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
Processing...

Test String

Code Generator

Language

Generated Code

package main import ( "regexp" "fmt" ) func main() { var re = regexp.MustCompile(`(?m)^(?P<KEY>[^=#\s]+)=(?P<VALUE>.*)$`) var str = `app=tcp/444 # Catchs only Key:app Value:tcp > should catch Key:app Value:tcp/444 catdt=Network-based # Current result: # catdt:'Network' # # Shoud be: # catdt:'Network-based' eventId=123123 externalId=11111 # Current result: # eventId:'123123 externalId=11111' # # Should catch # eventId: '123123' # externalId: '111111' src=2.3.4.5 # Current result: # src:'2' # # Should catch # src: '2.3.4.5' eventAnnotationEndTime=1493293598\=aaa00 # Should be: # eventAnnotationEndTime: '1493293598\=aaa00' eventAnnotationEndTimeA=1493293598A\=aaa01 eventAnnotationEndTimeB=1493293598\=aaa02 # Should be: # eventAnnotationEndTimeA: '1493293598\=aaa01' # eventAnnotationEndTimeB: '1493293598\=aaa02' sourceTranslatedZoneURI=/All Zones/ArcSight System/Private Address Space Zones/RFC1918: 172.3.0.0-172.3.255.255 # Should be: # ourceTranslatedZoneURI: '/All Zones/ArcSight System'` for i, match := range re.FindAllString(str, -1) { fmt.Println(match, "found at index", i) } }

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 Golang, please visit: https://golang.org/pkg/regexp/