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
Processing...

Test String

Code Generator

Language

Generated Code

use strict; my $str = '# Arista # aristaBgp4V2EstablishedNotification aristaBgp4V2PeerState 1.3.6.1.4.1.30065.4.1.0.1 0x06710000 1.3.6.1.4.1.30065.4.1.1.2.1.13(1,2)\\ # aristaBgp4V2PeerLocalPort 1.3.6.1.4.1.30065.4.1.1.2.1.6(3,0)\\ # aristaBgp4V2PeerRemotePort 1.3.6.1.4.1.30065.4.1.1.2.1.9(4,0) # aristaBgp4V2BackwardTransitionNotificationaristaBgp4V2PeerState 1.3.6.1.4.1.30065.4.1.0.2 0x06710001 1.3.6.1.4.1.30065.4.1.1.2.1.13(1,2)\\ # aristaBgp4V2PeerLocalPort 1.3.6.1.4.1.30065.4.1.1.2.1.6(3,0)\\ # aristaBgp4V2PeerRemotePort 1.3.6.1.4.1.30065.4.1.1.2.1.9(4,0)\\ # aristaBgp4V2PeerLastErrorCodeReceived 1.3.6.1.4.1.30065.4.1.1.3.1.1(5,0)\\ # aristaBgp4V2PeerLastErrorSubCodeReceived 1.3.6.1.4.1.30065.4.1.1.3.1.2(6,0)\\ # aristaBgp4V2PeerLastErrorReceivedText 1.3.6.1.4.1.30065.4.1.1.3.1.4(7,0) #portTestResultNotification 1.3.6.1.4.1.4998.1.1.10.1.0.14 0x048a000d 1.3.6.1.4.1.4998.1.1.10.1.1.2(1,0)\\ 1.3.6.1.4.1.4998.1.1.10.1.1.3(2,0)\\ 1.3.6.1.4.1.4998.1.1.10.1.2.1(3,0)\\ 1.3.6.1.4.1.4998.1.1.10.1.1.98(4,0)\\ 1.3.6.1.4.1.4998.1.1.10.1.1.99(5,0)\\ 1.3.6.1.4.1.4998.1.1.10.1.5.4.1.5(6,7)\\ 1.3.6.1.4.1.4998.1.1.10.1.5.4.1.12(8,0)\\ 1.3.6.1.4.1.4998.1.1.10.1.5.4.1.13(9,0)\\ 1.3.6.1.4.1.4998.1.1.10.1.5.4.1.14(10,0) # BigIp #diskVolumeUsageNotification 1.3.6.1.4.1.4998.1.1.10.1.0.17 0x048a000e 1.3.6.1.4.1.4998.1.1.10.1.1.2(1,0)\\ 1.3.6.1.4.1.4998.1.1.10.1.1.3(2,0)\\ 1.3.6.1.4.1.4998.1.1.10.1.2.1(3,0)\\ 1.3.6.1.4.1.4998.1.1.10.1.1.98(4,0)\\ 1.3.6.1.4.1.4998.1.1.10.1.1.100(5,0)\\ 1.3.6.1.4.1.4998.1.1.10.1.1.101(6,0)\\ 1.3.6.1.4.1.4998.1.1.10.1.4.4.1.7(7,8)\\ 1.3.6.1.4.1.4998.1.1.10.1.4.4.1.5(9,0) 1.3.6.1.4.1.30065.3.8.1.0.1 0x06710004 1.3.6.1.4.1.30065.3.8.0.0.3.1.3(1,2)\\ # aristaRedundancyLastSwOverReason 1.3.6.1.4.1.30065.3.8.0.0.4(3,0) # wlsrStaImpersonation wlsrNodeMac 1.3.6.1.4.1.14823.2.3.1.1.100.6.1002 0x05f7000f 1.3.6.1.4.1.14823.2.3.1.1.100.100.5(1,0)\\ # wlsrLocation 1.3.6.1.4.1.14823.2.3.1.1.1.1.1.20(2,3) '; my $regex = qr/(?m)^\#[^\S\r\n]*(\S+).*\s+^(?!\#)[^\S\r\n]*(\S+)/p; 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