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Diffstat (limited to 'dist2/doc/pcre2syntax.3')
| -rw-r--r-- | dist2/doc/pcre2syntax.3 | 113 |
1 files changed, 40 insertions, 73 deletions
diff --git a/dist2/doc/pcre2syntax.3 b/dist2/doc/pcre2syntax.3 index 70538e4e..c392bfb0 100644 --- a/dist2/doc/pcre2syntax.3 +++ b/dist2/doc/pcre2syntax.3 @@ -1,4 +1,4 @@ -.TH PCRE2SYNTAX 3 "11 February 2019" "PCRE2 10.33" +.TH PCRE2SYNTAX 3 "02 September 2018" "PCRE2 10.32" .SH NAME PCRE2 - Perl-compatible regular expressions (revised API) .SH "PCRE2 REGULAR EXPRESSION SYNTAX SUMMARY" @@ -22,8 +22,7 @@ documentation. This document contains a quick-reference summary of the syntax. .SH "ESCAPED CHARACTERS" .rs .sp -This table applies to ASCII and Unicode environments. An unrecognized escape -sequence causes an error. +This table applies to ASCII and Unicode environments. .sp \ea alarm, that is, the BEL character (hex 07) \ecx "control-x", where x is any ASCII printing character @@ -35,24 +34,12 @@ sequence causes an error. \e0dd character with octal code 0dd \eddd character with octal code ddd, or backreference \eo{ddd..} character with octal code ddd.. + \eU "U" if PCRE2_ALT_BSUX is set (otherwise is an error) \eN{U+hh..} character with Unicode code point hh.. (Unicode mode only) + \euhhhh character with hex code hhhh (if PCRE2_ALT_BSUX is set) \exhh character with hex code hh \ex{hh..} character with hex code hh.. .sp -If PCRE2_ALT_BSUX or PCRE2_EXTRA_ALT_BSUX is set ("ALT_BSUX mode"), the -following are also recognized: -.sp - \eU the character "U" - \euhhhh character with hex code hhhh - \eu{hh..} character with hex code hh.. but only for EXTRA_ALT_BSUX -.sp -When \ex is not followed by {, from zero to two hexadecimal digits are read, -but in ALT_BSUX mode \ex must be followed by two hexadecimal digits to be -recognized as a hexadecimal escape; otherwise it matches a literal "x". -Likewise, if \eu (in ALT_BSUX mode) is not followed by four hexadecimal digits -or (in EXTRA_ALT_BSUX mode) a sequence of hex digits in curly brackets, it -matches a literal "u". -.P Note that \e0dd is always an octal code. The treatment of backslash followed by a non-zero digit is complicated; for details see the section .\" HTML <a href="pcre2pattern.html#digitsafterbackslash"> @@ -67,6 +54,12 @@ documentation, where details of escape processing in EBCDIC environments are also given. \eN{U+hh..} is synonymous with \ex{hh..} in PCRE2 but is not supported in EBCDIC environments. Note that \eN not followed by an opening curly bracket has a different meaning (see below). +.P +When \ex is not followed by {, from zero to two hexadecimal digits are read, +but if PCRE2_ALT_BSUX is set, \ex must be followed by two hexadecimal digits to +be recognized as a hexadecimal escape; otherwise it matches a literal "x". +Likewise, if \eu (in ALT_BSUX mode) is not followed by four hexadecimal digits, +it matches a literal "u". . . .SH "CHARACTER TYPES" @@ -405,24 +398,19 @@ but some of them use Unicode properties if PCRE2_UCP is set. You can use .SH "CAPTURING" .rs .sp - (...) capture group - (?<name>...) named capture group (Perl) - (?'name'...) named capture group (Perl) - (?P<name>...) named capture group (Python) - (?:...) non-capture group - (?|...) non-capture group; reset group numbers for - capture groups in each alternative -.sp -In non-UTF modes, names may contain underscores and ASCII letters and digits; -in UTF modes, any Unicode letters and Unicode decimal digits are permitted. In -both cases, a name must not start with a digit. + (...) capturing group + (?<name>...) named capturing group (Perl) + (?'name'...) named capturing group (Perl) + (?P<name>...) named capturing group (Python) + (?:...) non-capturing group + (?