Regular Expressions 101

Save & Share

  • Regex Version: ver. 1
  • 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

~
~
gm

Test String

Code Generator

Language

Generated Code

$re = '~^(?:(?<network_srcIpv4>(?:[0-9]{1,3}\.){3}[0-9]{1,3})|(?<network_srcIpv6>[:\-0-9a-fA-F]+?)|(?<network_srcHost>.+?)) - (?:-|(?<user_username>.+)) \[(?<time>.*)\] \"(?<application_cmd>(?<application_http_method>[A-Z]+)\s(?:(?<application_proto>.*?)://)?(?<network_fqdn>[^/]*?)(?:\:(?<network_dstPort>\d+))?(?<file_path>/.*?)?(?:\?(?<application_http_queryString>.*?))?(?: HTTP/(?<application_http_version>[0-9\.]+)?))\" (?<application_http_status>\d+) (?<application_len>\d+) (?:"(?:-|(?<application_http_referrer>.*))")? (?:"(?:-|(?<application_http_userAgent>.*))")$~m'; $str = '218.1.111.50 - - [13/Mar/2005:10:36:12 -0500] "GET http://www.yahoo.com/ HTTP/1.1" 403 2898 "-" "Mozilla/4.0 (compatible; MSIE 4.01; Windows 95)" 24.23.244.160 - - [13/Mar/2005:13:48:40 -0500] "GET /scripts/..%25%35%63../winnt/system32/cmd.exe?/c+dir HTTP/1.0" 404 1041 "-" "-"'; preg_match_all($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