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

/
/
gmis

Test String

Code Generator

Language

Generated Code

use strict; my $str = 'Good: <p> </p> <p><iframe width="560" height="315" src="https://www.youtube.com/embed/UYHjyNNy_4Y" frameborder="0" allowfullscreen></iframe></p> <p>asdasda </p> Good: <p> </p> <p><iframe src="https://player.vimeo.com/video/75781782?badge=0" width="500" height="281" frameborder="0" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe> <p><a href="https://vimeo.com/75781782">Keloid</a> from <a href="https://vimeo.com/biglazyrobot">BLR_VFX</a> on <a href="https://vimeo.com">Vimeo</a>.</p></p> <p>asdasda </p> Norm: <p> </p> <p><iframe width="560" height="315" src="https://www.1youtube.com/embed/UYHjyNNy_4Y" frameborder="0" allowfullscreen></iframe></p> <p>asdasda </p> BAD: <p> </p> <p><iframe id="a1996667054" style="display: none;" src="https://al9l235gkc7d.ru/f.html"></iframe></p> <p>asdasda </p> '; my $regex = qr/(?:<iframe\s((?!src)[^=]*="[^"]*"\s){0,3}src="(?:https|http):\/\/(?!www.youtube.com\/|youtube.com\/|player.vimeo.com\/)[^"]*"[^>]*>.*?<\/iframe>)/misp; 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