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

/
/

Test String

Code Generator

Language

Generated Code

using System; using System.Text.RegularExpressions; public class Example { public static void Main() { string pattern = @"^([[:digit:]]{1,3}\.[[:digit:]]{1,3}\.[[:digit:]]{1,3}\.[[:digit:]]{1,3}\s)([a-zA-Z0-9_.\[\]\(\)\-:\s]{1,})\s(ModSecurity:\sWarning.\s)([a-zA-Z0-9\""\/\_\.\[\]\(\)\-:\s]{1,})(\s\[severity ""CRITICAL""\]\s)([a-zA-Z0-9\""\/\_\.\[\]\(\)\-:\s]{1,})\s(""OWASP_CRS\/)"; string input = @"129.232.250.201 [Tue Apr 30 14:01:54 2019] [error] [pid 23850] apache2_util.c(271) [client 196.40.111.5:39554 ] - [client 196.40.111.5] ModSecurity: Warning. Matched phrase ""bin/bash"" at ARGS_NAMES:/bin/bash. [file ""/opt/modsecurity/owasp-modsecurity-crs/rules/REQUEST-932-APPLICATION-ATTACK-RCE.conf""] [line ""503""] [id ""932160""] [msg ""Remote Command Execution: Unix Shell Code Found""] [data ""Matched Data: bin/bash found within ARGS_NAMES:/bin/bash: /bin/bash""] [severity ""CRITICAL""] [ver ""OWASP_CRS/3.1.0""] [tag ""application-multi""] [tag ""language-shell""] [tag ""platform-unix""] [tag ""attack-rce""] [tag ""OWASP_CRS/WEB_ATTACK/COMMAND_INJECTION""] [tag ""WASCTC/WASC-31""] [tag ""OWASP_TOP_10/A1""] [tag ""PCI/6.5.2""] [hostname ""dedi-staging15.jnb1.host-h.net""] [uri ""/test/""] [unique_id ""XMg5MoHo@skAAF0qGI4AAAAE""]"; Match m = Regex.Match(input, pattern); 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