1 RE2 regular expression syntax reference 2 ------------------------------------- 3 4 Single characters: 5 . any character, possibly including newline (s=true) 6 [xyz] character class 7 [^xyz] negated character class 8 \d Perl character class 9 \D negated Perl character class 10 [:alpha:] ASCII character class 11 [:^alpha:] negated ASCII character class 12 \pN Unicode character class (one-letter name) 13 \p{Greek} Unicode character class 14 \PN negated Unicode character class (one-letter name) 15 \P{Greek} negated Unicode character class 16 17 Composites: 18 xy x followed by y 19 x|y x or y (prefer x) 20 21 Repetitions: 22 x* zero or more x, prefer more 23 x+ one or more x, prefer more 24 x? zero or one x, prefer one 25 x{n,m} n or n+1 or ... or m x, prefer more 26 x{n,} n or more x, prefer more 27 x{n} exactly n x 28 x*? zero or more x, prefer fewer 29 x+? one or more x, prefer fewer 30 x?? zero or one x, prefer zero 31 x{n,m}? n or n+1 or ... or m x, prefer fewer 32 x{n,}? n or more x, prefer fewer 33 x{n}? exactly n x 34 x{} (== x*) NOT SUPPORTED vim 35 x{-} (== x*?) NOT SUPPORTED vim 36 x{-n} (== x{n}?) NOT SUPPORTED vim 37 x= (== x?) NOT SUPPORTED vim 38 39 Possessive repetitions: 40 x*+ zero or more x, possessive NOT SUPPORTED 41 x++ one or more x, possessive NOT SUPPORTED 42 x?+ zero or one x, possessive NOT SUPPORTED 43 x{n,m}+ n or ... or m x, possessive NOT SUPPORTED 44 x{n,}+ n or more x, possessive NOT SUPPORTED 45 x{n}+ exactly n x, possessive NOT SUPPORTED 46 47 Grouping: 48 (re) numbered capturing group 49 (?P<name>re) named & numbered capturing group 50 (?<name>re) named & numbered capturing group NOT SUPPORTED 51 (?'name're) named & numbered capturing group NOT SUPPORTED 52 (?:re) non-capturing group 53 (?flags) set flags within current group; non-capturing 54 (?flags:re) set flags during re; non-capturing 55 (?#text) comment NOT SUPPORTED 56 (?|x|y|z) branch numbering reset NOT SUPPORTED 57 (?>re) possessive match of re NOT SUPPORTED 58 re@> possessive match of re NOT SUPPORTED vim 59 %(re) non-capturing group NOT SUPPORTED vim 60 61 Flags: 62 i case-insensitive (default false) 63 m multi-line mode: ^ and $ match begin/end line in addition to begin/end text (default false) 64 s let . match \n (default false) 65 U ungreedy: swap meaning of x* and x*?, x+ and x+?, etc (default false) 66 Flag syntax is xyz (set) or -xyz (clear) or xy-z (set xy, clear z). 67 68 Empty strings: 69 ^ at beginning of text or line (m=true) 70 $ at end of text (like \z not \Z) or line (m=true) 71 \A at beginning of text 72 \b at word boundary (\w on one side and \W, \A, or \z on the other) 73 \B not a word boundary 74 \G at beginning of subtext being searched NOT SUPPORTED pcre 75 \G at end of last match NOT SUPPORTED perl 76 \Z at end of text, or before newline at end of text NOT SUPPORTED 77 \z at end of text 78 (?=re) before text matching re NOT SUPPORTED 79 (?!re) before text not matching re NOT SUPPORTED 80 (?<=re) after text matching re NOT SUPPORTED 81 (?