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Diffstat (limited to 'doc/pcre2test.txt')
| -rw-r--r-- | doc/pcre2test.txt | 973 |
1 files changed, 612 insertions, 361 deletions
diff --git a/doc/pcre2test.txt b/doc/pcre2test.txt index cfa0baa..93efd24 100644 --- a/doc/pcre2test.txt +++ b/doc/pcre2test.txt @@ -26,7 +26,7 @@ SYNOPSIS As the original fairly simple PCRE library evolved, it acquired many different features, and as a result, the original pcretest program - ended up with a lot of options in a messy, arcane syntax, for testing + ended up with a lot of options in a messy, arcane syntax for testing all the features. The move to the new PCRE2 API provided an opportunity to re-implement the test program as pcre2test, with a cleaner modifier syntax. Nevertheless, there are still many obscure modifiers, some of @@ -45,7 +45,7 @@ PCRE2's 8-BIT, 16-BIT AND 32-BIT LIBRARIES installed. The pcre2test program can be used to test all the libraries. However, its own input and output are always in 8-bit format. When testing the 16-bit or 32-bit libraries, patterns and subject strings - are converted to 16- or 32-bit format before being passed to the + are converted to 16-bit or 32-bit format before being passed to the library functions. Results are converted back to 8-bit code units for output. @@ -58,45 +58,81 @@ PCRE2's 8-BIT, 16-BIT AND 32-BIT LIBRARIES INPUT ENCODING Input to pcre2test is processed line by line, either by calling the C - library's fgets() function, or via the libreadline library (see below). + library's fgets() function, or via the libreadline library. In some + Windows environments character 26 (hex 1A) causes an immediate end of + file, and no further data is read, so this character should be avoided + unless you really want that action. + The input is processed using using C's string functions, so must not - contain binary zeroes, even though in Unix-like environments, fgets() - treats any bytes other than newline as data characters. In some Windows - environments character 26 (hex 1A) causes an immediate end of file, and - no further data is read. + contain binary zeros, even though in Unix-like environments, fgets() + treats any bytes other than newline as data characters. An error is + generated if a binary zero is encountered. By default subject lines are + processed for backslash escapes, which makes it possible to include any + data value in strings that are passed to the library for matching. For + patterns, there is a facility for specifying some or all of the 8-bit + input characters as hexadecimal pairs, which makes it possible to + include binary zeros. + + Input for the 16-bit and 32-bit libraries + + When testing the 16-bit or 32-bit libraries, there is a need to be able + to generate character code points greater than 255 in the strings that + are passed to the library. For subject lines, backslash escapes can be + used. In addition, when the utf modifier (see "Setting compilation + options" below) is set, the pattern and any following subject lines are + interpreted as UTF-8 strings and translated to UTF-16 or UTF-32 as + appropriate. - For maximum portability, therefore, it is safest to avoid non-printing - characters in pcre2test input files. There is a facility for specifying - some or all of a pattern's characters as hexadecimal pairs, thus making - it possible to include binary zeroes in a pattern for testing purposes. - Subject lines are processed for backslash escapes, which makes it pos- - sible to include any data value. + For non-UTF testing of wide characters, the utf8_input modifier can be + used. This is mutually exclusive with utf, and is allowed only in + 16-bit or 32-bit mode. It causes the pattern and following subject + lines to be treated as UTF-8 according to the original definition (RFC + 2279), which allows for character values up to 0x7fffffff. Each charac- + ter is placed in one 16-bit or 32-bit code unit (in the 16-bit case, + values greater than 0xffff cause an error to occur). + + UTF-8 (in its original definition) is not capable of encoding values + greater than 0x7fffffff, but such values can be handled by the 32-bit + library. When testing this library in non-UTF mode with utf8_input set, + if any character is preceded by the byte 0xff (which is an illegal byte + in UTF-8) 0x80000000 is added to the character's value. This is the + only way of passing such code points in a pattern string. For subject + strings, using an escape sequence is preferable. COMMAND LINE OPTIONS -8 If the 8-bit library has been built, this option causes it to - be used (this is the default). If the 8-bit library has not + be used (this is the default). If the 8-bit library has not been built, this option causes an error. - -16 If the 16-bit library has been built, this option causes it - to be used. If only the 16-bit library has been built, this - is the default. If the 16-bit library has not been built, + -16 If the 16-bit library has been built, this option causes it + to be used. If only the 16-bit library has been built, this + is the default. If the 16-bit library has not been