Regular Expressions 101

Save & Share

  • Regex Version: ver. 1
  • 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

/
/
gm

Test String

Code Generator

Language

Generated Code

use strict; my $str = '`{"server":"nginx/1.21.0","date":"Mon, 25 Apr 2022 11:34:20 GMT","content-type":"text/html; charset=UTF-8","transfer-encoding":"chunked","x-powered-by":"PHP/7.4.16","expires":"Sun, 19 Nov 1978 05:00:00 GMT","cache-control":"no-store, no-cache, must-revalidate, max-stale=0, private, post-check=0, pre-check=0","x-content-type-options":"nosniff","content-security-policy":"frame-ancestors \'self\';","set-cookie":["SSESS8b04132f4690dc8ceb7837d5134a5519=ZbgVsmpp6DBRWwNCRMm5DTpfEoKffsNM7l8ILoCWkug; path=/; domain=test.net; secure; HttpOnly","su=1; expires=Thu, 22-Apr-2032 11:34:20 GMT; Max-Age=315360000; path=/; domain=test.net","lt=deleted; expires=Thu, 01-Jan-1970 00:00:01 GMT; Max-Age=0; path=/; test.net","dtCookie=v_4_srv_10_sn_6364C36040ADFF47B91A838BB8B2CADD_perc_100000_ol_0_mul_1_app-3Aea7c4b59f27d43eb_1; Path=/; Domain=test.net","870be6fb89fc78ad2ca0eca3828e3019=7055c78f3c2b7311a5c77934caad6939; path=/; HttpOnly; Secure; SameSite=None"],"x-oneagent-js-injection":"true","x-ruxit-js-agent":"true","server-timing":"dtSInfo;desc=\\\\"0\\\\", dtRpid;desc=\\\\"493206686\\\\"","connection":"close"}`'; my $regex = qr/(SSESS[a-zA-Z0-9]*)=(.+?);/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