1986 lines
81 KiB
Groff
1986 lines
81 KiB
Groff
.TH PCRE2TEST 1 "27 June 2018" "PCRE 10.32"
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.SH NAME
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pcre2test - a program for testing Perl-compatible regular expressions.
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.SH SYNOPSIS
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.rs
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.sp
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.B pcre2test "[options] [input file [output file]]"
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.sp
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\fBpcre2test\fP 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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.\" HREF
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\fBpcre2pattern\fP
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.\"
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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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.\" HREF
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\fBpcre2api\fP
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.\"
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documentation.
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.P
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The input for \fBpcre2test\fP 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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As the original fairly simple PCRE library evolved, it acquired many different
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features, and as a result, the original \fBpcretest\fP 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 \fBpcre2test\fP, 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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.
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.
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.SH "PCRE2's 8-BIT, 16-BIT AND 32-BIT LIBRARIES"
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.rs
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.sp
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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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\fBpcre2test\fP 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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In the rest of this document, the names of library functions and structures
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are given in generic form, for example, \fBpcre_compile()\fP. The actual
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names used in the libraries have a suffix _8, _16, or _32, as appropriate.
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.
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.
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.\" HTML <a name="inputencoding"></a>
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.SH "INPUT ENCODING"
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.rs
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.sp
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Input to \fBpcre2test\fP is processed line by line, either by calling the C
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library's \fBfgets()\fP function, or via the \fBlibreadline\fP 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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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, \fBfgets()\fP
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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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.
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.
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.SS "Input for the 16-bit and 32-bit libraries"
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.rs
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.sp
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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 \fButf\fP modifier (see
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.\" HTML <a href="#optionmodifiers">
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.\" </a>
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"Setting compilation options"
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.\"
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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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For non-UTF testing of wide characters, the \fButf8_input\fP modifier can be
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used. This is mutually exclusive with \fButf\fP, 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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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 \fButf8_input\fP 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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.
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.
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.SH "COMMAND LINE OPTIONS"
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.rs
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.TP 10
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\fB-8\fP
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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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.TP 10
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\fB-16\fP
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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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.TP 10
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\fB-32\fP
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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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.TP 10
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\fB-ac\fP
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Behave as if each pattern has the \fBauto_callout\fP modifier, that is, insert
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automatic callouts into every pattern that is compiled.
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.TP 10
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\fB-AC\fP
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As for \fB-ac\fP, but in addition behave as if each subject line has the
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\fBcallout_extra\fP modifier, that is, show additional information from
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callouts.
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.TP 10
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\fB-b\fP
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Behave as if each pattern has the \fBfullbincode\fP modifier; the full
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internal binary form of the pattern is output after compilation.
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.TP 10
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\fB-C\fP
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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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.TP 10
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\fB-C\fP \fIoption\fP
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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 \fBRunTest\fP. The
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following options output the value and set the exit code as indicated:
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.sp
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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 \eR matches:
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ANYCRLF or ANY
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exit code is always 0
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.sp
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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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.sp
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backslash-C \eC 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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.sp
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If an unknown option is given, an error message is output; the exit code is 0.
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.TP 10
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\fB-d\fP
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Behave as if each pattern has the \fBdebug\fP modifier; the internal
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form and information about the compiled pattern is output after compilation;
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\fB-d\fP is equivalent to \fB-b -i\fP.
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.TP 10
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\fB-dfa\fP
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Behave as if each subject line has the \fBdfa\fP modifier; matching is done
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using the \fBpcre2_dfa_match()\fP function instead of the default
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\fBpcre2_match()\fP.
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.TP 10
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\fB-error\fP \fInumber[,number,...]\fP
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Call \fBpcre2_get_error_message()\fP 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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.TP 10
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\fB-help\fP
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Output a brief summary these options and then exit.
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.TP 10
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\fB-i\fP
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Behave as if each pattern has the \fBinfo\fP modifier; information about the
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compiled pattern is given after compilation.
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.TP 10
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\fB-jit\fP
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Behave as if each pattern line has the \fBjit\fP modifier; after successful
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compilation, each pattern is passed to the just-in-time compiler, if available.
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.TP 10
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\fB-jitverify\fP
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Behave as if each pattern line has the \fBjitverify\fP 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 is verified.
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.TP 10
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\fB-LM\fP
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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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.TP 10
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\fB-pattern\fB \fImodifier-list\fP
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Behave as if each pattern line contains the given modifiers.
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.TP 10
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\fB-q\fP
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Do not output the version number of \fBpcre2test\fP at the start of execution.
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.TP 10
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\fB-S\fP \fIsize\fP
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On Unix-like systems, set the size of the run-time stack to \fIsize\fP
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mebibytes (units of 1024*1024 bytes).
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.TP 10
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\fB-subject\fP \fImodifier-list\fP
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Behave as if each subject line contains the given modifiers.
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.TP 10
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\fB-t\fP
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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 \fB-t\fP 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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.TP 10
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\fB-tm\fP
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This is like \fB-t\fP except that it times only the matching phase, not the
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compile phase.
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.TP 10
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\fB-T\fP \fB-TM\fP
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These behave like \fB-t\fP and \fB-tm\fP, 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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.TP 10
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\fB-version\fP
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Output the PCRE2 version number and then exit.
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.
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.
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.SH "DESCRIPTION"
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.rs
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.sp
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If \fBpcre2test\fP 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 \fBpcre2test\fP 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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When \fBpcre2test\fP is built, a configuration option can specify that it
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should be linked with the \fBlibreadline\fP or \fBlibedit\fP library. When this
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is done, if the input is from a terminal, it is read using the \fBreadline()\fP
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function. This provides line-editing and history facilities. The output from
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the \fB-help\fP option states whether or not \fBreadline()\fP will be used.
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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 \fBperltest.sh\fP 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.
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.P
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When the input is a terminal, \fBpcre2test\fP 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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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 \en escape sequence (or \er or \er\en,
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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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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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.
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.
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.SH "COMMAND LINES"
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.rs
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.sp
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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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.sp
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#forbid_utf
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.sp
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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 \eP, \ep, or \eX,
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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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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 \fB#pattern\fP;
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the difference is that \fB#forbid_utf\fP 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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.sp
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#load <filename>
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.sp
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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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.\" HTML <a href="#saverestore">
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.\" </a>
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below.
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.\"
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.sp
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#newline_default [<newline-list>]
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.sp
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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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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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.sp
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#newline_default LF Any anyCRLF
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.sp
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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 \fBnewline\fP modifier that specifies the
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first newline convention in the list (LF in the above example) is added to any
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pattern that does not already have a \fBnewline\fP modifier. If the newline
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list is empty, the feature is turned off. This command is present in a number
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of the standard test input files.
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.P
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When the POSIX API is being tested there is no way to override the default
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newline convention, though it is possible to set the newline convention from
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within the pattern. A warning is given if the \fBposix\fP or \fBposix_nosub\fP
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modifier is used when \fB#newline_default\fP would set a default for the
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non-POSIX API.
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.sp
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#pattern <modifier-list>
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.sp
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This command sets a default modifier list that applies to all subsequent
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patterns. Modifiers on a pattern can change these settings.
