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

`
`
gim

Test String

Code Generator

Generated Code

#include <StringConstants.au3> ; to declare the Constants of StringRegExp #include <Array.au3> ; UDF needed for _ArrayDisplay and _ArrayConcatenate Local $sRegex = "(?im)^(?:(?:[_a-z0-9](?:[_a-z0-9-]{0,61}[a-z0-9])?|[0-9]{1,3}?/[0-9]{2})\.)+(?:[a-z](?:[a-z0-9-]{0,61}[a-z0-9])?)?$" Local $sString = "This regexp can be used to validate domain names in Golang." & @CRLF & _ "While it cannot enforce the 253 character limit (with optional trailing period not included)" & @CRLF & _ "that can be easily done with a `len(domain) <= 253` check." & @CRLF & _ "" & @CRLF & _ "This can be used as-is in other languages, even with RE2 regex engine." & @CRLF & _ "Non-capturing groups are used." & @CRLF & _ "Example validated domains (some may be invalid per TLD rules):" & @CRLF & _ "" & @CRLF & _ "example.com" & @CRLF & _ "_25._tcp.SRV.example" & @CRLF & _ "a.punycoded-idna.xn--zckzah" & @CRLF & _ "under_score.example" & @CRLF & _ "0/27.0.0.1.in-addr.arpa" & @CRLF & _ "128/32.255.255.123.in-addr.arpa" & @CRLF & _ "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa.aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa.aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa.aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa." & @CRLF & _ "" & @CRLF & _ "Example invalid domains:" & @CRLF & _ "" & @CRLF & _ "192.0.2.1" & @CRLF & _ "has spaces.com" & @CRLF & _ "easy,typo.example" & @CRLF & _ "23/1.invalid" & @CRLF & _ "domain\.escapes.invalid" & @CRLF & _ "trailing_.underscore.invalid" & @CRLF & _ "-leading.hyphens.invalid" & @CRLF & _ "trailing-.hyphens.invalid" & @CRLF & _ "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa" & @CRLF & _ "" & @CRLF & _ "TLDs have more validation, the following will not validate:" & @CRLF & _ "" & @CRLF & _ "a" & @CRLF & _ "example" & @CRLF & _ "digit.1example" & @CRLF & _ "underscore._example_com" & @CRLF & _ "" & @CRLF & _ "but with a trailing period, the same rules as non-TLD are applied:" & @CRLF & _ "" & @CRLF & _ "a." & @CRLF & _ "example." & @CRLF & _ "digit.1example." & @CRLF & _ "underscore._example_com." & @CRLF & _ "" Local $aArray = StringRegExp($sString, $sRegex, $STR_REGEXPARRAYGLOBALFULLMATCH) Local $aFullArray[0] For $i = 0 To UBound($aArray) -1 _ArrayConcatenate($aFullArray, $aArray[$i]) Next $aArray = $aFullArray ; Present the entire match result _ArrayDisplay($aArray, "Result")

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 AutoIt, please visit: https://www.autoitscript.com/autoit3/docs/functions/StringRegExp.htm