<!re) after text not matching re NOT SUPPORTED 82 re& before text matching re NOT SUPPORTED vim 83 re@= before text matching re NOT SUPPORTED vim 84 re@! before text not matching re NOT SUPPORTED vim 85 re@<= after text matching re NOT SUPPORTED vim 86 re@<! after text not matching re NOT SUPPORTED vim 87 \zs sets start of match (= \K) NOT SUPPORTED vim 88 \ze sets end of match NOT SUPPORTED vim 89 \%^ beginning of file NOT SUPPORTED vim 90 \%$ end of file NOT SUPPORTED vim 91 \%V on screen NOT SUPPORTED vim 92 \%# cursor position NOT SUPPORTED vim 93 \%'m mark m position NOT SUPPORTED vim 94 \%23l in line 23 NOT SUPPORTED vim 95 \%23c in column 23 NOT SUPPORTED vim 96 \%23v in virtual column 23 NOT SUPPORTED vim 97 98 Escape sequences: 99 \a bell (== \007) 100 \f form feed (== \014) 101 \t horizontal tab (== \011) 102 \n newline (== \012) 103 \r carriage return (== \015) 104 \v vertical tab character (== \013) 105 \* literal *, for any punctuation character * 106 \123 octal character code (up to three digits) 107 \x7F hex character code (exactly two digits) 108 \x{10FFFF} hex character code 109 \C match a single byte even in UTF-8 mode 110 \Q...\E literal text ... even if ... has punctuation 111 112 \1 backreference NOT SUPPORTED 113 \b backspace NOT SUPPORTED (use \010) 114 \cK control char ^K NOT SUPPORTED (use \001 etc) 115 \e escape NOT SUPPORTED (use \033) 116 \g1 backreference NOT SUPPORTED 117 \g{1} backreference NOT SUPPORTED 118 \g{+1} backreference NOT SUPPORTED 119 \g{-1} backreference NOT SUPPORTED 120 \g{name} named backreference NOT SUPPORTED 121 \g<name> subroutine call NOT SUPPORTED 122 \g'name' subroutine call NOT SUPPORTED 123 \k<name> named backreference NOT SUPPORTED 124 \k'name' named backreference NOT SUPPORTED 125 \lX lowercase X NOT SUPPORTED 126 \ux uppercase x NOT SUPPORTED 127 \L...\E lowercase text ... NOT SUPPORTED 128 \K reset beginning of $0 NOT SUPPORTED 129 \N{name} named Unicode character NOT SUPPORTED 130 \R line break NOT SUPPORTED 131 \U...\E upper case text ... NOT SUPPORTED 132 \X extended Unicode sequence NOT SUPPORTED 133 134 \%d123 decimal character 123 NOT SUPPORTED vim 135 \%xFF hex character FF NOT SUPPORTED vim 136 \%o123 octal character 123 NOT SUPPORTED vim 137 \%u1234 Unicode character 0x1234 NOT SUPPORTED vim 138 \%U12345678 Unicode character 0x12345678 NOT SUPPORTED vim 139 140 Character class elements: 141 x single character 142 A-Z character range (inclusive) 143 \d Perl character class 144 [:foo:] ASCII character class foo 145 \p{Foo} Unicode character class Foo 146 \pF Unicode character class F (one-letter name) 147 148 Named character classes as character class elements: 149 [\d] digits (== \d) 150 [^\d] not digits (== \D) 151 [\D] not digits (== \D) 152 [^\D] not not digits (== \d) 153 [[:name:]] named ASCII class inside character class (== [:name:]) 154 [^[:name:]] named ASCII class inside negated character class (== [:^name:]) 155 [\p{Name}] named Unicode property inside character class (== \p{Name}) 156 [^\p{Name}] named Unicode property inside negated character class (== \P{Name}) 157 158 Perl character classes: 159 \d digits (== [0-9]) 160 \D not digits (== [^0-9]) 161 \s whitespace (== [\t\n\f\r ]) 162 \S not whitespace (== [^\t\n\f\r ]) 163 \w word characters (== [0-9A-Za-z_]) 164 \W not word characters (== [^0-9A-Za-z_]) 165 166 \h horizontal space NOT SUPPORTED 167 \H not horizontal space NOT SUPPORTED 168 \v vertical space NOT SUPPORTED 169 \V not vertical space NOT SUPPORTED 170 171 ASCII character classes: 172 [:alnum:] alphanumeric (== [0-9A-Za-z]) 173 [:alpha:] alphabetic (== [A-Za-z]) 174 [:ascii:] ASCII (== [\x00-\x7F]) 175 [:blank:] blank (== [\t ]) 176 [:cntrl:] control (== [\x00-\x1F\x7F]) 177 [:digit:] digits (== [0-9]) 178 [:graph:] graphical (== [!-~] == [A-Za-z0-9!"#$%&'()*+,\-./:;<=>?@[\\\]^_`{|}~]) 179 [:lower:] lower case (== [a-z]) 180 [:print:] printable (== [ -~] == [ [:graph:]]) 181 [:punct:] punctuation (== [!-/:-@[-`{-~]) 182 [:space:] whitespace (== [\t\n\v\f\r ]) 183 [:upper:] upper case (== [A-Z]) 184 [:word:] word characters (== [0-9A-Za-z_]) 185 [:xdigit:] hex digit (== [0-9A-Fa-f]) 186 187 Unicode character class names--general category: 188 C other 189 Cc control 190 Cf format 191 Cn unassigned code points NOT SUPPORTED 192 Co private use 193 Cs surrogate 194 L letter 195 LC cased letter NOT SUPPORTED 196 L& cased letter NOT SUPPORTED 197 Ll lowercase letter 198 Lm modifier letter 199 Lo other letter 200 Lt titlecase letter 201 Lu uppercase letter 202 M mark 203 Mc spacing mark 204 Me enclosing mark 205 Mn non-spacing mark 206 N number 207 Nd decimal number 208 Nl letter number 209 No other number 210 P punctuation 211 Pc connector punctuation 212 Pd dash punctuation 213 Pe close punctuation 214 Pf final punctuation 215 Pi initial punctuation 216 Po other punctuation 217 Ps open punctuation 218 S symbol 219 Sc currency symbol 220 Sk modifier symbol 221 Sm math symbol 222 So other symbol 223 Z separator 224 Zl line separator 225 Zp paragraph separator 226 Zs space separator 227 228 Unicode character class names--scripts: 229 Arabic Arabic 230 Armenian Armenian 231 Balinese Balinese 232 Bengali Bengali 233 Bopomofo Bopomofo 234 Braille Braille 235 Buginese Buginese 236 Buhid Buhid 237 Canadian_Aboriginal Canadian Aboriginal 238 Carian Carian 239 Cham Cham 240 Cherokee Cherokee 241 Common characters not specific to one script 242 Coptic Coptic 243 Cuneiform Cuneiform 244 Cypriot Cypriot 245 Cyrillic Cyrillic 246 Deseret Deseret 247 Devanagari Devanagari 248 Ethiopic Ethiopic 249 Georgian Georgian 250 Glagolitic Glagolitic 251 Gothic Gothic 252 Greek Greek 253 Gujarati Gujarati 254 Gurmukhi Gurmukhi 255 Han Han 256 Hangul Hangul 257 Hanunoo Hanunoo 258 Hebrew Hebrew 259 Hiragana Hiragana 260 Inherited inherit script from previous character 261 Kannada Kannada 262 Katakana Katakana 263 Kayah_Li Kayah Li 264 Kharoshthi Kharoshthi 265 Khmer Khmer 266 Lao Lao 267 Latin Latin 268 Lepcha Lepcha 269 Limbu Limbu 270 Linear_B Linear B 271 Lycian Lycian 272 Lydian Lydian 273 Malayalam Malayalam 274 Mongolian Mongolian 275 Myanmar Myanmar 276 New_Tai_Lue New Tai Lue (aka Simplified Tai Lue) 277 Nko Nko 278 Ogham Ogham 279 Ol_Chiki Ol Chiki 280 Old_Italic Old Italic 