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

Language

Generated Code

use strict; my $str = 'ref #629 Ref #629 ref specification#629 Ref specification#629 ref https://gitlab.com/volterra/ves.io/specifications/-/issues/629 Ref https://gitlab.com/volterra/ves.io/specifications/-/issues/629 ref gitlab.com/volterra/ves.io/specifications/-/issues/629 Ref gitlab.com/volterra/ves.io/specifications/-/issues/629 ref: #629 Ref: #629 ref: specification#629 Ref: specification#629 ref: https://gitlab.com/volterra/ves.io/specifications/-/issues/629 Ref: https://gitlab.com/volterra/ves.io/specifications/-/issues/629 ref: gitlab.com/volterra/ves.io/specifications/-/issues/629 Ref: gitlab.com/volterra/ves.io/specifications/-/issues/629 closes #629 Closes #629 closes specification#629 Closes specification#629 closes https://gitlab.com/volterra/ves.io/specifications/-/issues/629 Closes https://gitlab.com/volterra/ves.io/specifications/-/issues/629 closes gitlab.com/volterra/ves.io/specifications/-/issues/629 Closes gitlab.com/volterra/ves.io/specifications/-/issues/629 closes: #629 Closes: #629 closes: specification#629 Closes: specification#629 closes: https://gitlab.com/volterra/ves.io/specifications/-/issues/629 Closes: https://gitlab.com/volterra/ves.io/specifications/-/issues/629 closes: gitlab.com/volterra/ves.io/specifications/-/issues/629 Closes: gitlab.com/volterra/ves.io/specifications/-/issues/629 related #629 Related #629 related specification#629 Related specification#629 related https://gitlab.com/volterra/ves.io/specifications/-/issues/629 Related https://gitlab.com/volterra/ves.io/specifications/-/issues/629 related gitlab.com/volterra/ves.io/specifications/-/issues/629 Related gitlab.com/volterra/ves.io/specifications/-/issues/629 related: #629 Related: #629 related: specification#629 Related: specification#629 related: https://gitlab.com/volterra/ves.io/specifications/-/issues/629 Related: https://gitlab.com/volterra/ves.io/specifications/-/issues/629 related: gitlab.com/volterra/ves.io/specifications/-/issues/629 Related: gitlab.com/volterra/ves.io/specifications/-/issues/629 fixes #629 Fixes #629 fixes specification#629 Fixes specification#629 fixes https://gitlab.com/volterra/ves.io/specifications/-/issues/629 Fixes https://gitlab.com/volterra/ves.io/specifications/-/issues/629 fixes gitlab.com/volterra/ves.io/specifications/-/issues/629 Fixes gitlab.com/volterra/ves.io/specifications/-/issues/629 fixes: #629 Fixes: #629 fixes: specification#629 Fixes: specification#629 fixes: https://gitlab.com/volterra/ves.io/specifications/-/issues/629 Fixes: https://gitlab.com/volterra/ves.io/specifications/-/issues/629 fixes: gitlab.com/volterra/ves.io/specifications/-/issues/629 Fixes: gitlab.com/volterra/ves.io/specifications/-/issues/629 partial #629 Partial #629 partial specification#629 Partial specification#629 partial https://gitlab.com/volterra/ves.io/specifications/-/issues/629 Partial https://gitlab.com/volterra/ves.io/specifications/-/issues/629 partial gitlab.com/volterra/ves.io/specifications/-/issues/629 Partial gitlab.com/volterra/ves.io/specifications/-/issues/629 partial: #629 Partial: #629 partial: specification#629 Partial: specification#629 partial: https://gitlab.com/volterra/ves.io/specifications/-/issues/629 Partial: https://gitlab.com/volterra/ves.io/specifications/-/issues/629 partial: gitlab.com/volterra/ves.io/specifications/-/issues/629 Partial: gitlab.com/volterra/ves.io/specifications/-/issues/629 noref '; my $regex = qr`^(([Rr]ef|[Cc]loses|[Rr]elated|[Ff]ixes|[Pp]artial)(:|) (#\d+|\w+\#\d+|(https://|)gitlab.com/volterra/.*/issues/\d+))|noref$`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