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 = 'Valid email addresses 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 (may go to user.name@example.com inbox depending on mail server) x@example.com (one-letter local-part) example-indeed@strange-example.com example@s.example (see the List of Internet top-level domains) " "@example.org (space between the quotes) "john..doe"@example.org (quoted double dot) ============================================================= Invalid email addresses Abc.example.com (no @ character) A@b@c@example.com (only one @ is allowed outside quotation marks) a"b(c)d,e:f;g<h>i[j\\k]l@example.com (none of the special characters in this local-part are allowed outside quotation marks) just"not"right@example.com (quoted strings must be dot separated or the only element making up the local-part) this is"not\\allowed@example.com (spaces, quotes, and backslashes may only exist when within quoted strings and preceded by a backslash) this\\ still\\"not\\\\allowed@example.com (even if escaped (preceded by a backslash), spaces, quotes, and backslashes must still be contained by quotes) 1234567890123456789012345678901234567890123456789012345678901234+x@example.com (local part is longer than 64 characters)'; my $regex = qr/^((?:[A-Za-z0-9!#$%&'*+\-\/=?^_`{|}~]|(?<=^|\.)"|"(?=$|\.|@)|(?<=".*)[ .](?=.*")|(?<!\.)\.){1,64})(@)((?:[A-Za-z0-9.\-])*(?:[A-Za-z0-9])\.(?:[A-Za-z0-9]){2,})$/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