add PIRegularExpression
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3rd/pcre2/doc/pcre2test.txt
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3rd/pcre2/doc/pcre2test.txt
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PCRE2TEST(1) General Commands Manual PCRE2TEST(1)
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NAME
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pcre2test - a program for testing Perl-compatible regular expressions.
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SYNOPSIS
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pcre2test [options] [input file [output file]]
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pcre2test 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.
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This document describes the features of the test program; for details
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of the regular expressions themselves, see the pcre2pattern documenta-
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tion. For details of the PCRE2 library function calls and their op-
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tions, see the pcre2api documentation.
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The input for pcre2test is a sequence of regular expression patterns
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and subject strings to be matched. There are also command lines for
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setting defaults and controlling some special actions. The output shows
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the result of each match attempt. Modifiers on external or internal
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command lines, the patterns, and the subject lines specify PCRE2 func-
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tion options, control how the subject is processed, and what output is
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produced.
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There are many obscure modifiers, some of which are specifically de-
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signed for use in conjunction with the test script and data files that
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are distributed as part of PCRE2. All the modifiers are documented
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here, some without much justification, but many of them are unlikely to
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be of use except when testing the libraries.
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PCRE2's 8-BIT, 16-BIT AND 32-BIT LIBRARIES
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Different versions of the PCRE2 library can be built to support charac-
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ter strings that are encoded in 8-bit, 16-bit, or 32-bit code units.
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One, two, or all three of these libraries may be simultaneously in-
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stalled. The pcre2test program can be used to test all the libraries.
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However, its own input and output are always in 8-bit format. When
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testing the 16-bit or 32-bit libraries, patterns and subject strings
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are converted to 16-bit or 32-bit format before being passed to the li-
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brary functions. Results are converted back to 8-bit code units for
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output.
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In the rest of this document, the names of library functions and struc-
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tures are given in generic form, for example, pcre2_compile(). The ac-
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tual names used in the libraries have a suffix _8, _16, or _32, as ap-
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propriate.
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INPUT ENCODING
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Input to pcre2test is processed line by line, either by calling the C
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library's fgets() function, or via the libreadline or libedit library.
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In some Windows environments character 26 (hex 1A) causes an immediate
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end of file, and no further data is read, so this character should be
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avoided unless you really want that action.
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The input is processed using C's string functions, so must not contain
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binary zeros, even though in Unix-like environments, fgets() treats any
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bytes other than newline as data characters. An error is generated if a
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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
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strings that are passed to the library for matching. For patterns,
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there is a facility for specifying some or all of the 8-bit input char-
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acters as hexadecimal pairs, which makes it possible to include binary
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zeros.
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Input for the 16-bit and 32-bit libraries
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When testing the 16-bit or 32-bit libraries, there is a need to be able
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to generate character code points greater than 255 in the strings that
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are passed to the library. For subject lines and some patterns, back-
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slash escapes can be used. In addition, when the utf modifier (see
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"Setting compilation options" below) is set, the pattern and any fol-
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lowing subject lines are interpreted as UTF-8 strings and translated to
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UTF-16 or UTF-32 as appropriate.
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For non-UTF testing of wide characters, the utf8_input modifier can be
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used. This is mutually exclusive with utf, and is allowed only in
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16-bit or 32-bit mode. It causes the pattern and following subject
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lines to be treated as UTF-8 according to the original definition (RFC
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2279), which allows for character values up to 0x7fffffff. Each charac-
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ter is placed in one 16-bit or 32-bit code unit (in the 16-bit case,
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values greater than 0xffff cause an error to occur).
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UTF-8 (in its original definition) is not capable of encoding values
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greater than 0x7fffffff, but such values can be handled by the 32-bit
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library. When testing this library in non-UTF mode with utf8_input set,
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if any character is preceded by the byte 0xff (which is an invalid byte
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in UTF-8) 0x80000000 is added to the character's value. For subject
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strings, using an escape sequence is preferable.
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COMMAND LINE OPTIONS
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-8 If the 8-bit library has been built, this option causes it to
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be used (this is the default). If the 8-bit library has not
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been built, this option causes an error.
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-16 If the 16-bit library has been built, this option causes it
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to be used. If the 8-bit library has not been built, this is
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the default. If the 16-bit library has not been built, this
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option causes an error.
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-32 If the 32-bit library has been built, this option causes it
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to be used. If no other library has been built, this is the
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default. If the 32-bit library has not been built, this op-
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tion causes an error.
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-ac Behave as if each pattern has the auto_callout modifier, that
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is, insert automatic callouts into every pattern that is com-
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piled.
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-AC As for -ac, but in addition behave as if each subject line
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has the callout_extra modifier, that is, show additional in-
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formation from callouts.
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-b Behave as if each pattern has the fullbincode modifier; the
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full internal binary form of the pattern is output after com-
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pilation.
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-C Output the version number of the PCRE2 library, and all
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available information about the optional features that are
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included, and then exit with zero exit code. All other op-
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tions are ignored. If both -C and -LM are present, whichever
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is first is recognized.
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-C option Output information about a specific build-time option, then
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exit. This functionality is intended for use in scripts such
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as RunTest. The following options output the value and set
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the exit code as indicated:
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ebcdic-nl the code for LF (= NL) in an EBCDIC environment:
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either 0x15 or 0x25
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0 if used in an ASCII/Unicode environment
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exit code is always 0
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linksize the configured internal link size (2, 3, or 4)
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exit code is set to the link size
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newline the default newline setting:
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CR, LF, CRLF, ANYCRLF, ANY, or NUL
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exit code is always 0
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bsr the default setting for what \R matches:
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ANYCRLF or ANY
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exit code is always 0
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The following options output 1 for true or 0 for false, and
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set the exit code to the same value:
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backslash-C \C is supported (not locked out)
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ebcdic compiled for an EBCDIC environment
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jit just-in-time support is available
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pcre2-16 the 16-bit library was built
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pcre2-32 the 32-bit library was built
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pcre2-8 the 8-bit library was built
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unicode Unicode support is available
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Note that the availability of JIT support in the library does
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not guarantee that it can actually be used because in some
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environments it is unable to allocate executable memory. The
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option "jitusable" gives more detailed information. It re-
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turns one of the following values:
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0 JIT is available and usable
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1 JIT is available but cannot allocate executable memory
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2 JIT is not available
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3 Unexpected return from test call to pcre2_jit_compile()
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If an unknown option is given, an error message is output;
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the exit code is 0.
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-d Behave as if each pattern has the debug modifier; the inter-
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nal form and information about the compiled pattern is output
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after compilation; -d is equivalent to -b -i.
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-dfa Behave as if each subject line has the dfa modifier; matching
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is done using the pcre2_dfa_match() function instead of the
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default pcre2_match().
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-error number[,number,...]
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Call pcre2_get_error_message() for each of the error numbers
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in the comma-separated list, display the resulting messages
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on the standard output, then exit with zero exit code. The
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numbers may be positive or negative. This is a convenience
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facility for PCRE2 maintainers.
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-help Output a brief summary these options and then exit.
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-i Behave as if each pattern has the info modifier; information
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about the compiled pattern is given after compilation.
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-jit Behave as if each pattern line has the jit modifier; after
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successful compilation, each pattern is passed to the just-
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in-time compiler, if available.
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-jitfast Behave as if each pattern line has the jitfast modifier; af-
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ter successful compilation, each pattern is passed to the
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just-in-time compiler, if available, and each subject line is
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passed directly to the JIT matcher via its "fast path".
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-jitverify
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Behave as if each pattern line has the jitverify modifier;
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after successful compilation, each pattern is passed to the
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just-in-time compiler, if available, and the use of JIT for
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matching is verified.
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-LM List modifiers: write a list of available pattern and subject
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modifiers to the standard output, then exit with zero exit
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code. All other options are ignored. If both -C and any -Lx
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options are present, whichever is first is recognized.
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-LP List properties: write a list of recognized Unicode proper-
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ties to the standard output, then exit with zero exit code.
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All other options are ignored. If both -C and any -Lx options
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are present, whichever is first is recognized.
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-LS List scripts: write a list of recognized Unicode script names
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to the standard output, then exit with zero exit code. All
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other options are ignored. If both -C and any -Lx options are
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present, whichever is first is recognized.
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-pattern modifier-list
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Behave as if each pattern line contains the given modifiers.
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-q Do not output the version number of pcre2test at the start of
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execution.
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-S size On Unix-like systems, set the size of the run-time stack to
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size mebibytes (units of 1024*1024 bytes).
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-subject modifier-list
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Behave as if each subject line contains the given modifiers.
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-t Run each compile and match many times with a timer, and out-
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put the resulting times per compile or match. When JIT is
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used, separate times are given for the initial compile and
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the JIT compile. You can control the number of iterations
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that are used for timing by following -t with a number (as a
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separate item on the command line). For example, "-t 1000"
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iterates 1000 times. The default is to iterate 500,000 times.
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-tm This is like -t except that it times only the matching phase,
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not the compile phase.
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-T -TM These behave like -t and -tm, but in addition, at the end of
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a run, the total times for all compiles and matches are out-
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put.
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-version Output the PCRE2 version number and then exit.
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DESCRIPTION
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If pcre2test is given two filename arguments, it reads from the first
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and writes to the second. If the first name is "-", input is taken from
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the standard input. If pcre2test is given only one argument, it reads
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from that file and writes to stdout. Otherwise, it reads from stdin and
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writes to stdout.
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When pcre2test is built, a configuration option can specify that it
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should be linked with the libreadline or libedit library. When this is
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done, if the input is from a terminal, it is read using the readline()
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function. This provides line-editing and history facilities. The output
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from the -help option states whether or not readline() will be used.
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The program handles any number of tests, each of which consists of a
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set of input lines. Each set starts with a regular expression pattern,
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followed by any number of subject lines to be matched against that pat-
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tern. In between sets of test data, command lines that begin with # may
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appear. This file format, with some restrictions, can also be processed
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by the perltest.sh script that is distributed with PCRE2 as a means of
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checking that the behaviour of PCRE2 and Perl is the same. For a speci-
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fication of perltest.sh, see the comments near its beginning. See also
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the #perltest command below.
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When the input is a terminal, pcre2test prompts for each line of input,
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using "re>" to prompt for regular expression patterns, and "data>" to
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prompt for subject lines. Command lines starting with # can be entered
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only in response to the "re>" prompt.
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Each subject line is matched separately and independently. If you want
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to do multi-line matches, you have to use the \n escape sequence (or \r
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or \r\n, etc., depending on the newline setting) in a single line of
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input to encode the newline sequences. There is no limit on the length
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of subject lines; the input buffer is automatically extended if it is
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too small. There are replication features that makes it possible to
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generate long repetitive pattern or subject lines without having to
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supply them explicitly.
