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

/
/
gmxJ

Test String

Code Generator

Language

Generated Code

use strict; my $str = '# Should match - [ ] Some task - [ ] Some task | [[link]] - [ ] Some task ^abcdef - [ ] Some task | [[link]] ^abcdef - [ ] ! Some task - [ ] ! Some task | [[link]] - [ ] ! Some task ^abcdef - [ ] ! Some task | [[link]] ^abcdef - [ ] Task one | [ ] ! Task two | [ ] Task three ^abcdef | Tracker | Task | Backlog | | ----------: | :---------------------- | :------- | | 00:00-00:00 | [ ] Task item | [[linK]] | | 00:00-00:00 | [ ] Task item ^abcdef | [[link]] | | 00:00-00:00 | [ ] [[task-item]] | [[link]] | | 00:00-00:00 | [ ] ! Task item | [[linK]] | | 00:00-00:00 | [ ] ! Task item ^abcdef | [[link]] | | 00:00-00:00 | [ ] ! [[task-item]] | [[link]] | # Should not match - [ ] - [ ] - [ ] - [ ] ! - [ ] ! - [ ] ! | Tracker | Task | Backlog | | ----------: | :---------------------- | :------- | | 00:00-00:00 | [ ] | [[linK]] | | 00:00-00:00 | [ ] ! | [[linK]] | # Desired outcome - group `notation`: - match: `[` and `]` - group `symbol`: - match: any single character (e.g., `\\s`) between `[` and `]` - group `modifier`: - match: `!`, `?`, or `*` that follows after `[ ]` - group `text`: - match: task text after `[ ]` without modifier present - group `textmod`: - match: task text after `[ ] !` with modifier present '; my $regex = qr/(?<= \s ) # Match opening braket (i.e., `[`). (?<g1> \[) # Match any single character (e.g., `x`). (?<g2> .) # Matching closing braket (i.e., `]`) (?<g1> \]) (?= \s* [?!*]? \s* ) # Exclude entries without text (i.e., incl. in tables). (?! \s* [?!*]? \s* \| | \s* [?!*]? \s* $ ) # Match the text (i.e., capture based on modifier presence). (?: # Match modifier (i.e., `!`, `?`, or `*`) and the text that follows. \s* (?<g3>[!?*]) \s* (?<g4>.*?) | # Match the text that does not follow a modifier. \s* (?! [!?*]) \s* (?<g5>.*?) ) # Match until either of the stops that follow are met. (?= \s+ \^[a-z0-9]{6,} | \s+ \| | \s*$)/mxp; 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