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.sp
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#perltest
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.sp
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The appearance of this line causes all subsequent modifier settings to be
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checked for compatibility with the \fBperltest.sh\fP script, which is used to
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confirm that Perl gives the same results as PCRE2. Also, apart from comment
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lines, none of the other command lines are permitted, because they and many
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of the modifiers are specific to \fBpcre2test\fP, and should not be used in
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test files that are also processed by \fBperltest.sh\fP. The \fB#perltest\fP
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command helps detect tests that are accidentally put in the wrong file.
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.sp
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#pop [<modifiers>]
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#popcopy [<modifiers>]
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.sp
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These commands are used to manipulate the stack of compiled patterns, as
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described in the section entitled "Saving and restoring compiled patterns"
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.\" HTML <a href="#saverestore">
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.\" </a>
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below.
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.\"
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.sp
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#save <filename>
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.sp
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This command is used to save a set of compiled patterns to a file, as described
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in the section entitled "Saving and restoring compiled patterns"
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.\" HTML <a href="#saverestore">
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.\" </a>
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below.
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.\"
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.sp
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#subject <modifier-list>
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.sp
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This command sets a default modifier list that applies to all subsequent
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subject lines. Modifiers on a subject line can change these settings.
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.
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.
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.SH "MODIFIER SYNTAX"
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.rs
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.sp
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Modifier lists are used with both pattern and subject lines. Items in a list
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are separated by commas followed by optional white space. Trailing whitespace
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in a modifier list is ignored. Some modifiers may be given for both patterns
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and subject lines, whereas others are valid only for one or the other. Each
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modifier has a long name, for example "anchored", and some of them must be
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followed by an equals sign and a value, for example, "offset=12". Values cannot
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contain comma characters, but may contain spaces. Modifiers that do not take
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values may be preceded by a minus sign to turn off a previous setting.
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.P
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A few of the more common modifiers can also be specified as single letters, for
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example "i" for "caseless". In documentation, following the Perl convention,
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these are written with a slash ("the /i modifier") for clarity. Abbreviated
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modifiers must all be concatenated in the first item of a modifier list. If the
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first item is not recognized as a long modifier name, it is interpreted as a
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sequence of these abbreviations. For example:
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.sp
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/abc/ig,newline=cr,jit=3
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.sp
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This is a pattern line whose modifier list starts with two one-letter modifiers
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(/i and /g). The lower-case abbreviated modifiers are the same as used in Perl.
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.
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.
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.SH "PATTERN SYNTAX"
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.rs
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.sp
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A pattern line must start with one of the following characters (common symbols,
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excluding pattern meta-characters):
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.sp
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/ ! " ' ` - = _ : ; , % & @ ~
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.sp
|
|
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
|
|
.sp
|
|
/abc\e/def/
|
|
.sp
|
|
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,
|
|
.sp
|
|
/abc/\e
|
|
.sp
|
|
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
|
|
.sp
|
|
/abc\e/
|
|
.sp
|
|
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
|
|
A pattern can be followed by a modifier list (details below).
|
|
.
|
|
.
|
|
.SH "SUBJECT LINE SYNTAX"
|
|
.rs
|
|
.sp
|
|
Before each subject line is passed to \fBpcre2_match()\fP or
|
|
\fBpcre2_dfa_match()\fP, leading and trailing white space is removed, and the
|
|
line is scanned for backslash escapes, unless the \fBsubject_literal\fP
|
|
modifier was set for the pattern. The following provide a means of encoding
|
|
non-printing characters in a visible way:
|
|
.sp
|
|
\ea alarm (BEL, \ex07)
|
|
\eb backspace (\ex08)
|
|
\ee escape (\ex27)
|
|
\ef form feed (\ex0c)
|
|
\en newline (\ex0a)
|
|
\er carriage return (\ex0d)
|
|
\et tab (\ex09)
|
|
\ev vertical tab (\ex0b)
|
|
\ennn octal character (up to 3 octal digits); always
|
|
a byte unless > 255 in UTF-8 or 16-bit or 32-bit mode
|
|
\eo{dd...} octal character (any number of octal digits}
|
|
\exhh hexadecimal byte (up to 2 hex digits)
|
|
\ex{hh...} hexadecimal character (any number of hex digits)
|
|
.sp
|
|
The use of \ex{hh...} is not dependent on the use of the \fButf\fP 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
|
|
Note that \exhh 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, \ex{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, \ex{hh} generates one byte
|
|
for values less than 256, and causes an error for greater values.
|
|
.P
|
|
In UTF-16 mode, all 4-digit \ex{hhhh} values are accepted. This makes it
|
|
possible to construct invalid UTF-16 sequences for testing purposes.
|
|
.P
|
|
In UTF-32 mode, all 4- to 8-digit \ex{...} values are accepted. This makes it
|
|
possible to construct invalid UTF-32 sequences for testing purposes.
|
|
.P
|
|
There is a special backslash sequence that specifies replication of one or more
|
|
characters:
|
|
.sp
|
|
\e[<characters>]{<count>}
|
|
.sp
|
|
This makes it possible to test long strings without having to provide them as
|
|
part of the file. For example:
|
|
.sp
|
|
\e[abc]{4}
|
|
.sp
|
|
is converted to "abcabcabcabc". This feature does not support nesting. To
|
|
include a closing square bracket in the characters, code it as \ex5D.
|
|
.P
|
|
A backslash followed by an equals sign marks the end of the subject string and
|
|
the start of a modifier list. For example:
|
|
.sp
|
|
abc\e=notbol,notempty
|
|
.sp
|
|
If the subject string is empty and \e= is followed by whitespace, the line is
|
|
treated as a comment line, and is not used for matching. For example:
|
|
.sp
|
|
\e= This is a comment.
|
|
abc\e= This is an invalid modifier list.
|
|
.sp
|
|
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
|
|
If the \fBsubject_literal\fP 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 \fB#subject\fP command.
|
|
.
|
|
.
|
|
.SH "PATTERN MODIFIERS"
|
|
.rs
|
|
.sp
|
|
There are several types of modifier that can appear in pattern lines. Except
|
|
where noted below, they may also be used in \fB#pattern\fP commands. A
|
|
pattern's modifier list can add to or override default modifiers that were set
|
|
by a previous \fB#pattern\fP command.
|
|
.
|
|
.
|
|
.\" HTML <a name="optionmodifiers"></a>
|
|
.SS "Setting compilation options"
|
|
.rs
|
|
.sp
|
|
The following modifiers set options for \fBpcre2_compile()\fP. 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 \fBpcre2_compile()\fP behaves. See
|
|
.\" HREF
|
|
\fBpcre2api\fP
|
|
.\"
|
|
for a description of the effects of these options.
|
|
.sp
|
|
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
|
|
/x extended set PCRE2_EXTENDED
|
|
/xx extended_more set PCRE2_EXTENDED_MORE
|
|
firstline set PCRE2_FIRSTLINE
|
|
literal set PCRE2_LITERAL
|
|
match_line set PCRE2_EXTRA_MATCH_LINE
|
|
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
|
|
.sp
|
|
As well as turning on the PCRE2_UTF option, the \fButf\fP modifier causes all
|
|
non-printing characters in output strings to be printed using the \ex{hh...}
|
|
notation. Otherwise, those less than 0x100 are output in hex without the curly
|
|
brackets. Setting \fButf\fP 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.
