2123 lines
91 KiB
HTML
2123 lines
91 KiB
HTML
<html>
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<head>
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<title>pcre2test 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>pcre2test man page</h1>
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<p>
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Return to the <a href="index.html">PCRE2 index page</a>.
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</p>
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<p>
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This page is part of the PCRE2 HTML documentation. It was generated
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automatically from the original man page. If there is any nonsense in it,
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please consult the 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">PCRE2's 8-BIT, 16-BIT AND 32-BIT LIBRARIES</a>
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<li><a name="TOC3" href="#SEC3">INPUT ENCODING</a>
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<li><a name="TOC4" href="#SEC4">COMMAND LINE OPTIONS</a>
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<li><a name="TOC5" href="#SEC5">DESCRIPTION</a>
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<li><a name="TOC6" href="#SEC6">COMMAND LINES</a>
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<li><a name="TOC7" href="#SEC7">MODIFIER SYNTAX</a>
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<li><a name="TOC8" href="#SEC8">PATTERN SYNTAX</a>
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<li><a name="TOC9" href="#SEC9">SUBJECT LINE SYNTAX</a>
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<li><a name="TOC10" href="#SEC10">PATTERN MODIFIERS</a>
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<li><a name="TOC11" href="#SEC11">SUBJECT MODIFIERS</a>
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<li><a name="TOC12" href="#SEC12">THE ALTERNATIVE MATCHING FUNCTION</a>
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<li><a name="TOC13" href="#SEC13">DEFAULT OUTPUT FROM pcre2test</a>
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<li><a name="TOC14" href="#SEC14">OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION</a>
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<li><a name="TOC15" href="#SEC15">RESTARTING AFTER A PARTIAL MATCH</a>
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<li><a name="TOC16" href="#SEC16">CALLOUTS</a>
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<li><a name="TOC17" href="#SEC17">NON-PRINTING CHARACTERS</a>
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<li><a name="TOC18" href="#SEC18">SAVING AND RESTORING COMPILED PATTERNS</a>
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<li><a name="TOC19" href="#SEC19">SEE ALSO</a>
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<li><a name="TOC20" href="#SEC20">AUTHOR</a>
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<li><a name="TOC21" href="#SEC21">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>pcre2test [options] [input file [output file]]</b>
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<br>
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<br>
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<b>pcre2test</b> is a test program for the PCRE2 regular expression libraries,
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but it can also be used for experimenting with regular expressions. This
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document describes the features of the test program; for details of the regular
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expressions themselves, see the
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<a href="pcre2pattern.html"><b>pcre2pattern</b></a>
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documentation. For details of the PCRE2 library function calls and their
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options, see the
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<a href="pcre2api.html"><b>pcre2api</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>pcre2test</b> is a sequence of regular expression patterns and
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subject strings to be matched. There are also command lines for setting
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defaults and controlling some special actions. The output shows the result of
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each match attempt. Modifiers on external or internal command lines, the
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patterns, and the subject lines specify PCRE2 function options, control how the
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subject is processed, and what output is produced.
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</P>
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<P>
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As the original fairly simple PCRE library evolved, it acquired many different
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features, and as a result, the original <b>pcretest</b> program ended up with a
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lot of options in a messy, arcane syntax for testing all the features. The
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move to the new PCRE2 API provided an opportunity to re-implement the test
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program as <b>pcre2test</b>, with a cleaner modifier syntax. Nevertheless, there
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are still many obscure modifiers, some of which are specifically designed for
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use in conjunction with the test script and data files that are distributed as
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part of PCRE2. All the modifiers are documented here, some without much
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justification, but many of them are unlikely to be of use except when testing
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the libraries.
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</P>
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<br><a name="SEC2" href="#TOC1">PCRE2's 8-BIT, 16-BIT AND 32-BIT LIBRARIES</a><br>
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<P>
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Different versions of the PCRE2 library can be built to support character
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strings that are encoded in 8-bit, 16-bit, or 32-bit code units. One, two, or
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all three of these libraries may be simultaneously installed. The
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<b>pcre2test</b> program can be used to test all the libraries. However, its own
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input and output are always in 8-bit format. When testing the 16-bit or 32-bit
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libraries, patterns and subject strings are converted to 16-bit or 32-bit
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format before being passed to the library functions. Results are converted back
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to 8-bit code units for output.
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</P>
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<P>
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In the rest of this document, the names of library functions and structures
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are given in generic form, for example, <b>pcre_compile()</b>. The actual
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names used in the libraries have a suffix _8, _16, or _32, as appropriate.
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<a name="inputencoding"></a></P>
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<br><a name="SEC3" href="#TOC1">INPUT ENCODING</a><br>
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<P>
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Input to <b>pcre2test</b> is processed line by line, either by calling the C
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library's <b>fgets()</b> function, or via the <b>libreadline</b> library. In some
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Windows environments character 26 (hex 1A) causes an immediate end of file, and
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no further data is read, so this character should be avoided unless you really
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want that action.
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</P>
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<P>
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The input is processed using using C's string functions, so must not
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contain binary zeros, even though in Unix-like environments, <b>fgets()</b>
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treats any bytes other than newline as data characters. An error is generated
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if a binary zero is encountered. By default subject lines are processed for
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backslash escapes, which makes it possible to include any data value in strings
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that are passed to the library for matching. For patterns, there is a facility
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for specifying some or all of the 8-bit input characters as hexadecimal pairs,
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which makes it possible to include binary zeros.
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</P>
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<br><b>
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Input for the 16-bit and 32-bit libraries
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</b><br>
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<P>
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When testing the 16-bit or 32-bit libraries, there is a need to be able to
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generate character code points greater than 255 in the strings that are passed
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to the library. For subject lines, backslash escapes can be used. In addition,
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when the <b>utf</b> modifier (see
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<a href="#optionmodifiers">"Setting compilation options"</a>
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below) is set, the pattern and any following subject lines are interpreted as
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UTF-8 strings and translated to UTF-16 or UTF-32 as appropriate.
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</P>
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<P>
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For non-UTF testing of wide characters, the <b>utf8_input</b> modifier can be
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used. This is mutually exclusive with <b>utf</b>, and is allowed only in 16-bit
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or 32-bit mode. It causes the pattern and following subject lines to be treated
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as UTF-8 according to the original definition (RFC 2279), which allows for
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character values up to 0x7fffffff. Each character is placed in one 16-bit or
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32-bit code unit (in the 16-bit case, values greater than 0xffff cause an error
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to occur).
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</P>
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<P>
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UTF-8 (in its original definition) is not capable of encoding values greater
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than 0x7fffffff, but such values can be handled by the 32-bit library. When
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testing this library in non-UTF mode with <b>utf8_input</b> set, if any
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character is preceded by the byte 0xff (which is an invalid byte in UTF-8)
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0x80000000 is added to the character's value. This is the only way of passing
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such code points in a pattern string. For subject strings, using an escape
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sequence is preferable.
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</P>
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<br><a name="SEC4" href="#TOC1">COMMAND LINE OPTIONS</a><br>
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<P>
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<b>-8</b>
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If the 8-bit library has been built, this option causes it to be used (this is
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the default). If the 8-bit library has not been built, this option causes an
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error.
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</P>
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<P>
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<b>-16</b>
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If the 16-bit library has been built, this option causes it to be used. If only
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the 16-bit library has been built, this is the default. If the 16-bit library
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has not 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 the 32-bit library has been built, this option causes it to be used. If only
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the 32-bit library has been built, this is the default. If the 32-bit library
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has not been built, this option causes an error.
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</P>
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<P>
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<b>-ac</b>
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Behave as if each pattern has the <b>auto_callout</b> modifier, that is, insert
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automatic callouts into every pattern that is compiled.
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</P>
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<P>
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<b>-AC</b>
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As for <b>-ac</b>, but in addition behave as if each subject line has the
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<b>callout_extra</b> modifier, that is, show additional information from
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callouts.
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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>fullbincode</b> modifier; the full
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internal binary form of the pattern 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 PCRE2 library, and all available information
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about the optional features that are included, and then exit with zero exit
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code. All other options are ignored. If both -C and -LM are present, whichever
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is first is recognized.
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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 and set the exit code as 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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exit code is always 0
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linksize the configured internal link size (2, 3, or 4)
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exit code is set to the link size
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newline the default newline setting:
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CR, LF, CRLF, ANYCRLF, ANY, or NUL
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exit code is always 0
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bsr the default setting for what \R matches:
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ANYCRLF or ANY
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exit code is always 0
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</pre>
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The following options output 1 for true or 0 for false, and set the exit code
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to the same value:
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<pre>
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backslash-C \C is supported (not locked out)
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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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pcre2-16 the 16-bit library was built
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pcre2-32 the 32-bit library was built
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pcre2-8 the 8-bit library was built
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unicode Unicode support is available
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</pre>
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If an unknown option is given, an error message is output; the exit code is 0.
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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>debug</b> 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 subject line has the <b>dfa</b> modifier; matching is done
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using the <b>pcre2_dfa_match()</b> function instead of the default
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<b>pcre2_match()</b>.
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</P>
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<P>
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<b>-error</b> <i>number[,number,...]</i>
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Call <b>pcre2_get_error_message()</b> for each of the error numbers in the
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comma-separated list, display the resulting messages on the standard output,
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then exit with zero exit code. The numbers may be positive or negative. This is
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a convenience facility for PCRE2 maintainers.
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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>info</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>-jit</b>
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Behave as if each pattern line has the <b>jit</b> modifier; after successful
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compilation, each pattern is passed to the just-in-time compiler, if available.
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</P>
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<P>
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<b>-jitfast</b>
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Behave as if each pattern line has the <b>jitfast</b> modifier; after
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successful compilation, each pattern is passed to the just-in-time compiler, if
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available, and each subject line is passed directly to the JIT matcher via its
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"fast path".
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</P>
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<P>
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<b>-jitverify</b>
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Behave as if each pattern line has the <b>jitverify</b> modifier; after
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successful compilation, each pattern is passed to the just-in-time compiler, if
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available, and the use of JIT for matching is verified.
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</P>
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<P>
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<b>-LM</b>
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List modifiers: write a list of available pattern and subject modifiers to the
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standard output, then exit with zero exit code. All other options are ignored.
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If both -C and -LM are present, whichever is first is recognized.
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</P>
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<P>
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<b>-pattern</b> <i>modifier-list</i>
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Behave as if each pattern line contains the given modifiers.
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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>pcre2test</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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mebibytes (units of 1024*1024 bytes).
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</P>
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<P>
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<b>-subject</b> <i>modifier-list</i>
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Behave as if each subject line contains the given modifiers.
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</P>
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<P>
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<b>-t</b>
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Run each compile and match many times with a timer, and output the resulting
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times per compile or match. When JIT is used, separate times are given for the
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initial compile and the JIT compile. You can control the number of iterations
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that are used for timing by following <b>-t</b> with a number (as a separate
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item on the command line). For example, "-t 1000" iterates 1000 times. The
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default is to iterate 500,000 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 phase.
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</P>
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<P>
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<b>-T</b> <b>-TM</b>
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These behave like <b>-t</b> and <b>-tm</b>, but in addition, at the end of a run,
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the total times for all compiles and matches are output.
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</P>
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<P>
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<b>-version</b>
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Output the PCRE2 version number and then exit.
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</P>
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<br><a name="SEC5" href="#TOC1">DESCRIPTION</a><br>
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<P>
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If <b>pcre2test</b> is given two filename arguments, it reads from the first and
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writes to the second. If the first name is "-", input is taken from the
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standard input. If <b>pcre2test</b> is given only one 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.
