Regular Expressions 101

Save & Share

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 = '"#### ![](https://secure.spiria.com/jira-staging/secure/viewavatar?size=xsmall&avatarId=12555&avatarType=issuetype) [MAINT-170 &nbsp;&nbsp;&nbsp; Setup a virtual IOS Development Environment](https://secure.spiria.com/jira-staging/browse/MAINT-170)#### **Description** | | | | | | |!https://www.pagerduty.com/wp-content/uploads/2016/05/pagerduty-logo-green.png!|[{color:#999999}shutterstock.pagerduty.com{color}|https://shutterstock.pagerduty.com/incidents]| | | | | |Hello Don Ramsey, you have one open incident assigned to you:| |{color:#767676}Incident #149053{color}| | | |[CRITICAL: \'check_renewal_tracking\' on \'prod-worker16.ma01.bigstockcorp.net\'|https://shutterstock.pagerduty.com/incidents/P4HX6H1]| | | |[{color:#333333}View Incident{color}|https://shutterstock.pagerduty.com/incidents/P4HX6H1]| | | |{color:#767676}Details{color}| |pd_nagios_object: service CONTACTPAGER: 5bb546134cb64acb845ebdf05fc3ae6b| | | |{color:#767676}Status{color}| |{color:#fc0f03}Triggered{color}| | | |{color:#767676}Urgency{color}| |↑ High| | | |{color:#767676}Assigned To{color}| |[{color:#005c9c}Don Ramsey{color}|https://shutterstock.pagerduty.com/users/PAHPTR7]| | | |{color:#767676}Opened On{color}| |[{color:#000000}Oct 24, 2017 at 11:03 AM (Eastern Time (US & Canada)) {color}\\|]| | | |{color:#767676}Service{color}| |[{color:#005c9c}nagios (Bigstock){color}|https://shutterstock.pagerduty.com/services/PVF3TQU]| | | |{color:#767676}Escalation Policy{color}| |[{color:#005c9c}Bigstock Team Escalation{color}|https://shutterstock.pagerduty.com/escalation_policies#PYK0IBT]| | | | | |You can disable these messages (or turn off HTML emails) by adjusting [{color:#005c9c}your notification rules{color}|https://shutterstock.pagerduty.com/users/PAHPTR7].| | | | | | |{color:#767676}PagerDuty, Inc., 600 Townsend St., #200, San Francisco, California, 94103 Copyright © 2008 — 2017 PagerDuty, Inc. All rights reserved.{color}| | |  "'; my $regex = qr/(\{color[^}]*\})|(\![^!]*(thumbnail)\!)|(^\|[\ \h]*)|(\|[\ ]*(?=[\n\r]))/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