|
|
.
|
|
.
|
|
.\" HTML <a name="controlmodifiers"></a>
|
|
.SS "Setting compilation controls"
|
|
.rs
|
|
.sp
|
|
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.
|
|
.sp
|
|
bsr=[anycrlf|unicode] specify \eR 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] select internal tables
|
|
use_length do not zero-terminate the pattern
|
|
utf8_input treat input as UTF-8
|
|
.sp
|
|
The effects of these modifiers are described in the following sections.
|
|
.
|
|
.
|
|
.SS "Newline and \eR handling"
|
|
.rs
|
|
.sp
|
|
The \fBbsr\fP modifier specifies what \eR in a pattern should match. If it is
|
|
set to "anycrlf", \eR matches CR, LF, or CRLF only. If it is set to "unicode",
|
|
\eR 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
|
|
The \fBnewline\fP 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).
|
|
.
|
|
.
|
|
.SS "Information about a pattern"
|
|
.rs
|
|
.sp
|
|
The \fBdebug\fP modifier is a shorthand for \fBinfo,fullbincode\fP, requesting
|
|
all available information.
|
|
.P
|
|
The \fBbincode\fP 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 \fBbincode\fP, the same
|
|
regression tests can be used in different environments.
|
|
.P
|
|
The \fBfullbincode\fP modifier, by contrast, \fIdoes\fP 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
|
|
The \fBinfo\fP 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 \fBpcre2_pattern_info()\fP function. Here are
|
|
some typical examples:
|
|
.sp
|
|
re> /(?i)(^a|^b)/m,info
|
|
Capturing subpattern count = 1
|
|
Compile options: multiline
|
|
Overall options: caseless multiline
|
|
First code unit at start or follows newline
|
|
Subject length lower bound = 1
|
|
.sp
|
|
re> /(?i)abc/info
|
|
Capturing subpattern count = 0
|
|
Compile options: <none>
|
|
Overall options: caseless
|
|
First code unit = 'a' (caseless)
|
|
Last code unit = 'c' (caseless)
|
|
Subject length lower bound = 3
|
|
.sp
|
|
"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.
|
|
.P
|
|
The \fBframesize\fP modifier shows the size, in bytes, of the storage frames
|
|
used by \fBpcre2_match()\fP for handling backtracking. The size depends on the
|
|
number of capturing parentheses in the pattern.
|
|
.P
|
|
The \fBcallout_info\fP 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.
|
|
.
|
|
.
|
|
.SS "Passing a NULL context"
|
|
.rs
|
|
.sp
|
|
Normally, \fBpcre2test\fP passes a context block to \fBpcre2_compile()\fP. If
|
|
the \fBnull_context\fP modifier is set, however, NULL is passed. This is for
|
|
testing that \fBpcre2_compile()\fP behaves correctly in this case (it uses
|
|
default values).
|
|
.
|
|
.
|
|
.SS "Specifying pattern characters in hexadecimal"
|
|
.rs
|
|
.sp
|
|
The \fBhex\fP 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:
|
|
.sp
|
|
/ab 32 59/hex
|
|
.sp
|
|
Parts of such a pattern are taken literally if quoted. This pattern contains
|
|
nine characters, only two of which are specified in hexadecimal:
|
|
.sp
|
|
/ab "literal" 32/hex
|
|
.sp
|
|
Either single or double quotes may be used. There is no way of including
|
|
the delimiter within a substring. The \fBhex\fP and \fBexpand\fP modifiers are
|
|
mutually exclusive.
|
|
.
|
|
.
|
|
.SS "Specifying the pattern's length"
|
|
.rs
|
|
.sp
|
|
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
|
|
\fBuse_length\fP modifier causes this to happen. Using a length happens
|
|
automatically (whether or not \fBuse_length\fP is set) when \fBhex\fP is set,
|
|
because patterns specified in hexadecimal may contain binary zeros.
|
|
.P
|
|
If \fBhex\fP or \fBuse_length\fP is used with the POSIX wrapper API (see
|
|
.\" HTML <a href="#posixwrapper">
|
|
.\" </a>
|
|
"Using the POSIX wrapper API"
|
|
.\"
|
|
below), the REG_PEND extension is used to pass the pattern's length.
|
|
.
|
|
.
|
|
.SS "Specifying wide characters in 16-bit and 32-bit modes"
|
|
.rs
|
|
.sp
|
|
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 \fButf\fP modifier is set. For testing
|
|
the 16-bit and 32-bit libraries in non-UTF mode, the \fButf8_input\fP modifier
|
|
can be used. It is mutually exclusive with \fButf\fP. Input lines are
|
|
interpreted as UTF-8 as a means of specifying wide characters. More details are
|
|
given in
|
|
.\" HTML <a href="#inputencoding">
|
|
.\" </a>
|
|
"Input encoding"
|
|
.\"
|
|
above.
|
|
.
|
|
.
|
|
.SS "Generating long repetitive patterns"
|
|
.rs
|
|
.sp
|
|
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
|
|
\fBexpand\fP modifier is present on a pattern, parts of the pattern that have
|
|
the form
|
|
.sp
|
|
\e[<characters>]{<count>}
|
|
.sp
|
|
are expanded before the pattern is passed to \fBpcre2_compile()\fP. For
|
|
example, \e[AB]{6000} is expanded to "ABAB..." 6000 times. This construction
|
|
cannot be nested. An initial "\e[" 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 \fBexpand\fP and \fBhex\fP modifiers are
|
|
mutually exclusive.
|
|
.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, \e[AB]{6000,6000} is not recognized as an
|
|
expansion item.
|
|
.P
|
|
If the \fBinfo\fP modifier is set on an expanded pattern, the result of the
|
|
expansion is included in the information that is output.
|
|
.
|
|
.
|
|
.SS "JIT compilation"
|
|
.rs
|
|
.sp
|
|
Just-in-time (JIT) compiling is a heavyweight optimization that can greatly
|
|
speed up pattern matching. See the
|
|
.\" HREF
|
|
\fBpcre2jit\fP
|
|
.\"
|
|
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 \fBpartial\fP
|
|
modifier in "Subject Modifiers"
|
|
.\" HTML <a href="#subjectmodifiers">
|
|
.\" </a>
|
|
below
|
|
.\"
|
|
for details of how these options are specified for each match attempt.
|
|
.P
|
|
JIT compilation is requested by the \fBjit\fP 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:
|
|
.sp
|
|
1 compile JIT code for non-partial matching
|
|
2 compile JIT code for soft partial matching
|
|
4 compile JIT code for hard partial matching
|
|
.sp
|
|
The possible values for the \fBjit\fP modifier are therefore:
|
|
.sp
|
|
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
|
|
.sp
|
|
If no number is given, 7 is assumed. The phrase "partial matching" means a call
|
|
to \fBpcre2_match()\fP 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 \fBpartial\fP modifier on a
|
|
subject line, that match will not use JIT code because none was compiled for
|
|
non-partial matching.