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</P>
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<P>
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When <b>pcre2test</b> is built, a configuration option can specify that it
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should be linked with the <b>libreadline</b> or <b>libedit</b> library. When this
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is done, if the input is from a terminal, it is read using the <b>readline()</b>
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function. This provides line-editing and history facilities. The output from
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the <b>-help</b> 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 tests, each of which consists of a set of
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input lines. Each set starts with a regular expression pattern, followed by any
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number of subject lines to be matched against that pattern. In between sets of
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test data, command lines that begin with # may appear. This file format, with
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some restrictions, can also be processed by the <b>perltest.sh</b> script that
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is distributed with PCRE2 as a means of checking that the behaviour of PCRE2
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and Perl is the same. For a specification of <b>perltest.sh</b>, see the
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comments near its beginning.
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</P>
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<P>
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When the input is a terminal, <b>pcre2test</b> prompts for each line of input,
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using "re>" to prompt for regular expression patterns, and "data>" to prompt
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for subject lines. Command lines starting with # can be entered only in
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response to the "re>" prompt.
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</P>
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<P>
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Each subject 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 subject lines; the input
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buffer is automatically extended if it is too small. There are replication
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features that makes it possible to generate long repetitive pattern or subject
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lines without having to supply them explicitly.
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</P>
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<P>
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An empty line or the end of the file signals the end of the subject lines for a
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test, at which point a new pattern or command line is expected if there is
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still input to be read.
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</P>
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<br><a name="SEC6" href="#TOC1">COMMAND LINES</a><br>
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<P>
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In between sets of test data, a line that begins with # is interpreted as a
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command line. If the first character is followed by white space or an
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exclamation mark, the line is treated as a comment, and ignored. Otherwise, the
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following commands are recognized:
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<pre>
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#forbid_utf
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</pre>
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Subsequent patterns automatically have the PCRE2_NEVER_UTF and PCRE2_NEVER_UCP
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options set, which locks out the use of the PCRE2_UTF and PCRE2_UCP options and
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the use of (*UTF) and (*UCP) at the start of patterns. This command also forces
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an error if a subsequent pattern contains any occurrences of \P, \p, or \X,
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which are still supported when PCRE2_UTF is not set, but which require Unicode
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property support to be included in the library.
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</P>
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<P>
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This is a trigger guard that is used in test files to ensure that UTF or
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Unicode property tests are not accidentally added to files that are used when
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Unicode support is not included in the library. Setting PCRE2_NEVER_UTF and
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PCRE2_NEVER_UCP as a default can also be obtained by the use of <b>#pattern</b>;
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the difference is that <b>#forbid_utf</b> cannot be unset, and the automatic
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options are not displayed in pattern information, to avoid cluttering up test
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output.
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<pre>
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#load <filename>
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</pre>
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This command is used to load a set of precompiled patterns from a file, as
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described in the section entitled "Saving and restoring compiled patterns"
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<a href="#saverestore">below.</a>
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<pre>
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#loadtables <filename>
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</pre>
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This command is used to load a set of binary character tables that can be
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accessed by the tables=3 qualifier. Such tables can be created by the
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<b>pcre2_dftables</b> program with the -b option.
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<pre>
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#newline_default [<newline-list>]
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</pre>
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When PCRE2 is built, a default newline convention can be specified. This
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determines which characters and/or character pairs are recognized as indicating
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a newline in a pattern or subject string. The default can be overridden when a
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pattern is compiled. The standard test files contain tests of various newline
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conventions, but the majority of the tests expect a single linefeed to be
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recognized as a newline by default. Without special action the tests would fail
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when PCRE2 is compiled with either CR or CRLF as the default newline.
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</P>
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<P>
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The #newline_default command specifies a list of newline types that are
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acceptable as the default. The types must be one of CR, LF, CRLF, ANYCRLF,
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ANY, or NUL (in upper or lower case), for example:
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<pre>
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#newline_default LF Any anyCRLF
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</pre>
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If the default newline is in the list, this command has no effect. Otherwise,
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except when testing the POSIX API, a <b>newline</b> modifier that specifies the
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|
first newline convention in the list (LF in the above example) is added to any
|
|
pattern that does not already have a <b>newline</b> modifier. If the newline
|
|
list is empty, the feature is turned off. This command is present in a number
|
|
of the standard test input files.
|
|
</P>
|
|
<P>
|
|
When the POSIX API is being tested there is no way to override the default
|
|
newline convention, though it is possible to set the newline convention from
|
|
within the pattern. A warning is given if the <b>posix</b> or <b>posix_nosub</b>
|
|
modifier is used when <b>#newline_default</b> would set a default for the
|
|
non-POSIX API.
|
|
<pre>
|
|
#pattern <modifier-list>
|
|
</pre>
|
|
This command sets a default modifier list that applies to all subsequent
|
|
patterns. Modifiers on a pattern can change these settings.
|
|
<pre>
|
|
#perltest
|
|
</pre>
|
|
The appearance of this line causes all subsequent modifier settings to be
|
|
checked for compatibility with the <b>perltest.sh</b> script, which is used to
|
|
confirm that Perl gives the same results as PCRE2. Also, apart from comment
|
|
lines, #pattern commands, and #subject commands that set or unset "mark", no
|
|
command lines are permitted, because they and many of the modifiers are
|
|
specific to <b>pcre2test</b>, and should not be used in test files that are also
|
|
processed by <b>perltest.sh</b>. The <b>#perltest</b> command helps detect tests
|
|
that are accidentally put in the wrong file.
|
|
<pre>
|
|
#pop [<modifiers>]
|
|
#popcopy [<modifiers>]
|
|
</pre>
|
|
These commands are used to manipulate the stack of compiled patterns, as
|
|
described in the section entitled "Saving and restoring compiled patterns"
|
|
<a href="#saverestore">below.</a>
|
|
<pre>
|
|
#save <filename>
|
|
</pre>
|
|
This command is used to save a set of compiled patterns to a file, as described
|
|
in the section entitled "Saving and restoring compiled patterns"
|
|
<a href="#saverestore">below.</a>
|
|
<pre>
|
|
#subject <modifier-list>
|
|
</pre>
|
|
This command sets a default modifier list that applies to all subsequent
|
|
subject lines. Modifiers on a subject line can change these settings.
|
|
</P>
|
|
<br><a name="SEC7" href="#TOC1">MODIFIER SYNTAX</a><br>
|
|
<P>
|
|
Modifier lists are used with both pattern and subject lines. Items in a list
|
|
are separated by commas followed by optional white space. Trailing whitespace
|
|
in a modifier list is ignored. Some modifiers may be given for both patterns
|
|
and subject lines, whereas others are valid only for one or the other. Each
|
|
modifier has a long name, for example "anchored", and some of them must be
|
|
followed by an equals sign and a value, for example, "offset=12". Values cannot
|
|
contain comma characters, but may contain spaces. Modifiers that do not take
|
|
values may be preceded by a minus sign to turn off a previous setting.
|
|
</P>
|
|
<P>
|
|
A few of the more common modifiers can also be specified as single letters, for
|
|
example "i" for "caseless". In documentation, following the Perl convention,
|
|
these are written with a slash ("the /i modifier") for clarity. Abbreviated
|
|
modifiers must all be concatenated in the first item of a modifier list. If the
|
|
first item is not recognized as a long modifier name, it is interpreted as a
|
|
sequence of these abbreviations. For example:
|
|
<pre>
|
|
/abc/ig,newline=cr,jit=3
|
|
</pre>
|
|
This is a pattern line whose modifier list starts with two one-letter modifiers
|
|
(/i and /g). The lower-case abbreviated modifiers are the same as used in Perl.
|
|
</P>
|
|
<br><a name="SEC8" href="#TOC1">PATTERN SYNTAX</a><br>
|
|
<P>
|
|
A pattern line must start with one of the following characters (common symbols,
|
|
excluding pattern meta-characters):
|
|
<pre>
|
|
/ ! " ' ` - = _ : ; , % & @ ~
|
|
</pre>
|
|
This is interpreted as the pattern's delimiter. A regular expression may be
|
|
continued over several input lines, in which case the newline characters are
|
|
included within it. It is possible to include the delimiter within the pattern
|
|
by escaping it with a backslash, for example
|
|
<pre>
|
|
/abc\/def/
|
|
</pre>
|
|
If you do this, the escape and the delimiter form part of the pattern, but
|
|
since the delimiters are all non-alphanumeric, this does not affect its
|
|
interpretation. If the terminating delimiter is immediately followed by a
|
|
backslash, for example,
|
|
<pre>
|
|
/abc/\
|
|
</pre>
|
|
then a backslash is added to the end of the pattern. This is done to provide a
|
|
way of testing the error condition that arises if a pattern finishes with a
|
|
backslash, because
|
|
<pre>
|
|
/abc\/
|
|
</pre>
|
|
is interpreted as the first line of a pattern that starts with "abc/", causing
|
|
pcre2test to read the next line as a continuation of the regular expression.
|
|
</P>
|
|
<P>
|
|
A pattern can be followed by a modifier list (details below).
|
|
</P>
|
|
<br><a name="SEC9" href="#TOC1">SUBJECT LINE SYNTAX</a><br>
|
|
<P>
|
|
Before each subject line is passed to <b>pcre2_match()</b> or
|
|
<b>pcre2_dfa_match()</b>, leading and trailing white space is removed, and the
|
|
line is scanned for backslash escapes, unless the <b>subject_literal</b>
|
|
modifier was set for the pattern. The following provide a means of encoding
|
|
non-printing characters in a visible way:
|
|
<pre>
|
|
\a alarm (BEL, \x07)
|
|
\b backspace (\x08)
|
|
\e escape (\x27)
|
|
\f form feed (\x0c)
|
|
\n newline (\x0a)
|
|
\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
|
|
\o{dd...} octal character (any number of octal digits}
|
|
\xhh hexadecimal byte (up to 2 hex digits)
|
|
\x{hh...} hexadecimal character (any number of hex digits)
|
|
</pre>
|
|
The use of \x{hh...} is not dependent on the use of the <b>utf</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>
|
|
There is a special backslash sequence that specifies replication of one or more
|
|
characters:
|
|
<pre>
|
|
\[<characters>]{<count>}
|
|
</pre>
|
|
This makes it possible to test long strings without having to provide them as
|
|
part of the file. For example:
|
|
<pre>
|
|
\[abc]{4}
|
|
</pre>
|
|
is converted to "abcabcabcabc". This feature does not support nesting. To
|
|
include a closing square bracket in the characters, code it as \x5D.
|
|
</P>
|
|
<P>
|
|
A backslash followed by an equals sign marks the end of the subject string and
|
|
the start of a modifier list. For example:
|
|
<pre>
|
|
abc\=notbol,notempty
|
|
</pre>
|
|
If the subject string is empty and \= is followed by whitespace, the line is
|
|
treated as a comment line, and is not used for matching. For example:
|
|
<pre>
|
|
\= This is a comment.
|
|
abc\= This is an invalid modifier list.
|
|
</pre>
|
|
A backslash followed by any other non-alphanumeric character just escapes that
|
|
character. A backslash followed by anything else causes an error. However, if
|
|
the very last character in the line is a backslash (and there is no modifier
|
|
list), 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>
|
|
If the <b>subject_literal</b> modifier is set for a pattern, all subject lines
|
|
that follow are treated as literals, with no special treatment of backslashes.
|
|
No replication is possible, and any subject modifiers must be set as defaults
|
|
by a <b>#subject</b> command.
|
|
</P>
|
|
<br><a name="SEC10" href="#TOC1">PATTERN MODIFIERS</a><br>
|
|
<P>
|
|
There are several types of modifier that can appear in pattern lines. Except
|
|
where noted below, they may also be used in <b>#pattern</b> commands. A
|
|
pattern's modifier list can add to or override default modifiers that were set
|
|
by a previous <b>#pattern</b> command.