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An empty line or the end of the file signals the end of the subject
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lines for a test, at which point a new pattern or command line is ex-
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pected if there is still input to be read.
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COMMAND LINES
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In between sets of test data, a line that begins with # is interpreted
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as a command line. If the first character is followed by white space or
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an exclamation mark, the line is treated as a comment, and ignored.
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Otherwise, the following commands are recognized:
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#forbid_utf
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Subsequent patterns automatically have the PCRE2_NEVER_UTF and
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PCRE2_NEVER_UCP options set, which locks out the use of the PCRE2_UTF
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and PCRE2_UCP options and the use of (*UTF) and (*UCP) at the start of
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patterns. This command also forces an error if a subsequent pattern
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contains any occurrences of \P, \p, or \X, which are still supported
|
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when PCRE2_UTF is not set, but which require Unicode property support
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to be included in the library.
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||||
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||||
This is a trigger guard that is used in test files to ensure that UTF
|
||||
or Unicode property tests are not accidentally added to files that are
|
||||
used when Unicode support is not included in the library. Setting
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PCRE2_NEVER_UTF and PCRE2_NEVER_UCP as a default can also be obtained
|
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by the use of #pattern; the difference is that #forbid_utf cannot be
|
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unset, and the automatic options are not displayed in pattern informa-
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tion, to avoid cluttering up test output.
|
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#load <filename>
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||||
|
||||
This command is used to load a set of precompiled patterns from a file,
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||||
as described in the section entitled "Saving and restoring compiled
|
||||
patterns" below.
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||||
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#loadtables <filename>
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||||
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||||
This command is used to load a set of binary character tables that can
|
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be accessed by the tables=3 qualifier. Such tables can be created by
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the pcre2_dftables program with the -b option.
|
||||
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||||
#newline_default [<newline-list>]
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||||
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||||
When PCRE2 is built, a default newline convention can be specified.
|
||||
This determines which characters and/or character pairs are recognized
|
||||
as indicating a newline in a pattern or subject string. The default can
|
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be overridden when a pattern is compiled. The standard test files con-
|
||||
tain tests of various newline conventions, but the majority of the
|
||||
tests expect a single linefeed to be recognized as a newline by de-
|
||||
fault. Without special action the tests would fail when PCRE2 is com-
|
||||
piled with either CR or CRLF as the default newline.
|
||||
|
||||
The #newline_default command specifies a list of newline types that are
|
||||
acceptable as the default. The types must be one of CR, LF, CRLF, ANY-
|
||||
CRLF, ANY, or NUL (in upper or lower case), for example:
|
||||
|
||||
#newline_default LF Any anyCRLF
|
||||
|
||||
If the default newline is in the list, this command has no effect. Oth-
|
||||
erwise, except when testing the POSIX API, a newline modifier that
|
||||
specifies the first newline convention in the list (LF in the above ex-
|
||||
ample) is added to any pattern that does not already have a newline
|
||||
modifier. If the newline list is empty, the feature is turned off. This
|
||||
command is present in a number of the standard test input files.
|
||||
|
||||
When the POSIX API is being tested there is no way to override the de-
|
||||
fault newline convention, though it is possible to set the newline con-
|
||||
vention from within the pattern. A warning is given if the posix or
|
||||
posix_nosub modifier is used when #newline_default would set a default
|
||||
for the non-POSIX API.
|
||||
|
||||
#pattern <modifier-list>
|
||||
|
||||
This command sets a default modifier list that applies to all subse-
|
||||
quent patterns. Modifiers on a pattern can change these settings.
|
||||
|
||||
#perltest
|
||||
|
||||
This line is used in test files that can also be processed by perl-
|
||||
test.sh to confirm that Perl gives the same results as PCRE2. Subse-
|
||||
quent tests are checked for the use of pcre2test features that are in-
|
||||
compatible with the perltest.sh script.
|
||||
|
||||
Patterns must use '/' as their delimiter, and only certain modifiers
|
||||
are supported. Comment lines, #pattern commands, and #subject commands
|
||||
that set or unset "mark" are recognized and acted on. The #perltest,
|
||||
#forbid_utf, and #newline_default commands, which are needed in the
|
||||
relevant pcre2test files, are silently ignored. All other command lines
|
||||
are ignored, but give a warning message. The #perltest command helps
|
||||
detect tests that are accidentally put in the wrong file or use the
|
||||
wrong delimiter. For more details of the perltest.sh script see the
|
||||
comments it contains.
|
||||
|
||||
#pop [<modifiers>]
|
||||
#popcopy [<modifiers>]
|
||||
|
||||
These commands are used to manipulate the stack of compiled patterns,
|
||||
as described in the section entitled "Saving and restoring compiled
|
||||
patterns" below.
|
||||
|
||||
#save <filename>
|
||||
|
||||
This command is used to save a set of compiled patterns to a file, as
|
||||
described in the section entitled "Saving and restoring compiled pat-
|
||||
terns" below.
|
||||
|
||||
#subject <modifier-list>
|
||||
|
||||
This command sets a default modifier list that applies to all subse-
|
||||
quent subject lines. Modifiers on a subject line can change these set-
|
||||
tings.
|
||||
|
||||
|
||||
MODIFIER SYNTAX
|
||||
|
||||
Modifier lists are used with both pattern and subject lines. Items in a
|
||||
list are separated by commas followed by optional white space. Trailing
|
||||
whitespace in a modifier list is ignored. Some modifiers may be given
|
||||
for both patterns and subject lines, whereas others are valid only for
|
||||
one or the other. Each modifier has a long name, for example "an-
|
||||
chored", and some of them must be followed by an equals sign and a
|
||||
value, for example, "offset=12". Values cannot contain comma charac-
|
||||
ters, but may contain spaces. Modifiers that do not take values may be
|
||||
preceded by a minus sign to turn off a previous setting.
|
||||
|
||||
A few of the more common modifiers can also be specified as single let-
|
||||
ters, for example "i" for "caseless". In documentation, following the
|
||||
Perl convention, these are written with a slash ("the /i modifier") for
|
||||
clarity. Abbreviated modifiers must all be concatenated in the first
|
||||
item of a modifier list. If the first item is not recognized as a long
|
||||
modifier name, it is interpreted as a sequence of these abbreviations.
|
||||
For example:
|
||||
|
||||
/abc/ig,newline=cr,jit=3
|
||||
|
||||
This is a pattern line whose modifier list starts with two one-letter
|
||||
modifiers (/i and /g). The lower-case abbreviated modifiers are the
|
||||
same as used in Perl.
|
||||
|
||||
|
||||
PATTERN SYNTAX
|
||||
|
||||
A pattern line must start with one of the following characters (common
|
||||
symbols, excluding pattern meta-characters):
|
||||
|
||||
/ ! " ' ` - = _ : ; , % & @ ~
|
||||
|
||||
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 delim-
|
||||
iter as a literal within the pattern by escaping it with a backslash,
|
||||
for example
|
||||
|
||||
/abc\/def/
|
||||
|
||||
If you do this, the escape and the delimiter form part of the pattern,
|
||||
but since the delimiters are all non-alphanumeric, the inclusion of the
|
||||
backslash does not affect the pattern's interpretation. Note, however,
|
||||
that this trick does not work within \Q...\E literal bracketing because
|
||||
the backslash will itself be interpreted as a literal. If the terminat-
|
||||
ing delimiter is immediately followed by a backslash, for example,
|
||||
|
||||
/abc/\
|
||||
|
||||
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
|
||||
|
||||
/abc\/
|
||||
|
||||
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 regu-
|
||||
lar expression.
|
||||
|
||||
A pattern can be followed by a modifier list (details below).
|
||||
|
||||
|
||||
SUBJECT LINE SYNTAX
|
||||
|
||||
Before each subject line is passed to pcre2_match(), pcre2_dfa_match(),
|
||||
or pcre2_jit_match(), leading and trailing white space is removed, and
|
||||
the line is scanned for backslash escapes, unless the subject_literal
|
||||
modifier was set for the pattern. The following provide a means of en-
|
||||
coding non-printing characters in a visible way:
|
||||
|
||||
\a alarm (BEL, \x07)
|
||||
\b backspace (\x08)
|
||||
\e escape (\x27)
|
||||
\f form feed (\x0c)
|
||||
\n newline (\x0a)
|
||||
\N{U+hh...} unicode character (any number of hex digits)
|
||||
\r carriage return (\x0d)
|
||||
\t tab (\x09)
|
||||
\v vertical tab (\x0b)
|
||||
\ddd octal number (up to 3 octal digits); represent a single
|
||||
code point unless larger than 255 with the 8-bit li-
|
||||
brary
|
||||
\o{dd...} octal number (any number of octal digits} representing a
|
||||
character in UTF mode or a code point
|
||||
\xhh hexadecimal byte (up to 2 hex digits)
|
||||
\x{hh...} hexadecimal number (up to 8 hex digits) representing a
|
||||
character in UTF mode or a code point
|
||||
|
||||
Invoking \N{U+hh...} or \x{hh...} doesn't require the use of the utf
|
||||
modifier on the pattern. It is always recognized. There may be any num-
|
||||
ber of hexadecimal digits inside the braces; invalid values provoke er-
|
||||
ror messages but when using \N{U+hh...} with some invalid unicode char-
|
||||
acters they will be accepted with a warning instead.
|
||||
|
||||
Note that even in UTF-8 mode, \xhh (and depending of how large, \ddd)
|
||||
describe one byte rather than one character; this makes it possible to
|
||||
construct invalid UTF-8 sequences for testing purposes. On the other
|
||||
hand, \x{hh...} is interpreted as a UTF-8 character in UTF-8 mode, only
|
||||
generating more than one byte if the value is greater than 127. To
|
||||
avoid the ambiguity it is preferred to use \N{U+hh...} when describing
|
||||
characters. When testing the 8-bit library not in UTF-8 mode, \x{hh}
|
||||
generates one byte for values that could fit on it, and causes an error
|
||||
for greater values.
|
||||
|
||||
When testing the 16-bit library, not in UTF-16 mode, all 4-digit
|
||||
\x{hhhh} values are accepted. This makes it possible to construct in-
|
||||
valid UTF-16 sequences for testing purposes.
|
||||
|
||||
When testing the 32-bit library, not in UTF-32 mode, all 4 to 8-digit
|
||||
\x{...} values are accepted. This makes it possible to construct in-
|
||||
valid UTF-32 sequences for testing purposes.
