450 lines
10 KiB
Groff
450 lines
10 KiB
Groff
.TH PCRESYNTAX 3
|
|
.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 just 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 character
|
|
\ee escape (hex 1B)
|
|
\ef formfeed (hex 0C)
|
|
\en newline (hex 0A)
|
|
\er carriage return (hex 0D)
|
|
\et tab (hex 09)
|
|
\eddd character with octal code ddd, or backreference
|
|
\exhh character with hex code hh
|
|
\ex{hhh..} character with hex code hhh..
|
|
.
|
|
.
|
|
.SH "CHARACTER TYPES"
|
|
.rs
|
|
.sp
|
|
. any character except newline;
|
|
in dotall mode, any character whatsoever
|
|
\eC one byte, even in UTF-8 mode (best avoided)
|
|
\ed a decimal digit
|
|
\eD a character that is not a decimal digit
|
|
\eh a horizontal whitespace character
|
|
\eH a character that is not a horizontal whitespace character
|
|
\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 whitespace character
|
|
\eS a character that is not a whitespace character
|
|
\ev a vertical whitespace character
|
|
\eV a character that is not a vertical whitespace character
|
|
\ew a "word" character
|
|
\eW a "non-word" character
|
|
\eX an extended Unicode sequence
|
|
.sp
|
|
In PCRE, \ed, \eD, \es, \eS, \ew, and \eW recognize only ASCII characters.
|
|
.
|
|
.
|
|
.SH "GENERAL CATEGORY PROPERTY CODES 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 "SCRIPT NAMES FOR \ep AND \eP"
|
|
.rs
|
|
.sp
|
|
Arabic,
|
|
Armenian,
|
|
Balinese,
|
|
Bengali,
|
|
Bopomofo,
|
|
Braille,
|
|
Buginese,
|
|
Buhid,
|
|
Canadian_Aboriginal,
|
|
Carian,
|
|
Cham,
|
|
Cherokee,
|
|
Common,
|
|
Coptic,
|
|
Cuneiform,
|
|
Cypriot,
|
|
Cyrillic,
|
|
Deseret,
|
|
Devanagari,
|
|
Ethiopic,
|
|
Georgian,
|
|
Glagolitic,
|
|
Gothic,
|
|
Greek,
|
|
Gujarati,
|
|
Gurmukhi,
|
|
Han,
|
|
Hangul,
|
|
Hanunoo,
|
|
Hebrew,
|
|
Hiragana,
|
|
Inherited,
|
|
Kannada,
|
|
Katakana,
|
|
Kayah_Li,
|
|
Kharoshthi,
|
|
Khmer,
|
|
Lao,
|
|
Latin,
|
|
Lepcha,
|
|
Limbu,
|
|
Linear_B,
|
|
Lycian,
|
|
Lydian,
|
|
Malayalam,
|
|
Mongolian,
|
|
Myanmar,
|
|
New_Tai_Lue,
|
|
Nko,
|
|
Ogham,
|
|
Old_Italic,
|
|
Old_Persian,
|
|
Ol_Chiki,
|
|
Oriya,
|
|
Osmanya,
|
|
Phags_Pa,
|
|
Phoenician,
|
|
Rejang,
|
|
Runic,
|
|
Saurashtra,
|
|
Shavian,
|
|
Sinhala,
|
|
Sudanese,
|
|
Syloti_Nagri,
|
|
Syriac,
|
|
Tagalog,
|
|
Tagbanwa,
|
|
Tai_Le,
|
|
Tamil,
|
|
Telugu,
|
|
Thaana,
|
|
Thai,
|
|
Tibetan,
|
|
Tifinagh,
|
|
Ugaritic,
|
|
Vai,
|
|
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 whitespace
|
|
upper upper case letter
|
|
word same as \ew
|
|
xdigit hexadecimal digit
|
|
.sp
|
|
In PCRE, POSIX character set names recognize only ASCII characters. 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 (only ASCII letters recognized)
|
|
\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
|
|
.
|
|
.
|
|
.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 is recognized only at the start of a pattern or after one of the
|
|
newline-setting options with similar syntax:
|
|
.sp
|
|
(*UTF8) set UTF-8 mode
|
|
.
|
|
.
|
|
.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)
|
|
.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
|
|
(*SKIP) advance start to current matching position
|
|
(*THEN) local failure, backtrack to next alternation
|
|
.
|
|
.
|
|
.SH "NEWLINE CONVENTIONS"
|
|
.rs
|
|
.sp
|
|
These are recognized only at the very start of the pattern or after a
|
|
(*BSR_...) or (*UTF8) option.
|
|
.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 a
|
|
(*...) option that sets the newline convention or UTF-8 mode.
|
|
.sp
|
|
(*BSR_ANYCRLF) CR, LF, or CRLF
|
|
(*BSR_UNICODE) any Unicode newline sequence
|
|
.
|
|
.
|
|
.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: 11 April 2009
|
|
Copyright (c) 1997-2009 University of Cambridge.
|
|
.fi
|