|
|
<a name="optionmodifiers"></a></P>
|
|
<br><b>
|
|
Setting compilation options
|
|
</b><br>
|
|
<P>
|
|
The following modifiers set options for <b>pcre2_compile()</b>. Most of them set
|
|
bits in the options argument of that function, but those whose names start with
|
|
PCRE2_EXTRA are additional options that are set in the compile context. For the
|
|
main options, there are some single-letter abbreviations that are the same as
|
|
Perl options. There is special handling for /x: if a second x is present,
|
|
PCRE2_EXTENDED is converted into PCRE2_EXTENDED_MORE as in Perl. A third
|
|
appearance adds PCRE2_EXTENDED as well, though this makes no difference to the
|
|
way <b>pcre2_compile()</b> behaves. See
|
|
<a href="pcre2api.html"><b>pcre2api</b></a>
|
|
for a description of the effects of these options.
|
|
<pre>
|
|
allow_empty_class set PCRE2_ALLOW_EMPTY_CLASS
|
|
allow_surrogate_escapes set PCRE2_EXTRA_ALLOW_SURROGATE_ESCAPES
|
|
alt_bsux set PCRE2_ALT_BSUX
|
|
alt_circumflex set PCRE2_ALT_CIRCUMFLEX
|
|
alt_verbnames set PCRE2_ALT_VERBNAMES
|
|
anchored set PCRE2_ANCHORED
|
|
auto_callout set PCRE2_AUTO_CALLOUT
|
|
bad_escape_is_literal set PCRE2_EXTRA_BAD_ESCAPE_IS_LITERAL
|
|
/i caseless set PCRE2_CASELESS
|
|
dollar_endonly set PCRE2_DOLLAR_ENDONLY
|
|
/s dotall set PCRE2_DOTALL
|
|
dupnames set PCRE2_DUPNAMES
|
|
endanchored set PCRE2_ENDANCHORED
|
|
escaped_cr_is_lf set PCRE2_EXTRA_ESCAPED_CR_IS_LF
|
|
/x extended set PCRE2_EXTENDED
|
|
/xx extended_more set PCRE2_EXTENDED_MORE
|
|
extra_alt_bsux set PCRE2_EXTRA_ALT_BSUX
|
|
firstline set PCRE2_FIRSTLINE
|
|
literal set PCRE2_LITERAL
|
|
match_line set PCRE2_EXTRA_MATCH_LINE
|
|
match_invalid_utf set PCRE2_MATCH_INVALID_UTF
|
|
match_unset_backref set PCRE2_MATCH_UNSET_BACKREF
|
|
match_word set PCRE2_EXTRA_MATCH_WORD
|
|
/m multiline set PCRE2_MULTILINE
|
|
never_backslash_c set PCRE2_NEVER_BACKSLASH_C
|
|
never_ucp set PCRE2_NEVER_UCP
|
|
never_utf set PCRE2_NEVER_UTF
|
|
/n no_auto_capture set PCRE2_NO_AUTO_CAPTURE
|
|
no_auto_possess set PCRE2_NO_AUTO_POSSESS
|
|
no_dotstar_anchor set PCRE2_NO_DOTSTAR_ANCHOR
|
|
no_start_optimize set PCRE2_NO_START_OPTIMIZE
|
|
no_utf_check set PCRE2_NO_UTF_CHECK
|
|
ucp set PCRE2_UCP
|
|
ungreedy set PCRE2_UNGREEDY
|
|
use_offset_limit set PCRE2_USE_OFFSET_LIMIT
|
|
utf set PCRE2_UTF
|
|
</pre>
|
|
As well as turning on the PCRE2_UTF option, the <b>utf</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. Setting <b>utf</b> in 16-bit or 32-bit mode also causes pattern and
|
|
subject strings to be translated to UTF-16 or UTF-32, respectively, before
|
|
being passed to library functions.
|
|
<a name="controlmodifiers"></a></P>
|
|
<br><b>
|
|
Setting compilation controls
|
|
</b><br>
|
|
<P>
|
|
The following modifiers affect the compilation process or request information
|
|
about the pattern. There are single-letter abbreviations for some that are
|
|
heavily used in the test files.
|
|
<pre>
|
|
bsr=[anycrlf|unicode] specify \R handling
|
|
/B bincode show binary code without lengths
|
|
callout_info show callout information
|
|
convert=<options> request foreign pattern conversion
|
|
convert_glob_escape=c set glob escape character
|
|
convert_glob_separator=c set glob separator character
|
|
convert_length set convert buffer length
|
|
debug same as info,fullbincode
|
|
framesize show matching frame size
|
|
fullbincode show binary code with lengths
|
|
/I info show info about compiled pattern
|
|
hex unquoted characters are hexadecimal
|
|
jit[=<number>] use JIT
|
|
jitfast use JIT fast path
|
|
jitverify verify JIT use
|
|
locale=<name> use this locale
|
|
max_pattern_length=<n> set the maximum pattern length
|
|
memory show memory used
|
|
newline=<type> set newline type
|
|
null_context compile with a NULL context
|
|
parens_nest_limit=<n> set maximum parentheses depth
|
|
posix use the POSIX API
|
|
posix_nosub use the POSIX API with REG_NOSUB
|
|
push push compiled pattern onto the stack
|
|
pushcopy push a copy onto the stack
|
|
stackguard=<number> test the stackguard feature
|
|
subject_literal treat all subject lines as literal
|
|
tables=[0|1|2|3] select internal tables
|
|
use_length do not zero-terminate the pattern
|
|
utf8_input treat input as UTF-8
|
|
</pre>
|
|
The effects of these modifiers are described in the following sections.
|
|
</P>
|
|
<br><b>
|
|
Newline and \R handling
|
|
</b><br>
|
|
<P>
|
|
The <b>bsr</b> modifier specifies what \R in a pattern should match. If it is
|
|
set to "anycrlf", \R matches CR, LF, or CRLF only. If it is set to "unicode",
|
|
\R matches any Unicode newline sequence. The default can be specified when
|
|
PCRE2 is built; if it is not, the default is set to Unicode.
|
|
</P>
|
|
<P>
|
|
The <b>newline</b> modifier specifies which characters are to be interpreted as
|
|
newlines, both in the pattern and in subject lines. The type must be one of CR,
|
|
LF, CRLF, ANYCRLF, ANY, or NUL (in upper or lower case).
|
|
</P>
|
|
<br><b>
|
|
Information about a pattern
|
|
</b><br>
|
|
<P>
|
|
The <b>debug</b> modifier is a shorthand for <b>info,fullbincode</b>, requesting
|
|
all available information.
|
|
</P>
|
|
<P>
|
|
The <b>bincode</b> modifier causes a representation of the compiled code to be
|
|
output after compilation. This information does not contain length and offset
|
|
values, which ensures that the same output is generated for different internal
|
|
link sizes and different code unit widths. By using <b>bincode</b>, the same
|
|
regression tests can be used in different environments.
|
|
</P>
|
|
<P>
|
|
The <b>fullbincode</b> modifier, by contrast, <i>does</i> include length and
|
|
offset values. This is used in a few special tests that run only for specific
|
|
code unit widths and link sizes, and is also useful for one-off tests.
|
|
</P>
|
|
<P>
|
|
The <b>info</b> modifier requests information about the compiled pattern
|
|
(whether it is anchored, has a fixed first character, and so on). The
|
|
information is obtained from the <b>pcre2_pattern_info()</b> function. Here are
|
|
some typical examples:
|
|
<pre>
|
|
re> /(?i)(^a|^b)/m,info
|
|
Capture group count = 1
|
|
Compile options: multiline
|
|
Overall options: caseless multiline
|
|
First code unit at start or follows newline
|
|
Subject length lower bound = 1
|
|
|
|
re> /(?i)abc/info
|
|
Capture group count = 0
|
|
Compile options: <none>
|
|
Overall options: caseless
|
|
First code unit = 'a' (caseless)
|
|
Last code unit = 'c' (caseless)
|
|
Subject length lower bound = 3
|
|
</pre>
|
|
"Compile options" are those specified by modifiers; "overall options" have
|
|
added options that are taken or deduced from the pattern. If both sets of
|
|
options are the same, just a single "options" line is output; if there are no
|
|
options, the line is omitted. "First code unit" is where any match must start;
|
|
if there is more than one they are listed as "starting code units". "Last code
|
|
unit" is the last literal code unit that must be present in any match. This is
|
|
not necessarily the last character. These lines are omitted if no starting or
|
|
ending code units are recorded. The subject length line is omitted when
|
|
<b>no_start_optimize</b> is set because the minimum length is not calculated
|
|
when it can never be used.
|
|
</P>
|
|
<P>
|
|
The <b>framesize</b> modifier shows the size, in bytes, of the storage frames
|
|
used by <b>pcre2_match()</b> for handling backtracking. The size depends on the
|
|
number of capturing parentheses in the pattern.
|
|
</P>
|
|
<P>
|
|
The <b>callout_info</b> modifier requests information about all the callouts in
|
|
the pattern. A list of them is output at the end of any other information that
|
|
is requested. For each callout, either its number or string is given, followed
|
|
by the item that follows it in the pattern.
|
|
</P>
|
|
<br><b>
|
|
Passing a NULL context
|
|
</b><br>
|
|
<P>
|
|
Normally, <b>pcre2test</b> passes a context block to <b>pcre2_compile()</b>. If
|
|
the <b>null_context</b> modifier is set, however, NULL is passed. This is for
|
|
testing that <b>pcre2_compile()</b> behaves correctly in this case (it uses
|
|
default values).
|
|
</P>
|
|
<br><b>
|
|
Specifying pattern characters in hexadecimal
|
|
</b><br>
|
|
<P>
|
|
The <b>hex</b> modifier specifies that the characters of the pattern, except for
|
|
substrings enclosed in single or double quotes, are to be interpreted as pairs
|
|
of hexadecimal digits. This feature is provided as a way of creating patterns
|
|
that contain binary zeros and other non-printing characters. White space is
|
|
permitted between pairs of digits. For example, this pattern contains three
|
|
characters:
|
|
<pre>
|
|
/ab 32 59/hex
|
|
</pre>
|
|
Parts of such a pattern are taken literally if quoted. This pattern contains
|
|
nine characters, only two of which are specified in hexadecimal:
|
|
<pre>
|
|
/ab "literal" 32/hex
|
|
</pre>
|
|
Either single or double quotes may be used. There is no way of including
|
|
the delimiter within a substring. The <b>hex</b> and <b>expand</b> modifiers are
|
|
mutually exclusive.
|
|
</P>
|
|
<br><b>
|
|
Specifying the pattern's length
|
|
</b><br>
|
|
<P>
|
|
By default, patterns are passed to the compiling functions as zero-terminated
|
|
strings but can be passed by length instead of being zero-terminated. The
|
|
<b>use_length</b> modifier causes this to happen. Using a length happens
|
|
automatically (whether or not <b>use_length</b> is set) when <b>hex</b> is set,
|
|
because patterns specified in hexadecimal may contain binary zeros.
|
|
</P>
|
|
<P>
|
|
If <b>hex</b> or <b>use_length</b> is used with the POSIX wrapper API (see
|
|
<a href="#posixwrapper">"Using the POSIX wrapper API"</a>
|
|
below), the REG_PEND extension is used to pass the pattern's length.
|
|
</P>
|
|
<br><b>
|
|
Specifying wide characters in 16-bit and 32-bit modes
|
|
</b><br>
|
|
<P>
|
|
In 16-bit and 32-bit modes, all input is automatically treated as UTF-8 and
|
|
translated to UTF-16 or UTF-32 when the <b>utf</b> modifier is set. For testing
|
|
the 16-bit and 32-bit libraries in non-UTF mode, the <b>utf8_input</b> modifier
|
|
can be used. It is mutually exclusive with <b>utf</b>. Input lines are
|
|
interpreted as UTF-8 as a means of specifying wide characters. More details are
|
|
given in
|
|
<a href="#inputencoding">"Input encoding"</a>
|
|
above.