|
||||
|
||||
There is a special backslash sequence that specifies replication of one
|
||||
or more characters:
|
||||
|
||||
\[<characters>]{<count>}
|
||||
|
||||
This makes it possible to test long strings without having to provide
|
||||
them as part of the file. For example:
|
||||
|
||||
\[abc]{4}
|
||||
|
||||
is converted to "abcabcabcabc". This feature does not support nesting.
|
||||
To include a closing square bracket in the characters, code it as \x5D.
|
||||
|
||||
A backslash followed by an equals sign marks the end of the subject
|
||||
string and the start of a modifier list. For example:
|
||||
|
||||
abc\=notbol,notempty
|
||||
|
||||
If the subject string is empty and \= is followed by whitespace, the
|
||||
line is treated as a comment line, and is not used for matching. For
|
||||
example:
|
||||
|
||||
\= This is a comment.
|
||||
abc\= This is an invalid modifier list.
|
||||
|
||||
A backslash followed by any other non-alphanumeric character just es-
|
||||
capes 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.
|
||||
|
||||
If the subject_literal modifier is set for a pattern, all subject lines
|
||||
that follow are treated as literals, with no special treatment of back-
|
||||
slashes. No replication is possible, and any subject modifiers must be
|
||||
set as defaults by a #subject command.
|
||||
|
||||
|
||||
PATTERN MODIFIERS
|
||||
|
||||
There are several types of modifier that can appear in pattern lines.
|
||||
Except where noted below, they may also be used in #pattern commands. A
|
||||
pattern's modifier list can add to or override default modifiers that
|
||||
were set by a previous #pattern command.
|
||||
|
||||
Setting compilation options
|
||||
|
||||
The following modifiers set options for pcre2_compile(). 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. Some of these options have single-letter abbrevia-
|
||||
tions. 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 dif-
|
||||
ference to the way pcre2_compile() behaves. See pcre2api for a descrip-
|
||||
tion of the effects of these options.
|
||||
|
||||
allow_empty_class set PCRE2_ALLOW_EMPTY_CLASS
|
||||
allow_lookaround_bsk set PCRE2_EXTRA_ALLOW_LOOKAROUND_BSK
|
||||
allow_surrogate_escapes set PCRE2_EXTRA_ALLOW_SURROGATE_ESCAPES
|
||||
alt_bsux set PCRE2_ALT_BSUX
|
||||
alt_circumflex set PCRE2_ALT_CIRCUMFLEX
|
||||
alt_extended_class set PCRE2_ALT_EXTENDED_CLASS
|
||||
alt_verbnames set PCRE2_ALT_VERBNAMES
|
||||
anchored set PCRE2_ANCHORED
|
||||
/a ascii_all set all ASCII options
|
||||
ascii_bsd set PCRE2_EXTRA_ASCII_BSD
|
||||
ascii_bss set PCRE2_EXTRA_ASCII_BSS
|
||||
ascii_bsw set PCRE2_EXTRA_ASCII_BSW
|
||||
ascii_digit set PCRE2_EXTRA_ASCII_DIGIT
|
||||
ascii_posix set PCRE2_EXTRA_ASCII_POSIX
|
||||
auto_callout set PCRE2_AUTO_CALLOUT
|
||||
bad_escape_is_literal set PCRE2_EXTRA_BAD_ESCAPE_IS_LITERAL
|
||||
/i caseless set PCRE2_CASELESS
|
||||
/r caseless_restrict set PCRE2_EXTRA_CASELESS_RESTRICT
|
||||
dollar_endonly set PCRE2_DOLLAR_ENDONLY
|
||||
/s dotall set PCRE2_DOTALL
|
||||
dupnames set PCRE2_DUPNAMES
|
||||
endanchored set PCRE2_ENDANCHORED
|
||||
escaped_cr_is_lf set PCRE2_EXTRA_ESCAPED_CR_IS_LF
|
||||
/x extended set PCRE2_EXTENDED
|
||||
/xx extended_more set PCRE2_EXTENDED_MORE
|
||||
extra_alt_bsux set PCRE2_EXTRA_ALT_BSUX
|
||||
firstline set PCRE2_FIRSTLINE
|
||||
literal set PCRE2_LITERAL
|
||||
match_line set PCRE2_EXTRA_MATCH_LINE
|
||||
match_invalid_utf set PCRE2_MATCH_INVALID_UTF
|
||||
match_unset_backref set PCRE2_MATCH_UNSET_BACKREF
|
||||
match_word set PCRE2_EXTRA_MATCH_WORD
|
||||
/m multiline set PCRE2_MULTILINE
|
||||
never_backslash_c set PCRE2_NEVER_BACKSLASH_C
|
||||
never_callout set PCRE2_EXTRA_NEVER_CALLOUT
|
||||
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_bs0 set PCRE2_EXTRA_NO_BS0
|
||||
no_dotstar_anchor set PCRE2_NO_DOTSTAR_ANCHOR
|
||||
no_start_optimize set PCRE2_NO_START_OPTIMIZE
|
||||
no_utf_check set PCRE2_NO_UTF_CHECK
|
||||
python_octal set PCRE2_EXTRA_PYTHON_OCTAL
|
||||
turkish_casing set PCRE2_EXTRA_TURKISH_CASING
|
||||
ucp set PCRE2_UCP
|
||||
ungreedy set PCRE2_UNGREEDY
|
||||
use_offset_limit set PCRE2_USE_OFFSET_LIMIT
|
||||
utf set PCRE2_UTF
|
||||
|
||||
As well as turning on the PCRE2_UTF option, the utf modifier causes all
|
||||
non-printing characters in output strings to be printed using the
|
||||
\x{hh...} notation. Otherwise, those less than 0x100 are output in hex
|
||||
without the curly brackets. Setting utf 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.
|
||||
|
||||
The following modifiers enable or disable performance optimizations by
|
||||
calling pcre2_set_optimize() before invoking the regex compiler.
|
||||
|
||||
optimization_full enable all optional optimizations
|
||||
optimization_none disable all optional optimizations
|
||||
auto_possess auto-possessify variable quantifiers
|
||||
auto_possess_off don't auto-possessify variable quantifiers
|
||||
dotstar_anchor anchor patterns starting with .*
|
||||
dotstar_anchor_off don't anchor patterns starting with .*
|
||||
start_optimize enable pre-scan of subject string
|
||||
start_optimize_off disable pre-scan of subject string
|
||||
|
||||
See the pcre2_set_optimize documentation for details on these optimiza-
|
||||
tions.
|
||||
|
||||
Setting compilation controls
|
||||
|
||||
The following modifiers affect the compilation process or request in-
|
||||
formation about the pattern. There are single-letter abbreviations for
|
||||
some that are heavily used in the test files.
|
||||
|
||||
/B bincode show binary code without lengths
|
||||
bsr=[anycrlf|unicode] specify \R handling
|
||||
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
|
||||
expand expand repetition syntax in pattern
|
||||
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_compiled ) set maximum compiled pattern
|
||||
_length=<n> ) length (bytes)
|
||||
max_pattern_length=<n> set maximum pattern length (code units)
|
||||
max_varlookbehind=<n> set maximum variable lookbehind length
|
||||
memory show memory used
|
||||
newline=<type> set newline type
|
||||
null_context compile with a NULL context
|
||||
null_pattern pass pattern as NULL
|
||||
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
|
||||
pushtablescopy push a copy with tables onto the stack
|
||||
stackguard=<number> test the stackguard feature
|
||||
subject_literal treat all subject lines as literal
|
||||
tables=[0|1|2|3] select internal tables
|
||||
use_length do not zero-terminate the pattern
|
||||
utf8_input treat input as UTF-8
|
||||
|
||||
The effects of these modifiers are described in the following sections.
|
||||
|
||||
Newline and \R handling
|
||||
|
||||
The bsr modifier specifies what \R in a pattern should match. If it is
|
||||
set to "anycrlf", \R matches CR, LF, or CRLF only. If it is set to
|
||||
"unicode", \R matches any Unicode newline sequence. The default can be
|
||||
specified when PCRE2 is built; if it is not, the default is set to Uni-
|
||||
code.
|
||||
|
||||
The newline 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).
|
||||
|
||||
Information about a pattern
|
||||
|
||||
The debug modifier is a shorthand for info,fullbincode, requesting all
|
||||
available information.
|
||||
|
||||
The bincode 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 dif-
|
||||
ferent internal link sizes and different code unit widths. By using
|
||||
bincode, the same regression tests can be used in different environ-
|
||||
ments.
|
||||
|
||||
The fullbincode modifier, by contrast, does 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.
|
||||
|
||||
The info 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 pcre2_pattern_info() function. Here
|
||||
are some typical examples:
|
||||
|
||||
re> /(?i)(^a|^b)/m,info
|
||||
Capture group count = 1
|
||||
Compile options: multiline
|
||||
Overall options: caseless multiline
|
||||
First code unit at start or follows newline
|
||||
Subject length lower bound = 1
|
||||
|
||||
re> /(?i)abc/info
|
||||
Capture group count = 0
|
||||
Compile options: <none>
|
||||
Overall options: caseless
|
||||
First code unit = 'a' (caseless)
|
||||
Last code unit = 'c' (caseless)
|
||||
Subject length lower bound = 3
|
||||
|
||||
"Compile options" are those specified by modifiers; "overall options"
|
||||
have added options that are taken or deduced from the pattern. If both
|
||||
sets of options are the same, just a single "options" line is output;
|
||||
if there are no options, the line is omitted. "First code unit" is
|
||||
where any match must start; if there is more than one they are listed
|
||||
as "starting code units". "Last code unit" is the last literal code
|
||||
unit that must be present in any match. This is not necessarily the
|
||||
last character. These lines are omitted if no starting or ending code
|
||||
units are recorded. The subject length line is omitted when
|
||||
no_start_optimize is set because the minimum length is not calculated
|
||||
when it can never be used.
|
||||
|
||||
The framesize modifier shows the size, in bytes, of each storage frame
|
||||
used by pcre2_match() for handling backtracking. The size depends on
|
||||
the number of capturing parentheses in the pattern. A vector of these
|
||||
frames is used at matching time; its overall size is shown when the
|
||||
heaframes_size subject modifier is set.
|
||||
|
||||
The callout_info modifier requests information about all the callouts
|
||||
in the pattern. A list of them is output at the end of any other infor-
|
||||
mation that is requested. For each callout, either its number or string
|
||||
is given, followed by the item that follows it in the pattern.
