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

Substitution

Processing...

Code Generator

Language

Generated Code

use strict; my $str = 'digraph A { rankdir = LR; node [shape=circle,style=filled] 0 node [shape=circle,style=filled] 1 node [shape=circle,style=filled] 2 node [shape=circle,style=filled] 3 node [shape=circle,style=filled] 4 node [shape=circle,style=filled] 5 node [shape=circle,style=filled] 6 node [shape=circle,style=filled] 7 node [shape=circle,style=filled] 8 node [shape=circle,style=filled] 9 node [shape=doublecircle,style=filled] 10 0 -> 4 [label="g "]; 0 -> 1 [label="b "]; 1 -> 2 [label="o "]; 2 -> 7 [label="y "]; 2 -> 3 [label="o "]; 3 -> 7 [label="k "]; 4 -> 5 [label="i "]; 5 -> 6 [label="r "]; 6 -> 7 [label="l "]; 7 -> 9 [label="<+N:s> "]; 7 -> 8 [label="<+N:0> "]; 8 -> 10 [label="<+Sg:0> "]; 9 -> 10 [label="<+Pl:0> "]; }'; my $regex = qr/node.*?=(\w+).*?\s(\d+)/mp; my $subst = ''; 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