|
|
</P>
|
|
<br><b>
|
|
Generating long repetitive patterns
|
|
</b><br>
|
|
<P>
|
|
Some tests use long patterns that are very repetitive. Instead of creating a
|
|
very long input line for such a pattern, you can use a special repetition
|
|
feature, similar to the one described for subject lines above. If the
|
|
<b>expand</b> modifier is present on a pattern, parts of the pattern that have
|
|
the form
|
|
<pre>
|
|
\[<characters>]{<count>}
|
|
</pre>
|
|
are expanded before the pattern is passed to <b>pcre2_compile()</b>. For
|
|
example, \[AB]{6000} is expanded to "ABAB..." 6000 times. This construction
|
|
cannot be nested. An initial "\[" sequence is recognized only if "]{" followed
|
|
by decimal digits and "}" is found later in the pattern. If not, the characters
|
|
remain in the pattern unaltered. The <b>expand</b> and <b>hex</b> modifiers are
|
|
mutually exclusive.
|
|
</P>
|
|
<P>
|
|
If part of an expanded pattern looks like an expansion, but is really part of
|
|
the actual pattern, unwanted expansion can be avoided by giving two values in
|
|
the quantifier. For example, \[AB]{6000,6000} is not recognized as an
|
|
expansion item.
|
|
</P>
|
|
<P>
|
|
If the <b>info</b> modifier is set on an expanded pattern, the result of the
|
|
expansion is included in the information that is output.
|
|
</P>
|
|
<br><b>
|
|
JIT compilation
|
|
</b><br>
|
|
<P>
|
|
Just-in-time (JIT) compiling is a heavyweight optimization that can greatly
|
|
speed up pattern matching. See the
|
|
<a href="pcre2jit.html"><b>pcre2jit</b></a>
|
|
documentation for details. JIT compiling happens, optionally, after a pattern
|
|
has been successfully compiled into an internal form. The JIT compiler converts
|
|
this to optimized machine code. It needs to know whether the match-time options
|
|
PCRE2_PARTIAL_HARD and PCRE2_PARTIAL_SOFT are going to be used, because
|
|
different code is generated for the different cases. See the <b>partial</b>
|
|
modifier in "Subject Modifiers"
|
|
<a href="#subjectmodifiers">below</a>
|
|
for details of how these options are specified for each match attempt.
|
|
</P>
|
|
<P>
|
|
JIT compilation is requested by the <b>jit</b> pattern modifier, which may
|
|
optionally be followed by an equals sign and a number in the range 0 to 7.
|
|
The three bits that make up the number specify which of the three JIT operating
|
|
modes are to be compiled:
|
|
<pre>
|
|
1 compile JIT code for non-partial matching
|
|
2 compile JIT code for soft partial matching
|
|
4 compile JIT code for hard partial matching
|
|
</pre>
|
|
The possible values for the <b>jit</b> modifier are therefore:
|
|
<pre>
|
|
0 disable JIT
|
|
1 normal matching only
|
|
2 soft partial matching only
|
|
3 normal and soft partial matching
|
|
4 hard partial matching only
|
|
6 soft and hard partial matching only
|
|
7 all three modes
|
|
</pre>
|
|
If no number is given, 7 is assumed. The phrase "partial matching" means a call
|
|
to <b>pcre2_match()</b> with either the PCRE2_PARTIAL_SOFT or the
|
|
PCRE2_PARTIAL_HARD option set. Note that such a call may return a complete
|
|
match; the options enable the possibility of a partial match, but do not
|
|
require it. Note also that if you request JIT compilation only for partial
|
|
matching (for example, jit=2) but do not set the <b>partial</b> modifier on a
|
|
subject line, that match will not use JIT code because none was compiled for
|
|
non-partial matching.
|
|
</P>
|
|
<P>
|
|
If JIT compilation is successful, the compiled JIT code will automatically be
|
|
used when an appropriate type of match is run, except when incompatible
|
|
run-time options are specified. For more details, see the
|
|
<a href="pcre2jit.html"><b>pcre2jit</b></a>
|
|
documentation. See also the <b>jitstack</b> modifier below for a way of
|
|
setting the size of the JIT stack.
|
|
</P>
|
|
<P>
|
|
If the <b>jitfast</b> modifier is specified, matching is done using the JIT
|
|
"fast path" interface, <b>pcre2_jit_match()</b>, which skips some of the sanity
|
|
checks that are done by <b>pcre2_match()</b>, and of course does not work when
|
|
JIT is not supported. If <b>jitfast</b> is specified without <b>jit</b>, jit=7 is
|
|
assumed.
|
|
</P>
|
|
<P>
|
|
If the <b>jitverify</b> modifier is specified, information about the compiled
|
|
pattern shows whether JIT compilation was or was not successful. If
|
|
<b>jitverify</b> is specified without <b>jit</b>, jit=7 is assumed. If JIT
|
|
compilation is successful when <b>jitverify</b> is set, the text "(JIT)" is
|
|
added to the first output line after a match or non match when JIT-compiled
|
|
code was actually used in the match.
|
|
</P>
|
|
<br><b>
|
|
Setting a locale
|
|
</b><br>
|
|
<P>
|
|
The <b>locale</b> modifier must specify the name of a locale, for example:
|
|
<pre>
|
|
/pattern/locale=fr_FR
|
|
</pre>
|
|
The given locale is set, <b>pcre2_maketables()</b> is called to build a set of
|
|
character tables for the locale, and this is then passed to
|
|
<b>pcre2_compile()</b> when compiling the regular expression. The same tables
|
|
are used when matching the following subject lines. The <b>locale</b> modifier
|
|
applies only to the pattern on which it appears, but can be given in a
|
|
<b>#pattern</b> command if a default is needed. Setting a locale and alternate
|
|
character tables are mutually exclusive.
|
|
</P>
|
|
<br><b>
|
|
Showing pattern memory
|
|
</b><br>
|
|
<P>
|
|
The <b>memory</b> modifier causes the size in bytes of the memory used to hold
|
|
the compiled pattern to be output. This does not include the size of the
|
|
<b>pcre2_code</b> block; it is just the actual compiled data. If the pattern is
|
|
subsequently passed to the JIT compiler, the size of the JIT compiled code is
|
|
also output. Here is an example:
|
|
<pre>
|
|
re> /a(b)c/jit,memory
|
|
Memory allocation (code space): 21
|
|
Memory allocation (JIT code): 1910
|
|
|
|
</PRE>
|
|
</P>
|
|
<br><b>
|
|
Limiting nested parentheses
|
|
</b><br>
|
|
<P>
|
|
The <b>parens_nest_limit</b> modifier sets a limit on the depth of nested
|
|
parentheses in a pattern. Breaching the limit causes a compilation error.
|
|
The default for the library is set when PCRE2 is built, but <b>pcre2test</b>
|
|
sets its own default of 220, which is required for running the standard test
|
|
suite.
|
|
</P>
|
|
<br><b>
|
|
Limiting the pattern length
|
|
</b><br>
|
|
<P>
|
|
The <b>max_pattern_length</b> modifier sets a limit, in code units, to the
|
|
length of pattern that <b>pcre2_compile()</b> will accept. Breaching the limit
|
|
causes a compilation error. The default is the largest number a PCRE2_SIZE
|
|
variable can hold (essentially unlimited).
|
|
<a name="posixwrapper"></a></P>
|
|
<br><b>
|
|
Using the POSIX wrapper API
|
|
</b><br>
|
|
<P>
|
|
The <b>posix</b> and <b>posix_nosub</b> modifiers cause <b>pcre2test</b> to call
|
|
PCRE2 via the POSIX wrapper API rather than its native API. When
|
|
<b>posix_nosub</b> is used, the POSIX option REG_NOSUB is passed to
|
|
<b>regcomp()</b>. The POSIX wrapper supports only the 8-bit library. Note that
|
|
it does not imply POSIX matching semantics; for more detail see the
|
|
<a href="pcre2posix.html"><b>pcre2posix</b></a>
|
|
documentation. The following pattern modifiers set options for the
|
|
<b>regcomp()</b> function:
|
|
<pre>
|
|
caseless REG_ICASE
|
|
multiline REG_NEWLINE
|
|
dotall REG_DOTALL )
|
|
ungreedy REG_UNGREEDY ) These options are not part of
|
|
ucp REG_UCP ) the POSIX standard
|
|
utf REG_UTF8 )
|
|
</pre>
|
|
The <b>regerror_buffsize</b> modifier specifies a size for the error buffer that
|
|
is passed to <b>regerror()</b> in the event of a compilation error. For example:
|
|
<pre>
|
|
/abc/posix,regerror_buffsize=20
|
|
</pre>
|
|
This provides a means of testing the behaviour of <b>regerror()</b> when the
|
|
buffer is too small for the error message. If this modifier has not been set, a
|
|
large buffer is used.
|
|
</P>
|
|
<P>
|
|
The <b>aftertext</b> and <b>allaftertext</b> subject modifiers work as described
|
|
below. All other modifiers are either ignored, with a warning message, or cause
|
|
an error.
|
|
</P>
|
|
<P>
|
|
The pattern is passed to <b>regcomp()</b> as a zero-terminated string by
|
|
default, but if the <b>use_length</b> or <b>hex</b> modifiers are set, the
|
|
REG_PEND extension is used to pass it by length.
|
|
</P>
|
|
<br><b>
|
|
Testing the stack guard feature
|
|
</b><br>
|
|
<P>
|
|
The <b>stackguard</b> modifier is used to test the use of
|
|
<b>pcre2_set_compile_recursion_guard()</b>, a function that is provided to
|
|
enable stack availability to be checked during compilation (see the
|
|
<a href="pcre2api.html"><b>pcre2api</b></a>
|
|
documentation for details). If the number specified by the modifier is greater
|
|
than zero, <b>pcre2_set_compile_recursion_guard()</b> is called to set up
|
|
callback from <b>pcre2_compile()</b> to a local function. The argument it
|
|
receives is the current nesting parenthesis depth; if this is greater than the
|
|
value given by the modifier, non-zero is returned, causing the compilation to
|
|
be aborted.
|
|
</P>
|
|
<br><b>
|
|
Using alternative character tables
|
|
</b><br>
|
|
<P>
|
|
The value specified for the <b>tables</b> modifier must be one of the digits 0,
|
|
1, 2, or 3. It causes a specific set of built-in character tables to be passed
|
|
to <b>pcre2_compile()</b>. This is used in the PCRE2 tests to check behaviour
|
|
with different character tables. The digit specifies the tables as follows:
|
|
<pre>
|
|
0 do not pass any special character tables
|
|
1 the default ASCII tables, as distributed in
|
|
pcre2_chartables.c.dist
|
|
2 a set of tables defining ISO 8859 characters
|
|
3 a set of tables loaded by the #loadtables command
|
|
</pre>
|
|
In tables 2, some characters whose codes are greater than 128 are identified as
|
|
letters, digits, spaces, etc. Tables 3 can be used only after a
|
|
<b>#loadtables</b> command has loaded them from a binary file. Setting alternate
|
|
character tables and a locale are mutually exclusive.
|
|
</P>
|
|
<br><b>
|
|
Setting certain match controls
|
|
</b><br>
|
|
<P>
|
|
The following modifiers are really subject modifiers, and are described under
|
|
"Subject Modifiers" below. However, they may be included in a pattern's
|
|
modifier list, in which case they are applied to every subject line that is
|
|
processed with that pattern. These modifiers do not affect the compilation
|
|
process.
|
|
<pre>
|
|
aftertext show text after match
|
|
allaftertext show text after captures
|
|
allcaptures show all captures
|
|
allvector show the entire ovector
|
|
allusedtext show all consulted text
|
|
altglobal alternative global matching
|
|
/g global global matching
|
|
jitstack=<n> set size of JIT stack
|
|
mark show mark values
|
|
replace=<string> specify a replacement string
|
|
startchar show starting character when relevant
|
|
substitute_callout use substitution callouts
|
|
substitute_extended use PCRE2_SUBSTITUTE_EXTENDED
|
|
substitute_literal use PCRE2_SUBSTITUTE_LITERAL
|
|
substitute_matched use PCRE2_SUBSTITUTE_MATCHED
|
|
substitute_overflow_length use PCRE2_SUBSTITUTE_OVERFLOW_LENGTH
|
|
substitute_replacement_only use PCRE2_SUBSTITUTE_REPLACEMENT_ONLY
|
|
substitute_skip=<n> skip substitution <n>
|
|
substitute_stop=<n> skip substitution <n> and following
|
|
substitute_unknown_unset use PCRE2_SUBSTITUTE_UNKNOWN_UNSET
|
|
substitute_unset_empty use PCRE2_SUBSTITUTE_UNSET_EMPTY
|
|
</pre>
|
|
These modifiers may not appear in a <b>#pattern</b> command. If you want them as
|
|
defaults, set them in a <b>#subject</b> command.
|
|
</P>
|
|
<br><b>
|
|
Specifying literal subject lines
|
|
</b><br>
|
|
<P>
|
|
If the <b>subject_literal</b> modifier is present on a pattern, all the subject
|
|
lines that it matches are taken as literal strings, with no interpretation of
|
|
backslashes. It is not possible to set subject modifiers on such lines, but any
|
|
that are set as defaults by a <b>#subject</b> command are recognized.
|
|
</P>
|
|
<br><b>
|
|
Saving a compiled pattern
|
|
</b><br>
|
|
<P>
|
|
When a pattern with the <b>push</b> modifier is successfully compiled, it is
|
|
pushed onto a stack of compiled patterns, and <b>pcre2test</b> expects the next
|
|
line to contain a new pattern (or a command) instead of a subject line. This
|
|
facility is used when saving compiled patterns to a file, as described in the
|
|
section entitled "Saving and restoring compiled patterns"
|
|
<a href="#saverestore">below.</a>
|
|
If <b>pushcopy</b> is used instead of <b>push</b>, a copy of the compiled
|
|
pattern is stacked, leaving the original as current, ready to match the
|
|
following input lines. This provides a way of testing the
|
|
<b>pcre2_code_copy()</b> function.
|
|
The <b>push</b> and <b>pushcopy </b> modifiers are incompatible with compilation
|
|
modifiers such as <b>global</b> that act at match time. Any that are specified
|
|
are ignored (for the stacked copy), with a warning message, except for
|
|
<b>replace</b>, which causes an error. Note that <b>jitverify</b>, which is
|
|
allowed, does not carry through to any subsequent matching that uses a stacked
|
|
pattern.
|
|
</P>
|
|
<br><b>
|
|
Testing foreign pattern conversion
|
|
</b><br>
|
|
<P>
|
|
The experimental foreign pattern conversion functions in PCRE2 can be tested by
|
|
setting the <b>convert</b> modifier. Its argument is a colon-separated list of
|
|
options, which set the equivalent option for the <b>pcre2_pattern_convert()</b>
|
|
function:
|
|
<pre>
|
|
glob PCRE2_CONVERT_GLOB
|
|
glob_no_starstar PCRE2_CONVERT_GLOB_NO_STARSTAR
|
|
glob_no_wild_separator PCRE2_CONVERT_GLOB_NO_WILD_SEPARATOR
|
|
posix_basic PCRE2_CONVERT_POSIX_BASIC
|
|
posix_extended PCRE2_CONVERT_POSIX_EXTENDED
|
|
unset Unset all options
|
|
</pre>
|
|
The "unset" value is useful for turning off a default that has been set by a
|
|
<b>#pattern</b> command. When one of these options is set, the input pattern is
|
|
passed to <b>pcre2_pattern_convert()</b>. If the conversion is successful, the
|
|
result is reflected in the output and then passed to <b>pcre2_compile()</b>. The
|
|
normal <b>utf</b> and <b>no_utf_check</b> options, if set, cause the
|
|
PCRE2_CONVERT_UTF and PCRE2_CONVERT_NO_UTF_CHECK options to be passed to
|
|
<b>pcre2_pattern_convert()</b>.
|
|
</P>
|
|
<P>
|
|
By default, the conversion function is allowed to allocate a buffer for its
|
|
output. However, if the <b>convert_length</b> modifier is set to a value greater
|
|
than zero, <b>pcre2test</b> passes a buffer of the given length. This makes it
|
|
possible to test the length check.
|
|
</P>
|
|
<P>
|
|
The <b>convert_glob_escape</b> and <b>convert_glob_separator</b> modifiers can be
|
|
used to specify the escape and separator characters for glob processing,
|
|
overriding the defaults, which are operating-system dependent.
|
|
<a name="subjectmodifiers"></a></P>
|
|
<br><a name="SEC11" href="#TOC1">SUBJECT MODIFIERS</a><br>
|
|
<P>
|
|
The modifiers that can appear in subject lines and the <b>#subject</b>
|
|
command are of two types.
|
|
</P>
|
|
<br><b>
|
|
Setting match options
|
|
</b><br>
|
|
<P>
|
|
The following modifiers set options for <b>pcre2_match()</b> or
|
|
<b>pcre2_dfa_match()</b>. See
|
|
<a href="pcreapi.html"><b>pcreapi</b></a>
|
|
for a description of their effects.
|
|
<pre>
|
|
anchored set PCRE2_ANCHORED
|
|
endanchored set PCRE2_ENDANCHORED
|
|
dfa_restart set PCRE2_DFA_RESTART
|
|
dfa_shortest set PCRE2_DFA_SHORTEST
|
|
no_jit set PCRE2_NO_JIT
|
|
no_utf_check set PCRE2_NO_UTF_CHECK
|
|
notbol set PCRE2_NOTBOL
|
|
notempty set PCRE2_NOTEMPTY
|
|
notempty_atstart set PCRE2_NOTEMPTY_ATSTART
|
|
noteol set PCRE2_NOTEOL
|
|
partial_hard (or ph) set PCRE2_PARTIAL_HARD
|
|
partial_soft (or ps) set PCRE2_PARTIAL_SOFT
|
|
</pre>
|
|
The partial matching modifiers are provided with abbreviations because they
|
|
appear frequently in tests.
|
|
</P>
|
|
<P>
|
|
If the <b>posix</b> or <b>posix_nosub</b> modifier was present on the pattern,
|
|
causing the POSIX wrapper API to be used, the only option-setting modifiers
|
|
that have any effect are <b>notbol</b>, <b>notempty</b>, and <b>noteol</b>,
|
|
causing REG_NOTBOL, REG_NOTEMPTY, and REG_NOTEOL, respectively, to be passed to
|
|
<b>regexec()</b>. The other modifiers are ignored, with a warning message.
|
|
</P>
|
|
<P>
|
|
There is one additional modifier that can be used with the POSIX wrapper. It is
|
|
ignored (with a warning) if used for non-POSIX matching.
|
|
<pre>
|
|
posix_startend=<n>[:<m>]
|
|
</pre>
|
|
This causes the subject string to be passed to <b>regexec()</b> using the
|
|
REG_STARTEND option, which uses offsets to specify which part of the string is
|
|
searched. If only one number is given, the end offset is passed as the end of
|
|
the subject string. For more detail of REG_STARTEND, see the
|
|
<a href="pcre2posix.html"><b>pcre2posix</b></a>
|
|
documentation. If the subject string contains binary zeros (coded as escapes
|
|
such as \x{00} because <b>pcre2test</b> does not support actual binary zeros in
|
|
its input), you must use <b>posix_startend</b> to specify its length.
|
|
</P>
|
|
<br><b>
|
|
Setting match controls
|
|
</b><br>
|
|
<P>
|
|
The following modifiers affect the matching process or request additional
|
|
information. Some of them may also be specified on a pattern line (see above),
|
|
in which case they apply to every subject line that is matched against that
|
|
pattern.
|
|
<pre>
|
|
aftertext show text after match
|
|
allaftertext show text after captures
|
|
allcaptures show all captures
|
|
allvector show the entire ovector
|
|
allusedtext show all consulted text (non-JIT only)
|
|
altglobal alternative global matching
|
|
callout_capture show captures at callout time
|
|
callout_data=<n> set a value to pass via callouts
|
|
callout_error=<n>[:<m>] control callout error
|
|
callout_extra show extra callout information
|
|
callout_fail=<n>[:<m>] control callout failure
|
|
callout_no_where do not show position of a callout
|
|
callout_none do not supply a callout function
|
|
copy=<number or name> copy captured substring
|
|
depth_limit=<n> set a depth limit
|
|
dfa use <b>pcre2_dfa_match()</b>
|
|
find_limits find match and depth limits
|
|
get=<number or name> extract captured substring
|
|
getall extract all captured substrings
|
|
/g global global matching
|
|
heap_limit=<n> set a limit on heap memory (Kbytes)
|
|
jitstack=<n> set size of JIT stack
|
|
mark show mark values
|
|
match_limit=<n> set a match limit
|
|
memory show heap memory usage
|
|
null_context match with a NULL context
|
|
offset=<n> set starting offset
|
|
offset_limit=<n> set offset limit
|
|
ovector=<n> set size of output vector
|
|
recursion_limit=<n> obsolete synonym for depth_limit
|
|
replace=<string> specify a replacement string
|
|
startchar show startchar when relevant
|
|
startoffset=<n> same as offset=<n>
|
|
substitute_callout use substitution callouts
|
|
substitute_extedded use PCRE2_SUBSTITUTE_EXTENDED
|
|
substitute_literal use PCRE2_SUBSTITUTE_LITERAL
|
|
substitute_matched use PCRE2_SUBSTITUTE_MATCHED
|
|
substitute_overflow_length use PCRE2_SUBSTITUTE_OVERFLOW_LENGTH
|
|
substitute_replacement_only use PCRE2_SUBSTITUTE_REPLACEMENT_ONLY
|
|
substitute_skip=<n> skip substitution number n
|
|
substitute_stop=<n> skip substitution number n and greater
|
|
substitute_unknown_unset use PCRE2_SUBSTITUTE_UNKNOWN_UNSET
|
|
substitute_unset_empty use PCRE2_SUBSTITUTE_UNSET_EMPTY
|
|
zero_terminate pass the subject as zero-terminated
|
|
</pre>
|
|
The effects of these modifiers are described in the following sections. When
|
|
matching via the POSIX wrapper API, the <b>aftertext</b>, <b>allaftertext</b>,
|
|
and <b>ovector</b> subject modifiers work as described below. All other
|
|
modifiers are either ignored, with a warning message, or cause an error.
|
|
</P>
|
|
<br><b>
|
|
Showing more text
|
|
</b><br>
|
|
<P>
|
|
The <b>aftertext</b> modifier requests that as well as outputting the part of
|
|
the subject string that matched the entire pattern, <b>pcre2test</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. The
|
|
<b>allaftertext</b> modifier requests the same action for captured substrings as
|
|
well as the main matched substring. In each case the remainder is output on the
|
|
following line with a plus character following the capture number.
|
|
</P>
|
|
<P>
|
|
The <b>allusedtext</b> modifier requests that all the text that was consulted
|
|
during a successful pattern match by the interpreter should be shown, for both
|
|
full and partial matches. This feature is not supported for JIT matching, and
|
|
if requested with JIT it is ignored (with a warning message). Setting this
|
|
modifier affects the output if there is a lookbehind at the start of a match,
|
|
or, for a complete match, a lookahead at the end, or if \K is used in the
|
|
pattern. Characters that precede or follow the start and end of the actual
|
|
match are indicated in the output by '<' or '>' characters underneath them.