|
||||
|
||||
Passing a NULL context
|
||||
|
||||
Normally, pcre2test passes a context block to pcre2_compile(). If the
|
||||
null_context modifier is set, however, NULL is passed. This is for
|
||||
testing that pcre2_compile() behaves correctly in this case (it uses
|
||||
default values).
|
||||
|
||||
Passing a NULL pattern
|
||||
|
||||
The null_pattern modifier is for testing the behaviour of pcre2_com-
|
||||
pile() when the pattern argument is NULL. The length value passed is
|
||||
the default PCRE2_ZERO_TERMINATED unless use_length is set. Any length
|
||||
other than zero causes an error.
|
||||
|
||||
Specifying pattern characters in hexadecimal
|
||||
|
||||
The hex modifier specifies that the characters of the pattern, except
|
||||
for substrings enclosed in single or double quotes, are to be inter-
|
||||
preted as pairs of hexadecimal digits. This feature is provided as a
|
||||
way of creating patterns that contain binary zeros and other non-print-
|
||||
ing characters. White space is permitted between pairs of digits. For
|
||||
example, this pattern contains three characters:
|
||||
|
||||
/ab 32 59/hex
|
||||
|
||||
Parts of such a pattern are taken literally if quoted. This pattern
|
||||
contains nine characters, only two of which are specified in hexadeci-
|
||||
mal:
|
||||
|
||||
/ab "literal" 32/hex
|
||||
|
||||
Either single or double quotes may be used. There is no way of includ-
|
||||
ing the delimiter within a substring. The hex and expand modifiers are
|
||||
mutually exclusive.
|
||||
|
||||
Specifying the pattern's length
|
||||
|
||||
By default, patterns are passed to the compiling functions as zero-ter-
|
||||
minated strings but can be passed by length instead of being zero-ter-
|
||||
minated. The use_length modifier causes this to happen. Using a length
|
||||
happens automatically (whether or not use_length is set) when hex is
|
||||
set, because patterns specified in hexadecimal may contain binary ze-
|
||||
ros.
|
||||
|
||||
If hex or use_length is used with the POSIX wrapper API (see "Using the
|
||||
POSIX wrapper API" below), the REG_PEND extension is used to pass the
|
||||
pattern's length.
|
||||
|
||||
Specifying a maximum for variable lookbehinds
|
||||
|
||||
Variable lookbehind assertions are supported only if, for each one,
|
||||
there is a maximum length (in characters) that it can match. There is a
|
||||
limit on this, whose default can be set at build time, with an ultimate
|
||||
default of 255. The max_varlookbehind modifier uses the
|
||||
pcre2_set_max_varlookbehind() function to change the limit. Lookbehinds
|
||||
whose branches each match a fixed length are limited to 65535 charac-
|
||||
ters per branch.
|
||||
|
||||
Specifying wide characters in 16-bit and 32-bit modes
|
||||
|
||||
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 utf modifier is set. For
|
||||
testing the 16-bit and 32-bit libraries in non-UTF mode, the utf8_input
|
||||
modifier can be used. It is mutually exclusive with utf. Input lines
|
||||
are interpreted as UTF-8 as a means of specifying wide characters. More
|
||||
details are given in "Input encoding" above.
|
||||
|
||||
Generating long repetitive patterns
|
||||
|
||||
Some tests use long patterns that are very repetitive. Instead of cre-
|
||||
ating 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 expand modifier is present on a pattern, parts of the
|
||||
pattern that have the form
|
||||
|
||||
\[<characters>]{<count>}
|
||||
|
||||
are expanded before the pattern is passed to pcre2_compile(). For exam-
|
||||
ple, \[AB]{6000} is expanded to "ABAB..." 6000 times. This construction
|
||||
cannot be nested. An initial "\[" sequence is recognized only if "]{"
|
||||
followed by decimal digits and "}" is found later in the pattern. If
|
||||
not, the characters remain in the pattern unaltered. The expand and hex
|
||||
modifiers are mutually exclusive.
|
||||
|
||||
If part of an expanded pattern looks like an expansion, but is really
|
||||
part of the actual pattern, unwanted expansion can be avoided by giving
|
||||
two values in the quantifier. For example, \[AB]{6000,6000} is not rec-
|
||||
ognized as an expansion item.
|
||||
|
||||
If the info modifier is set on an expanded pattern, the result of the
|
||||
expansion is included in the information that is output.
|
||||
|
||||
JIT compilation
|
||||
|
||||
Just-in-time (JIT) compiling is a heavyweight optimization that can
|
||||
greatly speed up pattern matching. See the pcre2jit 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
|
||||
partial modifier in "Subject Modifiers" below for details of how these
|
||||
options are specified for each match attempt.
|
||||
|
||||
JIT compilation is requested by the jit pattern modifier, which may op-
|
||||
tionally 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:
|
||||
|
||||
1 compile JIT code for non-partial matching
|
||||
2 compile JIT code for soft partial matching
|
||||
4 compile JIT code for hard partial matching
|
||||
|
||||
The possible values for the jit modifier are therefore:
|
||||
|
||||
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
|
||||
|
||||
If no number is given, 7 is assumed. The phrase "partial matching"
|
||||
means a call to pcre2_match() with either the PCRE2_PARTIAL_SOFT or the
|
||||
PCRE2_PARTIAL_HARD option set. Note that such a call may return a com-
|
||||
plete 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 partial
|
||||
modifier on a subject line, that match will not use JIT code because
|
||||
none was compiled for non-partial matching.
|
||||
|
||||
If JIT compilation is successful, the compiled JIT code will automati-
|
||||
cally be used when an appropriate type of match is run, except when in-
|
||||
compatible run-time options are specified. For more details, see the
|
||||
pcre2jit documentation. See also the jitstack modifier below for a way
|
||||
of setting the size of the JIT stack.
|
||||
|
||||
If the jitfast modifier is specified, matching is done using the JIT
|
||||
"fast path" interface, pcre2_jit_match(), which skips some of the san-
|
||||
ity checks that are done by pcre2_match(), and of course does not work
|
||||
when JIT is not supported. If jitfast is specified without jit, jit=7
|
||||
is assumed.
|
||||
|
||||
If the jitverify modifier is specified, information about the compiled
|
||||
pattern shows whether JIT compilation was or was not successful. If
|
||||
jitverify is specified without jit, jit=7 is assumed. If JIT compila-
|
||||
tion is successful when jitverify 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.
|
||||
|
||||
Setting a locale
|
||||
|
||||
The locale modifier must specify the name of a locale, for example:
|
||||
|
||||
/pattern/locale=fr_FR
|
||||
|
||||
The given locale is set, pcre2_maketables() is called to build a set of
|
||||
character tables for the locale, and this is then passed to pcre2_com-
|
||||
pile() when compiling the regular expression. The same tables are used
|
||||
when matching the following subject lines. The locale modifier applies
|
||||
only to the pattern on which it appears, but can be given in a #pattern
|
||||
command if a default is needed. Setting a locale and alternate charac-
|
||||
ter tables are mutually exclusive.
|
||||
|
||||
Showing pattern memory
|
||||
|
||||
The memory 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 pcre2_code block; it is just the actual compiled data. If the pat-
|
||||
tern is subsequently passed to the JIT compiler, the size of the JIT
|
||||
compiled code is also output. Here is an example:
|
||||
|
||||
re> /a(b)c/jit,memory
|
||||
Memory allocation (code space): 21
|
||||
Memory allocation (JIT code): 1910
|
||||
|
||||
|
||||
Limiting nested parentheses
|
||||
|
||||
The parens_nest_limit modifier sets a limit on the depth of nested
|
||||
parentheses in a pattern. Breaching the limit causes a compilation er-
|
||||
ror. The default for the library is set when PCRE2 is built, but
|
||||
pcre2test sets its own default of 220, which is required for running
|
||||
the standard test suite.
|
||||
|
||||
Limiting the pattern length
|
||||
|
||||
The max_pattern_length modifier sets a limit, in code units, to the
|
||||
length of pattern that pcre2_compile() will accept. Breaching the limit
|
||||
causes a compilation error. The default is the largest number a
|
||||
PCRE2_SIZE variable can hold (essentially unlimited).
|
||||
|
||||
Limiting the size of a compiled pattern
|
||||
|
||||
The max_pattern_compiled_length modifier sets a limit, in bytes, to the
|
||||
amount of memory used by a compiled pattern. Breaching the limit causes
|
||||
a compilation error. The default is the largest number a PCRE2_SIZE
|
||||
variable can hold (essentially unlimited).
|
||||
|
||||
Using the POSIX wrapper API
|
||||
|
||||
The posix and posix_nosub modifiers cause pcre2test to call PCRE2 via
|
||||
the POSIX wrapper API rather than its native API. When posix_nosub is
|
||||
used, the POSIX option REG_NOSUB is passed to regcomp(). The POSIX
|
||||
wrapper supports only the 8-bit library. Note that it does not imply
|
||||
POSIX matching semantics; for more detail see the pcre2posix documenta-
|
||||
tion. The following pattern modifiers set options for the regcomp()
|
||||
function:
|
||||
|
||||
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 )
|
||||
|
||||
The regerror_buffsize modifier specifies a size for the error buffer
|
||||
that is passed to regerror() in the event of a compilation error. For
|
||||
example:
|
||||
|
||||
/abc/posix,regerror_buffsize=20
|
||||
|
||||
This provides a means of testing the behaviour of regerror() when the
|
||||
buffer is too small for the error message. If this modifier has not
|
||||
been set, a large buffer is used.
|
||||
|
||||
The aftertext and allaftertext subject modifiers work as described be-
|
||||
low. All other modifiers are either ignored, with a warning message, or
|
||||
cause an error.
|
||||
|
||||
The pattern is passed to regcomp() as a zero-terminated string by de-
|
||||
fault, but if the use_length or hex modifiers are set, the REG_PEND ex-
|
||||
tension is used to pass it by length.
|
||||
|
||||
Testing the stack guard feature
|
||||
|
||||
The stackguard modifier is used to test the use of pcre2_set_com-
|
||||
pile_recursion_guard(), a function that is provided to enable stack
|
||||
availability to be checked during compilation (see the pcre2api docu-
|
||||
mentation for details). If the number specified by the modifier is
|
||||
greater than zero, pcre2_set_compile_recursion_guard() is called to set
|
||||
up callback from pcre2_compile() 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.