|
|
.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
|
|
.\" HREF
|
|
\fBpcre2jit\fP
|
|
.\"
|
|
documentation. See also the \fBjitstack\fP modifier below for a way of
|
|
setting the size of the JIT stack.
|
|
.P
|
|
If the \fBjitfast\fP modifier is specified, matching is done using the JIT
|
|
"fast path" interface, \fBpcre2_jit_match()\fP, which skips some of the sanity
|
|
checks that are done by \fBpcre2_match()\fP, and of course does not work when
|
|
JIT is not supported. If \fBjitfast\fP is specified without \fBjit\fP, jit=7 is
|
|
assumed.
|
|
.P
|
|
If the \fBjitverify\fP modifier is specified, information about the compiled
|
|
pattern shows whether JIT compilation was or was not successful. If
|
|
\fBjitverify\fP is specified without \fBjit\fP, jit=7 is assumed. If JIT
|
|
compilation is successful when \fBjitverify\fP 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.
|
|
.
|
|
.
|
|
.SS "Setting a locale"
|
|
.rs
|
|
.sp
|
|
The \fBlocale\fP modifier must specify the name of a locale, for example:
|
|
.sp
|
|
/pattern/locale=fr_FR
|
|
.sp
|
|
The given locale is set, \fBpcre2_maketables()\fP is called to build a set of
|
|
character tables for the locale, and this is then passed to
|
|
\fBpcre2_compile()\fP when compiling the regular expression. The same tables
|
|
are used when matching the following subject lines. The \fBlocale\fP modifier
|
|
applies only to the pattern on which it appears, but can be given in a
|
|
\fB#pattern\fP command if a default is needed. Setting a locale and alternate
|
|
character tables are mutually exclusive.
|
|
.
|
|
.
|
|
.SS "Showing pattern memory"
|
|
.rs
|
|
.sp
|
|
The \fBmemory\fP 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
|
|
\fBpcre2_code\fP 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:
|
|
.sp
|
|
re> /a(b)c/jit,memory
|
|
Memory allocation (code space): 21
|
|
Memory allocation (JIT code): 1910
|
|
.sp
|
|
.
|
|
.
|
|
.SS "Limiting nested parentheses"
|
|
.rs
|
|
.sp
|
|
The \fBparens_nest_limit\fP 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 \fBpcre2test\fP
|
|
sets its own default of 220, which is required for running the standard test
|
|
suite.
|
|
.
|
|
.
|
|
.SS "Limiting the pattern length"
|
|
.rs
|
|
.sp
|
|
The \fBmax_pattern_length\fP modifier sets a limit, in code units, to the
|
|
length of pattern that \fBpcre2_compile()\fP will accept. Breaching the limit
|
|
causes a compilation error. The default is the largest number a PCRE2_SIZE
|
|
variable can hold (essentially unlimited).
|
|
.
|
|
.
|
|
.\" HTML <a name="posixwrapper"></a>
|
|
.SS "Using the POSIX wrapper API"
|
|
.rs
|
|
.sp
|
|
The \fBposix\fP and \fBposix_nosub\fP modifiers cause \fBpcre2test\fP to call
|
|
PCRE2 via the POSIX wrapper API rather than its native API. When
|
|
\fBposix_nosub\fP is used, the POSIX option REG_NOSUB is passed to
|
|
\fBregcomp()\fP. The POSIX wrapper supports only the 8-bit library. Note that
|
|
it does not imply POSIX matching semantics; for more detail see the
|
|
.\" HREF
|
|
\fBpcre2posix\fP
|
|
.\"
|
|
documentation. The following pattern modifiers set options for the
|
|
\fBregcomp()\fP function:
|
|
.sp
|
|
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 )
|
|
.sp
|
|
The \fBregerror_buffsize\fP modifier specifies a size for the error buffer that
|
|
is passed to \fBregerror()\fP in the event of a compilation error. For example:
|
|
.sp
|
|
/abc/posix,regerror_buffsize=20
|
|
.sp
|
|
This provides a means of testing the behaviour of \fBregerror()\fP when the
|
|
buffer is too small for the error message. If this modifier has not been set, a
|
|
large buffer is used.
|
|
.P
|
|
The \fBaftertext\fP and \fBallaftertext\fP subject modifiers work as described
|
|
below. All other modifiers are either ignored, with a warning message, or cause
|
|
an error.
|
|
.P
|
|
The pattern is passed to \fBregcomp()\fP as a zero-terminated string by
|
|
default, but if the \fBuse_length\fP or \fBhex\fP modifiers are set, the
|
|
REG_PEND extension is used to pass it by length.
|
|
.
|
|
.
|
|
.SS "Testing the stack guard feature"
|
|
.rs
|
|
.sp
|
|
The \fBstackguard\fP modifier is used to test the use of
|
|
\fBpcre2_set_compile_recursion_guard()\fP, a function that is provided to
|
|
enable stack availability to be checked during compilation (see the
|
|
.\" HREF
|
|
\fBpcre2api\fP
|
|
.\"
|
|
documentation for details). If the number specified by the modifier is greater
|
|
than zero, \fBpcre2_set_compile_recursion_guard()\fP is called to set up
|
|
callback from \fBpcre2_compile()\fP 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.
|
|
.
|
|
.
|
|
.SS "Using alternative character tables"
|
|
.rs
|
|
.sp
|
|
The value specified for the \fBtables\fP modifier must be one of the digits 0,
|
|
1, or 2. It causes a specific set of built-in character tables to be passed to
|
|
\fBpcre2_compile()\fP. This is used in the PCRE2 tests to check behaviour with
|
|
different character tables. The digit specifies the tables as follows:
|
|
.sp
|
|
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
|
|
.sp
|
|
In table 2, some characters whose codes are greater than 128 are identified as
|
|
letters, digits, spaces, etc. Setting alternate character tables and a locale
|
|
are mutually exclusive.
|
|
.
|
|
.
|
|
.SS "Setting certain match controls"
|
|
.rs
|
|
.sp
|
|
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.
|
|
.sp
|
|
aftertext show text after match
|
|
allaftertext show text after captures
|
|
allcaptures show all captures
|
|
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_extended use PCRE2_SUBSTITUTE_EXTENDED
|
|
substitute_overflow_length use PCRE2_SUBSTITUTE_OVERFLOW_LENGTH
|
|
substitute_unknown_unset use PCRE2_SUBSTITUTE_UNKNOWN_UNSET
|
|
substitute_unset_empty use PCRE2_SUBSTITUTE_UNSET_EMPTY
|
|
.sp
|
|
These modifiers may not appear in a \fB#pattern\fP command. If you want them as
|
|
defaults, set them in a \fB#subject\fP command.
|
|
.
|
|
.
|
|
.SS "Specifying literal subject lines"
|
|
.rs
|
|
.sp
|
|
If the \fBsubject_literal\fP 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 \fB#subject\fP command are recognized.
|
|
.
|
|
.
|
|
.SS "Saving a compiled pattern"
|
|
.rs
|
|
.sp
|
|
When a pattern with the \fBpush\fP modifier is successfully compiled, it is
|
|
pushed onto a stack of compiled patterns, and \fBpcre2test\fP 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"
|
|
.\" HTML <a href="#saverestore">
|
|
.\" </a>
|
|
below.
