pcresyntax man page on FreeBSD

Man page or keyword search:  
man Server   9747 pages
apropos Keyword Search (all sections)
Output format
FreeBSD logo
[printable version]

PCRESYNTAX(3)							 PCRESYNTAX(3)

NAME
       PCRE - Perl-compatible regular expressions

PCRE REGULAR EXPRESSION SYNTAX SUMMARY

       The  full syntax and semantics of the regular expressions that are sup‐
       ported by PCRE are described in	the  pcrepattern  documentation.  This
       document contains just a quick-reference summary of the syntax.

QUOTING

	 \x	    where x is non-alphanumeric is a literal x
	 \Q...\E    treat enclosed characters as literal

CHARACTERS

	 \a	    alarm, that is, the BEL character (hex 07)
	 \cx	    "control-x", where x is any ASCII character
	 \e	    escape (hex 1B)
	 \f	    formfeed (hex 0C)
	 \n	    newline (hex 0A)
	 \r	    carriage return (hex 0D)
	 \t	    tab (hex 09)
	 \ddd	    character with octal code ddd, or backreference
	 \xhh	    character with hex code hh
	 \x{hhh..}  character with hex code hhh..

CHARACTER TYPES

	 .	    any character except newline;
		      in dotall mode, any character whatsoever
	 \C	    one byte, even in UTF-8 mode (best avoided)
	 \d	    a decimal digit
	 \D	    a character that is not a decimal digit
	 \h	    a horizontal whitespace character
	 \H	    a character that is not a horizontal whitespace character
	 \N	    a character that is not a newline
	 \p{xx}	    a character with the xx property
	 \P{xx}	    a character without the xx property
	 \R	    a newline sequence
	 \s	    a whitespace character
	 \S	    a character that is not a whitespace character
	 \v	    a vertical whitespace character
	 \V	    a character that is not a vertical whitespace character
	 \w	    a "word" character
	 \W	    a "non-word" character
	 \X	    an extended Unicode sequence

       In  PCRE,  by  default, \d, \D, \s, \S, \w, and \W recognize only ASCII
       characters, even in UTF-8 mode. However, this can be changed by setting
       the PCRE_UCP option.

GENERAL CATEGORY PROPERTIES FOR \p and \P

	 C	    Other
	 Cc	    Control
	 Cf	    Format
	 Cn	    Unassigned
	 Co	    Private use
	 Cs	    Surrogate

	 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

	 M	    Mark
	 Mc	    Spacing mark
	 Me	    Enclosing mark
	 Mn	    Non-spacing mark

	 N	    Number
	 Nd	    Decimal number
	 Nl	    Letter number
	 No	    Other number

	 P	    Punctuation
	 Pc	    Connector punctuation
	 Pd	    Dash punctuation
	 Pe	    Close punctuation
	 Pf	    Final punctuation
	 Pi	    Initial punctuation
	 Po	    Other punctuation
	 Ps	    Open punctuation

	 S	    Symbol
	 Sc	    Currency symbol
	 Sk	    Modifier symbol
	 Sm	    Mathematical symbol
	 So	    Other symbol

	 Z	    Separator
	 Zl	    Line separator
	 Zp	    Paragraph separator
	 Zs	    Space separator

PCRE SPECIAL CATEGORY PROPERTIES FOR \p and \P

	 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, FF, CR
	 Xwd	    Perl word: property Xan or underscore

SCRIPT NAMES FOR \p AND \P

       Arabic, Armenian, Avestan, Balinese, Bamum, Bengali, Bopomofo, Braille,
       Buginese, Buhid, Canadian_Aboriginal, Carian, Cham,  Cherokee,  Common,
       Coptic,	 Cuneiform,  Cypriot,  Cyrillic,  Deseret,  Devanagari,	 Egyp‐
       tian_Hieroglyphs,  Ethiopic,  Georgian,	Glagolitic,   Gothic,	Greek,
       Gujarati,  Gurmukhi,  Han,  Hangul,  Hanunoo,  Hebrew,  Hiragana, Impe‐
       rial_Aramaic, Inherited, Inscriptional_Pahlavi, Inscriptional_Parthian,
       Javanese,  Kaithi, Kannada, Katakana, Kayah_Li, Kharoshthi, Khmer, Lao,
       Latin,  Lepcha,	Limbu,	Linear_B,  Lisu,  Lycian,  Lydian,  Malayalam,
       Meetei_Mayek,  Mongolian, Myanmar, New_Tai_Lue, Nko, Ogham, Old_Italic,
       Old_Persian, Old_South_Arabian, Old_Turkic, Ol_Chiki,  Oriya,  Osmanya,
       Phags_Pa,  Phoenician,  Rejang,	Runic, Samaritan, Saurashtra, Shavian,
       Sinhala, Sundanese, Syloti_Nagri, Syriac,  Tagalog,  Tagbanwa,  Tai_Le,
       Tai_Tham,  Tai_Viet,  Tamil,  Telugu,  Thaana, Thai, Tibetan, Tifinagh,
       Ugaritic, Vai, Yi.

