Regular Expressions 101

Save & Manage Regex

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Function

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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

Substitution
Processing...

Code Generator

Language

Generated Code

using System; using System.Text.RegularExpressions; public class Example { public static void Main() { string pattern = @"^([0-9.]+)\s(.)\s(.)\s\[(.*)\s(\+[0-9]*)\]\s\""GET|POST\"""; string substitution = @""; string input = @"127.0.0.1 - - [11/Sep/2015:08:15:33 +0600] ""GET / HTTP/1.1"" 200 4189 127.0.0.1 - - [11/Sep/2015:08:15:33 +0600] ""GET /icons/blank.gif HTTP/1.1"" 200 148 127.0.0.1 - - [11/Sep/2015:08:15:33 +0600] ""GET /icons/folder.gif HTTP/1.1"" 200 225 127.0.0.1 - - [11/Sep/2015:08:15:33 +0600] ""GET /icons/text.gif HTTP/1.1"" 200 229 127.0.0.1 - - [11/Sep/2015:08:15:33 +0600] ""GET /icons/unknown.gif HTTP/1.1"" 200 245 127.0.0.1 - - [11/Sep/2015:08:15:33 +0600] ""GET /favicon.ico HTTP/1.1"" 404 1207 127.0.0.1 - - [11/Sep/2015:08:15:40 +0600] ""GET /public/ HTTP/1.1"" 200 1023 127.0.0.1 - - [11/Sep/2015:08:15:37 +0600] ""GET /public/ HTTP/1.1"" 200 1023 127.0.0.1 - - [08/Dec/2015:11:22:28 +0600] ""GET /public/index.php HTTP/1.1"" 200 1023 127.0.0.1 - - [08/Dec/2015:11:22:31 +0600] ""GET /favicon.ico HTTP/1.1"" 404 1239 127.0.0.1 - - [08/Dec/2015:11:22:34 +0600] ""GET / HTTP/1.1"" 200 4189 127.0.0.1 - - [08/Dec/2015:11:22:34 +0600] ""GET /icons/blank.gif HTTP/1.1"" 200 148 127.0.0.1 - - [08/Dec/2015:11:22:34 +0600] ""GET /icons/folder.gif HTTP/1.1"" 200 225 127.0.0.1 - - [08/Dec/2015:11:22:34 +0600] ""GET /icons/unknown.gif HTTP/1.1"" 200 245 127.0.0.1 - - [08/Dec/2015:11:22:34 +0600] ""GET /icons/text.gif HTTP/1.1"" 200 229 127.0.0.1 - - [08/Dec/2015:11:22:52 +0600] ""GET / HTTP/1.1"" 200 1023 127.0.0.1 - - [08/Dec/2015:11:23:05 +0600] ""GET / HTTP/1.1"" 200 1023 127.0.0.1 - - [08/Dec/2015:11:23:07 +0600] ""GET /public/index.php HTTP/1.1"" 404 16638 127.0.0.1 - - [08/Dec/2015:11:23:12 +0600] ""GET / HTTP/1.1"" 200 1023 127.0.0.1 - - [08/Dec/2015:11:23:40 +0600] ""GET /auth/ HTTP/1.1"" 301 332 127.0.0.1 - - [08/Dec/2015:11:23:40 +0600] ""GET /auth HTTP/1.1"" 404 16638 127.0.0.1 - - [08/Dec/2015:11:23:45 +0600] ""GET /auth/login HTTP/1.1"" 404 16638 127.0.0.1 - - [08/Dec/2015:11:23:49 +0600] ""GET / HTTP/1.1"" 200 1023 127.0.0.1 - - [08/Dec/2015:11:44:02 +0600] ""GET / HTTP/1.1"" 200 1046 127.0.0.1 - - [08/Dec/2015:12:11:53 +0600] ""GET / HTTP/1.1"" 200 1023 127.0.0.1 - - [29/Dec/2015:10:29:46 +0600] ""GET / HTTP/1.1"" 200 11160 127.0.0.1 - - [29/Dec/2015:10:29:47 +0600] ""GET /_debugbar/assets/stylesheets?1451362463 HTTP/1.1"" 200 196851 127.0.0.1 - - [29/Dec/2015:10:29:47 +0600] ""GET /_debugbar/assets/javascript?1451362459 HTTP/1.1"" 200 348784 127.0.0.1 - - [29/Dec/2015:10:29:48 +0600] ""GET /favicon.ico HTTP/1.1"" 200 - 127.0.0.1 - - [29/Dec/2015:10:30:58 +0600] ""GET /auth HTTP/1.1"" 404 29966 127.0.0.1 - - [29/Dec/2015:10:32:24 +0600] ""GET /_debugbar/open?max=20&offset=0 HTTP/1.1"" 200 289 127.0.0.1 - - [29/Dec/2015:11:08:46 +0600] ""GET /auth/register HTTP/1.1"" 404 28750 127.0.0.1 - - [30/Dec/2015:08:43:01 +0600] ""GET /auth/register HTTP/1.1"" 404 27092 127.0.0.1 - - [30/Dec/2015:08:43:14 +0600] ""GET /_debugbar/assets/stylesheets?1451362463 HTTP/1.1"" 200 196851 127.0.0.1 - - [30/Dec/2015:08:43:14 +0600] ""GET /_debugbar/assets/javascript?1451362459 HTTP/1.1"" 200 348784 127.0.0.1 - - [30/Dec/2015:08:43:15 +0600] ""GET /favicon.ico HTTP/1.1"" 200 - 127.0.0.1 - - [30/Dec/2015:11:51:32 +0600] ""GET / HTTP/1.1"" 200 9902 127.0.0.1 - - [30/Dec/2015:11:51:34 +0600] ""GET /favicon.ico HTTP/1.1"" 200 - 127.0.0.1 - - [30/Dec/2015:12:22:13 +0600] ""GET /auth HTTP/1.1"" 404 28622 127.0.0.1 - - [28/Mar/2016:12:32:18 +0600] ""GET / HTTP/1.1"" 200 9881 127.0.0.1 - - [28/Mar/2016:12:32:38 +0600] ""GET /_debugbar/assets/stylesheets?1451362463 HTTP/1.1"" 200 196851 127.0.0.1 - - [28/Mar/2016:12:32:38 +0600] ""GET /_debugbar/assets/javascript?1451362459 HTTP/1.1"" 200 348784 127.0.0.1 - - [28/Mar/2016:12:32:39 +0600] ""GET /favicon.ico HTTP/1.1"" 200 - "; RegexOptions options = RegexOptions.Multiline | RegexOptions.IgnoreCase; Regex regex = new Regex(pattern, options); string result = regex.Replace(input, substitution); } }

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