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

/
/
gm

Test String

Code Generator

Generated Code

use strict; my $str = '/usr/local/lib/node_modules/stylus/bin/stylus:685 throw err; ^ [Error: /Users/user/path/to/stylus/file/invalid.styl:34:5 30| ==/UserStyle== */ 31| 32| @-moz-document regexp("https?://(www\\\\.)?typescriptlang.org/(v2/)?docs.*$"), 33| regexp("https?://(www\\\\.)?(staging-)?typescript\\\\.org/docs/.*$") 34| error("compile error") -----------^ 35| compile error ] { fromStylus: true, lineno: 34, column: 5, filename: \'/Users/disk0/git.local/stylus-stylus/static/test/testFiles/invalid.styl\', stylusStack: \'\', input: \'/* ==UserStyle==\\n\' + \'@name TypeScript Docs\\n\' + \'@description Expands width of code blocks and moves navigation bar fully to the left\\n\' + \'@version 0.0.12\\n\' + \'@namespace github.com/disk0/stylus/typescript.org/docs\\n\' + \'\\n\' + \'@author disk0 (github.com/disco0)\\n\' + \'@license MIT\\n\' + \'\\n\' + \'@preprocessor stylus\\n\' + \'\\n\' + \'@var select CodeFont "Font for code displayed on page." [\\n\' + \' "Iosevka Extended*",\\n\' + \' "Iosevka Expanded",\\n\' + \' "Iosevka Term",\\n\' + \' "Iosevka",\\n\' + \'\\n\' + \' "SemanticHaskell",\\n\' + \' "SemanticJavascript",\\n\' + \' "SemanticCode",\\n\' + \' "Hasklig",\\n\' + \'\\n\' + \' "PragmataPro Mono Liga",\\n\' + \'\\n\' + \' "monospace"\\n\' + \']\\n\' + \'@var number CodeFontSize "Size of code in documentation" [ 14, 1, 500, 1, "px" ]\\n\' + \'@var number CodeFontWeight "Code font weight" [ 400, 100, 900, 100 ]\\n\' + \'@var number DocTextWidth "Width of text content in documentation" [ 1000, 300, 5000, 100, "px" ]\\n\' + \'==/UserStyle== */\\n\' + \'\\n\' + \'@-moz-document regexp("https?://(www\\\\\\\\.)?typescriptlang.org/(v2/)?docs.*$"),\\n\' + \'\\t regexp("https?://(www\\\\\\\\.)?(staging-)?typescript\\\\\\\\.org/docs/.*$")\\n\' + \' error("compile error")\\n\' } '; my $regex = qr/^\[Error: +(?<source_path>(?<file>[^\s\n](?:[^\n:\\]+|\\.)+?)(?::(?<line>\d+)(?::(?<column>\d+)))?) *$/mp; 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