
|
specified.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
When the POSIX interface is not in use, you can cause <b>pcretest</b> to write a
|
||
|
|
compiled pattern to a file, by following the modifiers with > and a file name.
|
||
|
|
For example:
|
||
|
|
<pre>
|
||
|
|
/pattern/im >/some/file
|
||
|
|
</pre>
|
||
|
|
See the
|
||
|
|
<a href="pcreprecompile.html"><b>pcreprecompile</b></a>
|
||
|
|
documentation for a discussion about saving and re-using compiled patterns.
|
||
|
|
Note that if the pattern was successfully studied with JIT optimization, the
|
||
|
|
JIT data cannot be saved.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
The data that is written is binary. The first eight bytes are the length of the
|
||
|
|
compiled pattern data followed by the length of the optional study data, each
|
||
|
|
written as four bytes in big-endian order (most significant byte first). If
|
||
|
|
there is no study data (either the pattern was not studied, or studying did not
|
||
|
|
return any data), the second length is zero. The lengths are followed by an
|
||
|
|
exact copy of the compiled pattern. If there is additional study data, this
|
||
|
|
(excluding any JIT data) follows immediately after the compiled pattern. After
|
||
|
|
writing the file, <b>pcretest</b> expects to read a new pattern.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
A saved pattern can be reloaded into <b>pcretest</b> by specifying < and a file
|
||
|
|
name instead of a pattern. The name of the file must not contain a < character,
|
||
|
|
as otherwise <b>pcretest</b> will interpret the line as a pattern delimited by <
|
||
|
|
characters.
|
||
|
|
For example:
|
||
|
|
<pre>
|
||
|
|
re> </some/file
|
||
|
|
Compiled pattern loaded from /some/file
|
||
|
|
No study data
|
||
|
|
</pre>
|
||
|
|
If the pattern was previously studied with the JIT optimization, the JIT
|
||
|
|
information cannot be saved and restored, and so is lost. When the pattern has
|
||
|
|
been loaded, <b>pcretest</b> proceeds to read data lines in the usual way.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
You can copy a file written by <b>pcretest</b> to a different host and reload it
|
||
|
|
there, even if the new host has opposite endianness to the one on which the
|
||
|
|
pattern was compiled. For example, you can compile on an i86 machine and run on
|
||
|
|
a SPARC machine. When a pattern is reloaded on a host with different
|
||
|
|
endianness, the confirmation message is changed to:
|
||
|
|
<pre>
|
||
|
|
Compiled pattern (byte-inverted) loaded from /some/file
|
||
|
|
</pre>
|
||
|
|
The test suite contains some saved pre-compiled patterns with different
|
||
|
|
endianness. These are reloaded using "<!" instead of just "<". This suppresses
|
||
|
|
the "(byte-inverted)" text so that the output is the same on all hosts. It also
|
||
|
|
forces debugging output once the pattern has been reloaded.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
File names for saving and reloading can be absolute or relative, but note that
|
||
|
|
the shell facility of expanding a file name that starts with a tilde (~) is not
|
||
|
|
available.
|
||
|
|
</P>
|
||
|
|
<P>
|
||
|
|
The ability to save and reload files in <b>pcretest</b> is intended for testing
|
||
|
|
and experimentation. It is not intended for production use because only a
|
||
|
|
single pattern can be written to a file. Furthermore, there is no facility for
|
||
|
|
supplying custom character tables for use with a reloaded pattern. If the
|
||
|
|
original pattern was compiled with custom tables, an attempt to match a subject
|
||
|
|
string using a reloaded pattern is likely to cause <b>pcretest</b> to crash.
|
||
|
|
Finally, if you attempt to load a file that is not in the correct format, the
|
||
|
|
result is undefined.
|
||
|
|
</P>
|
||
|
|
<br><a name="SEC14" href="#TOC1">SEE ALSO</a><br>
|
||
|
|
<P>
|
||
|
|
<b>pcre</b>(3), <b>pcre16</b>(3), <b>pcre32</b>(3), <b>pcreapi</b>(3),
|
||
|
|
<b>pcrecallout</b>(3),
|
||
|
|
<b>pcrejit</b>, <b>pcrematching</b>(3), <b>pcrepartial</b>(d),
|
||
|
|
<b>pcrepattern</b>(3), <b>pcreprecompile</b>(3).
|
||
|
|
</P>
|
||
|
|
<br><a name="SEC15" href="#TOC1">AUTHOR</a><br>
|
||
|
|
<P>
|
||
|
|
Philip Hazel
|
||
|
|
<br>
|
||
|
|
University Computing Service
|
||
|
|
<br>
|
||
|
|
Cambridge CB2 3QH, England.
|
||
|
|
<br>
|
||
|
|
</P>
|
||
|
|
<br><a name="SEC16" href="#TOC1">REVISION</a><br>
|
||
|
|
<P>
|
||
|
|
Last updated: 10 September 2012
|
||
|
|
<br>
|
||
|
|
Copyright © 1997-2012 University of Cambridge.
|
||
|
|
<br>
|
||
|
|
<p>
|
||
|
|
Return to the <a href="index.html">PCRE index page</a>.
|
||
|
|
</p>
|