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
No Match

r"
"
gm

Test String

Code Generator

Language

Generated Code

#include <StringConstants.au3> ; to declare the Constants of StringRegExp #include <Array.au3> ; UDF needed for _ArrayDisplay and _ArrayConcatenate Local $sRegex = "(?m)^[\d.]+\/\d\d\S*" Local $sString = "0.0.0.0/0 *[OSPF/150] 5w2d 19:06:26, metric 24, tag 100" & @CRLF & _ " to 10.239.248.129 via ae101.0" & @CRLF & _ " > to 10.239.248.137 via ae102.0" & @CRLF & _ "1.1.21.0/30 *[OSPF/10] 5w2d 19:06:26, metric 23" & @CRLF & _ " > to 10.239.248.129 via ae101.0" & @CRLF & _ " to 10.239.248.137 via ae102.0" & @CRLF & _ " [BGP/170] 10w3d 08:00:01, localpref 260, from 189.40.251.20" & @CRLF & _ " AS path: 17379 I, validation-state: unverified" & @CRLF & _ " > to 10.239.248.129 via ae101.0, Push 16151" & @CRLF & _ " to 10.239.248.137 via ae102.0, Push 16109" & @CRLF & _ " [BGP/170] 10w3d 08:00:54, localpref 260, from 189.40.251.21" & @CRLF & _ " AS path: 17379 I, validation-state: unverified" & @CRLF & _ " > to 10.239.248.129 via ae101.0, Push 16151" & @CRLF & _ " to 10.239.248.137 via ae102.0, Push 16109" & @CRLF & _ "1.1.21.4/30 *[OSPF/10] 5w2d 19:06:26, metric 23" & @CRLF & _ " to 10.239.248.129 via ae101.0" & @CRLF & _ " > to 10.239.248.137 via ae102.0" & @CRLF & _ " [BGP/170] 10w3d 07:57:12, MED 120, localpref 100, from 189.40.251.21" & @CRLF & _ " AS path: ?, validation-state: unverified" & @CRLF & _ " > to 10.239.248.129 via ae101.0" & @CRLF & _ " [BGP/170] 10w3d 07:56:39, MED 120, localpref 100, from 189.40.251.20" & @CRLF & _ " AS path: ?, validation-state: unverified" & @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