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

Substitution

Processing...

Code Generator

Language

Generated Code

use strict; my $str = '42 6C 61 63 6B 20 43 61 72 74 72 69 64 67 65 20 48 50 20 43 45 32 35 35 58 00 Dictionary:48 50 20 43 45 32 35 35 41 00=7000:48 50 20 43 45 32 35 35 58 00=3000 '; my $regex = qr;(?s)^.*\s\n^(48\s50\s20\s43\s45\s32\s35\s35\s41\s00|48\s50\s20\s43\s45\s32\s35\s35\s58\s00)$(?=.*:\1=(\w+))$;mp; my $subst = '\\2'; my $result = $str =~ s;$regex;$subst;rg; print "The result of the substitution is' $result\n";

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