|
||||
|
||||
Using alternative character tables
|
||||
|
||||
The value specified for the tables modifier must be one of the digits
|
||||
0, 1, 2, or 3. It causes a specific set of built-in character tables to
|
||||
be passed to pcre2_compile(). This is used in the PCRE2 tests to check
|
||||
behaviour with different character tables. The digit specifies the ta-
|
||||
bles as follows:
|
||||
|
||||
0 do not pass any special character tables
|
||||
1 the default ASCII tables, as distributed in
|
||||
pcre2_chartables.c.dist
|
||||
2 a set of tables defining ISO 8859 characters
|
||||
3 a set of tables loaded by the #loadtables command
|
||||
|
||||
In tables 2, some characters whose codes are greater than 128 are iden-
|
||||
tified as letters, digits, spaces, etc. Tables 3 can be used only after
|
||||
a #loadtables command has loaded them from a binary file. Setting al-
|
||||
ternate character tables and a locale are mutually exclusive.
|
||||
|
||||
Setting certain match controls
|
||||
|
||||
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 sub-
|
||||
ject line that is processed with that pattern. These modifiers do not
|
||||
affect the compilation process.
|
||||
|
||||
aftertext show text after match
|
||||
allaftertext show text after captures
|
||||
allcaptures show all captures
|
||||
allvector show the entire ovector
|
||||
allusedtext show all consulted text
|
||||
altglobal alternative global matching
|
||||
/g global global matching
|
||||
heapframes_size show match data heapframes size
|
||||
jitstack=<n> set size of JIT stack
|
||||
mark show mark values
|
||||
replace=<string> specify a replacement string
|
||||
startchar show starting character when relevant
|
||||
substitute_callout use substitution callouts
|
||||
substitute_case_callout use substitution case callouts
|
||||
substitute_extended use PCRE2_SUBSTITUTE_EXTENDED
|
||||
substitute_literal use PCRE2_SUBSTITUTE_LITERAL
|
||||
substitute_matched use PCRE2_SUBSTITUTE_MATCHED
|
||||
substitute_overflow_length use PCRE2_SUBSTITUTE_OVERFLOW_LENGTH
|
||||
substitute_replacement_only use PCRE2_SUBSTITUTE_REPLACEMENT_ONLY
|
||||
substitute_skip=<n> skip substitution <n>
|
||||
substitute_stop=<n> skip substitution <n> and following
|
||||
substitute_unknown_unset use PCRE2_SUBSTITUTE_UNKNOWN_UNSET
|
||||
substitute_unset_empty use PCRE2_SUBSTITUTE_UNSET_EMPTY
|
||||
|
||||
These modifiers may not appear in a #pattern command. If you want them
|
||||
as defaults, set them in a #subject command.
|
||||
|
||||
Specifying literal subject lines
|
||||
|
||||
If the subject_literal modifier is present on a pattern, all the sub-
|
||||
ject lines that it matches are taken as literal strings, with no inter-
|
||||
pretation of backslashes. It is not possible to set subject modifiers
|
||||
on such lines, but any that are set as defaults by a #subject command
|
||||
are recognized.
|
||||
|
||||
Saving a compiled pattern
|
||||
|
||||
When a pattern with the push modifier is successfully compiled, it is
|
||||
pushed onto a stack of compiled patterns, and pcre2test 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 pat-
|
||||
terns" below. If pushcopy is used instead of push, a copy of the com-
|
||||
piled pattern is stacked, leaving the original as current, ready to
|
||||
match the following input lines. This provides a way of testing the
|
||||
pcre2_code_copy() function. The push and pushcopy modifiers are in-
|
||||
compatible with compilation modifiers such as global that act at match
|
||||
time. Any that are specified are ignored (for the stacked copy), with a
|
||||
warning message, except for replace, which causes an error. Note that
|
||||
jitverify, which is allowed, does not carry through to any subsequent
|
||||
matching that uses a stacked pattern.
|
||||
|
||||
Testing foreign pattern conversion
|
||||
|
||||
The experimental foreign pattern conversion functions in PCRE2 can be
|
||||
tested by setting the convert modifier. Its argument is a colon-sepa-
|
||||
rated list of options, which set the equivalent option for the
|
||||
pcre2_pattern_convert() function:
|
||||
|
||||
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
|
||||
|
||||
The "unset" value is useful for turning off a default that has been set
|
||||
by a #pattern command. When one of these options is set, the input pat-
|
||||
tern is passed to pcre2_pattern_convert(). If the conversion is suc-
|
||||
cessful, the result is reflected in the output and then passed to
|
||||
pcre2_compile(). The normal utf and no_utf_check options, if set, cause
|
||||
the PCRE2_CONVERT_UTF and PCRE2_CONVERT_NO_UTF_CHECK options to be
|
||||
passed to pcre2_pattern_convert().
|
||||
|
||||
By default, the conversion function is allowed to allocate a buffer for
|
||||
its output. However, if the convert_length modifier is set to a value
|
||||
greater than zero, pcre2test passes a buffer of the given length. This
|
||||
makes it possible to test the length check.
|
||||
|
||||
The convert_glob_escape and convert_glob_separator modifiers can be
|
||||
used to specify the escape and separator characters for glob process-
|
||||
ing, overriding the defaults, which are operating-system dependent.
|
||||
|
||||
|
||||
SUBJECT MODIFIERS
|
||||
|
||||
The modifiers that can appear in subject lines and the #subject command
|
||||
are of two types.
|
||||
|
||||
Setting match options
|
||||
|
||||
The following modifiers set options for pcre2_match() or
|
||||
pcre2_dfa_match(). See pcre2api for a description of their effects.
|
||||
|
||||
anchored set PCRE2_ANCHORED
|
||||
copy_matched_subject set PCRE2_COPY_MATCHED_SUBJECT
|
||||
endanchored set PCRE2_ENDANCHORED
|
||||
dfa_restart set PCRE2_DFA_RESTART
|
||||
dfa_shortest set PCRE2_DFA_SHORTEST
|
||||
disable_recurseloop_check set PCRE2_DISABLE_RECURSELOOP_CHECK
|
||||
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
|
||||
|
||||
The partial matching modifiers are provided with abbreviations because
|
||||
they appear frequently in tests.
|
||||
|
||||
If the posix or posix_nosub modifier was present on the pattern, caus-
|
||||
ing the POSIX wrapper API to be used, the only option-setting modifiers
|
||||
that have any effect are notbol, notempty, and noteol, causing REG_NOT-
|
||||
BOL, REG_NOTEMPTY, and REG_NOTEOL, respectively, to be passed to
|
||||
regexec(). The other modifiers are ignored, with a warning message.
|
||||
|
||||
There is one additional modifier that can be used with the POSIX wrap-
|
||||
per. It is ignored (with a warning) if used for non-POSIX matching.
|
||||
|
||||
posix_startend=<n>[:<m>]
|
||||
|
||||
This causes the subject string to be passed to regexec() 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_STAR-
|
||||
TEND, see the pcre2posix documentation. If the subject string contains
|
||||
binary zeros (coded as escapes such as \x{00} because pcre2test does
|
||||
not support actual binary zeros in its input), you must use posix_star-
|
||||
tend to specify its length.
|
||||
|
||||
Setting match controls
|
||||
|
||||
The following modifiers affect the matching process or request addi-
|
||||
tional 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, but can be overridden by modifiers on
|
||||
the subject.
|
||||
|
||||
aftertext show text after match
|
||||
allaftertext show text after captures
|
||||
allcaptures show all captures
|
||||
allusedtext show all consulted text (non-JIT only)
|
||||
allvector show the entire ovector
|
||||
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 pcre2_dfa_match()
|
||||
find_limits find heap, match and depth limits
|
||||
find_limits_noheap find match and depth limits
|
||||
get=<number or name> extract captured substring
|
||||
getall extract all captured substrings
|
||||
/g global global matching
|
||||
heapframes_size show match data heapframes size
|
||||
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
|
||||
null_replacement substitute with NULL replacement
|
||||
null_subject match with NULL subject
|
||||
offset=<n> set starting offset
|
||||
offset_limit=<n> set offset limit
|
||||
ovector=<n> set size of output vector
|
||||
recursion_limit=<n> obsolete synonym for depth_limit
|
||||
replace=<string> specify a replacement string
|
||||
startchar show startchar when relevant
|
||||
startoffset=<n> same as offset=<n>
|
||||
substitute_callout use substitution callouts
|
||||
substitute_case_callout use substitution case callouts
|
||||
substitute_extended use PCRE2_SUBSTITUTE_EXTENDED
|
||||
substitute_literal use PCRE2_SUBSTITUTE_LITERAL
|
||||
substitute_matched use PCRE2_SUBSTITUTE_MATCHED
|
||||
substitute_overflow_length use PCRE2_SUBSTITUTE_OVERFLOW_LENGTH
|
||||
substitute_replacement_only use PCRE2_SUBSTITUTE_REPLACEMENT_ONLY
|
||||
substitute_skip=<n> skip substitution number n
|
||||
substitute_stop=<n> skip substitution number n and greater
|
||||
substitute_unknown_unset use PCRE2_SUBSTITUTE_UNKNOWN_UNSET
|
||||
substitute_unset_empty use PCRE2_SUBSTITUTE_UNSET_EMPTY
|
||||
zero_terminate pass the subject as zero-terminated
|
||||
|
||||
The effects of these modifiers are described in the following sections.
|
||||
When matching via the POSIX wrapper API, the aftertext, allaftertext,
|
||||
and ovector subject modifiers work as described below. All other modi-
|
||||
fiers are either ignored, with a warning message, or cause an error.
|
||||
|
||||
Showing more text
|
||||
|
||||
The aftertext modifier requests that as well as outputting the part of
|
||||
the subject string that matched the entire pattern, pcre2test 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 allaftertext modifier requests the same action for captured sub-
|
||||
strings as well as the main matched substring. In each case the remain-
|
||||
der is output on the following line with a plus character following the
|
||||
capture number.
|
||||
|
||||
The allusedtext modifier requests that all the text that was consulted
|
||||
during a successful pattern match by the interpreter should be shown,
|
||||
for both full and partial matches. This feature is not supported for
|
||||
JIT matching, and if requested with JIT it is ignored (with a warning
|
||||
message). Setting this modifier affects the output if there is a look-
|
||||
behind at the start of a match, or, for a complete match, a lookahead
|
||||
at the end, or if \K is used in the pattern. Characters that precede or
|
||||
follow the start and end of the actual match are indicated in the out-
|
||||
put by '<' or '>' characters underneath them. Here is an example:
|
||||
|
||||
re> /(?<=pqr)abc(?=xyz)/
|
||||
data> 123pqrabcxyz456\=allusedtext
|
||||
0: pqrabcxyz
|
||||
<<< >>>
|
||||
data> 123pqrabcxy\=ph,allusedtext
|
||||
Partial match: pqrabcxy
|
||||
<<<
|
||||
|
||||
The first, complete match shows that the matched string is "abc", with
|
||||
the preceding and following strings "pqr" and "xyz" having been con-
|
||||
sulted during the match (when processing the assertions). The partial
|
||||
match can indicate only the preceding string.