CHARACTER CLASSES

	 [...]	     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

	 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 \w
	 xdigit	     hexadecimal digit

       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 \Q...\E inside a character class.

QUANTIFIERS

	 ?	     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

ANCHORS AND SIMPLE ASSERTIONS

	 \b	     word boundary
	 \B	     not a word boundary
	 ^	     start of subject
		      also after internal newline in multiline mode
	 \A	     start of subject
	 $	     end of subject
		      also before newline at end of subject
		      also before internal newline in multiline mode
	 \Z	     end of subject
		      also before newline at end of subject
	 \z	     end of subject
	 \G	     first matching position in subject

MATCH POINT RESET

	 \K	     reset start of match

ALTERNATION

	 expr|expr|expr...

CAPTURING

	 (...)		 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

ATOMIC GROUPS

	 (?>...)	 atomic, non-capturing group

COMMENT

	 (?#....)	 comment (not nestable)

OPTION SETTING

	 (?i)		 caseless
	 (?J)		 allow duplicate names
	 (?m)		 multiline
	 (?s)		 single line (dotall)
	 (?U)		 default ungreedy (lazy)
	 (?x)		 extended (ignore white space)
	 (?-...)	 unset option(s)

       The following are recognized only at the start of a  pattern  or	 after
       one of the newline-setting options with similar syntax:

	 (*NO_START_OPT) no start-match optimization (PCRE_NO_START_OPTIMIZE)
	 (*UTF8)	 set UTF-8 mode (PCRE_UTF8)
	 (*UCP)		 set PCRE_UCP (use Unicode properties for \d etc)

LOOKAHEAD AND LOOKBEHIND ASSERTIONS

	 (?=...)	 positive look ahead
	 (?!...)	 negative look ahead
	 (?<=...)	 positive look behind
	 (?<!...)	 negative look behind

       Each top-level branch of a look behind must be of a fixed length.

BACKREFERENCES

	 \n		 reference by number (can be ambiguous)
	 \gn		 reference by number
	 \g{n}		 reference by number
	 \g{-n}		 relative reference by number
	 \k<name>	 reference by name (Perl)
	 \k'name'	 reference by name (Perl)
	 \g{name}	 reference by name (Perl)
	 \k{name}	 reference by name (.NET)
	 (?P=name)	 reference by name (Python)

SUBROUTINE REFERENCES (POSSIBLY RECURSIVE)

	 (?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)
	 \g<name>	 call subpattern by name (Oniguruma)
	 \g'name'	 call subpattern by name (Oniguruma)
	 \g<n>		 call subpattern by absolute number (Oniguruma)
	 \g'n'		 call subpattern by absolute number (Oniguruma)
	 \g<+n>		 call subpattern by relative number (PCRE extension)
	 \g'+n'		 call subpattern by relative number (PCRE extension)
	 \g<-n>		 call subpattern by relative number (PCRE extension)
	 \g'-n'		 call subpattern by relative number (PCRE extension)

CONDITIONAL PATTERNS

	 (?(condition)yes-pattern)
	 (?(condition)yes-pattern|no-pattern)

	 (?(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

BACKTRACKING CONTROL

       The following act immediately they are reached:

	 (*ACCEPT)	 force successful match
	 (*FAIL)	 force backtrack; synonym (*F)

       The  following  act only when a subsequent match failure causes a back‐
       track 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.

	 (*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

NEWLINE CONVENTIONS

       These are recognized only at the very start of the pattern or  after  a
       (*BSR_...) or (*UTF8) or (*UCP) option.

	 (*CR)		 carriage return only
	 (*LF)		 linefeed only
	 (*CRLF)	 carriage return followed by linefeed
	 (*ANYCRLF)	 all three of the above
	 (*ANY)		 any Unicode newline sequence

WHAT \R MATCHES

       These  are  recognized only at the very start of the pattern or after a
       (*...) option that sets the newline convention or UTF-8 or UCP mode.

	 (*BSR_ANYCRLF)	 CR, LF, or CRLF
	 (*BSR_UNICODE)	 any Unicode newline sequence

CALLOUTS

	 (?C)	   callout
	 (?Cn)	   callout with data n

SEE ALSO

       pcrepattern(3), pcreapi(3), pcrecallout(3), pcrematching(3), pcre(3).

AUTHOR

       Philip Hazel
       University Computing Service
       Cambridge CB2 3QH, England.

REVISION

       Last updated: 21 November 2010
       Copyright (c) 1997-2010 University of Cambridge.

								 PCRESYNTAX(3)
[top]

List of man pages available for FreeBSD

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Tweet
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
...................................................................
Vote for polarhome
Free Shell Accounts :: the biggest list on the net