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 = @"(?:""id\.resp_h""[""\[:]*|""rx_hosts""[""\[:]*)(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})"; string input = @"schema_id=17127524534057985804:skip_writers="":{""_path"":""conn"",""_system_name"":""hostname"",""_write_ts"":""2020-01-12T22:09:28.853417Z"",""ts"":""2020-01-12T22:07:14.642074Z"",""uid"":""Cm4cbmvRjlmd2I52c"",""id.orig_h"":""192.168.1.1"",""id.orig_p"":xxx,""id.resp_h"":""192.168.1.2"",""id.resp_p"":xxx,""proto"":""udp"", schema_id=17223896091372211545:skip_writers="":{""_path"":""files"",""_system_name"":""Hostname"",""_write_ts"":""2020-01-12T22:09:00.016260Z"",""ts"":""2020-01-12T22:07:14.108217Z"",""fuid"":""FnmzOv3Fkhr8lP0qL"",""tx_hosts"":[""192.168.1.1"",""192.168.1.1""],""rx_hosts"":[""192.168.1.10""],"; 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