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

r"
"
gm

Test String

Code Generator

Language

Generated Code

use strict; my $str = '1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue qlen 1 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: lan1: <BROADCAST,MULTICAST,UP,LOWER_UP8000> mtu 1500 qdisc mq qlen 1000 link/ether 00:60:e0:6a:48:26 brd ff:ff:ff:ff:ff:ff inet 10.32.39.55/24 brd 10.32.39.255 scope global lan1 valid_lft forever preferred_lft forever 3: lan2: <BROADCAST,MULTICAST,UP,LOWER_UP8000> mtu 1500 qdisc mq qlen 1000 link/ether 00:60:e0:6a:48:27 brd ff:ff:ff:ff:ff:ff inet 192.168.90.1/20 brd 192.168.95.255 scope global lan2 valid_lft forever preferred_lft forever 4: sit0@NONE: <NOARP> mtu 1480 qdisc noop qlen 1 link/sit 0.0.0.0 brd 0.0.0.0 6: wwp0s29u1u3i12: <BROADCAST,MULTICAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000 link/ether 00:00:11:12:13:14 brd ff:ff:ff:ff:ff:ff inet 172.16.224.124/16 brd 172.16.255.255 scope global wwp0s29u1u3i12 valid_lft forever preferred_lft forever '; my $regex = qr/\d: ([\w@]+): <(.+)> mtu (\d+) qdisc (\w+) qlen (\d+)\n[ ]+(\w+\/\w+) ([\d:\w.]+) brd ([\d:\w.]+)\n?(?:(?: )+inet6? ([\d.:\/]+) (?:brd ([\d:\w.]+) )?scope (\w+) (?:\w+)?\n(?: )+valid_lft (\w+) preferred_lft (\w+))?/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