|...) non-capturing group; reset group numbers for + capturing groups in each alternative . . .SH "ATOMIC GROUPS" .rs .sp - (?>...) atomic non-capture group - (*atomic:...) atomic non-capture group + (?>...) atomic, non-capturing group . . .SH "COMMENT" @@ -450,7 +438,7 @@ of the group. Unsetting x or xx unsets both. Several options may be set at once, and a mixture of setting and unsetting such as (?i-x) is allowed, but there may be only one hyphen. Setting (but no unsetting) is allowed after (?^ for example -(?^in). An option setting may appear at the start of a non-capture group, for +(?^in). An option setting may appear at the start of a non-capturing group, for example (?i:...). .P The following are recognized only at the very start of a pattern or after one @@ -503,33 +491,12 @@ setting with a similar syntax. .SH "LOOKAHEAD AND LOOKBEHIND ASSERTIONS" .rs .sp - (?=...) ) - (*pla:...) ) positive lookahead - (*positive_lookahead:...) ) -.sp - (?!...) ) - (*nla:...) ) negative lookahead - (*negative_lookahead:...) ) -.sp - (?<=...) ) - (*plb:...) ) positive lookbehind - (*positive_lookbehind:...) ) -.sp - (?<!...) ) - (*nlb:...) ) negative lookbehind - (*negative_lookbehind:...) ) -.sp -Each top-level branch of a lookbehind must be of a fixed length. -. -. -.SH "SCRIPT RUNS" -.rs -.sp - (*script_run:...) ) script run, can be backtracked into - (*sr:...) ) + (?=...) positive look ahead + (?!...) negative look ahead + (?<=...) positive look behind + (?<!...) negative look behind .sp - (*atomic_script_run:...) ) atomic script run - (*asr:...) ) +Each top-level branch of a look behind must be of a fixed length. . . .SH "BACKREFERENCES" @@ -553,19 +520,19 @@ Each top-level branch of a lookbehind must be of a fixed length. .rs .sp (?R) recurse whole pattern - (?n) call subroutine by absolute number - (?+n) call subroutine by relative number - (?-n) call subroutine by relative number - (?&name) call subroutine by name (Perl) - (?P>name) call subroutine by name (Python) - \eg<name> call subroutine by name (Oniguruma) - \eg'name' call subroutine by name (Oniguruma) - \eg<n> call subroutine by absolute number (Oniguruma) - \eg'n' call subroutine by absolute number (Oniguruma) - \eg<+n> call subroutine by relative number (PCRE2 extension) - \eg'+n' call subroutine by relative number (PCRE2 extension) - \eg<-n> call subroutine by relative number (PCRE2 extension) - \eg'-n' call subroutine by relative number (PCRE2 extension) + (?n) call subpattern by absolute number + (?+n) call subpattern by relative number + (?-n) call subpattern by relative number + (?&name) call subpattern by name (Perl) + (?P>name) call subpattern by name (Python) + \eg<name> call subpattern by name (Oniguruma) + \eg'name' call subpattern by name (Oniguruma) + \eg<n> call subpattern by absolute number (Oniguruma) + \eg'n' call subpattern by absolute number (Oniguruma) + \eg<+n> call subpattern by relative number (PCRE2 extension) + \eg'+n' call subpattern by relative number (PCRE2 extension) + \eg<-n> call subpattern by relative number (PCRE2 extension) + \eg'-n' call subpattern by relative number (PCRE2 extension) . . .SH "CONDITIONAL PATTERNS" @@ -583,7 +550,7 @@ Each top-level branch of a lookbehind must be of a fixed length. (?(R) overall recursion condition (?(Rn) specific numbered group recursion condition (?(R&name) specific named group recursion condition - (?(DEFINE) define groups for reference + (?(DEFINE) define subpattern for reference (?(VERSION[>]=n.m) test PCRE2 version (?(assert) assertion condition .sp @@ -654,6 +621,6 @@ Cambridge, England. .rs .sp .nf -Last updated: 11 February 2019 -Copyright (c) 1997-2019 University of Cambridge. +Last updated: 02 September 2018 +Copyright (c) 1997-2018 University of Cambridge. .fi |