Regular Expressions 101

Save & Manage Regex

  • Current Version: 1
  • Save & Share
  • Community Library

Flavor

  • PCRE2 (PHP)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java
  • .NET 7.0 (C#)
  • Rust
  • PCRE (Legacy)
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests
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
Processing...

Test String

Code Generator

Language

Generated Code

use strict; my $str = '[21-Feb-2019 10:24:23 Europe/Berlin] PHP Warning: SimpleXMLElement::__construct(): \'hostel\',\'other_accommodation\',\'other_accommodation\',\'other_accommodation\'), "/> in /srv/hometogo_import/releases/20190221091925/src/Htg/Backend/StandardFeedBundle/Validators/ObjectValidator.php on line 133 [21-Feb-2019 10:24:23 Europe/Berlin] PHP Warning: SimpleXMLElement::__construct(): ^ in /srv/hometogo_import/releases/20190221091925/src/Htg/Backend/StandardFeedBundle/Validators/ObjectValidator.php on line 133 [21-Feb-2019 10:23:45 Europe/Berlin] PHP Notice: Undefined index: es_ES in /srv/hometogo_import/releases/20190221071657/vendor/hometogo/data-model/src/Model/DestinationModel.php on line 358 [21-Feb-2019 10:24:23 Europe/Berlin] PHP Warning: SimpleXMLElement::__construct(): Entity: line 1: parser error : Extra content at the end of the document in /srv/hometogo_import/releases/20190221091925/src/Htg/Backend/StandardFeedBundle/Validators/ObjectValidator.php on line 133 [21-Feb-2019 10:35:53 Europe/Berlin] PHP Notice: Undefined index: en_US in /srv/hometogo_import/releases/20190221071657/vendor/hometogo/data-model/src/Model/DestinationModel.php on line 358 [21-Feb-2019 10:35:53 Europe/Berlin] PHP Notice: Undefined index: es_ES in /srv/hometogo_import/releases/20190221071657/vendor/hometogo/data-model/src/Model/DestinationModel.php on line 358 [21-Feb-2019 09:43:05 Europe/Berlin] PHP Warning: PDOStatement::execute(): MySQL server has gone away in /srv/hometogo_import/releases/20190221082132/vendor/doctrine/dbal/lib/Doctrine/DBAL/Driver/PDOStatement.php on line 105 [21-Feb-2019 09:43:05 Europe/Berlin] PHP Warning: PDOStatement::execute(): Error reading result set\'s header in /srv/hometogo_import/releases/20190221082132/vendor/doctrine/dbal/lib/Doctrine/DBAL/Driver/PDOStatement.php on line 105 [21-Feb-2019 09:10:25 Europe/Berlin] PHP Notice: Undefined index: en_US in /srv/hometogo_import/releases/20190220180846/vendor/hometogo/data-model/src/Model/DestinationModel.php on line 358 [21-Feb-2019 09:10:25 Europe/Berlin] PHP Notice: Undefined index: es_ES in /srv/hometogo_import/releases/20190220180846/vendor/hometogo/data-model/src/Model/DestinationModel.php on line 358 [21-Feb-2019 09:10:30 Europe/Berlin] PHP Notice: Undefined index: en_US in /srv/hometogo_import/releases/20190221071657/vendor/hometogo/data-model/src/Model/DestinationModel.php on line 358 [21-Feb-2019 09:10:30 Europe/Berlin] PHP Notice: Undefined index: es_ES in /srv/hometogo_import/releases/20190221071657/vendor/hometogo/data-model/src/Model/DestinationModel.php on line 358 [21-Feb-2019 09:10:42 Europe/Berlin] PHP Fatal error: Uncaught RuntimeException: Process interrupted in /srv/hometogo_import/releases/20190221080147/src/Htg/Backend/KafkaBundle/Command/SinkToBufferCommand.php:193 Stack trace: #0 [internal function]: Htg\\Backend\\KafkaBundle\\Command\\SinkToBufferCommand->processEnd() #1 {main} thrown in /srv/hometogo_import/releases/20190221080147/src/Htg/Backend/KafkaBundle/Command/SinkToBufferCommand.php on line 193 [21-Feb-2019 09:10:42 Europe/Berlin] PHP Notice: Undefined index: en_US in /srv/hometogo_import/releases/20190220180846/vendor/hometogo/data-model/src/Model/DestinationModel.php on line 358 [21-Feb-2019 09:10:42 Europe/Berlin] PHP Notice: Undefined index: es_ES in /srv/hometogo_import/releases/20190220180846/vendor/hometogo/data-model/src/Model/DestinationModel.php on line 358 [21-Feb-2019 09:10:42 Europe/Berlin] PHP Warning: PDO::query(): MySQL server has gone away in /srv/hometogo_import/releases/20190221080147/vendor/doctrine/dbal/lib/Doctrine/DBAL/Driver/PDOConnection.php on line 104 [21-Feb-2019 09:10:42 Europe/Berlin] PHP Warning: PDO::query(): Error reading result set\'s header in /srv/hometogo_import/releases/20190221080147/vendor/doctrine/dbal/lib/Doctrine/DBAL/Driver/PDOConnection.php on line 104 [21-Feb-2019 09:11:54 Europe/Berlin] PHP Notice: Undefined index: en_US in /srv/hometogo_import/releases/20190221071657/vendor/hometogo/data-model/src/Model/DestinationModel.php on line 358 [21-Feb-2019 09:05:20 Europe/Berlin] PHP Warning: call_user_func() expects parameter 1 to be a valid callback, no array or string given in /srv/hometogo_import/releases/20190221071657/src/Vrt/AggregatorBundle/Writer/Runner/Json.php on line 57 [21-Feb-2019 09:05:30 Europe/Berlin] PHP Notice: Undefined index: en_US in /srv/hometogo_import/releases/20190220180846/vendor/hometogo/data-model/src/Model/DestinationModel.php on line 358 [21-Feb-2019 09:05:30 Europe/Berlin] PHP Notice: Undefined index: es_ES in /srv/hometogo_import/releases/20190220180846/vendor/hometogo/data-model/src/Model/DestinationModel.php on line 358 [21-Feb-2019 09:07:40 Europe/Berlin] PHP Warning: imagecreatefromstring(): Data is not in a recognized format in /srv/hometogo_image/releases/20181119092803/src/Htg/Transform/TransformationManager.php on line 159'; my $regex = qr/^\[(?<time>[^\]]*)\] (?<level>[^:]*):\s+(?<reason>.+?) \/[^\/]*\/(?<repo>[^\/]*)\/[^\/]*\/(?<release>[0-9]*)\/(?<file>[^\s|:]*)[^0-9]*(?<line>[0-9]*)/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