Regular Expressions 101

Save & Share

  • Regex Version: ver. 5
  • Update Regex
    ctrl+⇧+s
  • Save new Regex
    ctrl+s
  • Add to Community Library

Flavor

  • PCRE2 (PHP >=7.3)
  • PCRE (PHP <7.3)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java 8
  • .NET 7.0 (C#)
  • Rust
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests

Tools

Sponsors
There are currently no sponsors. Become a sponsor today!
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

Code Generator

Language

Generated Code

use strict; my $str = '* << BeReq >> 416335894 - BackendOpen 137 boot.https_app3 10.1.10.8 8443 10.1.10.10 45467 - BerespStatus 200 - Timestamp BerespBody: 1536053067.307297 0.002362 0.000701 * << BeReq >> 417244880 - BackendOpen 62 boot.https_app4 10.1.10.9 8443 10.1.10.10 50995 - BerespStatus 200 - Timestamp BerespBody: 1536053067.427519 0.120675 0.001029 * << BeReq >> 411778166 - BackendOpen 77 boot.https_app3 10.1.10.8 8443 10.1.10.10 39506 - BerespStatus 304 - BerespStatus 200 - Timestamp BerespBody: 1536052222.383470 0.009091 0.000151'; my $regex = qr/^\*\s+<< BeReq\s+>> (?P<request>\d+) ?$ ^-\s+BackendOpen\s+\d+ (?P<backend>[^ ]+) .+$ ^-\s+BerespStatus\s+(?P<status>\d{3})$ ^-\s+Timestamp\s+BerespBody: (?P<timestamp>[\d.]+) (?P<response_time>[\d.]+) .+$/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