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diff --git a/doc/pcresyntax.3 b/doc/pcresyntax.3 new file mode 100644 index 0000000..0850369 --- /dev/null +++ b/doc/pcresyntax.3 @@ -0,0 +1,540 @@ +.TH PCRESYNTAX 3 "08 January 2014" "PCRE 8.35" +.SH NAME +PCRE - Perl-compatible regular expressions +.SH "PCRE REGULAR EXPRESSION SYNTAX SUMMARY" +.rs +.sp +The full syntax and semantics of the regular expressions that are supported by +PCRE are described in the +.\" HREF +\fBpcrepattern\fP +.\" +documentation. This document contains a quick-reference summary of the syntax. +. +. +.SH "QUOTING" +.rs +.sp + \ex where x is non-alphanumeric is a literal x + \eQ...\eE treat enclosed characters as literal +. +. +.SH "CHARACTERS" +.rs +.sp + \ea alarm, that is, the BEL character (hex 07) + \ecx "control-x", where x is any ASCII character + \ee escape (hex 1B) + \ef form feed (hex 0C) + \en newline (hex 0A) + \er carriage return (hex 0D) + \et tab (hex 09) + \e0dd character with octal code 0dd + \eddd character with octal code ddd, or backreference + \eo{ddd..} character with octal code ddd.. + \exhh character with hex code hh + \ex{hhh..} character with hex code hhh.. +.sp +Note that \e0dd is always an octal code, and that \e8 and \e9 are the literal +characters "8" and "9". +. +. +.SH "CHARACTER TYPES" +.rs +.sp + . any character except newline; + in dotall mode, any character whatsoever + \eC one data unit, even in UTF mode (best avoided) + \ed a decimal digit + \eD a character that is not a decimal digit + \eh a horizontal white space character + \eH a character that is not a horizontal white space character + \eN a character that is not a newline + \ep{\fIxx\fP} a character with the \fIxx\fP property + \eP{\fIxx\fP} a character without the \fIxx\fP property + \eR a newline sequence + \es a white space character + \eS a character that is not a white space character + \ev a vertical white space character + \eV a character that is not a vertical white space character + \ew a "word" character + \eW a "non-word" character + \eX a Unicode extended grapheme cluster +.sp +By default, \ed, \es, and \ew match only ASCII characters, even in UTF-8 mode +or in the 16- bit and 32-bit libraries. However, if locale-specific matching is +happening, \es and \ew may also match characters with code points in the range +128-255. If the PCRE_UCP option is set, the behaviour of these escape sequences +is changed to use Unicode properties and they match many more characters. +. +. +.SH "GENERAL CATEGORY PROPERTIES FOR \ep and \eP" +.rs +.sp + C Other + Cc Control + Cf Format + Cn Unassigned + Co Private use + Cs Surrogate +.sp + L Letter + Ll Lower case letter + Lm Modifier letter + Lo Other letter + Lt Title case letter + Lu Upper case letter + L& Ll, Lu, or Lt +.sp + M Mark + Mc Spacing mark + Me Enclosing mark + Mn Non-spacing mark +.sp + N Number + Nd Decimal number + Nl Letter number + No Other number +.sp + P Punctuation + Pc Connector punctuation + Pd Dash punctuation + Pe Close punctuation + Pf Final punctuation + Pi Initial punctuation + Po Other punctuation + Ps Open punctuation +.sp + S Symbol + Sc Currency symbol + Sk Modifier symbol + Sm Mathematical symbol + So Other symbol +.sp + Z Separator + Zl Line separator + Zp Paragraph separator + Zs Space separator +. +. +.SH "PCRE SPECIAL CATEGORY PROPERTIES FOR \ep and \eP" +.rs +.sp + Xan Alphanumeric: union of properties L and N + Xps POSIX space: property Z or tab, NL, VT, FF, CR + Xsp Perl space: property Z or tab, NL, VT, FF, CR + Xuc Univerally-named character: one that can be + represented by a Universal Character Name + Xwd Perl word: property Xan or underscore +.sp +Perl and POSIX space are now the same. Perl added VT to its space character set +at release 5.18 and PCRE changed at release 8.34. +. +. +.SH "SCRIPT NAMES FOR \ep AND \eP" +.rs +.sp +Arabic, +Armenian, +Avestan, +Balinese, +Bamum, +Bassa_Vah, +Batak, +Bengali, +Bopomofo, +Brahmi, +Braille, +Buginese, +Buhid, +Canadian_Aboriginal, +Carian, +Caucasian_Albanian, +Chakma, +Cham, +Cherokee, +Common, +Coptic, +Cuneiform, +Cypriot, +Cyrillic, +Deseret, +Devanagari, +Duployan, +Egyptian_Hieroglyphs, +Elbasan, +Ethiopic, +Georgian, +Glagolitic, +Gothic, +Grantha, +Greek, +Gujarati, +Gurmukhi, +Han, +Hangul, +Hanunoo, +Hebrew, +Hiragana, +Imperial_Aramaic, +Inherited, +Inscriptional_Pahlavi, +Inscriptional_Parthian, +Javanese, +Kaithi, +Kannada, +Katakana, +Kayah_Li, +Kharoshthi, +Khmer, +Khojki, +Khudawadi, +Lao, +Latin, +Lepcha, +Limbu, +Linear_A, +Linear_B, +Lisu, +Lycian, +Lydian, +Mahajani, +Malayalam, +Mandaic, +Manichaean, +Meetei_Mayek, +Mende_Kikakui, +Meroitic_Cursive, +Meroitic_Hieroglyphs, +Miao, +Modi, +Mongolian, +Mro, +Myanmar, +Nabataean, +New_Tai_Lue, +Nko, +Ogham, +Ol_Chiki, +Old_Italic, +Old_North_Arabian, +Old_Permic, +Old_Persian, +Old_South_Arabian, +Old_Turkic, +Oriya, +Osmanya, +Pahawh_Hmong, +Palmyrene, +Pau_Cin_Hau, +Phags_Pa, +Phoenician, +Psalter_Pahlavi, +Rejang, +Runic, +Samaritan, +Saurashtra, +Sharada, +Shavian, +Siddham, +Sinhala, +Sora_Sompeng, +Sundanese, +Syloti_Nagri, +Syriac, +Tagalog, +Tagbanwa, +Tai_Le, +Tai_Tham, +Tai_Viet, +Takri, +Tamil, +Telugu, +Thaana, +Thai, +Tibetan, +Tifinagh, +Tirhuta, +Ugaritic, +Vai, +Warang_Citi, +Yi. +. +. +.SH "CHARACTER CLASSES" +.rs +.sp + [...] positive character class + [^...] negative character class + [x-y] range (can be used for hex characters) + [[:xxx:]] positive POSIX named set + [[:^xxx:]] negative POSIX named set +.sp + alnum alphanumeric + alpha alphabetic + ascii 0-127 + blank space or tab + cntrl control character + digit decimal digit + graph printing, excluding space + lower lower case letter + print printing, including space + punct printing, excluding alphanumeric + space white space + upper upper case letter + word same as \ew + xdigit hexadecimal digit +.sp +In PCRE, POSIX character set names recognize only ASCII characters by default, +but some of them use Unicode properties if PCRE_UCP is set. You can use +\eQ...\eE inside a character class. +. +. +.SH "QUANTIFIERS" +.rs +.sp + ? 0 or 1, greedy + ?+ 0 or 1, possessive + ?? 0 or 1, lazy + * 0 or more, greedy + *+ 0 or more, possessive + *? 0 or more, lazy + + 1 or more, greedy + ++ 1 or more, possessive + +? 1 or more, lazy + {n} exactly n + {n,m} at least n, no more than m, greedy + {n,m}+ at least n, no more than m, possessive + {n,m}? at least n, no more than m, lazy + {n,} n or more, greedy + {n,}+ n or more, possessive + {n,}? n or more, lazy +. +. +.SH "ANCHORS AND SIMPLE ASSERTIONS" +.rs +.sp + \eb word boundary + \eB not a word boundary + ^ start of subject + also after internal newline in multiline mode + \eA start of subject + $ end of subject + also before newline at end of subject + also before internal newline in multiline mode + \eZ end of subject + also before newline at end of subject + \ez end of subject + \eG first matching position in subject +. +. +.SH "MATCH POINT RESET" +.rs +.sp + \eK reset start of match +.sp +\eK is honoured in positive assertions, but ignored in negative ones. +. +. +.SH "ALTERNATION" +.rs +.sp + expr|expr|expr... +. +. +.SH "CAPTURING" +.rs +.sp + (...) 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-capturing group +. +. +. +. +.SH "COMMENT" +.rs +.sp + (?#....) comment (not nestable) +. +. +.SH "OPTION SETTING" +.rs +.sp + (?i) caseless + (?J) allow duplicate names + (?m) multiline + (?s) single line (dotall) + (?U) default ungreedy (lazy) + (?x) extended (ignore white space) + (?