|
|
.\"
|
|
If \fBpushcopy\fP is used instead of \fBpush\fP, 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
|
|
\fBpcre2_code_copy()\fP function.
|
|
.\"
|
|
The \fBpush\fP and \fBpushcopy \fP modifiers are incompatible with compilation
|
|
modifiers such as \fBglobal\fP that act at match time. Any that are specified
|
|
are ignored (for the stacked copy), with a warning message, except for
|
|
\fBreplace\fP, which causes an error. Note that \fBjitverify\fP, which is
|
|
allowed, does not carry through to any subsequent matching that uses a stacked
|
|
pattern.
|
|
.
|
|
.
|
|
.SS "Testing foreign pattern conversion"
|
|
.rs
|
|
.sp
|
|
The experimental foreign pattern conversion functions in PCRE2 can be tested by
|
|
setting the \fBconvert\fP modifier. Its argument is a colon-separated list of
|
|
options, which set the equivalent option for the \fBpcre2_pattern_convert()\fP
|
|
function:
|
|
.sp
|
|
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
|
|
.sp
|
|
The "unset" value is useful for turning off a default that has been set by a
|
|
\fB#pattern\fP command. When one of these options is set, the input pattern is
|
|
passed to \fBpcre2_pattern_convert()\fP. If the conversion is successful, the
|
|
result is reflected in the output and then passed to \fBpcre2_compile()\fP. The
|
|
normal \fButf\fP and \fBno_utf_check\fP options, if set, cause the
|
|
PCRE2_CONVERT_UTF and PCRE2_CONVERT_NO_UTF_CHECK options to be passed to
|
|
\fBpcre2_pattern_convert()\fP.
|
|
.P
|
|
By default, the conversion function is allowed to allocate a buffer for its
|
|
output. However, if the \fBconvert_length\fP modifier is set to a value greater
|
|
than zero, \fBpcre2test\fP passes a buffer of the given length. This makes it
|
|
possible to test the length check.
|
|
.P
|
|
The \fBconvert_glob_escape\fP and \fBconvert_glob_separator\fP modifiers can be
|
|
used to specify the escape and separator characters for glob processing,
|
|
overriding the defaults, which are operating-system dependent.
|
|
.
|
|
.
|
|
.\" HTML <a name="subjectmodifiers"></a>
|
|
.SH "SUBJECT MODIFIERS"
|
|
.rs
|
|
.sp
|
|
The modifiers that can appear in subject lines and the \fB#subject\fP
|
|
command are of two types.
|
|
.
|
|
.
|
|
.SS "Setting match options"
|
|
.rs
|
|
.sp
|
|
The following modifiers set options for \fBpcre2_match()\fP or
|
|
\fBpcre2_dfa_match()\fP. See
|
|
.\" HREF
|
|
\fBpcreapi\fP
|
|
.\"
|
|
for a description of their effects.
|
|
.sp
|
|
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
|
|
.sp
|
|
The partial matching modifiers are provided with abbreviations because they
|
|
appear frequently in tests.
|
|
.P
|
|
If the \fBposix\fP or \fBposix_nosub\fP modifier was present on the pattern,
|
|
causing the POSIX wrapper API to be used, the only option-setting modifiers
|
|
that have any effect are \fBnotbol\fP, \fBnotempty\fP, and \fBnoteol\fP,
|
|
causing REG_NOTBOL, REG_NOTEMPTY, and REG_NOTEOL, respectively, to be passed to
|
|
\fBregexec()\fP. The other modifiers are ignored, with a warning message.
|
|
.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.
|
|
.sp
|
|
posix_startend=<n>[:<m>]
|
|
.sp
|
|
This causes the subject string to be passed to \fBregexec()\fP 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
|
|
.\" HREF
|
|
\fBpcre2posix\fP
|
|
.\"
|
|
documentation. If the subject string contains binary zeros (coded as escapes
|
|
such as \ex{00} because \fBpcre2test\fP does not support actual binary zeros in
|
|
its input), you must use \fBposix_startend\fP to specify its length.
|
|
.
|
|
.
|
|
.SS "Setting match controls"
|
|
.rs
|
|
.sp
|
|
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.
|
|
.sp
|
|
aftertext show text after match
|
|
allaftertext show text after captures
|
|
allcaptures show all captures
|
|
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 \fBpcre2_dfa_match()\fP
|
|
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_extedded use PCRE2_SUBSTITUTE_EXTENDED
|
|
substitute_overflow_length use PCRE2_SUBSTITUTE_OVERFLOW_LENGTH
|
|
substitute_unknown_unset use PCRE2_SUBSTITUTE_UNKNOWN_UNSET
|
|
substitute_unset_empty use PCRE2_SUBSTITUTE_UNSET_EMPTY
|
|
zero_terminate pass the subject as zero-terminated
|
|
.sp
|
|
The effects of these modifiers are described in the following sections. When
|
|
matching via the POSIX wrapper API, the \fBaftertext\fP, \fBallaftertext\fP,
|
|
and \fBovector\fP subject modifiers work as described below. All other
|
|
modifiers are either ignored, with a warning message, or cause an error.
|
|
.
|
|
.
|
|
.SS "Showing more text"
|
|
.rs
|
|
.sp
|
|
The \fBaftertext\fP modifier requests that as well as outputting the part of
|
|
the subject string that matched the entire pattern, \fBpcre2test\fP 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
|
|
\fBallaftertext\fP 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
|
|
The \fBallusedtext\fP modifier requests that all the text that was consulted
|
|
during a successful pattern match by the interpreter should be shown. 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 a lookahead at the end, or if
|
|
\eK 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:
|
|
.sp
|
|
re> /(?<=pqr)abc(?=xyz)/
|
|
data> 123pqrabcxyz456\e=allusedtext
|
|
0: pqrabcxyz
|
|
<<< >>>
|
|
.sp
|
|
This 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).
|
|
.P
|
|
The \fBstartchar\fP 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 \eK 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:
|
|
.sp
|
|
re> /abc\eKxyz/
|
|
data> abcxyz\e=startchar
|
|
0: abcxyz
|
|
^^^
|
|
.sp
|
|
Unlike \fBallusedtext\fP, the \fBstartchar\fP modifier can be used with JIT.
|
|
However, these two modifiers are mutually exclusive.
|
|
.
|
|
.
|
|
.SS "Showing the value of all capture groups"
|
|
.rs
|
|
.sp
|
|
The \fBallcaptures\fP 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 \fBpcre2_match()\fP). 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); it is ignored, with a warning message, if present.
|
|
.
|
|
.
|
|
.SS "Testing callouts"
|
|
.rs
|
|
.sp
|
|
A callout function is supplied when \fBpcre2test\fP calls the library matching
|
|
functions, unless \fBcallout_none\fP is specified. Its behaviour can be
|
|
controlled by various modifiers listed above whose names begin with
|
|
\fBcallout_\fP. Details are given in the section entitled "Callouts"
|
|
.\" HTML <a href="#callouts">
|
|
.\" </a>
|
|
below.
|
|
.\"
|
|
.
|
|
.
