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

/
/

Test String

Code Generator

Language

Generated Code

use strict; my $str = 'ffmpeg version git-2012-01-25-247d30a Copyright (c) 2000-2012 the FFmpeg developers built on Jan 25 2012 16:56:18 with gcc 4.6.2 configuration: --extra-cflags=-I../static/include --extra-ldflags=\'-L../static/lib -static\' --enable-gpl --enable-version3 --enable-static --disable-shared --disable-debug --enable-runtime-cpudetect --enable-x11grab --enable-libmp3lame --enable-libx264 --enable-libspeex --enable-libvorbis --enable-libvpx --enable-libfreetype --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libxavs --enable-libtheora --enable-libvo-aacenc --enable-libvo-amrwbenc --disable-ffserver libavutil 51. 34.101 / 51. 34.101 libavcodec 53. 59.100 / 53. 59.100 libavformat 53. 30.100 / 53. 30.100 libavdevice 53. 4.100 / 53. 4.100 libavfilter 2. 60.100 / 2. 60.100 libswscale 2. 1.100 / 2. 1.100 libswresample 0. 6.100 / 0. 6.100 libpostproc 52. 0.100 / 52. 0.100 Input #0, mov,mp4,m4a,3gp,3g2,mj2, from \'3825402d75f04cadad96fa9f3af62c82.mp4\': Metadata: major_brand : mp42 minor_version : 0 compatible_brands: mp41isom creation_time : 2016-09-30 16:14:06 Duration: 00:00:15.04, start: 0.000000, bitrate: 1609 kb/s Stream #0:0(und): Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yuv420p, 1152x720 [SAR 1:1 DAR 8:5], 1611 kb/s, 30.30 fps, 30.30 tbr, 30k tbn, 60 tbc Metadata: creation_time : 2016-09-30 16:14:06 handler_name : VideoHandler At least one output file must be specified '; my $regex = qr/[(bitrate:\ )] (\d*) [(kb\/s)]/p; if ( $str =~ /$regex/ ) { 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