Regular Expressions 101

Save & Share

  • Regex Version: ver. 1
  • Update Regex
    ctrl+⇧+s
  • Save new Regex
    ctrl+s
  • Add to Community Library

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

const regex = new RegExp('^(?!.*(?:is OK|is a broken|file could not be opened)).*', 'gm') const str = `eth0 10.0.11.196 00:0C:29:AF:6A:A7 parameters passed to uvscan: --DRIVER /opt/McAfee/uvscan/datfiles/current -- ANALYZE --AFC=32 ATIME-PRESERVE --PLAD --RPTALL RPTOBJECTS SUMMARY --UNZIP -- RECURSIVE --SHOWCOMP --MIME --THREADS=4 /tmp temp XML output is: /tmp/HIQZRq7t2R McAfee VirusScan Command Line for Linux64 Version: 6.0.5.614 Copyright (C) 2014 McAfee, Inc. (408) 988-3832 LICENSED COPY - April 03 2016 AV Engine version: 5700.7163 for Linux64. Dat set version: 8124 created Apr 3 2016 Scanning for 670707 viruses, trojans and variants. No file or directory found matching /root/SVN/swd-lhn-build/trunk/utils/ATIME-PRESERVE No file or directory found matching /root/SVN/swd-lhn-build/trunk/utils/RPTOBJECTS No file or directory found matching /root/SVN/swd-lhn-build/trunk/utils/SUMMARY /tmp/tmp.BQshVRSiBo ... is OK. /tmp/keyring-F6vVGf/socket ... file could not be opened. /tmp/keyring-F6vVGf/socket.ssh ... file could not be opened. /tmp/keyring-F6vVGf/socket.pkcs11 ... file could not be opened. /tmp/yum.log ... is OK. /tmp/tmp.oW75zGUh4S ... is OK. /tmp/.X11-unix/X0 ... file could not be opened. /tmp/tmp.LCZ9Ji6OLs ... is OK. /tmp/tmp.QdAt1TNQSH ... is OK. /tmp/ks-script-MqIN9F ... is OK. /tmp/tmp.mHXPvYeKjb/mcupgrade.conf ... is OK. /tmp/tmp.mHXPvYeKjb/uvscan/uninstall-uvscan ... is OK. /tmp/tmp.mHXPvYeKjb/mcscan ... is OK. /tmp/tmp.mHXPvYeKjb/uvscan/install-uvscan ... is OK. /tmp/tmp.mHXPvYeKjb/uvscan/readme.txt ... is OK. /tmp/tmp.mHXPvYeKjb/uvscan/uvscan_secure ... is OK. /tmp/tmp.mHXPvYeKjb/uvscan/signlic.txt ... is OK. /tmp/tmp.mHXPvYeKjb/uvscan/uvscan ... is OK. /tmp/tmp.mHXPvYeKjb/uvscan/liblnxfv.so.4 ... is OK.`; // 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