|
|
.SS "Finding all matches in a string"
|
|
.rs
|
|
.sp
|
|
Searching for all possible matches within a subject can be requested by the
|
|
\fBglobal\fP or \fBaltglobal\fP modifier. After finding a match, the matching
|
|
function is called again to search the remainder of the subject. The difference
|
|
between \fBglobal\fP and \fBaltglobal\fP is that the former uses the
|
|
\fIstart_offset\fP argument to \fBpcre2_match()\fP or \fBpcre2_dfa_match()\fP
|
|
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 \eb or \eB).
|
|
.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 \fB/g\fP modifier or
|
|
the \fBsplit()\fP 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.
|
|
.
|
|
.
|
|
.SS "Testing substring extraction functions"
|
|
.rs
|
|
.sp
|
|
The \fBcopy\fP and \fBget\fP modifiers can be used to test the
|
|
\fBpcre2_substring_copy_xxx()\fP and \fBpcre2_substring_get_xxx()\fP functions.
|
|
They can be given more than once, and each can specify a group name or number,
|
|
for example:
|
|
.sp
|
|
abcd\e=copy=1,copy=3,get=G1
|
|
.sp
|
|
If the \fB#subject\fP 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
|
|
The \fBgetall\fP modifier tests \fBpcre2_substring_list_get()\fP, which
|
|
extracts all captured substrings.
|
|
.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.
|
|
.
|
|
.
|
|
.SS "Testing the substitution function"
|
|
.rs
|
|
.sp
|
|
If the \fBreplace\fP modifier is set, the \fBpcre2_substitute()\fP function is
|
|
called instead of one of the matching functions. 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
|
|
Unlike subject strings, \fBpcre2test\fP 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
|
|
The following modifiers set options (in additional to the normal match options)
|
|
for \fBpcre2_substitute()\fP:
|
|
.sp
|
|
global PCRE2_SUBSTITUTE_GLOBAL
|
|
substitute_extended PCRE2_SUBSTITUTE_EXTENDED
|
|
substitute_overflow_length PCRE2_SUBSTITUTE_OVERFLOW_LENGTH
|
|
substitute_unknown_unset PCRE2_SUBSTITUTE_UNKNOWN_UNSET
|
|
substitute_unset_empty PCRE2_SUBSTITUTE_UNSET_EMPTY
|
|
.sp
|
|
.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:
|
|
.sp
|
|
/abc/replace=xxx
|
|
=abc=abc=
|
|
1: =xxx=abc=
|
|
=abc=abc=\e=global
|
|
2: =xxx=xxx=
|
|
.sp
|
|
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 \fBpcre2_substitute()\fP 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:
|
|
.sp
|
|
/abc/
|
|
123abc123\e=replace=[10]XYZ
|
|
1: 123XYZ123
|
|
123abc123\e=replace=[9]XYZ
|
|
Failed: error -47: no more memory
|
|
.sp
|
|
The default action of \fBpcre2_substitute()\fP 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
|
|
\fBsubstitute_overflow_length\fP modifier), \fBpcre2_substitute()\fP continues
|
|
to go through the motions of matching and substituting, in order to compute the
|
|
size of buffer that is required. When this happens, \fBpcre2test\fP shows the
|
|
required buffer length (which includes space for the trailing zero) as part of
|
|
the error message. For example:
|
|
.sp
|
|
/abc/substitute_overflow_length
|
|
123abc123\e=replace=[9]XYZ
|
|
Failed: error -47: no more memory: 10 code units are needed
|
|
.sp
|
|
A replacement string is ignored with POSIX and DFA matching. Specifying partial
|
|
matching provokes an error return ("bad option value") from
|
|
\fBpcre2_substitute()\fP.
|
|
.
|
|
.
|
|
.SS "Setting the JIT stack size"
|
|
.rs
|
|
.sp
|
|
The \fBjitstack\fP 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 \fBjitstack\fP is set non-zero on a subject line it overrides any
|
|
value that was set on the pattern.
|
|
.
|
|
.
|
|
.SS "Setting heap, match, and depth limits"
|
|
.rs
|
|
.sp
|
|
The \fBheap_limit\fP, \fBmatch_limit\fP, and \fBdepth_limit\fP modifiers set
|
|
the appropriate limits in the match context. These values are ignored when the
|
|
\fBfind_limits\fP modifier is specified.
|
|
.
|
|
.
|
|
.SS "Finding minimum limits"
|
|
.rs
|
|
.sp
|
|
If the \fBfind_limits\fP modifier is present on a subject line, \fBpcre2test\fP
|
|
calls the relevant matching function several times, setting different values in
|
|
the match context via \fBpcre2_set_heap_limit()\fP,
|
|
\fBpcre2_set_match_limit()\fP, or \fBpcre2_set_depth_limit()\fP 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
|
|
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 \fBpcre2_set_match_limit()\fP etc. are only able to reduce the value of
|
|
an in-pattern limit; they cannot increase it.
|
|
.P
|
|
For non-DFA matching, the minimum \fIdepth_limit\fP 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, \fIdepth_limit\fP controls the depth of
|
|
recursive calls of the internal function that is used for handling pattern
|
|
recursion, lookaround assertions, and atomic groups.
|
|
.P
|
|
For non-DFA matching, the \fImatch_limit\fP 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, \fImatch_limit\fP 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
|
|
For both kinds of matching, the \fIheap_limit\fP 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.
|
|
.
|
|
.
|
|
.SS "Showing MARK names"
|
|
.rs
|
|
.sp
|
|
.P
|
|
The \fBmark\fP modifier causes the names from backtracking control verbs that
|
|
are returned from calls to \fBpcre2_match()\fP to be displayed. If a mark is
|
|
returned for a match, non-match, or partial match, \fBpcre2test\fP shows it.
|
|
For a match, it is on a line by itself, tagged with "MK:". Otherwise, it
|
|
is added to the non-match message.
|
|
.
|
|
.
|
|
.SS "Showing memory usage"
|
|
.rs
|
|
.sp
|
|
The \fBmemory\fP modifier causes \fBpcre2test\fP to log the sizes of all heap
|
|
memory allocation and freeing calls that occur during a call to
|
|
\fBpcre2_match()\fP or \fBpcre2_dfa_match()\fP. These occur only when a match
|
|
requires a bigger vector than the default for remembering backtracking points
|
|
(\fBpcre2_match()\fP) or for internal workspace (\fBpcre2_dfa_match()\fP). 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 \fBmemory\fP modifier never has any effect. For this modifier to work, the
|
|
\fBnull_context\fP modifier must not be set on both the pattern and the
|
|
subject, though it can be set on one or the other.
|
|
.
|
|
.
|
|
.SS "Setting a starting offset"
|
|
.rs
|
|
.sp
|
|
The \fBoffset\fP modifier sets an offset in the subject string at which
|
|
matching starts. Its value is a number of code units, not characters.
|
|
.
|
|
.
|
|
.SS "Setting an offset limit"
|
|
.rs
|
|
.sp
|
|
The \fBoffset_limit\fP 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 \fBuse_offset_limit\fP modifier must have been set
|
|
for the pattern; if not, an error is generated.
|
|
.
|
|
.
|
|
.SS "Setting the size of the output vector"
|
|
.rs
|
|
.sp
|
|
The \fBovector\fP 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
|
|
\fB#subject\fP command. It specifies the number of pairs of offsets that are
|
|
available for storing matching information. The default is 15.