281 Old_Persian Old Persian 282 Oriya Oriya 283 Osmanya Osmanya 284 Phags_Pa 'Phags Pa 285 Phoenician Phoenician 286 Rejang Rejang 287 Runic Runic 288 Saurashtra Saurashtra 289 Shavian Shavian 290 Sinhala Sinhala 291 Sundanese Sundanese 292 Syloti_Nagri Syloti Nagri 293 Syriac Syriac 294 Tagalog Tagalog 295 Tagbanwa Tagbanwa 296 Tai_Le Tai Le 297 Tamil Tamil 298 Telugu Telugu 299 Thaana Thaana 300 Thai Thai 301 Tibetan Tibetan 302 Tifinagh Tifinagh 303 Ugaritic Ugaritic 304 Vai Vai 305 Yi Yi 306 307 Vim character classes: 308 \i identifier character NOT SUPPORTED vim 309 \I \i except digits NOT SUPPORTED vim 310 \k keyword character NOT SUPPORTED vim 311 \K \k except digits NOT SUPPORTED vim 312 \f file name character NOT SUPPORTED vim 313 \F \f except digits NOT SUPPORTED vim 314 \p printable character NOT SUPPORTED vim 315 \P \p except digits NOT SUPPORTED vim 316 \s whitespace character (== [ \t]) NOT SUPPORTED vim 317 \S non-white space character (== [^ \t]) NOT SUPPORTED vim 318 \d digits (== [0-9]) vim 319 \D not \d vim 320 \x hex digits (== [0-9A-Fa-f]) NOT SUPPORTED vim 321 \X not \x NOT SUPPORTED vim 322 \o octal digits (== [0-7]) NOT SUPPORTED vim 323 \O not \o NOT SUPPORTED vim 324 \w word character vim 325 \W not \w vim 326 \h head of word character NOT SUPPORTED vim 327 \H not \h NOT SUPPORTED vim 328 \a alphabetic NOT SUPPORTED vim 329 \A not \a NOT SUPPORTED vim 330 \l lowercase NOT SUPPORTED vim 331 \L not lowercase NOT SUPPORTED vim 332 \u uppercase NOT SUPPORTED vim 333 \U not uppercase NOT SUPPORTED vim 334 \_x \x plus newline, for any x NOT SUPPORTED vim 335 336 Vim flags: 337 \c ignore case NOT SUPPORTED vim 338 \C match case NOT SUPPORTED vim 339 \m magic NOT SUPPORTED vim 340 \M nomagic NOT SUPPORTED vim 341 \v verymagic NOT SUPPORTED vim 342 \V verynomagic NOT SUPPORTED vim 343 \Z ignore differences in Unicode combining characters NOT SUPPORTED vim 344 345 Magic: 346 (?{code}) arbitrary Perl code NOT SUPPORTED perl 347 (??{code}) postponed arbitrary Perl code NOT SUPPORTED perl 348 (?n) recursive call to regexp capturing group n NOT SUPPORTED 349 (?+n) recursive call to relative group +n NOT SUPPORTED 350 (?-n) recursive call to relative group -n NOT SUPPORTED 351 (?C) PCRE callout NOT SUPPORTED pcre 352 (?R) recursive call to entire regexp (== (?0)) NOT SUPPORTED 353 (?&name) recursive call to named group NOT SUPPORTED 354 (?P=name) named backreference NOT SUPPORTED 355 (?P>name) recursive call to named group NOT SUPPORTED 356 (?(cond)true|false) conditional branch NOT SUPPORTED 357 (?(cond)true) conditional branch NOT SUPPORTED 358 (*ACCEPT) make regexps more like Prolog NOT SUPPORTED 359 (*COMMIT) NOT SUPPORTED 360 (*F) NOT SUPPORTED 361 (*FAIL) NOT SUPPORTED 362 (*MARK) NOT SUPPORTED 363 (*PRUNE) NOT SUPPORTED 364 (*SKIP) NOT SUPPORTED 365 (*THEN) NOT SUPPORTED 366 (*ANY) set newline convention NOT SUPPORTED 367 (*ANYCRLF) NOT SUPPORTED 368 (*CR) NOT SUPPORTED 369 (*CRLF) NOT SUPPORTED 370 (*LF) NOT SUPPORTED 371 (*BSR_ANYCRLF) set \R convention NOT SUPPORTED pcre 372 (*BSR_UNICODE) NOT SUPPORTED pcre 373 374