built, this option causes an error. - -32 If the 32-bit library has been built, this option causes it - to be used. If only the 32-bit library has been built, this - is the default. If the 32-bit library has not been built, + -32 If the 32-bit library has been built, this option causes it + to be used. If only the 32-bit library has been built, this + is the default. If the 32-bit library has not been built, this option causes an error. - -b Behave as if each pattern has the /fullbincode modifier; the + -ac Behave as if each pattern has the auto_callout modifier, that + is, insert automatic callouts into every pattern that is com- + piled. + + -AC As for -ac, but in addition behave as if each subject line + has the callout_extra modifier, that is, show additional + information from callouts. + + -b Behave as if each pattern has the fullbincode modifier; the full internal binary form of the pattern is output after com- pilation. - -C Output the version number of the PCRE2 library, and all - available information about the optional features that are - included, and then exit with zero exit code. All other - options are ignored. + -C Output the version number of the PCRE2 library, and all + available information about the optional features that are + included, and then exit with zero exit code. All other + options are ignored. If both -C and -LM are present, which- + ever is first is recognized. -C option Output information about a specific build-time option, then exit. This functionality is intended for use in scripts such @@ -110,7 +146,7 @@ COMMAND LINE OPTIONS linksize the configured internal link size (2, 3, or 4) exit code is set to the link size newline the default newline setting: - CR, LF, CRLF, ANYCRLF, or ANY + CR, LF, CRLF, ANYCRLF, ANY, or NUL exit code is always 0 bsr the default setting for what \R matches: ANYCRLF or ANY @@ -147,13 +183,24 @@ COMMAND LINE OPTIONS -help Output a brief summary these options and then exit. - -i Behave as if each pattern has the /info modifier; information + -i Behave as if each pattern has the info modifier; information about the compiled pattern is given after compilation. -jit Behave as if each pattern line has the jit modifier; after successful compilation, each pattern is passed to the just- in-time compiler, if available. + -jitverify + Behave as if each pattern line has the jitverify modifier; + after successful compilation, each pattern is passed to the + just-in-time compiler, if available, and the use of JIT is + verified. + + -LM List modifiers: write a list of available pattern and subject + modifiers to the standard output, then exit with zero exit + code. All other options are ignored. If both -C and -LM are + present, whichever is first is recognized. + -pattern modifier-list Behave as if each pattern line contains the given modifiers. @@ -269,7 +316,7 @@ COMMAND LINES 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, or ANY (in upper or lower case), for example: + CRLF, ANY, or NUL (in upper or lower case), for example: #newline_default LF Any anyCRLF @@ -282,9 +329,9 @@ COMMAND LINES When the POSIX API is being tested there is no way to override the default newline convention, though it is possible to set the newline - convention from within the pattern. A warning is given if the posix - modifier is used when #newline_default would set a default for the non- - POSIX API. + convention 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> @@ -387,8 +434,9 @@ SUBJECT LINE SYNTAX Before each subject line is passed to pcre2_match() or pcre2_dfa_match(), leading and trailing white space is removed, and the - line is scanned for backslash escapes. The following provide a means of - encoding non-printing characters in a visible way: + line is scanned for backslash escapes, unless the subject_literal modi- + fier was set for the pattern. The following provide a means of encoding + non-printing characters in a visible way: \a alarm (BEL, \x07) \b backspace (\x08) @@ -405,23 +453,23 @@ SUBJECT LINE SYNTAX \x{hh...} hexadecimal character (any number of hex digits) The use of \x{hh...} is not dependent on the use of the utf modifier on - the pattern. It is recognized always. There may be any number of hexa- - decimal digits inside the braces; invalid values provoke error mes- + the pattern. It is recognized always. There may be any number of hexa- + decimal digits inside the braces; invalid values provoke error mes- sages. - Note that \xhh specifies one byte rather than one character in UTF-8 - mode; this makes it possible to construct invalid UTF-8 sequences for - testing purposes. On the other hand, \x{hh} is interpreted as a UTF-8 - character in UTF-8 mode, generating more than one byte if the value is - greater than 127. When testing the 8-bit library not in UTF-8 mode, + Note that \xhh specifies one byte rather than one character in UTF-8 + mode; this makes it possible to construct invalid UTF-8 sequences for + testing purposes. On the other hand, \x{hh} is interpreted as a UTF-8 + character in UTF-8 mode, generating more than one byte if the value is + greater than 127. When testing the 8-bit library not in UTF-8 mode, \x{hh} generates one byte for values less than 256, and causes an error for greater values. In UTF-16 mode, all 4-digit \x{hhhh} values are accepted. This makes it possible to construct invalid UTF-16 sequences for testing purposes. - In UTF-32 mode, all 4- to 8-digit \x{...