|
|
Here is an example:
|
|
<pre>
|
|
re> /(?<=pqr)abc(?=xyz)/
|
|
data> 123pqrabcxyz456\=allusedtext
|
|
0: pqrabcxyz
|
|
<<< >>>
|
|
data> 123pqrabcxy\=ph,allusedtext
|
|
Partial match: pqrabcxy
|
|
<<<
|
|
</pre>
|
|
The first, complete match shows that the matched string is "abc", with the
|
|
preceding and following strings "pqr" and "xyz" having been consulted during
|
|
the match (when processing the assertions). The partial match can indicate only
|
|
the preceding string.
|
|
</P>
|
|
<P>
|
|
The <b>startchar</b> modifier requests that the starting character for the match
|
|
be indicated, if it is different to the start of the matched string. The only
|
|
time when this occurs is when \K has been processed as part of the match. In
|
|
this situation, the output for the matched string is displayed from the
|
|
starting character instead of from the match point, with circumflex characters
|
|
under the earlier characters. For example:
|
|
<pre>
|
|
re> /abc\Kxyz/
|
|
data> abcxyz\=startchar
|
|
0: abcxyz
|
|
^^^
|
|
</pre>
|
|
Unlike <b>allusedtext</b>, the <b>startchar</b> modifier can be used with JIT.
|
|
However, these two modifiers are mutually exclusive.
|
|
</P>
|
|
<br><b>
|
|
Showing the value of all capture groups
|
|
</b><br>
|
|
<P>
|
|
The <b>allcaptures</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>pcre2_match()</b>). Groups that did not take part in the match
|
|
are output as "<unset>". This modifier is not relevant for DFA matching (which
|
|
does no capturing) and does not apply when <b>replace</b> is specified; it is
|
|
ignored, with a warning message, if present.
|
|
</P>
|
|
<br><b>
|
|
Showing the entire ovector, for all outcomes
|
|
</b><br>
|
|
<P>
|
|
The <b>allvector</b> modifier requests that the entire ovector be shown,
|
|
whatever the outcome of the match. Compare <b>allcaptures</b>, which shows only
|
|
up to the maximum number of capture groups for the pattern, and then only for a
|
|
successful complete non-DFA match. This modifier, which acts after any match
|
|
result, and also for DFA matching, provides a means of checking that there are
|
|
no unexpected modifications to ovector fields. Before each match attempt, the
|
|
ovector is filled with a special value, and if this is found in both elements
|
|
of a capturing pair, "<unchanged>" is output. After a successful match, this
|
|
applies to all groups after the maximum capture group for the pattern. In other
|
|
cases it applies to the entire ovector. After a partial match, the first two
|
|
elements are the only ones that should be set. After a DFA match, the amount of
|
|
ovector that is used depends on the number of matches that were found.
|
|
</P>
|
|
<br><b>
|
|
Testing pattern callouts
|
|
</b><br>
|
|
<P>
|
|
A callout function is supplied when <b>pcre2test</b> calls the library matching
|
|
functions, unless <b>callout_none</b> is specified. Its behaviour can be
|
|
controlled by various modifiers listed above whose names begin with
|
|
<b>callout_</b>. Details are given in the section entitled "Callouts"
|
|
<a href="#callouts">below.</a>
|
|
Testing callouts from <b>pcre2_substitute()</b> is decribed separately in
|
|
"Testing the substitution function"
|
|
<a href="#substitution">below.</a>
|
|
</P>
|
|
<br><b>
|
|
Finding all matches in a string
|
|
</b><br>
|
|
<P>
|
|
Searching for all possible matches within a subject can be requested by the
|
|
<b>global</b> or <b>altglobal</b> modifier. After finding a match, the matching
|
|
function is called again to search the remainder of the subject. The difference
|
|
between <b>global</b> and <b>altglobal</b> is that the former uses the
|
|
<i>start_offset</i> argument to <b>pcre2_match()</b> or <b>pcre2_dfa_match()</b>
|
|
to start searching at a new point within the entire string (which is what Perl
|
|
does), whereas the latter passes over a shortened subject. This makes a
|
|
difference to the matching process if the pattern begins with a lookbehind
|
|
assertion (including \b or \B).
|
|
</P>
|
|
<P>
|
|
If an empty string is matched, the next match is done with the
|
|
PCRE2_NOTEMPTY_ATSTART and PCRE2_ANCHORED flags set, in order to search for
|
|
another, non-empty, match at the same point in the subject. If this 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 characters occurs.
|
|
</P>
|
|
<br><b>
|
|
Testing substring extraction functions
|
|
</b><br>
|
|
<P>
|
|
The <b>copy</b> and <b>get</b> modifiers can be used to test the
|
|
<b>pcre2_substring_copy_xxx()</b> and <b>pcre2_substring_get_xxx()</b> functions.
|
|
They can be given more than once, and each can specify a capture group name or
|
|
number, for example:
|
|
<pre>
|
|
abcd\=copy=1,copy=3,get=G1
|
|
</pre>
|
|
If the <b>#subject</b> command is used to set default copy and/or get lists,
|
|
these can be unset by specifying a negative number to cancel all numbered
|
|
groups and an empty name to cancel all named groups.
|
|
</P>
|
|
<P>
|
|
The <b>getall</b> modifier tests <b>pcre2_substring_list_get()</b>, which
|
|
extracts all captured substrings.
|
|
</P>
|
|
<P>
|
|
If the subject line 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 substring, followed by the name when the extraction was
|
|
by name.
|
|
<a name="substitution"></a></P>
|
|
<br><b>
|
|
Testing the substitution function
|
|
</b><br>
|
|
<P>
|
|
If the <b>replace</b> modifier is set, the <b>pcre2_substitute()</b> function is
|
|
called instead of one of the matching functions (or after one call of
|
|
<b>pcre2_match()</b> in the case of PCRE2_SUBSTITUTE_MATCHED). Note that
|
|
replacement strings cannot contain commas, because a comma signifies the end of
|
|
a modifier. This is not thought to be an issue in a test program.
|
|
</P>
|
|
<P>
|
|
Unlike subject strings, <b>pcre2test</b> does not process replacement strings
|
|
for escape sequences. In UTF mode, a replacement string is checked to see if it
|
|
is a valid UTF-8 string. If so, it is correctly converted to a UTF string of
|
|
the appropriate code unit width. If it is not a valid UTF-8 string, the
|
|
individual code units are copied directly. This provides a means of passing an
|
|
invalid UTF-8 string for testing purposes.
|
|
</P>
|
|
<P>
|
|
The following modifiers set options (in additional to the normal match options)
|
|
for <b>pcre2_substitute()</b>:
|
|
<pre>
|
|
global PCRE2_SUBSTITUTE_GLOBAL
|
|
substitute_extended PCRE2_SUBSTITUTE_EXTENDED
|
|
substitute_literal PCRE2_SUBSTITUTE_LITERAL
|
|
substitute_matched PCRE2_SUBSTITUTE_MATCHED
|
|
substitute_overflow_length PCRE2_SUBSTITUTE_OVERFLOW_LENGTH
|
|
substitute_replacement_only PCRE2_SUBSTITUTE_REPLACEMENT_ONLY
|
|
substitute_unknown_unset PCRE2_SUBSTITUTE_UNKNOWN_UNSET
|
|
substitute_unset_empty PCRE2_SUBSTITUTE_UNSET_EMPTY
|
|
</pre>
|
|
See the
|
|
<a href="pcre2api.html"><b>pcre2api</b></a>
|
|
documentation for details of these options.
|
|
</P>
|
|
<P>
|
|
After a successful substitution, the modified string is output, preceded by the
|
|
number of replacements. This may be zero if there were no matches. Here is a
|
|
simple example of a substitution test:
|
|
<pre>
|
|
/abc/replace=xxx
|
|
=abc=abc=
|
|
1: =xxx=abc=
|
|
=abc=abc=\=global
|
|
2: =xxx=xxx=
|
|
</pre>
|
|
Subject and replacement strings should be kept relatively short (fewer than 256
|
|
characters) for substitution tests, as fixed-size buffers are used. To make it
|
|
easy to test for buffer overflow, if the replacement string starts with a
|
|
number in square brackets, that number is passed to <b>pcre2_substitute()</b> as
|
|
the size of the output buffer, with the replacement string starting at the next
|
|
character. Here is an example that tests the edge case:
|
|
<pre>
|
|
/abc/
|
|
123abc123\=replace=[10]XYZ
|
|
1: 123XYZ123
|
|
123abc123\=replace=[9]XYZ
|
|
Failed: error -47: no more memory
|
|
</pre>
|
|
The default action of <b>pcre2_substitute()</b> is to return
|
|
PCRE2_ERROR_NOMEMORY when the output buffer is too small. However, if the
|
|
PCRE2_SUBSTITUTE_OVERFLOW_LENGTH option is set (by using the
|
|
<b>substitute_overflow_length</b> modifier), <b>pcre2_substitute()</b> continues
|
|
to go through the motions of matching and substituting (but not doing any
|
|
callouts), in order to compute the size of buffer that is required. When this
|
|
happens, <b>pcre2test</b> shows the required buffer length (which includes space
|
|
for the trailing zero) as part of the error message. For example:
|
|
<pre>
|
|
/abc/substitute_overflow_length
|
|
123abc123\=replace=[9]XYZ
|
|
Failed: error -47: no more memory: 10 code units are needed
|
|
</pre>
|
|
A replacement string is ignored with POSIX and DFA matching. Specifying partial
|
|
matching provokes an error return ("bad option value") from
|
|
<b>pcre2_substitute()</b>.
|
|
</P>
|
|
<br><b>
|
|
Testing substitute callouts
|
|
</b><br>
|
|
<P>
|
|
If the <b>substitute_callout</b> modifier is set, a substitution callout
|
|
function is set up. The <b>null_context</b> modifier must not be set, because
|
|
the address of the callout function is passed in a match context. When the
|
|
callout function is called (after each substitution), details of the the input
|
|
and output strings are output. For example:
|
|
<pre>
|
|
/abc/g,replace=<$0>,substitute_callout
|
|
abcdefabcpqr
|
|
1(1) Old 0 3 "abc" New 0 5 "<abc>"
|
|
2(1) Old 6 9 "abc" New 8 13 "<abc>"
|
|
2: <abc>def<abc>pqr
|
|
</pre>
|
|
The first number on each callout line is the count of matches. The
|
|
parenthesized number is the number of pairs that are set in the ovector (that
|
|
is, one more than the number of capturing groups that were set). Then are
|
|
listed the offsets of the old substring, its contents, and the same for the
|
|
replacement.
|
|
</P>
|
|
<P>
|
|
By default, the substitution callout function returns zero, which accepts the
|
|
replacement and causes matching to continue if /g was used. Two further
|
|
modifiers can be used to test other return values. If <b>substitute_skip</b> is
|
|
set to a value greater than zero the callout function returns +1 for the match
|
|
of that number, and similarly <b>substitute_stop</b> returns -1. These cause the
|
|
replacement to be rejected, and -1 causes no further matching to take place. If
|
|
either of them are set, <b>substitute_callout</b> is assumed. For example:
|
|
<pre>
|
|
/abc/g,replace=<$0>,substitute_skip=1
|
|
abcdefabcpqr
|
|
1(1) Old 0 3 "abc" New 0 5 "<abc> SKIPPED"
|
|
2(1) Old 6 9 "abc" New 6 11 "<abc>"
|
|
2: abcdef<abc>pqr
|
|
abcdefabcpqr\=substitute_stop=1
|
|
1(1) Old 0 3 "abc" New 0 5 "<abc> STOPPED"
|
|
1: abcdefabcpqr
|
|
</pre>
|
|
If both are set for the same number, stop takes precedence. Only a single skip
|
|
or stop is supported, which is sufficient for testing that the feature works.
