Regular Expressions 101

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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
No Match

/
/
gm

Test String

Code Generator

Language

Generated Code

using System; using System.Text.RegularExpressions; public class Example { public static void Main() { string pattern = @"""(?:GET|POST)\s+([^\s?]*)"; string input = @" 83.198.250.175 - - [22/Mar/2009:07:40:06 +0100] ""GET /images/ht1.gif HTTP/1.1"" 200 61 ""http://www.facades.fr/"" ""Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; Wanadoo 6.7; Orange 8.0)"" ""-"" 65.33.94.190 - - [05/Apr/2003:17:26:27 -0500] ""POST /samples/dem/tt.php?x=e2323 HTTP/1.0"" 404 276 151.227.152.48 - - [02/Jul/2014:14:35:55 +0100] ""GET /css/main.css HTTP/1.1"" 200 4658 ""http://stanmore.menczykowski.co.uk/"" ""Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/35.0.1916.153 Safari/537.36"" 10.143.2.119 64.103.161.112 - [06/Jan/1970:00:48:01 +0000] ""GET /right_arrow.jpg HTTP/1.1"" 304 0 ""http://64.103.161.112/index_eth_diag.html"" ""Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/28.0.1500.95 Safari/537.36"" "; RegexOptions options = RegexOptions.Multiline; 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