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 = 'Using regex to identify two different sets of data with multiple parts I have some file folders that I want to use reg expressions to "cut up" sections so I can reformat them. This is their general pattern: * 2 Cold Scorpio 1998-04-13 v1 > Mick Foley 1997-09-22 v2 \\[Cactus Jack\\] - Whole Lotta Groove {Production} * 2 Cold Scorpio 1998-11-08 v2 > JOB Squad 1998-11-08 v1 - Armed & Rambunctious {Production} * 2 Cold Scorpio 1998-11-15 v3 > Al Snow 1998-10-17 v2 - Scurry v1.2 {Production} * Acolytes, The 1998-11-21 v1 > Kurrgan 1997-12-08 v2 - Interrogation * Acolytes, The 1999-01-02 v2 > Ministry Of Darkness, The 1999-02-13 - Follower * Acolytes, The 1999-03-22 v3 > Undertaker, The 1995-11-19 v2 - Graveyard Symphony v3 * Acolytes, The 1999-10-18 v4 > Steve Williams 1999-03-21 * Acolytes, The 1999-10-31 v5 - T-Rex {Production} * Adrian Adonis 1985-09-28 > Jimmy Hart 1985-03-31 - Eat Your Heart Out, Rick Springfield * Adrian Adonis 1986-04-05 - You\'re So Vain {Mainstream} * Aja Kong 1995-12-11 \\[Kwang\\] > Savio Vega 1994-01-30 v1 - Kwang Theme v1 * Akio 2003-11-20 v1 > Tajiri 2003-08-14 - Green Mist * Al Snow 1996-02-24 v1 \\[Avatar\\] > Orient Express 1990-03-03 - Orient Express Theme * Al Snow 1996-04-15 v2 \\[Leif Cassidy\\] > Rockers, The 1988-06-18 - Rockin Rockers – Rock Out v1 * Al Snow 1998-11-08 v3 > JOB Squad 1998-11-08 v1 - Armed & Rambunctious {Production} * Al Snow 1999-11-04 v1 > Mick Foley 1999-01-25 v2 - Wreck v2 * Al Snow 2000-02-28 v1 > Head Cheese 2000-02-28 - Head Cheese Before I was able to use the following expression to grab info when it was just a single portion: (?<name>.*?[a-z]) (?<year>\\d{4})-(?<date>\\d\\d-\\d\\d( v\\d+)?) - (?<rest>.*) However, the second set throws a monkey wrench in for those with >\'s. I tried just duplicating the expression a second time like this: (?<name>.*?[a-z]) (?<year>\\d{4})-(?<date>\\d\\d-\\d\\d) (v\\d+)? > (?<name>.*?[a-z]) (?<year>\\d{4})-(?<date>\\d\\d-\\d\\d) (v\\d+)? (?<rest>.*) However, it\'s saying "A subpattern name must be unique". I have no idea how to fix this. Can anyone help?'; my $regex = qr/^(?<name1>[^>\n]*?[a-z]) (?<year1>\d{4})-(?<date1>\d\d-\d\d) ?(v\d+)?(?<rest1>[^>\n]*?(?= >|$))(?: > (?<name2>[^>\n]*?[a-z]) (?<year2>\d{4})-(?<date2>\d\d-\d\d) ?(v\d+)?)?(?<rest2>[^>\n]*)$/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