} values are accepted. This - makes it possible to construct invalid UTF-32 sequences for testing + In UTF-32 mode, all 4- to 8-digit \x{...} values are accepted. This + makes it possible to construct invalid UTF-32 sequences for testing purposes. There is a special backslash sequence that specifies replication of one @@ -429,33 +477,38 @@ SUBJECT LINE SYNTAX \[<characters>]{<count>} - This makes it possible to test long strings without having to provide + 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. + 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 + 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 + 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 + A backslash followed by any other non-alphanumeric character just escapes that character. A backslash followed by anything else causes an - error. However, if the very last character in the line is a backslash - (and there is no modifier list), it is ignored. This gives a way of - passing an empty line as data, since a real empty line terminates the + 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 @@ -466,28 +519,42 @@ PATTERN MODIFIERS Setting compilation options - The following modifiers set options for pcre2_compile(). The most com- - mon ones have single-letter abbreviations. See pcre2api for a descrip- - tion of their effects. + 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. For the main options, there are some single-letter + abbreviations that are the same as Perl options. There is special han- + dling for /x: if a second x is present, PCRE2_EXTENDED is converted + into PCRE2_EXTENDED_MORE as in Perl. A third appearance adds + PCRE2_EXTENDED as well, though this makes no difference to the way + pcre2_compile() behaves. See pcre2api for a description of the effects + of these options. allow_empty_class set PCRE2_ALLOW_EMPTY_CLASS + allow_surrogate_escapes set PCRE2_EXTRA_ALLOW_SURROGATE_ESCAPES alt_bsux set PCRE2_ALT_BSUX alt_circumflex set PCRE2_ALT_CIRCUMFLEX alt_verbnames set PCRE2_ALT_VERBNAMES anchored set PCRE2_ANCHORED auto_callout set PCRE2_AUTO_CALLOUT + bad_escape_is_literal set PCRE2_EXTRA_BAD_ESCAPE_IS_LITERAL /i caseless set PCRE2_CASELESS dollar_endonly set PCRE2_DOLLAR_ENDONLY /s dotall set PCRE2_DOTALL dupnames set PCRE2_DUPNAMES + endanchored set PCRE2_ENDANCHORED /x extended set PCRE2_EXTENDED + /xx extended_more set PCRE2_EXTENDED_MORE firstline set PCRE2_FIRSTLINE + literal set PCRE2_LITERAL + match_line set PCRE2_EXTRA_MATCH_LINE match_unset_backref set PCRE2_MATCH_UNSET_BACKREF + match_word set PCRE2_EXTRA_MATCH_WORD /m multiline set PCRE2_MULTILINE never_backslash_c set PCRE2_NEVER_BACKSLASH_C never_ucp set PCRE2_NEVER_UCP never_utf set PCRE2_NEVER_UTF - no_auto_capture set PCRE2_NO_AUTO_CAPTURE + /n no_auto_capture set PCRE2_NO_AUTO_CAPTURE no_auto_possess set PCRE2_NO_AUTO_POSSESS no_dotstar_anchor set PCRE2_NO_DOTSTAR_ANCHOR no_start_optimize set PCRE2_NO_START_OPTIMIZE @@ -498,19 +565,27 @@ PATTERN MODIFIERS 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. + 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. Setting compilation controls - The following modifiers affect the compilation process or request - information about the pattern: + The following modifiers affect the compilation process or request + information about the pattern. There are single-letter abbreviations + for some that are heavily used in the test files. bsr=[anycrlf|unicode] specify \R handling /B bincode show binary code without lengths callout_info show callout information + convert=<options> request foreign pattern conversion + convert_glob_escape=c set glob escape character + convert_glob_separator=c set glob separator character + convert_length set convert buffer length debug same as info,fullbincode + framesize show matching frame size fullbincode show binary code with lengths /I info show info about compiled pattern hex unquoted characters are hexadecimal @@ -528,7 +603,10 @@ PATTERN MODIFIERS push push compiled pattern onto the stack pushcopy push a copy onto the stack stackguard=<number> test the stackguard feature + subject_literal treat all subject lines as literal tables=[0|1|2] select internal tables + use_length do not zero-terminate the pattern + utf8_input treat input as UTF-8 The effects of these modifiers are described in the following sections. @@ -541,7 +619,7 @@ PATTERN MODIFIERS 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, or ANY (in upper or lower case). + one of CR, LF, CRLF, ANYCRLF, ANY, or NUL (in upper or lower case). Information about a pattern @@ -589,6 +667,10 @@ PATTERN MODIFIERS last character. These lines are omitted if no starting or ending code units are recorded. + The framesize modifier shows the size, in bytes, of the storage frames + used by pcre2_match() for