-...) unset option(s) +.sp +The following are recognized only at the very start of a pattern or after one +of the newline or \eR options with similar syntax. More than one of them may +appear. +.sp + (*LIMIT_MATCH=d) set the match limit to d (decimal number) + (*LIMIT_RECURSION=d) set the recursion limit to d (decimal number) + (*NO_AUTO_POSSESS) no auto-possessification (PCRE_NO_AUTO_POSSESS) + (*NO_START_OPT) no start-match optimization (PCRE_NO_START_OPTIMIZE) + (*UTF8) set UTF-8 mode: 8-bit library (PCRE_UTF8) + (*UTF16) set UTF-16 mode: 16-bit library (PCRE_UTF16) + (*UTF32) set UTF-32 mode: 32-bit library (PCRE_UTF32) + (*UTF) set appropriate UTF mode for the library in use + (*UCP) set PCRE_UCP (use Unicode properties for \ed etc) +.sp +Note that LIMIT_MATCH and LIMIT_RECURSION can only reduce the value of the +limits set by the caller of pcre_exec(), not increase them. +. +. +.SH "NEWLINE CONVENTION" +.rs +.sp +These are recognized only at the very start of the pattern or after option +settings with a similar syntax. +.sp + (*CR) carriage return only + (*LF) linefeed only + (*CRLF) carriage return followed by linefeed + (*ANYCRLF) all three of the above + (*ANY) any Unicode newline sequence +. +. +.SH "WHAT \eR MATCHES" +.rs +.sp +These are recognized only at the very start of the pattern or after option +setting with a similar syntax. +.sp + (*BSR_ANYCRLF) CR, LF, or CRLF + (*BSR_UNICODE) any Unicode newline sequence +. +. +.SH "LOOKAHEAD AND LOOKBEHIND ASSERTIONS" +.rs +.sp + (?=...) positive look ahead + (?!...) negative look ahead + (?<=...) positive look behind + (?<!...) negative look behind +.sp +Each top-level branch of a look behind must be of a fixed length. +. +. +.SH "BACKREFERENCES" +.rs +.sp + \en reference by number (can be ambiguous) + \egn reference by number + \eg{n} reference by number + \eg{-n} relative reference by number + \ek<name> reference by name (Perl) + \ek'name' reference by name (Perl) + \eg{name} reference by name (Perl) + \ek{name} reference by name (.NET) + (?P=name) reference by name (Python) +. +. +.SH "SUBROUTINE REFERENCES (POSSIBLY RECURSIVE)" +.rs +.sp + (?R) recurse whole pattern + (?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 (PCRE extension) + \eg'+n' call subpattern by relative number (PCRE extension) + \eg<-n> call subpattern by relative number (PCRE extension) + \eg'-n' call subpattern by relative number (PCRE extension) +. +. +.SH "CONDITIONAL PATTERNS" +.rs +.sp + (?(condition)yes-pattern) + (?(condition)yes-pattern|no-pattern) +.sp + (?(n)... absolute reference condition + (?(+n)... relative reference condition + (?(-n)... relative reference condition + (?(<name>)... named reference condition (Perl) + (?('name')... named reference condition (Perl) + (?(name)... named reference condition (PCRE) + (?(R)... overall recursion condition + (?(Rn)... specific group recursion condition + (?(R&name)... specific recursion condition + (?(DEFINE)... define subpattern for reference + (?(assert)... assertion condition +. +. +.SH "BACKTRACKING CONTROL" +.rs +.sp +The following act immediately they are reached: +.sp + (*ACCEPT) force successful match + (*FAIL) force backtrack; synonym (*F) + (*MARK:NAME) set name to be passed back; synonym (*:NAME) +.sp +The following act only when a subsequent match failure causes a backtrack to +reach them. They all force a match failure, but they differ in what happens +afterwards. Those that advance the start-of-match point do so only if the +pattern is not anchored. +.sp + (*COMMIT) overall failure, no advance of starting point + (*PRUNE) advance to next starting character + (*PRUNE:NAME) equivalent to (*MARK:NAME)(*PRUNE) + (*SKIP) advance to current matching position + (*SKIP:NAME) advance to position corresponding to an earlier + (*MARK:NAME); if not found, the (*SKIP) is ignored + (*THEN) local failure, backtrack to next alternation + (*THEN:NAME) equivalent to (*MARK:NAME)(*THEN) +. +. +.SH "CALLOUTS" +.rs +.sp + (?C) callout + (?Cn) callout with data n +. +. +.SH "SEE ALSO" +.rs +.sp +\fBpcrepattern\fP(3), \fBpcreapi\fP(3), \fBpcrecallout\fP(3), +\fBpcrematching\fP(3), \fBpcre\fP(3). +. +. +.SH AUTHOR +.rs +.sp +.nf +Philip Hazel +University Computing Service +Cambridge CB2 3QH, England. +.fi +. +. +.SH REVISION +.rs +.sp +.nf +Last updated: 08 January 2014 +Copyright (c) 1997-2014 University of Cambridge. +.fi |