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 = 'https://www.facebook.com/video.php?v=637842556329505&fref=nf https://www.facebook.com/video.php?v=274175099429670 https://www.facebook.com/video.php?v=957955867617029 https://www.facebook.com/maxlayn/posts/10153807558977570 https://m.facebook.com/story.php?story_fbid=1035862816472149&id=116132035111903 https://www.facebook.com/barackobama/posts/10153664894881749 https://www.facebook.com/cnn/videos/10155529876156509/ https://www.facebook.com/yaroslav.korpan/videos/1417995061575415/ https://www.facebook.com/LaGuiaDelVaron/posts/1072691702860471 https://www.facebook.com/groups/1024490957622648/permalink/1396382447100162/ https://www.facebook.com/video.php?v=10204634152394104 https://www.facebook.com/amogood/videos/1618742068337349/?fref=nf https://www.facebook.com/ChristyClarkForBC/videos/vb.22819070941/10153870694020942/?type=2&theater facebook:544765982287235 https://www.facebook.com/groups/164828000315060/permalink/764967300301124/ https://zh-hk.facebook.com/peoplespower/videos/1135894589806027/ https://www.facebookwkhpilnemxj7asaniu7vnjjbiltxjqhye3mhbshg7kx5tfyd.onion/video.php?v=274175099429670 https://www.facebook.com/onlycleverentertainment/videos/1947995502095005/ https://www.facebook.com/WatchESLOne/videos/359649331226507/ https://www.facebook.com/100033620354545/videos/106560053808006/ https://www.facebook.com/watch/?v=647537299265662 https://www.facebook.com/PankajShahLondon/posts/10157667649866271 https://m.facebook.com/Alliance.Police.Department/posts/4048563708499330 https://www.facebook.com/groups/ateistiskselskab/permalink/10154930137678856/ https://www.facebook.com/watch/live/?v=1823658634322275 https://www.facebook.com/watchparty/211641140192478'; my $regex = qr/(?:https?://(?:[\w-]+\.)?(?:facebook\.com|facebookwkhpilnemxj7asaniu7vnjjbiltxjqhye3mhbshg7kx5tfyd\.onion)/(?:[^#]*?\#!/)?(?:(?:video/video\.php|photo\.php|video\.php|video/embed|story\.php|watch(?:/live)?/?)\?(?:.*?)(?:v|video_id|story_fbid)=|[^/]+/videos/(?:[^/]+/)?|[^/]+/posts/|groups/[^/]+/permalink/|watchparty/)|facebook:)(\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