Regular Expressions 101

Save & Share

  • Regex Version: ver. 28
  • Update Regex
    ctrl+⇧+s
  • Save new Regex
    ctrl+s
  • Add to Community Library

Flavor

  • PCRE2 (PHP >=7.3)
  • PCRE (PHP <7.3)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java 8
  • .NET 7.0 (C#)
  • Rust
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests

Tools

Sponsors
There are currently no sponsors. Become a sponsor today!
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 single character of: a, b, c or d
    [[ab][cd]]
  • 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]
  • Character class intersection
    [\w&&[^\d]]
  • 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

"
"

Test String

Code Generator

Language

Generated Code

package main import ( "regexp" "fmt" ) func main() { var re = regexp.MustCompile(`([^ ]*) ([^ ]*) ([^ ]*) ([^ ]*):([0-9]*) ([^ ]*)[:-]([0-9]*) ([-.0-9]*) ([-.0-9]*) ([-.0-9]*) (|[-0-9]*) (-|[-0-9]*) ([-0-9]*) ([-0-9]*) \"([^ ]*) (.*) (- |[^ ]*)\" \"([^\"]*)\" ([A-Z0-9-_]+) ([A-Za-z0-9.-]*) ([^ ]*) \"([^\"]*)\" \"([^\"]*)\" \"([^\"]*)\" ([-.0-9]*) ([^ ]*) \"([^\"]*)\" \"([^\"]*)\" \"([^ ]*)\" \"([^\s]+?)\" \"([^\s]+)\" \"([^ ]*)\" \"([^ ]*)\"`) var str = `2023-03-05T23:00:35.803942Z download 46.20.32.146:37117 10.0.28.135:81 0.000034 0.030235 0.000039 200 200 0 12719 "GET https://download.cylance.com:443/updates/CylanceDetectUpdater/3.1.1000.48/Cylance.Host.Versions.dll?AWSAccessKeyId=ASIAXGEMKUZOLIJU7ANT&Expires=1678143581&response-cache-control=No-cache&x-amz-security-token=FwoGZXIvYXdzEF4aDKZOKkZNWIHzKxCTuSKCAc9SM0qqQ4Cyq5EN69MjRSP4KklVkfKe3l%2FP9auMBc0GcenWYD5MSbBSpabg%2FHhg8iz9KkEEkHtceAp1hIQE25i%2BZldQHjEIrHXyDJZKMh4SK2i7AUegHhrh0bOzAstDH9PRRqm%2FUWbLOm5X26NHcQtA%2FFVJSOl8T9CE%2BxxGOFwmR38ov%2BuToAYyKGAsGRb9noEAnd2jZZub%2B8kUU5ipH5u9%2Ff79%2BFuMSu4SOWaJ3utlz2Q%3D&Signature=pktaTIw8ucS5fcQYGq40zAge6JE%3D HTTP/1.1" "-" ECDHE-RSA-AES128-GCM-SHA256 TLSv1.2` if len(re.FindStringIndex(str)) > 0 { fmt.Println(re.FindString(str),"found at index",re.FindStringIndex(str)[0]) } }

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/