handling backtracking. The size depends on + the number of capturing parentheses in the pattern. + 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 @@ -619,12 +701,30 @@ PATTERN MODIFIERS /ab "literal" 32/hex Either single or double quotes may be used. There is no way of includ- - ing the delimiter within a substring. + 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 + zeros. + + 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 wide characters in 16-bit and 32-bit modes - By default, pcre2test passes patterns as zero-terminated strings to - pcre2_compile(), giving the length as PCRE2_ZERO_TERMINATED. However, - for patterns specified with the hex modifier, the actual length of the - pattern is passed. + 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 @@ -640,38 +740,39 @@ PATTERN MODIFIERS 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. + 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 + 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 + 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 + 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 + 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 + JIT compilation is requested by the jit pattern modifier, which may optionally be followed by an equals sign and a number in the range 0 to - 7. The three bits that make up the number specify which of the three + 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: + The possible values for the jit modifier are therefore: 0 disable JIT 1 normal matching only @@ -681,54 +782,54 @@ PATTERN MODIFIERS 6 soft and hard partial matching only 7 all three modes - If no number is given, 7 is assumed. The phrase "partial matching" + 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- + 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 + 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 - incompatible run-time options are specified. For more details, see the - pcre2jit documentation. See also the jitstack modifier below for a way + If JIT compilation is successful, the compiled JIT code will automati- + cally be used when an appropriate type of match is run, except when + incompatible 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 + 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 + 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: + 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 + 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- + 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 - pattern is subsequently passed to the JIT compiler, the size of the JIT + 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 @@ -738,27 +839,27 @@ PATTERN MODIFIERS 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 - error. 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 parens_nest_limit modifier sets a limit on the depth of nested + parentheses in a pattern. Breaching the limit causes a compilation + error. The default for the library is set when PCRE2 is built, but + 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 + 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 + 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 + 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() + tion. The following pattern modifiers set options for the regcomp() function: caseless REG_ICASE @@ -768,35 +869,39 @@ PATTERN MODIFIERS 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 + 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 + 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 - below. All other modifiers are either ignored, with a warning message, + The aftertext and allaftertext subject modifiers work as described + below. 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 + default, but if the use_length or hex modifiers are set, the REG_PEND + extension 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 + 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 + 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 + The value specified for the tables modifier must be one of the digits 0, 1, or 2. It causes a specific set of built-in character tables to be passed to pcre2_compile(). This is used in the PCRE2 tests to check be- haviour with different character tables. The digit specifies the tables @@ -807,23 +912,25 @@ PATTERN MODIFIERS pcre2_chartables.c.dist 2 a set of tables defining ISO 8859 characters - In table 2, some characters whose codes are greater than 128 are iden- - tified as letters, digits, spaces, etc. Setting alternate character + In table 2, some characters whose codes are greater than 128 are iden- + tified as letters, digits, spaces, etc. Setting alternate character tables and a locale are mutually exclusive. Setting certain match controls The following modifiers are really subject modifiers, and are described - below. However, they may be included in a pattern's modifier list, in - which case they are applied to every subject line that is processed - with that pattern. They may not appear in #pattern commands. These mod- - ifiers do not affect the compilation process. + 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 allusedtext show all consulted text + altglobal alternative global matching /g global global matching + jitstack=<n> set size of JIT stack mark show mark values replace=<string> specify a replacement string startchar show starting character when relevant @@ -832,26 +939,65 @@ PATTERN MODIFIERS 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 + 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 + 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 - incompatible with compilation modifiers such as global that act at - match time. Any that are specified are ignored (for the stacked copy), + 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 + incompatible 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 subse- + that jitverify, which is allowed, does not carry through to any subse- quent 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 @@ -860,10 +1006,11 @@ SUBJECT MODIFIERS Setting match options - The following modifiers set options for pcre2_match() or + The following modifiers set options for pcre2_match() or pcre2_dfa_match(). See pcreapi for a description of their effects. anchored set PCRE2_ANCHORED + endanchored set PCRE2_ENDANCHORED dfa_restart set PCRE2_DFA_RESTART dfa_shortest set PCRE2_DFA_SHORTEST no_jit set PCRE2_NO_JIT @@ -875,20 +1022,34 @@ SUBJECT MODIFIERS 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 + The partial matching modifiers are provided with abbreviations because they appear frequently in tests. - If the /posix modifier was present on the pattern, causing the POSIX - wrapper API to be used, the only option-setting modifiers that have any - effect are notbol, notempty, and noteol, causing REG_NOTBOL, - REG_NOTEMPTY, and REG_NOTEOL, respectively, to be passed to regexec(). - The other modifiers are ignored, with a warning message. + 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 + 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. aftertext show text after match @@ -898,23 +1059,28 @@ SUBJECT MODIFIERS 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 match and recursion limits + find_limits find match and depth limits get=<number or name> extract captured substring getall extract all captured substrings /g global global matching + heap_limit=<n> set a limit on heap memory jitstack=<n> set size of JIT stack mark show mark values match_limit=<n> set a match limit - memory show memory usage + memory show heap memory usage null_context match with a NULL context offset=<n> set starting offset offset_limit=<n> set offset limit ovector=<n> set size of output vector - recursion_limit=<n> set a recursion limit + 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> @@ -925,29 +1091,29 @@ SUBJECT MODIFIERS 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- + 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 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- + 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. - This feature is not supported for JIT matching, and if requested with - JIT it is ignored (with a warning message). Setting this modifier + The allusedtext modifier requests that all the text that was consulted + during a successful pattern match by the interpreter should be shown. + This feature is not supported for JIT matching, and if requested with + JIT it is ignored (with a warning message). Setting this modifier affects the output if there is a lookbehind at the start of a match, or - a lookahead at the end, or if \K is used in the pattern. Characters - that precede or follow the start and end of the actual match are indi- - cated in the output by '<' or '>' characters underneath them. Here is + 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 indi- + cated in the output by '<' or '>' characters underneath them. Here is an example: re> /(?<=pqr)abc(?=xyz)/ @@ -955,16 +1121,16 @@ SUBJECT MODIFIERS 0: pqrabcxyz <<< >>> - This shows that the matched string is "abc", with the preceding and - following strings "pqr" and "xyz" having been consulted during the + This shows that the matched string is "abc", with the preceding and + following strings "pqr" and "xyz" having been consulted during the match (when processing the assertions). - The startchar modifier requests that the starting character for the - match be indicated, if it is different to the start of the matched + 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 + is displayed from the starting character instead of from the match + point, with circumflex characters under the earlier characters. For example: re> /abc\Kxyz/ @@ -972,7 +1138,7 @@ SUBJECT MODIFIERS 0: abcxyz ^^^ - Unlike allusedtext, the startchar modifier can be used with JIT. How- + 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 @@ -980,90 +1146,78 @@ SUBJECT MODIFIERS 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); it is ignored, with a warning + 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); it is ignored, with a warning message, if present. Testing callouts - A callout function is supplied when pcre2test calls the library match- - ing functions, unless callout_none is specified. If callout_capture is - set, the current captured groups are output when a callout occurs. - - The callout_fail modifier can be given one or two numbers. If there is - only one number, 1 is returned instead of 0 when a callout of that num- - ber is reached. If two numbers are given, 1 is returned when callout - <n> is reached for the <m>th time. Note that callouts with string argu- - ments are always given the number zero. See "Callouts" below for a - description of the output when a callout it taken. - - 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. + 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. 