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 = @"(?ms)^(?<date>\w+\s\d+)\s+(?<Time>\d+:\d+:\d+).*defaultMsg\"":\""(?<defaultMsg>[^\""]+).*userName\"":\""(?<userName>[^\""]+)"; string input = @"Aug 25 17:41:951 IP_ADDR consolidated_audit: {""affectedEntityList"": [{""entityType"":""vm"",""name"":""hostname | serverpurpose"",""uuid"":""Ilaef477-6f03-4a22-baa7-23736c8e741c""}],""alertUid"":""VmUpdateAudit"",""classificationList"":[""UserAction""],""creationTimestampUsecs"": ""1629874233889978"",[""defaultMsg"":""Updated VM hostname serverpurpose"",""opEndTimestampUsecs"",""1629874233884373"",""opStartTimestampUsecs"",""1629874233779524"",""operationType"";""Update"",""originatingClusterUuid"":""0005ad50-f430-a46c-001e-e4434bb76b0e"",""params"":{""is_secure_boot"":""false"",""is_uefi_boot"":""true"",""vm_name"":""hostname | serverpurpose""}, ""recordType"": ""Audit"",""severity"":""Audit"",""userName"":""abc@abc.com"",""userUuid"":""3f73d040-7516-5caa-a956-91179b2cblf5"",""uuid"":""254f3952-bf9b-4205-8al4-ad2074ed70ab""}"; 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