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

/
/
g

Test String

Code Generator

Language

Generated Code

use strict; my $str = '// Mix valid/invalid david.jones@proseware.com d.j@server1.proseware.com jones@ms1.proseware.com j.@server1.proseware.com j@proseware.com9 js#internal@proseware.com j_9@[129.126.118.1] j..s@proseware.com js*@proseware.com js@proseware..com js@proseware.com9 j.s@server1.proseware.com "j\\"s\\""@proseware.com js@contoso.中国.com ========================================= // Valid simple@example.com very.common@example.com disposable.style.email.with+symbol@example.com other.email-with-hyphen@example.com fully-qualified-domain@example.com user.name+tag+sorting@example.com fully-qualified-domain@example.com x@example.com carlosd\'intino@arnet.com.ar example-indeed@strange-example.com admin@mailserver1 example@s.example " "@example.org "john..doe"@example.org // Invalid Abc.example.com A@b@c@example.com a\\"b(c)d,e:f;g<h>i[j\\\\k]l@example.com just\\"not\\"right@example.com this is\\"not\\\\allowed@example.com this\\\\ still\\"not\\\\allowed@example.com 1234567890123456789012345678901234567890123456789012345678901234+x@example.com john..doe@example.com john.doe@example..com '; my $regex = qr/(?im)^(?=.{1,64}@)(?:("[^"\\]*(?:\\.[^"\\]*)*"@)|((?:[0-9a-z](?:\.(?!\.)|[-!#\$%&'\*\+\/=\?\^`\{\}\|~\w])*)?[0-9a-z]@))(?=.{1,255}$)(?:(\[(?:\d{1,3}\.){3}\d{1,3}\])|((?:(?=.{1,63}\.)[0-9a-z][-\w]*[0-9a-z]*\.)+[a-z0-9][\-a-z0-9]{0,22}[a-z0-9])|((?=.{1,63}$)[0-9a-z][-\w]*))$/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