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 + 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 + If an empty string is matched, the next match is done with the PCRE2_NOTEMPTY_ATSTART and PCRE2_ANCHORED flags set, in order to search for another, non-empty, match at the same point in the subject. If this - match fails, the start offset is advanced, and the normal match is - retried. This imitates the way Perl handles such cases when using the - /g modifier or the split() function. Normally, the start offset is - advanced by one character, but if the newline convention recognizes - CRLF as a newline, and the current character is CR followed by LF, an + match fails, the start offset is advanced, and the normal match is + retried. This imitates the way Perl handles such cases when using the + /g modifier or the split() function. Normally, the start offset is + advanced by one character, but if the newline convention recognizes + CRLF as a newline, and the current character is CR followed by LF, an advance of two characters occurs. Testing substring extraction functions - The copy and get modifiers can be used to test the pcre2_sub- + 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 group name or number, for + given more than once, and each can specify a group name or number, 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- + 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 + 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 + 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. Note that replacement - strings cannot contain commas, because a comma signifies the end of a + If the replace modifier is set, the pcre2_substitute() function is + called instead of one of the matching functions. Note that replacement + strings cannot contain commas, because a comma signifies the end of a modifier. This is not thought to be an issue in a test program. - 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- + 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 + The following modifiers set options (in additional to the normal match options) for pcre2_substitute(): global PCRE2_SUBSTITUTE_GLOBAL @@ -1073,8 +1227,8 @@ SUBJECT MODIFIERS substitute_unset_empty PCRE2_SUBSTITUTE_UNSET_EMPTY - After a successful substitution, the modified string is output, pre- - ceded by the number of replacements. This may be zero if there were no + 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 @@ -1083,12 +1237,12 @@ SUBJECT MODIFIERS =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 - replacement string starting at the next character. Here is an example + 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 + replacement string starting at the next character. Here is an example that tests the edge case: /abc/ @@ -1097,11 +1251,11 @@ SUBJECT MODIFIERS 123abc123\=replace=[9]XYZ Failed: error -47: no more memory - The default action of pcre2_substitute() is to return - PCRE2_ERROR_NOMEMORY when the output buffer is too small. However, if - the PCRE2_SUBSTITUTE_OVERFLOW_LENGTH option is set (by using the sub- - stitute_overflow_length modifier), pcre2_substitute() continues to go - through the motions of matching and substituting, in order to compute + The default action of pcre2_substitute() is to return + PCRE2_ERROR_NOMEMORY when the output buffer is too small. However, if + the PCRE2_SUBSTITUTE_OVERFLOW_LENGTH option is set (by using the sub- + stitute_overflow_length modifier), pcre2_substitute() continues to go + through the motions of matching and substituting, 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: @@ -1111,43 +1265,48 @@ SUBJECT MODIFIERS 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 + partial matching provokes an error return ("bad option value") from pcre2_substitute(). 