|
|
</P>
|
|
<br><b>
|
|
Setting the JIT stack size
|
|
</b><br>
|
|
<P>
|
|
The <b>jitstack</b> modifier 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. The value is a number of kibibytes (units of
|
|
1024 bytes). Setting zero reverts to the default of 32KiB. Providing a stack
|
|
that is larger than the default is necessary only for very complicated
|
|
patterns. If <b>jitstack</b> is set non-zero on a subject line it overrides any
|
|
value that was set on the pattern.
|
|
</P>
|
|
<br><b>
|
|
Setting heap, match, and depth limits
|
|
</b><br>
|
|
<P>
|
|
The <b>heap_limit</b>, <b>match_limit</b>, and <b>depth_limit</b> modifiers set
|
|
the appropriate limits in the match context. These values are ignored when the
|
|
<b>find_limits</b> modifier is specified.
|
|
</P>
|
|
<br><b>
|
|
Finding minimum limits
|
|
</b><br>
|
|
<P>
|
|
If the <b>find_limits</b> modifier is present on a subject line, <b>pcre2test</b>
|
|
calls the relevant matching function several times, setting different values in
|
|
the match context via <b>pcre2_set_heap_limit()</b>,
|
|
<b>pcre2_set_match_limit()</b>, or <b>pcre2_set_depth_limit()</b> until it finds
|
|
the minimum values for each parameter that allows the match to complete without
|
|
error. If JIT is being used, only the match limit is relevant.
|
|
</P>
|
|
<P>
|
|
When using this modifier, the pattern should not contain any limit settings
|
|
such as (*LIMIT_MATCH=...) within it. If such a setting is present and is
|
|
lower than the minimum matching value, the minimum value cannot be found
|
|
because <b>pcre2_set_match_limit()</b> etc. are only able to reduce the value of
|
|
an in-pattern limit; they cannot increase it.
|
|
</P>
|
|
<P>
|
|
For non-DFA matching, the minimum <i>depth_limit</i> number is a measure of how
|
|
much nested backtracking happens (that is, how deeply the pattern's tree is
|
|
searched). In the case of DFA matching, <i>depth_limit</i> controls the depth of
|
|
recursive calls of the internal function that is used for handling pattern
|
|
recursion, lookaround assertions, and atomic groups.
|
|
</P>
|
|
<P>
|
|
For non-DFA matching, the <i>match_limit</i> number is a measure of the amount
|
|
of backtracking that takes place, and learning the minimum value 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. In the case of DFA
|
|
matching, <i>match_limit</i> controls the total number of calls, both recursive
|
|
and non-recursive, to the internal matching function, thus controlling the
|
|
overall amount of computing resource that is used.
|
|
</P>
|
|
<P>
|
|
For both kinds of matching, the <i>heap_limit</i> number, which is in kibibytes
|
|
(units of 1024 bytes), limits the amount of heap memory used for matching. A
|
|
value of zero disables the use of any heap memory; many simple pattern matches
|
|
can be done without using the heap, so zero is not an unreasonable setting.
|
|
</P>
|
|
<br><b>
|
|
Showing MARK names
|
|
</b><br>
|
|
<P>
|
|
The <b>mark</b> modifier causes the names from backtracking control verbs that
|
|
are returned from calls to <b>pcre2_match()</b> to be displayed. If a mark is
|
|
returned for a match, non-match, or partial match, <b>pcre2test</b> shows it.
|
|
For a match, it is on a line by itself, tagged with "MK:". Otherwise, it
|
|
is added to the non-match message.
|
|
</P>
|
|
<br><b>
|
|
Showing memory usage
|
|
</b><br>
|
|
<P>
|
|
The <b>memory</b> modifier causes <b>pcre2test</b> to log the sizes of all heap
|
|
memory allocation and freeing calls that occur during a call to
|
|
<b>pcre2_match()</b> or <b>pcre2_dfa_match()</b>. These occur only when a match
|
|
requires a bigger vector than the default for remembering backtracking points
|
|
(<b>pcre2_match()</b>) or for internal workspace (<b>pcre2_dfa_match()</b>). In
|
|
many cases there will be no heap memory used and therefore no additional
|
|
output. No heap memory is allocated during matching with JIT, so in that case
|
|
the <b>memory</b> modifier never has any effect. For this modifier to work, the
|
|
<b>null_context</b> modifier must not be set on both the pattern and the
|
|
subject, though it can be set on one or the other.
|
|
</P>
|
|
<br><b>
|
|
Setting a starting offset
|
|
</b><br>
|
|
<P>
|
|
The <b>offset</b> modifier sets an offset in the subject string at which
|
|
matching starts. Its value is a number of code units, not characters.
|
|
</P>
|
|
<br><b>
|
|
Setting an offset limit
|
|
</b><br>
|
|
<P>
|
|
The <b>offset_limit</b> modifier sets a limit for unanchored matches. If a match
|
|
cannot be found starting at or before this offset in the subject, a "no match"
|
|
return is given. The data value is a number of code units, not characters. When
|
|
this modifier is used, the <b>use_offset_limit</b> modifier must have been set
|
|
for the pattern; if not, an error is generated.
|
|
</P>
|
|
<br><b>
|
|
Setting the size of the output vector
|
|
</b><br>
|
|
<P>
|
|
The <b>ovector</b> modifier applies only to the subject line in which it
|
|
appears, though of course it can also be used to set a default in a
|
|
<b>#subject</b> command. It specifies the number of pairs of offsets that are
|
|
available for storing matching information. The default is 15.
|
|
</P>
|
|
<P>
|
|
A value of zero is useful when testing the POSIX API because it causes
|
|
<b>regexec()</b> to be called with a NULL capture vector. When not testing the
|
|
POSIX API, a value of zero is used to cause
|
|
<b>pcre2_match_data_create_from_pattern()</b> to be called, in order to create a
|
|
match block of exactly the right size for the pattern. (It is not possible to
|
|
create a match block with a zero-length ovector; there is always at least one
|
|
pair of offsets.)
|
|
</P>
|
|
<br><b>
|
|
Passing the subject as zero-terminated
|
|
</b><br>
|
|
<P>
|
|
By default, the subject string is passed to a native API matching function with
|
|
its correct length. In order to test the facility for passing a zero-terminated
|
|
string, the <b>zero_terminate</b> modifier is provided. It causes the length to
|
|
be passed as PCRE2_ZERO_TERMINATED. When matching via the POSIX interface,
|
|
this modifier is ignored, with a warning.
|
|
</P>
|
|
<P>
|
|
When testing <b>pcre2_substitute()</b>, this modifier also has the effect of
|
|
passing the replacement string as zero-terminated.
|
|
</P>
|
|
<br><b>
|
|
Passing a NULL context
|
|
</b><br>
|
|
<P>
|
|
Normally, <b>pcre2test</b> passes a context block to <b>pcre2_match()</b>,
|
|
<b>pcre2_dfa_match()</b>, <b>pcre2_jit_match()</b> or <b>pcre2_substitute()</b>.
|
|
If the <b>null_context</b> modifier is set, however, NULL is passed. This is for
|
|
testing that the matching and substitution functions behave correctly in this
|
|
case (they use default values). This modifier cannot be used with the
|
|
<b>find_limits</b> or <b>substitute_callout</b> modifiers.
|
|
</P>
|
|
<br><a name="SEC12" href="#TOC1">THE ALTERNATIVE MATCHING FUNCTION</a><br>
|
|
<P>
|
|
By default, <b>pcre2test</b> uses the standard PCRE2 matching function,
|
|
<b>pcre2_match()</b> to match each subject line. PCRE2 also supports an
|
|
alternative matching function, <b>pcre2_dfa_match()</b>, which operates in a
|
|
different way, and has some restrictions. The differences between the two
|
|
functions are described in the
|
|
<a href="pcre2matching.html"><b>pcre2matching</b></a>
|
|
documentation.
|
|
</P>
|
|
<P>
|
|
If the <b>dfa</b> modifier is set, the alternative matching function is used.
|
|
This function finds all possible matches at a given point in the subject. If,
|
|
however, the <b>dfa_shortest</b> modifier is set, processing stops after the
|
|
first match is found. This is always the shortest possible match.
|
|
</P>
|
|
<br><a name="SEC13" href="#TOC1">DEFAULT OUTPUT FROM pcre2test</a><br>
|
|
<P>
|
|
This section describes the output when the normal matching function,
|
|
<b>pcre2_match()</b>, is being used.
|
|
</P>
|
|
<P>
|
|
When a match succeeds, <b>pcre2test</b> outputs the list of captured substrings,
|
|
starting with number 0 for the string that matched the whole pattern.
|
|
Otherwise, it outputs "No match" when the return is PCRE2_ERROR_NOMATCH, or
|
|
"Partial match:" followed by the partially matching substring when the
|
|
return is PCRE2_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.)
|
|
</P>
|
|
<P>
|
|
For any other return, <b>pcre2test</b> outputs the PCRE2 negative error number
|
|
and a short descriptive phrase. If the error is a failed UTF string check, the
|
|
code unit offset of the start of the failing character is also output. Here is
|
|
an example of an interactive <b>pcre2test</b> run.
|
|
<pre>
|
|
$ pcre2test
|
|
PCRE2 version 10.22 2016-07-29
|
|
|
|
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
|
|
shown by <b>pcre2test</b> unless the <b>allcaptures</b> modifier is specified. 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 <b>aftertext</b> modifier is set, the output for substring
|
|
0 is followed by the the rest of the subject string, identified by "0+" like
|
|
this:
|
|
<pre>
|
|
re> /cat/aftertext
|
|
data> cataract
|
|
0: cat
|
|
0+ aract
|
|
</pre>
|
|
If global matching is requested, 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 the <b>offset</b>
|
|
modifier is past the end of the subject string):
|
|
<pre>
|
|
re> /xyz/
|
|
data> xyz\=offset=4
|
|
Error -24 (bad offset value)
|
|
</PRE>
|
|
</P>
|
|
<P>
|
|
Note that whereas patterns can be continued over several lines (a plain ">"
|
|
prompt is used for continuations), subject lines may not. However newlines can
|
|
be included in a subject by means of the \n escape (or \r, \r\n, etc.,
|
|
depending on the newline sequence setting).
|
|
</P>
|
|
<br><a name="SEC14" href="#TOC1">OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION</a><br>
|
|
<P>
|
|
When the alternative matching function, <b>pcre2_dfa_match()</b>, is used, 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\=dfa
|
|
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
|
|
PCRE2_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, \b, or \B was involved. (\K is not
|
|
supported for DFA matching.)
|
|
</P>
|
|
<P>
|
|
If global matching is requested, 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\=dfa
|
|
0: tangerine
|
|
1: tang
|
|
2: tan
|
|
0: tang
|
|
1: tan
|
|
0: tan
|
|
</pre>
|
|
The alternative matching function does not support substring capture, so the
|
|
modifiers that are concerned with captured substrings are not relevant.
|
|
</P>
|
|
<br><a name="SEC15" href="#TOC1">RESTARTING AFTER A PARTIAL MATCH</a><br>
|
|
<P>
|
|
When the alternative matching function has given the PCRE2_ERROR_PARTIAL
|
|
return, indicating that the subject partially matched the pattern, you can
|
|
restart the match with additional subject data by means of the
|
|
<b>dfa_restart</b> modifier. For example:
|
|
<pre>
|
|
re> /^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$/
|
|
data> 23ja\=ps,dfa
|
|
Partial match: 23ja
|
|
data> n05\=dfa,dfa_restart
|
|
0: n05
|
|
</pre>
|
|
For further information about partial matching, see the
|
|
<a href="pcre2partial.html"><b>pcre2partial</b></a>
|
|
documentation.
