Regular Expressions 101

Save & Share

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 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

/
/
gm

Test String

Substitution

Processing...

Code Generator

Generated Code

#include <MsgBoxConstants.au3> ; to declare the Constants of MsgBox Local $sRegex = "(?m)(?xXmi)" & @CRLF & _ "(?:" & @CRLF & _ " (?# use non-capture for details in debugging)" & @CRLF & _ " (?:" & @CRLF & _ " (?<match>" & @CRLF & _ " (?# If quoted value)" & @CRLF & _ " (?<quot_char>(?<!\\)["'])" & @CRLF & _ " (?# Quoted content)" & @CRLF & _ " (?:" & @CRLF & _ " (?:" & @CRLF & _ " (?# Match as many characters that aren't quotation char)" & @CRLF & _ " (?# or escape char as possible. )" & @CRLF & _ " (?:(?:(?!\k<quot_char>|\\)).+)" & @CRLF & _ " (?:" & @CRLF & _ " (?# Match any/all escape chars that do not have the)" & @CRLF & _ " (?# quotation char following it. )" & @CRLF & _ " (?:(?:\\)*(?!\k<quot_char>))?" & @CRLF & _ " (?# If there is an escape char followed by the quotation)" & @CRLF & _ " (?# quotation char match them. )" & @CRLF & _ " (?:[\\]\k<quot_char>)?" & @CRLF & _ " )*?" & @CRLF & _ " )" & @CRLF & _ " )" & @CRLF & _ " (?<close_quot>\k<quot_char>)" & @CRLF & _ " |" & @CRLF & _ " (?# if simple token)" & @CRLF & _ " (?<basic>[^ \n]+)+" & @CRLF & _ " )" & @CRLF & _ " )" & @CRLF & _ " (?<trail_ws>[ ]+)?" & @CRLF & _ ")" Local $sString = "-t1a1" & @CRLF & _ "-t2a1 -t2a2" & @CRLF & _ " -t3a1 -t3a2 " & @CRLF & _ "-t4a1 Test1value -t4a2 test4a2value -t4a3 t4a3value" & @CRLF & _ "-t5a1EscQuot \'t5a1valueESQ\' -t5a2EscQuot \"t5a2valueEDQ\"" & @CRLF & _ "-t6a1 "t6a1value1DQWord1 t6a1value1DQWord1" -t6a2SQuot 't6a2value1SQWord1 t6a2value1SQWord2 t6a2value1SQWord3 '" & @CRLF & _ "-t7a1SQuotEmpty '' -t7a2DQuotEmpty """ & @CRLF & _ "" Local $sSubst = "\n${match}" Local $sResult = StringRegExpReplace($sString, $sRegex, $sSubst) MsgBox($MB_SYSTEMMODAL, "Result", $sResult)

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