|
|
.P
|
|
A value of zero is useful when testing the POSIX API because it causes
|
|
\fBregexec()\fP to be called with a NULL capture vector. When not testing the
|
|
POSIX API, a value of zero is used to cause
|
|
\fBpcre2_match_data_create_from_pattern()\fP 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.)
|
|
.
|
|
.
|
|
.SS "Passing the subject as zero-terminated"
|
|
.rs
|
|
.sp
|
|
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 \fBzero_terminate\fP 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
|
|
When testing \fBpcre2_substitute()\fP, this modifier also has the effect of
|
|
passing the replacement string as zero-terminated.
|
|
.
|
|
.
|
|
.SS "Passing a NULL context"
|
|
.rs
|
|
.sp
|
|
Normally, \fBpcre2test\fP passes a context block to \fBpcre2_match()\fP,
|
|
\fBpcre2_dfa_match()\fP or \fBpcre2_jit_match()\fP. If the \fBnull_context\fP
|
|
modifier is set, however, NULL is passed. This is for testing that the matching
|
|
functions behave correctly in this case (they use default values). This
|
|
modifier cannot be used with the \fBfind_limits\fP modifier or when testing the
|
|
substitution function.
|
|
.
|
|
.
|
|
.SH "THE ALTERNATIVE MATCHING FUNCTION"
|
|
.rs
|
|
.sp
|
|
By default, \fBpcre2test\fP uses the standard PCRE2 matching function,
|
|
\fBpcre2_match()\fP to match each subject line. PCRE2 also supports an
|
|
alternative matching function, \fBpcre2_dfa_match()\fP, which operates in a
|
|
different way, and has some restrictions. The differences between the two
|
|
functions are described in the
|
|
.\" HREF
|
|
\fBpcre2matching\fP
|
|
.\"
|
|
documentation.
|
|
.P
|
|
If the \fBdfa\fP 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 \fBdfa_shortest\fP modifier is set, processing stops after the
|
|
first match is found. This is always the shortest possible match.
|
|
.
|
|
.
|
|
.SH "DEFAULT OUTPUT FROM pcre2test"
|
|
.rs
|
|
.sp
|
|
This section describes the output when the normal matching function,
|
|
\fBpcre2_match()\fP, is being used.
|
|
.P
|
|
When a match succeeds, \fBpcre2test\fP 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, \eK, \eb,
|
|
or \eB was involved.)
|
|
.P
|
|
For any other return, \fBpcre2test\fP 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 \fBpcre2test\fP run.
|
|
.sp
|
|
$ pcre2test
|
|
PCRE2 version 10.22 2016-07-29
|
|
.sp
|
|
re> /^abc(\ed+)/
|
|
data> abc123
|
|
0: abc123
|
|
1: 123
|
|
data> xyz
|
|
No match
|
|
.sp
|
|
Unset capturing substrings that are not followed by one that is set are not
|
|
shown by \fBpcre2test\fP unless the \fBallcaptures\fP 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.
|
|
.sp
|
|
re> /(a)|(b)/
|
|
data> a
|
|
0: a
|
|
1: a
|
|
data> b
|
|
0: b
|
|
1: <unset>
|
|
2: b
|
|
.sp
|
|
If the strings contain any non-printing characters, they are output as \exhh
|
|
escapes if the value is less than 256 and UTF mode is not set. Otherwise they
|
|
are output as \ex{hh...} escapes. See below for the definition of non-printing
|
|
characters. If the \fBaftertext\fP modifier is set, the output for substring
|
|
0 is followed by the the rest of the subject string, identified by "0+" like
|
|
this:
|
|
.sp
|
|
re> /cat/aftertext
|
|
data> cataract
|
|
0: cat
|
|
0+ aract
|
|
.sp
|
|
If global matching is requested, the results of successive matching attempts
|
|
are output in sequence, like this:
|
|
.sp
|
|
re> /\eBi(\ew\ew)/g
|
|
data> Mississippi
|
|
0: iss
|
|
1: ss
|
|
0: iss
|
|
1: ss
|
|
0: ipp
|
|
1: pp
|
|
.sp
|
|
"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 \fBoffset\fP
|
|
modifier is past the end of the subject string):
|
|
.sp
|
|
re> /xyz/
|
|
data> xyz\e=offset=4
|
|
Error -24 (bad offset value)
|
|
.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 \en escape (or \er, \er\en, etc.,
|
|
depending on the newline sequence setting).
|
|
.
|
|
.
|
|
.
|
|
.SH "OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION"
|
|
.rs
|
|
.sp
|
|
When the alternative matching function, \fBpcre2_dfa_match()\fP, 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:
|
|
.sp
|
|
re> /(tang|tangerine|tan)/
|
|
data> yellow tangerine\e=dfa
|
|
0: tangerine
|
|
1: tang
|
|
2: tan
|
|
.sp
|
|
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, \eb, or \eB was involved. (\eK is not
|
|
supported for DFA matching.)
|
|
.P
|
|
If global matching is requested, the search for further matches resumes
|
|
at the end of the longest match. For example:
|
|
.sp
|
|
re> /(tang|tangerine|tan)/g
|
|
data> yellow tangerine and tangy sultana\e=dfa
|
|
0: tangerine
|
|
1: tang
|
|
2: tan
|
|
0: tang
|
|
1: tan
|
|
0: tan
|
|
.sp
|
|
The alternative matching function does not support substring capture, so the
|
|
modifiers that are concerned with captured substrings are not relevant.
|
|
.
|
|
.
|
|
.SH "RESTARTING AFTER A PARTIAL MATCH"
|
|
.rs
|
|
.sp
|
|
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
|
|
\fBdfa_restart\fP modifier. For example:
|
|
.sp
|
|
re> /^\ed?\ed(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\ed\ed$/
|
|
data> 23ja\e=P,dfa
|
|
Partial match: 23ja
|
|
data> n05\e=dfa,dfa_restart
|
|
0: n05
|
|
.sp
|
|
For further information about partial matching, see the
|
|
.\" HREF
|
|
\fBpcre2partial\fP
|
|
.\"
|
|
documentation.
|
|
.
|
|
.
|
|
.\" HTML <a name="callouts"></a>
|
|
.SH CALLOUTS
|
|
.rs
|
|
.sp
|
|
If the pattern contains any callout requests, \fBpcre2test\fP's callout
|
|
function is called during matching unless \fBcallout_none\fP 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.
|
|
.
|
|
.
|
|
.SS "Callouts with numerical arguments"
|
|
.rs
|
|
.sp
|
|
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:
|
|
.sp
|
|
--->pqrabcdef
|
|
0 ^ ^ \ed
|
|
.sp
|
|
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 \ed. 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
|
|
Callouts numbered 255 are assumed to be automatic callouts, inserted as a
|
|
result of the \fBauto_callout\fP pattern modifier. In this case, instead of
|
|
showing the callout number, the offset in the pattern, preceded by a plus, is
|
|
output. For example:
|
|
.sp
|
|
re> /\ed?[A-E]\e*/auto_callout
|
|
data> E*
|
|
--->E*
|
|
+0 ^ \ed?
