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
  • Match everything enclosed
    (?:...)
  • Capture everything enclosed
    (...)
  • 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 = 'step1: script: "/workspace/feature-test-lib/tests/upgrade_blr/BQT.py" skip: 0 args: ["testbed"] step2: script: "/workspace/feature-test-lib/tests/upgrade_blr/DC_init.py" skip: 0 args: ["testbed", "dcinit"] step3: script: "/workspace/feature-test-lib/tests/upgrade_blr/sensor_upgrade.py" skip: 0 args: ["testbed", "upgrade"] step4: script: "/workspace/feature-test-lib/tests/upgrade_blr/Apply_Policy.py" skip: 0 args: ["testbed"] step5: script: "/workspace/feature-test-lib/tests/upgrade_blr/sensor_checks.py" skip: 0 args: ["testbed"] step6: script: "/workspace/feature-test-lib/tests/upgrade_blr/delete_device.py" skip: 0 args: ["testbed", "dcinit"] step7: script: "/workspace/feature-test-lib/tests/upgrade_blr/DC_init.py" skip: 0 args: ["testbed", "dcinit"] '; my $regex = qr/step.+\s+script: \".*blr/(.*).py\"\s+.*\s+args: \[([\"\w\W\s]+?)\]\n/mp; my $subst = '\\1, \\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