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

/
/
g

Test String

Code Generator

Language

Generated Code

const regex = /Integrity checksum changed for:\s\'(?<pathName>[^\']+)/g; // Alternative syntax using RegExp constructor // const regex = new RegExp('Integrity checksum changed for:\\s\\\'(?<pathName>[^\\\']+)', 'g') const str = `2016 Oct 30 19:13:08 (AAV) 145.46.122.14->syscheck-registry Rule: 596 (level 5) -> 'Registry Integrity Checksum Changed Again (3rd time)' Integrity checksum changed for: 'HKEY_LOCAL_MACHINE\\Security\\SAM\\Domains\\Account' Old md5sum was: '27511968a811898f0d7f1fed393d31d7' 5. New md5sum is : '5876c6ae278cce7ff2108d8396e10ddc' Old sha1sum was: 'd94f9ea544b6b04caabc80d5bbe6b94854ae3406' New sha1sum is : 'b46d17a3ddc54b5d03464374514398a1835f857e' 2016 Oct 29 06:53:09 (AAB) 145.46.40.146->syscheck-registry Rule: 594 (level 5) -> 'Registry Integrity Checksum Changed' Integrity checksum changed for: 'HKEY_LOCAL_MACHINE\\System\\CurrentControlSet\\Services\\Tomcat' Old md5sum was: '3288a8f072b45b2fa9d879b2ba0fe453' 5. New md5sum is : 'ff17914ec4722e9b7d3scdb508c5d55d' Old sha1sum was: '4d6b33e40721s837cd8de090ef0468b6b20a1f3b' New sha1sum is : '270dca37b8681ca739de4493b704333fb3be86a3' `; // 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