|
||||
|
||||
The startchar modifier requests that the starting character for the
|
||||
match be indicated, if it is different to the start of the matched
|
||||
string. The only time when this occurs is when \K has been processed as
|
||||
part of the match. In this situation, the output for the matched string
|
||||
is displayed from the starting character instead of from the match
|
||||
point, with circumflex characters under the earlier characters. For ex-
|
||||
ample:
|
||||
|
||||
re> /abc\Kxyz/
|
||||
data> abcxyz\=startchar
|
||||
0: abcxyz
|
||||
^^^
|
||||
|
||||
Unlike allusedtext, the startchar modifier can be used with JIT. How-
|
||||
ever, these two modifiers are mutually exclusive.
|
||||
|
||||
Showing the value of all capture groups
|
||||
|
||||
The allcaptures modifier requests that the values of all potential cap-
|
||||
tured 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 pcre2_match()). Groups that did not take part in
|
||||
the match are output as "<unset>". This modifier is not relevant for
|
||||
DFA matching (which does no capturing) and does not apply when replace
|
||||
is specified; it is ignored, with a warning message, if present.
|
||||
|
||||
Showing the entire ovector, for all outcomes
|
||||
|
||||
The allvector modifier requests that the entire ovector be shown, what-
|
||||
ever the outcome of the match. Compare allcaptures, which shows only up
|
||||
to the maximum number of capture groups for the pattern, and then only
|
||||
for a successful complete non-DFA match. This modifier, which acts af-
|
||||
ter any match result, and also for DFA matching, provides a means of
|
||||
checking that there are no unexpected modifications to ovector fields.
|
||||
Before each match attempt, the ovector is filled with a special value,
|
||||
and if this is found in both elements of a capturing pair, "<un-
|
||||
changed>" is output. After a successful match, this applies to all
|
||||
groups after the maximum capture group for the pattern. In other cases
|
||||
it applies to the entire ovector. After a partial match, the first two
|
||||
elements are the only ones that should be set. After a DFA match, the
|
||||
amount of ovector that is used depends on the number of matches that
|
||||
were found.
|
||||
|
||||
Testing pattern callouts
|
||||
|
||||
A callout function is supplied when pcre2test calls the library match-
|
||||
ing functions, unless callout_none is specified. Its behaviour can be
|
||||
controlled by various modifiers listed above whose names begin with
|
||||
callout_. Details are given in the section entitled "Callouts" below.
|
||||
Testing callouts from pcre2_substitute() is described separately in
|
||||
"Testing the substitution function" below.
|
||||
|
||||
Finding all matches in a string
|
||||
|
||||
Searching for all possible matches within a subject can be requested by
|
||||
the global or altglobal modifier. After finding a match, the matching
|
||||
function is called again to search the remainder of the subject. The
|
||||
difference between global and altglobal is that the former uses the
|
||||
start_offset argument to pcre2_match() or pcre2_dfa_match() 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 lookbe-
|
||||
hind assertion (including \b or \B).
|
||||
|
||||
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 re-
|
||||
tried. This imitates the way Perl handles such cases when using the /g
|
||||
modifier or the split() function. Normally, the start offset is ad-
|
||||
vanced by one character, but if the newline convention recognizes CRLF
|
||||
as a newline, and the current character is CR followed by LF, an ad-
|
||||
vance of two characters occurs.
|
||||
|
||||
Testing substring extraction functions
|
||||
|
||||
The copy and get modifiers can be used to test the pcre2_sub-
|
||||
string_copy_xxx() and pcre2_substring_get_xxx() functions. They can be
|
||||
given more than once, and each can specify a capture group name or num-
|
||||
ber, for example:
|
||||
|
||||
abcd\=copy=1,copy=3,get=G1
|
||||
|
||||
If the #subject command is used to set default copy and/or get lists,
|
||||
these can be unset by specifying a negative number to cancel all num-
|
||||
bered groups and an empty name to cancel all named groups.
|
||||
|
||||
The getall modifier tests pcre2_substring_list_get(), which extracts
|
||||
all captured substrings.
|
||||
|
||||
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.
|
||||
|
||||
Testing the substitution function
|
||||
|
||||
If the replace modifier is set, the pcre2_substitute() function is
|
||||
called instead of one of the matching functions (or after one call of
|
||||
pcre2_match() in the case of PCRE2_SUBSTITUTE_MATCHED). Note that re-
|
||||
placement strings cannot contain commas, because a comma signifies the
|
||||
end of a modifier. This is not thought to be an issue in a test pro-
|
||||
gram.
|
||||
|
||||
Specifying a completely empty replacement string disables this modi-
|
||||
fier. However, it is possible to specify an empty replacement by pro-
|
||||
viding a buffer length, as described below, for an otherwise empty re-
|
||||
placement.
|
||||
|
||||
Unlike subject strings, pcre2test 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 pro-
|
||||
vides a means of passing an invalid UTF-8 string for testing purposes.
|
||||
|
||||
The following modifiers set options (in additional to the normal match
|
||||
options) for pcre2_substitute():
|
||||
|
||||
global PCRE2_SUBSTITUTE_GLOBAL
|
||||
substitute_extended PCRE2_SUBSTITUTE_EXTENDED
|
||||
substitute_literal PCRE2_SUBSTITUTE_LITERAL
|
||||
substitute_matched PCRE2_SUBSTITUTE_MATCHED
|
||||
substitute_overflow_length PCRE2_SUBSTITUTE_OVERFLOW_LENGTH
|
||||
substitute_replacement_only PCRE2_SUBSTITUTE_REPLACEMENT_ONLY
|
||||
substitute_unknown_unset PCRE2_SUBSTITUTE_UNKNOWN_UNSET
|
||||
substitute_unset_empty PCRE2_SUBSTITUTE_UNSET_EMPTY
|
||||
|
||||
See the pcre2api documentation for details of these options.
|
||||
|
||||
After a successful substitution, the modified string is output, pre-
|
||||
ceded by the number of replacements. This may be zero if there were no
|
||||
matches. Here is a simple example of a substitution test:
|
||||
|
||||
/abc/replace=xxx
|
||||
=abc=abc=
|
||||
1: =xxx=abc=
|
||||
=abc=abc=\=global
|
||||
2: =xxx=xxx=
|
||||
|
||||
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 pcre2_substitute() as the size of the output buffer, with the re-
|
||||
placement string starting at the next character. Here is an example
|
||||
that tests the edge case:
|
||||
|
||||
/abc/
|
||||
123abc123\=replace=[10]XYZ
|
||||
1: 123XYZ123
|
||||
123abc123\=replace=[9]XYZ
|
||||
Failed: error -47: no more memory
|
||||
|
||||
The default action of pcre2_substitute() is to return PCRE2_ER-
|
||||
ROR_NOMEMORY when the output buffer is too small. However, if the
|
||||
PCRE2_SUBSTITUTE_OVERFLOW_LENGTH option is set (by using the substi-
|
||||
tute_overflow_length modifier), pcre2_substitute() continues to go
|
||||
through the motions of matching and substituting (but not doing any
|
||||
callouts), in order to compute the size of buffer that is required.
|
||||
When this happens, pcre2test shows the required buffer length (which
|
||||
includes space for the trailing zero) as part of the error message. For
|
||||
example:
|
||||
|
||||
/abc/substitute_overflow_length
|
||||
123abc123\=replace=[9]XYZ
|
||||
Failed: error -47: no more memory: 10 code units are needed
|
||||
|
||||
A replacement string is ignored with POSIX and DFA matching. Specifying
|
||||
partial matching provokes an error return ("bad option value") from
|
||||
pcre2_substitute().
|
||||
|
||||
Testing substitute callouts
|
||||
|
||||
If the substitute_callout modifier is set, a substitution callout func-
|
||||
tion is set up. The null_context modifier must not be set, because the
|
||||
address of the callout function is passed in a match context. When the
|
||||
callout function is called (after each substitution), details of the
|
||||
input and output strings are output. For example:
|
||||
|
||||
/abc/g,replace=<$0>,substitute_callout
|
||||
abcdefabcpqr
|
||||
1(1) Old 0 3 "abc" New 0 5 "<abc>"
|
||||
2(1) Old 6 9 "abc" New 8 13 "<abc>"
|
||||
2: <abc>def<abc>pqr
|
||||
|
||||
The first number on each callout line is the count of matches. The
|
||||
parenthesized number is the number of pairs that are set in the ovector
|
||||
(that is, one more than the number of capturing groups that were set).
|
||||
Then are listed the offsets of the old substring, its contents, and the
|
||||
same for the replacement.
|
||||
|
||||
By default, the substitution callout function returns zero, which ac-
|
||||
cepts the replacement and causes matching to continue if /g was used.
|
||||
Two further modifiers can be used to test other return values. If sub-
|
||||
stitute_skip is set to a value greater than zero the callout function
|
||||
returns +1 for the match of that number, and similarly substitute_stop
|
||||
returns -1. These cause the replacement to be rejected, and -1 causes
|
||||
no further matching to take place. If either of them are set, substi-
|
||||
tute_callout is assumed. For example:
|
||||
|
||||
/abc/g,replace=<$0>,substitute_skip=1
|
||||
abcdefabcpqr
|
||||
1(1) Old 0 3 "abc" New 0 5 "<abc> SKIPPED"
|
||||
2(1) Old 6 9 "abc" New 6 11 "<abc>"
|
||||
2: abcdef<abc>pqr
|
||||
abcdefabcpqr\=substitute_stop=1
|
||||
1(1) Old 0 3 "abc" New 0 5 "<abc> STOPPED"
|
||||
1: abcdefabcpqr
|
||||
|
||||
If both are set for the same number, stop takes precedence. Only a sin-
|
||||
gle skip or stop is supported, which is sufficient for testing that the
|
||||
feature works.
|
||||
|
||||
Testing substitute case callouts
|
||||
|
||||
If the substitute_case_callout modifier is set, a substitution case
|
||||
callout function is set up. The callout function is called for each
|
||||
substituted chunk which is to be case-transformed.
|
||||
|
||||
The callout function passed is a fixed function with implementation for
|
||||
certain behaviours: inputs which shrink when case-transformed; inputs
|
||||
which grow; inputs with distinct upper/lower/titlecase forms. The char-
|
||||
acters which are not special-cased for testing purposes are left unmod-
|
||||
ified, as if they are caseless characters.
|
||||
|
||||
Setting the JIT stack size
|
||||
|
||||
The jitstack 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 jitstack is set non-zero on a subject
|
||||
line it overrides any value that was set on the pattern.
|
||||
|
||||
Setting heap, match, and depth limits
|
||||
|
||||
The heap_limit, match_limit, and depth_limit modifiers set the appro-
|
||||
priate limits in the match context. These values are ignored when the
|
||||
find_limits or find_limits_noheap modifier is specified.
|
||||
|
||||
Finding minimum limits
|
||||
|
||||
If the find_limits modifier is present on a subject line, pcre2test
|
||||
calls the relevant matching function several times, setting different
|
||||
values in the match context via pcre2_set_heap_limit(),
|
||||
pcre2_set_match_limit(), or pcre2_set_depth_limit() until it finds the
|
||||
smallest value for each parameter that allows the match to complete
|
||||
without a "limit exceeded" error. The match itself may succeed or fail.
|
||||
An alternative modifier, find_limits_noheap, omits the heap limit. This
|
||||
is used in the standard tests, because the minimum heap limit varies
|
||||
between systems. If JIT is being used, only the match limit is rele-
|
||||
vant, and the other two are automatically omitted.
|
||||
|
||||
When using this modifier, the pattern should not contain any limit set-
|
||||
tings 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 pcre2_set_match_limit() etc. are only able to
|
||||
reduce the value of an in-pattern limit; they cannot increase it.
|
||||
|
||||
For non-DFA matching, the minimum depth_limit 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, depth_limit controls
|
||||
the depth of recursive calls of the internal function that is used for
|
||||
handling pattern recursion, lookaround assertions, and atomic groups.
|
||||
|
||||
For non-DFA matching, the match_limit 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, match_limit controls the total number of
|
||||
calls, both recursive and non-recursive, to the internal matching func-
|
||||
tion, thus controlling the overall amount of computing resource that is
|
||||
used.
|
||||
|
||||
For both kinds of matching, the heap_limit number, which is in
|
||||
kibibytes (units of 1024 bytes), limits the amount of heap memory used
|
||||
for matching.
|
||||
|
||||
Showing MARK names
|
||||
|
||||
|
||||
The mark modifier causes the names from backtracking control verbs that
|
||||
are returned from calls to pcre2_match() to be displayed. If a mark is
|
||||
returned for a match, non-match, or partial match, pcre2test shows it.
|
||||
For a match, it is on a line by itself, tagged with "MK:". Otherwise,
|
||||
it is added to the non-match message.
|
||||
|
||||
Showing memory usage
|
||||
|
||||
The memory modifier causes pcre2test to log the sizes of all heap mem-
|
||||
ory allocation and freeing calls that occur during a call to
|
||||
pcre2_match() or pcre2_dfa_match(). In the latter case, heap memory is
|
||||
used only when a match requires more internal workspace that the de-
|
||||
fault allocation on the stack, so in many cases there will be no out-
|
||||
put. No heap memory is allocated during matching with JIT. For this
|
||||
modifier to work, the null_context modifier must not be set on both the
|
||||
pattern and the subject, though it can be set on one or the other.
|
||||
|
||||
Showing the heap frame overall vector size
|
||||
|
||||
The heapframes_size modifier is relevant for matches using
|
||||
pcre2_match() without JIT. After a match has run (whether successful or
|
||||
not) the size, in bytes, of the allocated heap frames vector that is
|
||||
left attached to the match data block is shown. If the matching action
|
||||
involved several calls to pcre2_match() (for example, global matching
|
||||
or for timing) only the final value is shown.
|
||||
|
||||
This modifier is ignored, with a warning, for POSIX or DFA matching.
|
||||
JIT matching does not use the heap frames vector, so the size is always
|
||||
zero, unless there was a previous non-JIT match. Note that specifing a
|
||||
size of zero for the output vector (see below) causes pcre2test to free
|
||||
its match data block (and associated heap frames vector) and allocate a
|
||||
new one.
|
||||
|
||||
Setting a starting offset
|
||||
|
||||
The offset modifier sets an offset in the subject string at which
|
||||
matching starts. Its value is a number of code units, not characters.
|
||||
|
||||
Setting an offset limit
|
||||
|
||||
The offset_limit 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 use_offset_limit modi-
|
||||
fier must have been set for the pattern; if not, an error is generated.
|
||||
|
||||
Setting the size of the output vector
|
||||
|
||||
The ovector modifier applies only to the subject line in which it ap-
|
||||
pears, though of course it can also be used to set a default in a #sub-
|
||||
ject command. It specifies the number of pairs of offsets that are
|
||||
available for storing matching information. The default is 15.
|
||||
|
||||
A value of zero is useful when testing the POSIX API because it causes
|
||||
regexec() to be called with a NULL capture vector. When not testing the
|
||||
POSIX API, a value of zero is used to cause pcre2_match_data_cre-
|
||||
ate_from_pattern() to be called, in order to create a new match block
|
||||
of exactly the right size for the pattern. (It is not possible to cre-
|
||||
ate a match block with a zero-length ovector; there is always at least
|
||||
one pair of offsets.) The old match data block is freed.
|
||||
|
||||
Passing the subject as zero-terminated
|
||||
|
||||
By default, the subject string is passed to a native API matching func-
|
||||
tion with its correct length. In order to test the facility for passing
|
||||
a zero-terminated string, the zero_terminate 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.
|
||||
|
||||
When testing pcre2_substitute(), this modifier also has the effect of
|
||||
passing the replacement string as zero-terminated.
|
||||
|
||||
Passing a NULL context, subject, or replacement
|
||||
|
||||
Normally, pcre2test passes a context block to pcre2_match(),
|
||||
pcre2_dfa_match(), pcre2_jit_match() or pcre2_substitute(). If the
|
||||
null_context modifier is set, however, NULL is passed. This is for
|
||||
testing that the matching and substitution functions behave correctly
|
||||
in this case (they use default values). This modifier cannot be used
|
||||
with the find_limits, find_limits_noheap, or substitute_callout modi-
|
||||
fiers.
|
||||
|
||||
Similarly, for testing purposes, if the null_subject or null_replace-
|
||||
ment modifier is set, the subject or replacement string pointers are
|
||||
passed as NULL, respectively, to the relevant functions.
|
||||
|
||||
|
||||
THE ALTERNATIVE MATCHING FUNCTION
|
||||
|
||||
By default, pcre2test uses the standard PCRE2 matching function,
|
||||
pcre2_match() to match each subject line. PCRE2 also supports an alter-
|
||||
native matching function, pcre2_dfa_match(), which operates in a dif-
|
||||
ferent way, and has some restrictions. The differences between the two
|
||||
functions are described in the pcre2matching documentation.
|
||||
|
||||
If the dfa modifier is set, the alternative matching function is used.
|
||||
This function finds all possible matches at a given point in the sub-
|
||||
ject. If, however, the dfa_shortest modifier is set, processing stops
|
||||
after the first match is found. This is always the shortest possible
|
||||
match.
|
||||
|
||||
|
||||
DEFAULT OUTPUT FROM pcre2test
|
||||
|
||||
This section describes the output when the normal matching function,
|
||||
pcre2_match(), is being used.
|
||||
|
||||
When a match succeeds, pcre2test outputs the list of captured sub-
|
||||
strings, starting with number 0 for the string that matched the whole
|
||||
pattern. Otherwise, it outputs "No match" when the return is PCRE2_ER-
|
||||
ROR_NOMATCH, or "Partial match:" followed by the partially matching
|
||||
substring when the return is PCRE2_ERROR_PARTIAL. (Note that this is
|
||||
the entire substring that was inspected during the partial match; it
|
||||
may include characters before the actual match start if a lookbehind
|
||||
assertion, \K, \b, or \B was involved.)
|
||||
|
||||
For any other return, pcre2test 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 pcre2test run.
|
||||
|
||||
$ pcre2test
|
||||
PCRE2 version 10.22 2016-07-29
|
||||
|
||||
re> /^abc(\d+)/
|
||||
data> abc123
|
||||
0: abc123
|
||||
1: 123
|
||||
data> xyz
|
||||
No match
|
||||
|
||||
Unset capturing substrings that are not followed by one that is set are
|
||||
not shown by pcre2test unless the allcaptures 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.
|
||||
|
||||
re> /(a)|(b)/
|
||||
data> a
|
||||
0: a
|
||||
1: a
|
||||
data> b
|
||||
0: b
|
||||
1: <unset>
|
||||
2: b
|
||||
|
||||
If the strings contain any non-printing characters, they are output as
|
||||
\xhh escapes if the value is less than 256 and UTF mode is not set.
|
||||
Otherwise they are output as \x{hh...} escapes. See below for the defi-
|
||||
nition of non-printing characters. If the aftertext modifier is set,
|
||||
the output for substring 0 is followed by the rest of the subject
|
||||
string, identified by "0+" like this:
|
||||
|
||||
re> /cat/aftertext
|
||||
data> cataract
|
||||
0: cat
|
||||
0+ aract
|
||||
|
||||
If global matching is requested, the results of successive matching at-
|
||||
tempts are output in sequence, like this:
|
||||
|
||||
re> /\Bi(\w\w)/g
|
||||
data> Mississippi
|
||||
0: iss
|
||||
1: ss
|
||||
0: iss
|
||||
1: ss
|
||||
0: ipp
|
||||
1: pp
|
||||
|
||||
"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
|
||||
offset modifier is past the end of the subject string):
|
||||
|
||||
re> /xyz/
|
||||
data> xyz\=offset=4
|
||||
Error -24 (bad offset value)
|
||||
|
||||
Note that whereas patterns can be continued over several lines (a plain
|
||||
">" prompt is used for continuations), subject lines may not. However
|
||||
newlines can be included in a subject by means of the \n escape (or \r,
|
||||
\r\n, etc., depending on the newline sequence setting).
|
||||
|
||||
|
||||
OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION
|
||||
|
||||
When the alternative matching function, pcre2_dfa_match(), 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:
|
||||
|
||||
re> /(tang|tangerine|tan)/
|
||||
data> yellow tangerine\=dfa
|
||||
0: tangerine
|
||||
1: tang
|
||||
2: tan
|
||||
|
||||
Using the normal matching function on this data finds only "tang". The
|
||||
longest matching string is always given first (and numbered zero). Af-
|
||||
ter a PCRE2_ERROR_PARTIAL return, the output is "Partial match:", fol-
|
||||
lowed by the partially matching substring. Note that this is the entire
|
||||
substring that was inspected during the partial match; it may include
|
||||
characters before the actual match start if a lookbehind assertion, \b,
|
||||
or \B was involved. (\K is not supported for DFA matching.)
|
||||
|
||||
If global matching is requested, the search for further matches resumes
|
||||
at the end of the longest match. For example:
|
||||
|
||||
re> /(tang|tangerine|tan)/g
|
||||
data> yellow tangerine and tangy sultana\=dfa
|
||||
0: tangerine
|
||||
1: tang
|
||||
2: tan
|
||||
0: tang
|
||||
1: tan
|
||||
0: tan
|
||||
|
||||
The alternative matching function does not support substring capture,
|
||||
so the modifiers that are concerned with captured substrings are not
|
||||
relevant.
|
||||
|
||||
|
||||
RESTARTING AFTER A PARTIAL MATCH
|
||||
|
||||
When the alternative matching function has given the PCRE2_ERROR_PAR-
|
||||
TIAL return, indicating that the subject partially matched the pattern,
|
||||
you can restart the match with additional subject data by means of the
|
||||
dfa_restart modifier. For example:
|
||||
|
||||
re> /^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$/
|
||||
data> 23ja\=ps,dfa
|
||||
Partial match: 23ja
|
||||
data> n05\=dfa,dfa_restart
|
||||
0: n05
|
||||
|
||||
For further information about partial matching, see the pcre2partial
|
||||
documentation.
|
||||
|
||||
|
||||
CALLOUTS
|
||||
|
||||
If the pattern contains any callout requests, pcre2test's callout func-
|
||||
tion is called during matching unless callout_none is specified. This
|
||||
works with both matching functions, and with JIT, though there are some
|
||||
differences in behaviour. The output for callouts with numerical argu-
|
||||
ments and those with string arguments is slightly different.
|
||||
|
||||
Callouts with numerical arguments
|
||||
|
||||
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:
|
||||
|
||||
--->pqrabcdef
|
||||
0 ^ ^ \d
|
||||
|
||||
This output indicates that callout number 0 occurred for a match at-
|
||||
tempt starting at the fourth character of the subject string, when the
|
||||
pointer was at the seventh character, and when the next pattern item
|
||||
was \d. Just one circumflex is output if the start and current posi-
|
||||
tions are the same, or if the current position precedes the start posi-
|
||||
tion, which can happen if the callout is in a lookbehind assertion.
|
||||
|
||||
Callouts numbered 255 are assumed to be automatic callouts, inserted as
|
||||
a result of the auto_callout pattern modifier. In this case, instead of
|
||||
showing the callout number, the offset in the pattern, preceded by a
|
||||
plus, is output. For example:
|
||||
|
||||
re> /\d?[A-E]\*/auto_callout
|
||||
data> E*
|
||||
--->E*
|
||||
+0 ^ \d?
|
||||
+3 ^ [A-E]
|
||||
+8 ^^ \*
|
||||
+10 ^ ^
|
||||
0: E*
|
||||
|
||||
If a pattern contains (*MARK) items, an additional line is output when-
|
||||
ever a change of latest mark is passed to the callout function. For ex-
|
||||
ample:
|
||||
|
||||
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
|
||||
|
||||
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.
|
||||
|
||||
Callouts with string arguments
|
||||
|
||||
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 be-
|
||||
fore the reflection of the subject string, and the subject string is
|
||||
reflected for each callout. For example:
|
||||
|
||||
re> /^ab(?C'first')cd(?C"second")ef/
|
||||
data> abcdefg
|
||||
Callout (7): 'first'
|
||||
--->abcdefg
|
||||
^ ^ c
|
||||
Callout (20): "second"
|
||||
--->abcdefg
|
||||
^ ^ e
|
||||
0: abcdef
|
||||
|
||||
|
||||
Callout modifiers
|
||||
|
||||
The callout function in pcre2test returns zero (carry on matching) by
|
||||
default, but you can use a callout_fail modifier in a subject line to
|
||||
change this and other parameters of the callout (see below).
|
||||
|
||||
If the callout_capture modifier is set, the current captured groups are
|
||||
output when a callout occurs. This is useful only for non-DFA matching,
|
||||
as pcre2_dfa_match() does not support capturing, so no captures are
|
||||
ever shown.
|
||||
|
||||
The normal callout output, showing the callout number or pattern offset
|
||||
(as described above) is suppressed if the callout_no_where modifier is
|
||||
set.
|
||||
|
||||
When using the interpretive matching function pcre2_match() without
|
||||
JIT, setting the callout_extra modifier causes additional output from
|
||||
pcre2test'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 call-
|
||||
out (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:
|
||||
|
||||
re> /(a+)b/auto_callout,no_start_optimize,no_auto_possess
|
||||
data> aac\=callout_extra
|
||||
New match attempt
|
||||
--->aac
|
||||
+0 ^ (
|
||||
+1 ^ a+
|
||||
+3 ^ ^ )
|
||||
+4 ^ ^ b
|
||||
Backtrack
|
||||
--->aac
|
||||
+3 ^^ )
|
||||
+4 ^^ b
|
||||
Backtrack
|
||||
No other matching paths
|
||||
New match attempt
|
||||
--->aac
|
||||
+0 ^ (
|
||||
+1 ^ a+
|
||||
+3 ^^ )
|
||||
+4 ^^ b
|
||||
Backtrack
|
||||
No other matching paths
|
||||
New match attempt
|
||||
--->aac
|
||||
+0 ^ (
|
||||
+1 ^ a+
|
||||
Backtrack
|
||||
No other matching paths
|
||||
New match attempt
|
||||
--->aac
|
||||
+0 ^ (
|
||||
+1 ^ a+
|
||||
No match
|
||||
|
||||
Notice that various optimizations must be turned off if you want all
|
||||
possible matching paths to be scanned. If no_start_optimize 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 no_auto_possess is not used,
|
||||
the "a+" item is turned into "a++", which reduces the number of back-
|
||||
tracks.
|
||||
|
||||
The callout_extra modifier has no effect if used with the DFA matching
|
||||
function, or with JIT.
|
||||
|
||||
Return values from callouts
|
||||
|
||||
The default return from the callout function is zero, which allows
|
||||
matching to continue. The callout_fail modifier can be given one or two
|
||||
numbers. If there is only one number, 1 is returned instead of 0 (caus-
|
||||
ing 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 callout_error
|
||||
modifier is similar, except that PCRE2_ERROR_CALLOUT is returned, caus-
|
||||
ing the entire matching process to be aborted. If both these modifiers
|
||||
are set for the same callout number, callout_error takes precedence.
|
||||
Note that callouts with string arguments are always given the number
|
||||
zero.
|
||||
|
||||
The callout_data modifier can be given an unsigned or a negative num-
|
||||
ber. 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 pcre2test's callout
|
||||
function.
|
||||
|
||||
Inserting callouts can be helpful when using pcre2test to check compli-
|
||||
cated regular expressions. For further information about callouts, see
|
||||
the pcre2callout documentation.
|
||||
|
||||
|
||||
NON-PRINTING CHARACTERS
|
||||
|
||||
When pcre2test 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.
|
||||
|
||||
When pcre2test 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 locale modifier). In this case, the is-
|
||||
print() function is used to distinguish printing and non-printing char-
|
||||
acters.
|
||||
|
||||
|
||||
SAVING AND RESTORING COMPILED PATTERNS
|
||||
|
||||
It is possible to save compiled patterns on disc or elsewhere, and re-
|
||||
load 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, con-
|
||||
verted to a stream of bytes. A single byte stream may contain any num-
|
||||
ber of compiled patterns, but they must all use the same character ta-
|
||||
bles. A single copy of the tables is included in the byte stream (its
|
||||
size is 1088 bytes).
|
||||
|
||||
The functions whose names begin with pcre2_serialize_ are used for se-
|
||||
rializing and de-serializing. They are described in the pcre2serialize
|
||||
documentation. In this section we describe the features of pcre2test
|
||||
that can be used to test these functions.
|
||||
|
||||
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.
|
||||
|
||||
In pcre2test, when a pattern with push modifier is successfully com-
|
||||
piled, it is pushed onto a stack of compiled patterns, and pcre2test
|
||||
expects the next line to contain a new pattern (or command) instead of
|
||||
a subject line. By contrast, the pushcopy modifier causes a copy of the
|
||||
compiled pattern to be stacked, leaving the original available for im-
|
||||
mediate matching. By using push and/or pushcopy, a number of patterns
|
||||
can be compiled and retained. These modifiers are incompatible with
|
||||
posix, and control modifiers that act at match time are ignored (with a
|
||||
message) for the stacked patterns. The jitverify modifier applies only
|
||||
at compile time.
|
||||
|
||||
The command
|
||||
|
||||
#save <filename>
|
||||
|
||||
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
|
||||
|
||||
#load <filename>
|
||||
|
||||
reads the data in the file, and then arranges for it to be de-serial-
|
||||
ized, with the resulting compiled patterns added to the pattern stack.
|
||||
The pattern on the top of the stack can be retrieved by the #pop com-
|
||||
mand, 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 control modifiers that act after a pattern has been compiled. In
|
||||
particular, hex, posix, posix_nosub, push, and pushcopy are not al-
|
||||
lowed, nor are any option-setting modifiers. The JIT modifiers are,
|
||||
however permitted. Here is an example that saves and reloads two pat-
|
||||
terns.
|
||||
|
||||
/abc/push
|
||||
/xyz/push
|
||||
#save tempfile
|
||||
#load tempfile
|
||||
#pop info
|
||||
xyz
|
||||
|
||||
#pop jit,bincode
|
||||
abc
|
||||
|
||||
If jitverify is used with #pop, it does not automatically imply jit,
|
||||
which is different behaviour from when it is used on a pattern.
|
||||
|
||||
The #popcopy command is analogous to the pushcopy modifier in that it
|
||||
makes current a copy of the topmost stack pattern, leaving the original
|
||||
still on the stack.
|
||||
|
||||
|
||||
SEE ALSO
|
||||
|
||||
pcre2(3), pcre2api(3), pcre2callout(3), pcre2jit, pcre2matching(3),
|
||||
pcre2partial(d), pcre2pattern(3), pcre2serialize(3).
|
||||
|
||||
|
||||
AUTHOR
|
||||
|
||||
Philip Hazel
|
||||
Retired from University Computing Service
|
||||
Cambridge, England.
|
||||
|
||||
|
||||
REVISION
|
||||
|
||||
Last updated: 26 December 2024
|
||||
Copyright (c) 1997-2024 University of Cambridge.
|
||||
|
||||
|
||||
PCRE2 10.45 26 December 2024 PCRE2TEST(1)
|
||||
Reference in New Issue
Block a user