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"
"
xs

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 = "(?xs) ^(?P<timestamp>\d{4}/\d{2}/\d{2}\ \d{2}:\d{2}:\d{2})" & @CRLF & _ " \ \[(?P<severity>emerg|alert|crit|error|warn|notice|info)\]" & @CRLF & _ " \ (?P<process_id>\d+)" & @CRLF & _ " \#(?P<thread_id>\d+):" & @CRLF & _ " \ \*(?P<connection_id>\d+)" & @CRLF & _ " \ (?P<error>.+?)" & @CRLF & _ " (?:\ while\ (?P<context>.+?))?" & @CRLF & _ " ,\ client:\ (?P<client_ip>\d+\.\d+\.\d+\.\d+)" & @CRLF & _ " ,\ server:\ (?P<server>.+?)" & @CRLF & _ " (?:,\ request:\ \"(?P<request_method>[A-Z]+?)" & @CRLF & _ " \ (?P<request_path>\/.+?)" & @CRLF & _ " \ (?P<request_protocol>.+?)\")?" & @CRLF & _ " (?:,\ upstream:\ \"(?P<upstream>.+?)\")?" & @CRLF & _ " (?:,\ host:\ \"(?P<host>.+?)\")?" & @CRLF & _ " (?:,\ referrer:\ \"(?P<referrer>.+?)\")?" & @CRLF & _ " $" Local $sString = "2019/07/11 07:19:30 [error] 934#934: *18897816 open() "/local/nginx/static/ads.txt" failed (2: No such file or directory), client: 85.195.82.90, server: app.digitale-sammlungen.de, request: "GET /ads.txt HTTP/1.1", host: "app.digitale-sammlungen.de"" Local $aArray = StringRegExp($sString, $sRegex, $STR_REGEXPARRAYFULLMATCH) ; Present the entire match result _ArrayDisplay($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