Regular Expressions 101

Save & Share

  • Regex Version: ver. 2
  • 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

/
/
gs

Test String

Code Generator

Language

Generated Code

$re = '/\[\@if(not)?:([a-zA-Z0-9]+)(?:=(.*?))?\].*?\[\@endif:\2\]/s'; $str = '<!-- <h1>[!WLANSettings]</h1> --> [@if:examplevar=notgiven]this text won\'t show[@endif:examplevar] [@if:wlanena] [@if:wlanauto] <table id="wlanavail" class="colorrows inputtable"> <tr id="firstrow"> <th width="30px"></th> <th width="240px">[!Name] (SSID)</th> <th width="110px">[!Encryption]</th> <th width="150px">[!SignalStrength]</th> <th width="200px">[!MAC]</th> </tr> <tr id="loadingrow"> <td colspan=5 class="centertext"><img src="resources/loading.gif" id="loadingWlanScan"></td> </tr> <tr> <td></td> <td colspan=4><input type="button" id="rescan" value="[!Refresh]" style="width: 200px"></td> </tr> </table> <p></p> [@endif:wlanauto] <table id="wlansettings" class="inputTable"> <tr id="wlannamerow" [@if:wlanauto]style="display: none;"[@endif:wlanauto]> <td>[!WLANName]</td> <td><input type="text" name="wlanname" id="wlanname" [@if:wlanauto]value="[@wlanname]"[@endif:wlanauto] style="width: 309px;"></td> </tr> <tr> <td>[!Password]:</td> <td><input type="text" name="wlanpass" id="wlanpass" style="width: 309px;"></td> </tr> <tr> <td colspan="2" > <input type="button" [@if:wlanauto]id="manualcfg" name="manualcfg" value="[!ManualConfig]"[@endif:wlanauto] [@ifnot:wlanauto]id="autocfg" name="autocfg" value="[!AutomaticConfig]"[@endif:wlanauto] onclick="handleMultiform(event, this);" style="width: 180px;"> </td> </tr> <tr> <td> <input type="hidden" name="encinput" id="encinput" value=""></td> <td id="wlaninfo"></td> </tr> </table> [@ipsettings] [@endif:wlanena] [@ifnot:wlanena] [!NoWLANDevicePluggedIn] <p> <input type="button" name="back" onclick="handleMultiform(event, this);" value="[!Back]" /> </p> [@endif:wlanena] '; preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0); // Print the entire match result var_dump($matches);

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 PHP, please visit: http://php.net/manual/en/ref.pcre.php