|
|
<a name="callouts"></a></P>
|
|
<br><a name="SEC16" href="#TOC1">CALLOUTS</a><br>
|
|
<P>
|
|
If the pattern contains any callout requests, <b>pcre2test</b>'s callout
|
|
function is called during matching unless <b>callout_none</b> is specified. This
|
|
works with both matching functions, and with JIT, though there are some
|
|
differences in behaviour. The output for callouts with numerical arguments and
|
|
those with string arguments is slightly different.
|
|
</P>
|
|
<br><b>
|
|
Callouts with numerical arguments
|
|
</b><br>
|
|
<P>
|
|
By default, the callout function displays the callout number, the start and
|
|
current positions in the subject 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, and when the next pattern item was \d. Just
|
|
one circumflex is output if the start and current positions are the same, or if
|
|
the current position precedes the start position, which can happen if the
|
|
callout is in a lookbehind assertion.
|
|
</P>
|
|
<P>
|
|
Callouts numbered 255 are assumed to be automatic callouts, inserted as a
|
|
result of the <b>auto_callout</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]\*/auto_callout
|
|
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/auto_callout
|
|
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>
|
|
<br><b>
|
|
Callouts with string arguments
|
|
</b><br>
|
|
<P>
|
|
The output for a callout with a string argument is similar, except that instead
|
|
of outputting a callout number before the position indicators, the callout
|
|
string and its offset in the pattern string are output before the reflection of
|
|
the subject string, and the subject string is reflected for each callout. For
|
|
example:
|
|
<pre>
|
|
re> /^ab(?C'first')cd(?C"second")ef/
|
|
data> abcdefg
|
|
Callout (7): 'first'
|
|
--->abcdefg
|
|
^ ^ c
|
|
Callout (20): "second"
|
|
--->abcdefg
|
|
^ ^ e
|
|
0: abcdef
|
|
|
|
</PRE>
|
|
</P>
|
|
<br><b>
|
|
Callout modifiers
|
|
</b><br>
|
|
<P>
|
|
The callout function in <b>pcre2test</b> returns zero (carry on matching) by
|
|
default, but you can use a <b>callout_fail</b> modifier in a subject line to
|
|
change this and other parameters of the callout (see below).
|
|
</P>
|
|
<P>
|
|
If the <b>callout_capture</b> modifier is set, the current captured groups are
|
|
output when a callout occurs. This is useful only for non-DFA matching, as
|
|
<b>pcre2_dfa_match()</b> does not support capturing, so no captures are ever
|
|
shown.
|
|
</P>
|
|
<P>
|
|
The normal callout output, showing the callout number or pattern offset (as
|
|
described above) is suppressed if the <b>callout_no_where</b> modifier is set.
|
|
</P>
|
|
<P>
|
|
When using the interpretive matching function <b>pcre2_match()</b> without JIT,
|
|
setting the <b>callout_extra</b> modifier causes additional output from
|
|
<b>pcre2test</b>'s callout function to be generated. For the first callout in a
|
|
match attempt at a new starting position in the subject, "New match attempt" is
|
|
output. If there has been a backtrack since the last callout (or start of
|
|
matching if this is the first callout), "Backtrack" is output, followed by "No
|
|
other matching paths" if the backtrack ended the previous match attempt. For
|
|
example:
|
|
<pre>
|
|
re> /(a+)b/auto_callout,no_start_optimize,no_auto_possess
|
|
data> aac\=callout_extra
|
|
New match attempt
|
|
--->aac
|
|
+0 ^ (
|
|
+1 ^ a+
|
|
+3 ^ ^ )
|
|
+4 ^ ^ b
|
|
Backtrack
|
|
--->aac
|
|
+3 ^^ )
|
|
+4 ^^ b
|
|
Backtrack
|
|
No other matching paths
|
|
New match attempt
|
|
--->aac
|
|
+0 ^ (
|
|
+1 ^ a+
|
|
+3 ^^ )
|
|
+4 ^^ b
|
|
Backtrack
|
|
No other matching paths
|
|
New match attempt
|
|
--->aac
|
|
+0 ^ (
|
|
+1 ^ a+
|
|
Backtrack
|
|
No other matching paths
|
|
New match attempt
|
|
--->aac
|
|
+0 ^ (
|
|
+1 ^ a+
|
|
No match
|
|
</pre>
|
|
Notice that various optimizations must be turned off if you want all possible
|
|
matching paths to be scanned. If <b>no_start_optimize</b> is not used, there is
|
|
an immediate "no match", without any callouts, because the starting
|
|
optimization fails to find "b" in the subject, which it knows must be present
|
|
for any match. If <b>no_auto_possess</b> is not used, the "a+" item is turned
|
|
into "a++", which reduces the number of backtracks.
|
|
</P>
|
|
<P>
|
|
The <b>callout_extra</b> modifier has no effect if used with the DFA matching
|
|
function, or with JIT.
|
|
</P>
|
|
<br><b>
|
|
Return values from callouts
|
|
</b><br>
|
|
<P>
|
|
The default return from the callout function is zero, which allows matching to
|
|
continue. The <b>callout_fail</b> modifier can be given one or two numbers. If
|
|
there is only one number, 1 is returned instead of 0 (causing matching to
|
|
backtrack) when a callout of that number is reached. If two numbers (<n>:<m>)
|
|
are given, 1 is returned when callout <n> is reached and there have been at
|
|
least <m> callouts. The <b>callout_error</b> modifier is similar, except that
|
|
PCRE2_ERROR_CALLOUT is returned, causing the entire matching process to be
|
|
aborted. If both these modifiers are set for the same callout number,
|
|
<b>callout_error</b> takes precedence. Note that callouts with string arguments
|
|
are always given the number zero.
|
|
</P>
|
|
<P>
|
|
The <b>callout_data</b> modifier can be given an unsigned or a negative number.
|
|
This is set as the "user data" that is passed to the matching function, and
|
|
passed back when the callout function is invoked. Any value other than zero is
|
|
used as a return from <b>pcre2test</b>'s callout function.
|
|
</P>
|
|
<P>
|
|
Inserting callouts can be helpful when using <b>pcre2test</b> to check
|
|
complicated regular expressions. For further information about callouts, see
|
|
the
|
|
<a href="pcre2callout.html"><b>pcre2callout</b></a>
|
|
documentation.
|
|
</P>
|
|
<br><a name="SEC17" href="#TOC1">NON-PRINTING CHARACTERS</a><br>
|
|
<P>
|
|
When <b>pcre2test</b> is outputting text in the compiled version of a pattern,
|
|
bytes other than 32-126 are always treated as non-printing characters and are
|
|
therefore shown as hex escapes.
|
|
</P>
|
|
<P>
|
|
When <b>pcre2test</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>locale</b> modifier). In this case, the
|
|
<b>isprint()</b> function is used to distinguish printing and non-printing
|
|
characters.
|
|
<a name="saverestore"></a></P>
|
|
<br><a name="SEC18" href="#TOC1">SAVING AND RESTORING COMPILED PATTERNS</a><br>
|
|
<P>
|
|
It is possible to save compiled patterns on disc or elsewhere, and reload them
|
|
later, subject to a number of restrictions. JIT data cannot be saved. The host
|
|
on which the patterns are reloaded must be running the same version of PCRE2,
|
|
with the same code unit width, and must also have the same endianness, pointer
|
|
width and PCRE2_SIZE type. Before compiled patterns can be saved they must be
|
|
serialized, that is, converted to a stream of bytes. A single byte stream may
|
|
contain any number of compiled patterns, but they must all use the same
|
|
character tables. A single copy of the tables is included in the byte stream
|
|
(its size is 1088 bytes).
|
|
</P>
|
|
<P>
|
|
The functions whose names begin with <b>pcre2_serialize_</b> are used
|
|
for serializing and de-serializing. They are described in the
|
|
<a href="pcre2serialize.html"><b>pcre2serialize</b></a>
|
|
documentation. In this section we describe the features of <b>pcre2test</b> that
|
|
can be used to test these functions.
|
|
</P>
|
|
<P>
|
|
Note that "serialization" in PCRE2 does not convert compiled patterns to an
|
|
abstract format like Java or .NET. It just makes a reloadable byte code stream.
|
|
Hence the restrictions on reloading mentioned above.
|
|
</P>
|
|
<P>
|
|
In <b>pcre2test</b>, when a pattern with <b>push</b> modifier is successfully
|
|
compiled, it is pushed onto a stack of compiled patterns, and <b>pcre2test</b>
|
|
expects the next line to contain a new pattern (or command) instead of a
|
|
subject line. By contrast, the <b>pushcopy</b> modifier causes a copy of the
|
|
compiled pattern to be stacked, leaving the original available for immediate
|
|
matching. By using <b>push</b> and/or <b>pushcopy</b>, a number of patterns can
|
|
be compiled and retained. These modifiers are incompatible with <b>posix</b>,
|
|
and control modifiers that act at match time are ignored (with a message) for
|
|
the stacked patterns. The <b>jitverify</b> modifier applies only at compile
|
|
time.
|
|
</P>
|
|
<P>
|
|
The command
|
|
<pre>
|
|
#save <filename>
|
|
</pre>
|
|
causes all the stacked patterns to be serialized and the result written to the
|
|
named file. Afterwards, all the stacked patterns are freed. The command
|
|
<pre>
|
|
#load <filename>
|
|
</pre>
|
|
reads the data in the file, and then arranges for it to be de-serialized, with
|
|
the resulting compiled patterns added to the pattern stack. The pattern on the
|
|
top of the stack can be retrieved by the #pop command, which must be followed
|
|
by lines of subjects that are to be matched with the pattern, terminated as
|
|
usual by an empty line or end of file. This command may be followed by a
|
|
modifier list containing only
|
|
<a href="#controlmodifiers">control modifiers</a>
|
|
that act after a pattern has been compiled. In particular, <b>hex</b>,
|
|
<b>posix</b>, <b>posix_nosub</b>, <b>push</b>, and <b>pushcopy</b> are not allowed,
|
|
nor are any
|
|
<a href="#optionmodifiers">option-setting modifiers.</a>
|
|
The JIT modifiers are, however permitted. Here is an example that saves and
|
|
reloads two patterns.
|
|
<pre>
|
|
/abc/push
|
|
/xyz/push
|
|
#save tempfile
|
|
#load tempfile
|
|
#pop info
|
|
xyz
|
|
|
|
#pop jit,bincode
|
|
abc
|
|
</pre>
|
|
If <b>jitverify</b> is used with #pop, it does not automatically imply
|
|
<b>jit</b>, which is different behaviour from when it is used on a pattern.
|
|
</P>
|
|
<P>
|
|
The #popcopy command is analagous to the <b>pushcopy</b> modifier in that it
|
|
makes current a copy of the topmost stack pattern, leaving the original still
|
|
on the stack.
|
|
</P>
|
|
<br><a name="SEC19" href="#TOC1">SEE ALSO</a><br>
|
|
<P>
|
|
<b>pcre2</b>(3), <b>pcre2api</b>(3), <b>pcre2callout</b>(3),
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<b>pcre2jit</b>, <b>pcre2matching</b>(3), <b>pcre2partial</b>(d),
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<b>pcre2pattern</b>(3), <b>pcre2serialize</b>(3).
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</P>
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<br><a name="SEC20" href="#TOC1">AUTHOR</a><br>
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<P>
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Philip Hazel
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<br>
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University Computing Service
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<br>
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Cambridge, England.
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<br>
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</P>
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<br><a name="SEC21" href="#TOC1">REVISION</a><br>
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<P>
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Last updated: 20 March 2020
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<br>
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Copyright © 1997-2020 University of Cambridge.
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<br>
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<p>
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Return to the <a href="index.html">PCRE2 index page</a>.
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</p>
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