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

const regex = /(?ms)^(?<date>\w+\s\d+)\s+(?<Time>\d+:\d+:\d+).*defaultMsg\":\"(?<defaultMsg>[^\"]+).*userName\":\"(?<userName>[^\"]+)/gm; // Alternative syntax using RegExp constructor // const regex = new RegExp('(?ms)^(?<date>\\w+\\s\\d+)\\s+(?<Time>\\d+:\\d+:\\d+).*defaultMsg\\":\\"(?<defaultMsg>[^\\"]+).*userName\\":\\"(?<userName>[^\\"]+)', 'gm') const str = `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"}`; // Reset `lastIndex` if this regex is defined globally // regex.lastIndex = 0; let m; while ((m = regex.exec(str)) !== null) { // This is necessary to avoid infinite loops with zero-width matches if (m.index === regex.lastIndex) { regex.lastIndex++; } // The result can be accessed through the `m`-variable. m.forEach((match, groupIndex) => { console.log(`Found match, group ${groupIndex}: ${match}`); }); }

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 JavaScript, please visit: https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions