Regular Expressions 101

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An explanation of your regex will be automatically generated as you type.
Detailed match information will be displayed here automatically.
  • All Tokens
  • Common Tokens
  • General Tokens
  • Anchors
  • Meta Sequences
  • Quantifiers
  • Group Constructs
  • Character Classes
  • Flags/Modifiers
  • Substitution
  • A single character of: a, b or c
    [abc]
  • A character except: a, b or c
    [^abc]
  • A character in the range: a-z
    [a-z]
  • A character not in the range: a-z
    [^a-z]
  • A character in the range: a-z or A-Z
    [a-zA-Z]
  • Any single character
    .
  • Alternate - match either a or b
    a|b
  • Any whitespace character
    \s
  • Any non-whitespace character
    \S
  • Any digit
    \d
  • Any non-digit
    \D
  • Any word character
    \w
  • Any non-word character
    \W
  • Non-capturing group
    (?:...)
  • Capturing group
    (...)
  • Zero or one of a
    a?
  • Zero or more of a
    a*
  • One or more of a
    a+
  • Exactly 3 of a
    a{3}
  • 3 or more of a
    a{3,}
  • Between 3 and 6 of a
    a{3,6}
  • Start of string
    ^
  • End of string
    $
  • A word boundary
    \b
  • Non-word boundary
    \B

Regular Expression
No Match

/
/
gmui

Test String

Code Generator

Language

Generated Code

use strict; my $str = 'Bão Yagi (được Việt Nam định danh là bão số 3, được phía Philippines đặt tên bão Enteng - tiếng Anh: Severe Tropical Storm Enteng , nguyên văn \'Bão nhiệt đới dữ dội Enteng\') Some legal "[d]ocuments" contain corrected spel[l]ing, gram(m)ar, or simple typos; and lots of references[1]. By Extension, I included curl{e}y brackets, but not tag brack<e>ts, which are not seenin modern legal documents. These.are.properly.separated.even.U.S.A., and multiple punctuations are properly ignored. A. Multiple B. Choices -ABC-DEF- -A-B-C-D- -1-2-3-4- -test- .ABC.DEF. .AB.CD.EF.D. .A.B.C.D.E. .123.456.789. .12.34.56.78. .1.2.3.4. cod3 var1aBl3s test.U.S.A.test We\'d want hyphenated words in cases when large words are broken for wrapping in tight column news papers/megazines, while we can still properly separate numbers such as "30-35 pages". Non-Latin character are separated per character: 出典: フリー百科事典『ウィキペディア（Wikipedia）』 ウィキペディアには現在この名前の項目はありません。 Acceptable failed cases: - [E]xpected: "[" is considered external "wrapper/enclosure", while the internal "wrappers" are included so that they can be further processed/removed in the future. - test.U.S.A.test: this happens when no space trailing textContents of a block-level elemetn in HTML files. - 『ウィキペディア（Wikipedia）』: mixed languages - CamelCasing s not separated, but can be easily separated in "post-processing step, even though _snake_casing_ works fine by happenstance. -cod3 var1aBl3s: mixing letters and numbers. It\'s not intentional, but not a big deal when the side-effect is new word is always started with a number.'; my $regex = qr/(?:[^\p{Script=Latin}\s\w;:.,\-[\](){}'"+\/=<>])\B|(?:(?:[\p{Script=Latin}]|[^\s\w;:.,\-[\](){}'"+\/=<>]){2,}(?:(?:[\p{Script=Latin}]|[^\s\w+.,–:;\/\\=<>])?(?:[\p{Script=Latin}]|[^\s\w;\-:.,\[\](){}'"+\/\\=<>]))*)|(?:(?:[0-9\p{Script=Latin}]|[^\s\w;:.,[\](){}\-'"+\/\\=<>])(?:(?:[0-9\p{Script=Latin}]|[^\s\w+\-:;\/\\=<>])?(?:[0-9\p{Script=Latin}]|[^\s\w;:.,\-[\](){}'"+\/\\=<>]))*)/muip; if ( $str =~ /$regex/g ) { print "Whole match is ${^MATCH} and its start/end positions can be obtained via \$-[0] and \$+[0]\n"; # print "Capture Group 1 is $1 and its start/end positions can be obtained via \$-[1] and \$+[1]\n"; # print "Capture Group 2 is $2 ... and so on\n"; } # ${^POSTMATCH} and ${^PREMATCH} are also available with the use of '/p' # Named capture groups can be called via $+{name}

Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Perl, please visit: http://perldoc.perl.org/perlre.html