| . | any character, possibly including newline (s=true) |
| [xyz] | character class |
| [^xyz] | negated character class |
| \d, | Perl character class |
| \D, | negated Perl character class |
| [[:alpha:]], | ASCII character class |
| [[:^alpha:]], | negated ASCII character class |
| \pN, | Unicode character class (one-letter name) |
| \p{Greek}, | Unicode character class |
| \PN | negated, Unicode character class (one-letter name) |
| \P{Greek}, | negated Unicode character class |
- xy «x» followed by «y»
- x|y «x» or «y» (prefer «x»)
| x* | zero or more «x»,prefer more |
| x+ | one or more «x» ,prefer more |
| x? | zero or one «x» , prefer one |
| x{n,m} | «n» or «n»+1 or ... or «m» «x»,prefer more |
| x{n,} | «n» or more «x», prefer more |
| x{n} | exactly «n» «x» |
| x*? | zero or more «x», prefer fewer |
| x+? | one or more «x», prefer fewer |
| x?? | zero or one «x», prefer zero |
| x{n,m}? | «n» or «n»+1 or ... or «m» «x», prefer fewer |
| x{n,}? | «n» or more «x», prefer fewer |
| x{n}? | exactly «n» «x»x |
Implementation restriction: The counting forms «x{n,m}», «x{n,}», and «x{n}» reject forms that create a minimum or maximum repetition count above 1000. Unlimited repetitions are not subject to this restriction.
| (re) | numbered capturing group (submatch) |
| (?Pre) | named & numbered capturing group (submatch) |
| (?:re) | non-capturing group |
| (?flags) | set flags within current group; non-capturing |
| (?flags:re) | set flags during re; non-capturing |
| i | case-insensitive (default false) |
| m | multi-line mode: «^» and «$» match begin/end line in addition to begin/end text (default false) |
| s | let «.» match «\n» (default false) |
| U | ungreedy: swap meaning of «x*» and «x*?», «x+» and «x+?», etc (default false) |
Flag syntax is «xyz» (set) or «-xyz» (clear) or «xy-z» (set «xy», clear «z»).
| ^ | at beginning of text or line («m»=true) |
| $ | at end of text (like «\z» not «\Z») or line («m»=true) |
| \A | at beginning of text |
| \b | at ASCII word boundary («\w» on one side and «\W», «\A», or «\z» on the other) |
| \B | not at ASCII word boundary |
| \z | at end of text |
| \a | bell (== \007) |
| \f | form feed (== \014) |
| \t | horizontal tab (== \011) |
| \n | newline (== \012) |
| \r | carriage return (== \015) |
| \v | vertical tab character (== \013) |
| * | literal «», for any punctuation character «» |
| \123 | octal character code (up to three digits) |
| \x7F | hex character code (exactly two digits) |
| \x{10FFFF} | hex character code |
| \C | match a single byte even in UTF-8 mode |
| \Q...\E | literal text «...» even if «...» has punctuation |
Character class elements:
x single character A-Z character range (inclusive) \d Perl character class [:foo:] ASCII character class «foo» \p{Foo} Unicode character class «Foo» \pF Unicode character class «F» (one-letter name)
Named character classes as character class elements:
[\d] digits (== \d) [^\d] not digits (== \D) [\D] not digits (== \D) [^\D] not not digits (== \d) [[:name:]] named ASCII class inside character class (== [:name:]) [^[:name:]] named ASCII class inside negated character class (== [:^name:]) [\p{Name}] named Unicode property inside character class (== \p{Name}) [^\p{Name}] named Unicode property inside negated character class (== \P{Name})
Perl character classes (all ASCII-only):
\d digits (== [0-9]) \D not digits (== [^0-9]) \s whitespace (== [\t\n\f\r ]) \S not whitespace (== [^\t\n\f\r ]) \w word characters (== [0-9A-Za-z_]) \W not word characters (== [^0-9A-Za-z_])
ASCII character classes:
[[:alnum:]] alphanumeric (== [0-9A-Za-z])
[[:alpha:]] alphabetic (== [A-Za-z])
[[:ascii:]] ASCII (== [\x00-\x7F])
[[:blank:]] blank (== [\t ])
[[:cntrl:]] control (== [\x00-\x1F\x7F])
[[:digit:]] digits (== [0-9])
[[:graph:]] graphical (== [!-] == [A-Za-z0-9!"#$%&'()*+,-./:;<=>?@[\]^_])
[[:space:]] whitespace (== [\t\n\v\f\r ])
[[:upper:]] upper case (== [A-Z])
[[:word:]] word characters (== [0-9A-Za-z_])
[[:xdigit:]] hex digit (== [0-9A-Fa-f]){|}~]) [[:lower:]] lower case (== [a-z]) [[:print:]] printable (== [ -~] == [ [:graph:]]) [[:punct:]] punctuation (== [!-/:-@[-{-
Unicode character class names--general category:
C other Cc control Cf format Co private use Cs surrogate L letter Ll lowercase letter Lm modifier letter Lo other letter Lt titlecase letter Lu uppercase letter 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 math symbol So other symbol Z separator Zl line separator Zp paragraph separator Zs space separator
Unicode character class names--scripts:
Adlam Ahom Anatolian_Hieroglyphs Arabic Armenian Avestan Balinese Bamum Bassa_Vah Batak Bengali Bhaiksuki Bopomofo Brahmi Braille Buginese Buhid Canadian_Aboriginal Carian Caucasian_Albanian Chakma Cham Cherokee Chorasmian Common Coptic Cuneiform Cypriot Cypro_Minoan Cyrillic Deseret Devanagari Dives_Akuru Dogra Duployan Egyptian_Hieroglyphs Elbasan Elymaic Ethiopic Georgian Glagolitic Gothic Grantha Greek Gujarati Gunjala_Gondi Gurmukhi Han Hangul Hanifi_Rohingya Hanunoo Hatran Hebrew Hiragana Imperial_Aramaic Inherited Inscriptional_Pahlavi Inscriptional_Parthian Javanese Kaithi Kannada Katakana Kayah_Li Kharoshthi Khitan_Small_Script Khmer Khojki Khudawadi Lao Latin Lepcha Limbu Linear_A Linear_B Lisu Lycian Lydian Mahajani Makasar Malayalam Mandaic Manichaean Marchen Masaram_Gondi Medefaidrin Meetei_Mayek Mende_Kikakui Meroitic_Cursive Meroitic_Hieroglyphs Miao Modi Mongolian Mro Multani Myanmar Nabataean Nandinagari New_Tai_Lue Newa Nko Nushu Nyiakeng_Puachue_Hmong Ogham Ol_Chiki Old_Hungarian Old_Italic Old_North_Arabian Old_Permic Old_Persian Old_Sogdian Old_South_Arabian Old_Turkic Old_Uyghur Oriya Osage Osmanya Pahawh_Hmong Palmyrene Pau_Cin_Hau Phags_Pa Phoenician Psalter_Pahlavi Rejang Runic Samaritan Saurashtra Sharada Shavian Siddham SignWriting Sinhala Sogdian Sora_Sompeng Soyombo Sundanese Syloti_Nagri Syriac Tagalog Tagbanwa Tai_Le Tai_Tham Tai_Viet Takri Tamil Tangsa Tangut Telugu Thaana Thai Tibetan Tifinagh Tirhuta Toto Ugaritic Vai Vithkuqi Wancho Warang_Citi Yezidi Yi Zanabazar_Square
Vim character classes:
\d digits (== [0-9]) vim \D not «\d» vim \w word character vim \W not «\w» vim