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 + 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 kilobytes. - Providing a stack that is larger than the default 32K is necessary only - for very complicated patterns. + Setting zero reverts to the default of 32K. Providing a stack that is + larger than the default is necessary only for very complicated pat- + terns. If jitstack is set non-zero on a subject line it overrides any + value that was set on the pattern. - Setting match and recursion limits + Setting heap, match, and depth limits - The match_limit and recursion_limit modifiers set the appropriate lim- - its in the match context. These values are ignored when the find_limits - modifier is specified. + 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 modifier is specified. Finding minimum limits - If the find_limits modifier is present, pcre2test calls pcre2_match() - several times, setting different values in the match context via - pcre2_set_match_limit() and pcre2_set_recursion_limit() until it finds - the minimum values for each parameter that allow pcre2_match() to com- - plete without error. + 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 + minimum values for each parameter that allows the match to complete + without error. If JIT is being used, only the match limit is relevant. If DFA matching - is being used, neither limit is relevant, and this modifier is ignored - (with a warning message). - - 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. The - match_limit_recursion number is a measure of how much stack (or, if - PCRE2 is compiled with NO_RECURSE, how much heap) memory is needed to - complete the match attempt. + is being used, only the depth limit is relevant. + + 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. + + 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. Showing MARK names @@ -1160,8 +1319,16 @@ SUBJECT MODIFIERS Showing memory usage - The memory modifier causes pcre2test to log all memory allocation and - freeing calls that occur during a match operation. + 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(). These occur only when a match requires a bigger vector + than the default for remembering backtracking points. In many cases + there will be no heap memory used and therefore no additional output. + No heap memory is allocated during matching with pcre2_dfa_match or + with JIT, so in those cases the memory modifier never has any effect. + 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. Setting a starting offset @@ -1196,59 +1363,58 @@ SUBJECT MODIFIERS 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 has no effect, as there is no - facility for passing a length.) + 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 + When testing pcre2_substitute(), this modifier also has the effect of passing the replacement string as zero-terminated. Passing a NULL context - Normally, pcre2test passes a context block to pcre2_match(), + Normally, pcre2test passes a context block to pcre2_match(), pcre2_dfa_match() or pcre2_jit_match(). If the null_context modifier is - set, however, NULL is passed. This is for testing that the matching + set, however, NULL is passed. This is for testing that the matching functions behave correctly in this case (they use default values). This - modifier cannot be used with the find_limits modifier or when testing + modifier cannot be used with the find_limits modifier or when testing the substitution function. THE ALTERNATIVE MATCHING FUNCTION - By default, pcre2test uses the standard PCRE2 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 + 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 + 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, + 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_ERROR_NOMATCH, or "Partial match:" followed by the partially - matching substring when the return is PCRE2_ERROR_PARTIAL. (Note that - this is the entire substring that was inspected during the partial - match; it may include characters before the actual match start if a + 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_ERROR_NOMATCH, or "Partial match:" followed by the partially + matching substring when the return is PCRE2_ERROR_PARTIAL. (Note that + this is the entire substring that was inspected during the partial + match; it may include characters before the actual match start if a lookbehind assertion, \K, \b, or \B was involved.) 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 + 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 9.00 2014-05-10 + PCRE2 version 10.22 2016-07-29 re> /^abc(\d+)/ data> abc123 @@ -1260,8 +1426,8 @@ DEFAULT OUTPUT FROM pcre2test 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 + 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)/ @@ -1273,11 +1439,11 @@ DEFAULT OUTPUT FROM pcre2test 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. + 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 the rest of the subject + nition of non-printing characters. If the aftertext modifier is set, + the output for substring 0 is followed by the the rest of the subject string, identified by "0+" like this: re> /cat/aftertext @@ -1285,7 +1451,7 @@ DEFAULT OUTPUT FROM pcre2test 0: cat 0+ aract - If global matching is requested, the results of successive matching + If global matching is requested, the results of successive matching attempts are output in sequence, like this: re> /\Bi(\w\w)/g @@ -1297,8 +1463,8 @@ DEFAULT OUTPUT FROM pcre2test 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 + "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/ @@ -1306,7 +1472,7 @@ DEFAULT OUTPUT FROM pcre2test 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 + ">" 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). @@ -1314,7 +1480,7 @@ DEFAULT OUTPUT FROM pcre2test 