Regular Expressions 101

Save & Manage Regex

  • Current Version: 1
  • Save & Share
  • Community Library

Flavor

  • PCRE2 (PHP)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java
  • .NET 7.0 (C#)
  • Rust
  • PCRE (Legacy)
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests
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
Processing...

Test String

Code Generator

Language

Generated Code

const regex = /(^\d*.\d*.\d*.\d*) \: (\d*) \-\-.*\|\|(.*)\|\|.*forward\:.*in\:(.*).out\:(.*), src-mac (.*), proto (.*), (\d*.\d*.\d*.\d*\:\d*)\-\>(\d*.\d*.\d*.\d*\:\d*)/gm; // Alternative syntax using RegExp constructor // const regex = new RegExp('(^\\d*.\\d*.\\d*.\\d*) \\: (\\d*) \\-\\-.*\\|\\|(.*)\\|\\|.*forward\\:.*in\\:(.*).out\\:(.*), src-mac (.*), proto (.*), (\\d*.\\d*.\\d*.\\d*\\:\\d*)\\-\\>(\\d*.\\d*.\\d*.\\d*\\:\\d*)', 'gm') const str = `185.123.0.119 : 36733 -- <46>Jan 20 13:35:08 Balkon Cafe ||BALKON_CAFE||: forward: in:Direk_Cikis out:pppoe-out1, src-mac 98:ca:33:d8:5f:8d, proto TCP (ACK,PSH), 192.168.1.36:52071->17.248.147.44:443, NAT (192.168.1.36:52071->185.123.0.119:52071)->17.248.147.44:443, len 341 185.123.0.119 : 36733 -- <46>Jan 20 13:35:08 Balkon Cafe ||BALKON_CAFE||: forward: in:pppoe-out1 out:Direk_Cikis, src-mac 60:73:5c:36:2b:30, proto TCP (ACK,PSH), 17.252.28.30:5223->192.168.1.55:52530, NAT 17.252.28.30:5223->(185.123.0.119:52530->192.168.1.55:52530), len 105 185.123.0.235 : 50416 -- <46>Jan 20 14:34:42 41680773556@46.netcity.net.tr ||enesev||: forward: in:pppoe-41680773556@46.netcity.net.tr out:ether1, src-mac 60:73:5c:36:2b:30, proto TCP (ACK,FIN), 216.58.201.78:443->192.168.1.12:5347, NAT 216.58.201.78:443->(185.123.0.235:5347->192.168.1.12:5347), len 40 185.123.0.235 : 50416 -- <46>Jan 20 14:34:42 41680773556@46.netcity.net.tr ||enesev||: forward: in:ether1 out:pppoe-41680773556@46.netcity.net.tr, src-mac 40:e2:30:ee:7b:c7, proto TCP (ACK), 192.168.1.12:5347->216.58.201.78:443, NAT (192.168.1.12:5347->185.123.0.235:5347)->216.58.201.78:443, len 40 `; // Reset `lastIndex` if this regex is defined globally // regex.lastIndex = 0; let m; while ((m = regex.exec(str)) !== null) { // This is necessary to avoid infinite loops with zero-width matches if (m.index === regex.lastIndex) { regex.lastIndex++; } // The result can be accessed through the `m`-variable. m.forEach((match, groupIndex) => { console.log(`Found match, group ${groupIndex}: ${match}`); }); }

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 JavaScript, please visit: https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions