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

/
/
si

Test String

Code Generator

Language

Generated Code

using System; using System.Text.RegularExpressions; public class Example { public static void Main() { string pattern = @"^(get|post|head|options|put|delete|trace|connect) [\x09-\x0d -~]*? http\/(0\.9|1\.0|1\.1)|^http\/(0\.9|1\.0|1\.1) [1-5][0-9][0-9]"; string input = @"HTTP/1.1 206 Partial Content Server: nginx Date: Wed, 11 Nov 2015 03:56:37 GMT Content-Type: application/octet-stream Content-Length: 356602 Last-Modified: Sat, 09 May 2015 01:02:03 GMT Connection: keep-alive Cache-Control: no-store Pragma: no-cache Access-Control-Allow-Origin: * Access-Control-Expose-Headers: X-TCP-Info,X-Session-Info X-TCP-Info: h0=1468775468;h1=1393591241;h2=2806702307;h3=4238532199;h4=1088413687; X-Session-Info: addr=14.203.114.166;port=64848;argp=6.r_LuFhNjxnyyv1lFwH73LPg5P97q98pNwisQ1a9GcfM Content-Range: bytes 221217390-221573991/345312900 ...{moof....mfhd...........ctraf....tfhd... ............tfdt....... .tj`...Asaiz........0...................................."; RegexOptions options = RegexOptions.Singleline | RegexOptions.IgnoreCase; Match m = Regex.Match(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