|
|
+3 ^ [A-E]
|
|
+8 ^^ \e*
|
|
+10 ^ ^
|
|
0: E*
|
|
.sp
|
|
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:
|
|
.sp
|
|
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
|
|
.sp
|
|
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.
|
|
.
|
|
.
|
|
.SS "Callouts with string arguments"
|
|
.rs
|
|
.sp
|
|
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:
|
|
.sp
|
|
re> /^ab(?C'first')cd(?C"second")ef/
|
|
data> abcdefg
|
|
Callout (7): 'first'
|
|
--->abcdefg
|
|
^ ^ c
|
|
Callout (20): "second"
|
|
--->abcdefg
|
|
^ ^ e
|
|
0: abcdef
|
|
.sp
|
|
.
|
|
.
|
|
.SS "Callout modifiers"
|
|
.rs
|
|
.sp
|
|
The callout function in \fBpcre2test\fP returns zero (carry on matching) by
|
|
default, but you can use a \fBcallout_fail\fP modifier in a subject line to
|
|
change this and other parameters of the callout (see below).
|
|
.P
|
|
If the \fBcallout_capture\fP modifier is set, the current captured groups are
|
|
output when a callout occurs. This is useful only for non-DFA matching, as
|
|
\fBpcre2_dfa_match()\fP does not support capturing, so no captures are ever
|
|
shown.
|
|
.P
|
|
The normal callout output, showing the callout number or pattern offset (as
|
|
described above) is suppressed if the \fBcallout_no_where\fP modifier is set.
|
|
.P
|
|
When using the interpretive matching function \fBpcre2_match()\fP without JIT,
|
|
setting the \fBcallout_extra\fP modifier causes additional output from
|
|
\fBpcre2test\fP'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:
|
|
.sp
|
|
re> /(a+)b/auto_callout,no_start_optimize,no_auto_possess
|
|
data> aac\e=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
|
|
.sp
|
|
Notice that various optimizations must be turned off if you want all possible
|
|
matching paths to be scanned. If \fBno_start_optimize\fP 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 \fBno_auto_possess\fP is not used, the "a+" item is turned
|
|
into "a++", which reduces the number of backtracks.
|
|
.P
|
|
The \fBcallout_extra\fP modifier has no effect if used with the DFA matching
|
|
function, or with JIT.
|
|
.
|
|
.
|
|
.SS "Return values from callouts"
|
|
.rs
|
|
.sp
|
|
The default return from the callout function is zero, which allows matching to
|
|
continue. The \fBcallout_fail\fP 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 \fBcallout_error\fP 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,
|
|
\fBcallout_error\fP takes precedence. Note that callouts with string arguments
|
|
are always given the number zero.
|
|
.P
|
|
The \fBcallout_data\fP 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 \fBpcre2test\fP's callout function.
|
|
.P
|
|
Inserting callouts can be helpful when using \fBpcre2test\fP to check
|
|
complicated regular expressions. For further information about callouts, see
|
|
the
|
|
.\" HREF
|
|
\fBpcre2callout\fP
|
|
.\"
|
|
documentation.
|
|
.
|
|
.
|
|
.
|
|
.SH "NON-PRINTING CHARACTERS"
|
|
.rs
|
|
.sp
|
|
When \fBpcre2test\fP 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
|
|
When \fBpcre2test\fP 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 \fBlocale\fP modifier). In this case, the
|
|
\fBisprint()\fP function is used to distinguish printing and non-printing
|
|
characters.
|
|
.
|
|
.
|
|
.
|
|
.\" HTML <a name="saverestore"></a>
|
|
.SH "SAVING AND RESTORING COMPILED PATTERNS"
|
|
.rs
|
|
.sp
|
|
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
|
|
The functions whose names begin with \fBpcre2_serialize_\fP are used
|
|
for serializing and de-serializing. They are described in the
|
|
.\" HREF
|
|
\fBpcre2serialize\fP
|
|
.\"
|
|
documentation. In this section we describe the features of \fBpcre2test\fP that
|
|
can be used to test these functions.
|
|
.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
|
|
In \fBpcre2test\fP, when a pattern with \fBpush\fP modifier is successfully
|
|
compiled, it is pushed onto a stack of compiled patterns, and \fBpcre2test\fP
|
|
expects the next line to contain a new pattern (or command) instead of a
|
|
subject line. By contrast, the \fBpushcopy\fP modifier causes a copy of the
|
|
compiled pattern to be stacked, leaving the original available for immediate
|
|
matching. By using \fBpush\fP and/or \fBpushcopy\fP, a number of patterns can
|
|
be compiled and retained. These modifiers are incompatible with \fBposix\fP,
|
|
and control modifiers that act at match time are ignored (with a message) for
|
|
the stacked patterns. The \fBjitverify\fP modifier applies only at compile
|
|
time.
|
|
.P
|
|
The command
|
|
.sp
|
|
#save <filename>
|
|
.sp
|
|
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
|
|
.sp
|
|
#load <filename>
|
|
.sp
|
|
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
|
|
.\" HTML <a href="#controlmodifiers">
|
|
.\" </a>
|
|
control modifiers
|
|
.\"
|
|
that act after a pattern has been compiled. In particular, \fBhex\fP,
|
|
\fBposix\fP, \fBposix_nosub\fP, \fBpush\fP, and \fBpushcopy\fP are not allowed,
|
|
nor are any
|
|
.\" HTML <a href="#optionmodifiers">
|
|
.\" </a>
|
|
option-setting modifiers.
|
|
.\"
|
|
The JIT modifiers are, however permitted. Here is an example that saves and
|
|
reloads two patterns.
|
|
.sp
|
|
/abc/push
|
|
/xyz/push
|
|
#save tempfile
|
|
#load tempfile
|
|
#pop info
|
|
xyz
|
|
.sp
|
|
#pop jit,bincode
|
|
abc
|
|
.sp
|
|
If \fBjitverify\fP is used with #pop, it does not automatically imply
|
|
\fBjit\fP, which is different behaviour from when it is used on a pattern.
|
|
.P
|
|
The #popcopy command is analagous to the \fBpushcopy\fP modifier in that it
|
|
makes current a copy of the topmost stack pattern, leaving the original still
|
|
on the stack.
|
|
.
|
|
.
|
|
.
|
|
.SH "SEE ALSO"
|
|
.rs
|
|
.sp
|
|
\fBpcre2\fP(3), \fBpcre2api\fP(3), \fBpcre2callout\fP(3),
|
|
\fBpcre2jit\fP, \fBpcre2matching\fP(3), \fBpcre2partial\fP(d),
|
|
\fBpcre2pattern\fP(3), \fBpcre2serialize\fP(3).
|
|
.
|
|
.
|
|
.SH AUTHOR
|
|
.rs
|
|
.sp
|
|
.nf
|
|
Philip Hazel
|
|
University Computing Service
|
|
Cambridge, England.
|
|
.fi
|
|
.
|
|
.
|
|
.SH REVISION
|
|
.rs
|
|
.sp
|
|
.nf
|
|
Last updated: 27 June 2018
|
|
Copyright (c) 1997-2018 University of Cambridge.
|
|
.fi
|