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 + 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)/ @@ -1323,11 +1489,11 @@ OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION 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). - After a PCRE2_ERROR_PARTIAL return, the output is "Partial match:", - followed by the partially matching substring. Note that this is the - entire substring that was inspected during the partial match; it may + Using the normal matching function on this data finds only "tang". The + longest matching string is always given first (and numbered zero). + After a PCRE2_ERROR_PARTIAL return, the output is "Partial match:", + followed by the partially matching substring. Note that this is the + entire substring that was inspected during the partial match; it may include characters before the actual match start if a lookbehind asser- tion, \b, or \B was involved. (\K is not supported for DFA matching.) @@ -1343,16 +1509,16 @@ OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION 1: tan 0: tan - The alternative matching function does not support substring capture, - so the modifiers that are concerned with captured substrings are not + 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- + 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 + 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$/ @@ -1361,26 +1527,17 @@ RESTARTING AFTER A PARTIAL MATCH data> n05\=dfa,dfa_restart 0: n05 - For further information about partial matching, see the pcre2partial + 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. - - The callout function in pcre2test returns zero (carry on matching) by - default, but you can use a callout_fail modifier in a subject line (as - described above) to change this and other parameters of the callout. - - Inserting callouts can be helpful when using pcre2test to check compli- - cated regular expressions. For further information about callouts, see - the pcre2callout documentation. - - The output for callouts with numerical arguments and those with string - arguments is slightly different. + 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 @@ -1399,8 +1556,8 @@ CALLOUTS position, 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 + 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 @@ -1451,46 +1608,140 @@ CALLOUTS 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 + 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 - isprint() function is used to distinguish printing and non-printing + 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 + isprint() function is used to distinguish printing and non-printing characters. SAVING AND RESTORING COMPILED PATTERNS - It is possible to save compiled patterns on disc or elsewhere, and + It is possible to save compiled patterns on disc or elsewhere, and reload them later, subject to a number of restrictions. JIT data cannot - be saved. The host on which the patterns are reloaded must be running + 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 + 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 tables. 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 - serializing and de-serializing. They are described in the pcre2serial- + The functions whose names begin with pcre2_serialize_ are used for + serializing and de-serializing. They are described in the pcre2serial- ize documentation. In this section we describe the features of pcre2test that can be used to test these functions. - When a pattern with 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 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 immediate - matching. By using push and/or pushcopy, a number of patterns can be + When a pattern with 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 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 immediate + 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 com- + control modifiers that act at match time are ignored (with a message) + for the stacked patterns. The jitverify modifier applies only at com- pile time. The command @@ -1498,21 +1749,21 @@ SAVING AND RESTORING COMPILED PATTERNS #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 + 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 + 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 - allowed, nor are any option-setting modifiers. The JIT modifiers are, - however permitted. Here is an example that saves and reloads two pat- + allowed, 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 @@ -1525,10 +1776,10 @@ SAVING AND RESTORING COMPILED PATTERNS #pop jit,bincode abc - If jitverify is used with #pop, it does not automatically imply jit, + 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 analagous to the pushcopy modifier in that it + The #popcopy command is analagous to the pushcopy modifier in that it makes current a copy of the topmost stack pattern, leaving the original still on the stack. @@ -1548,5 +1799,5 @@ AUTHOR REVISION - Last updated: 06 July 2016 - Copyright (c) 1997-2016 University of Cambridge. + Last updated: 21 December 2017 + Copyright (c) 1997-2017 University of Cambridge. |