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
  • Match everything enclosed
    (?:...)
  • Capture everything enclosed
    (...)
  • 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

/
/
gs

Test String

Code Generator

Language

Generated Code

use strict; my $str = '1765 <86>1 2020-11-16T09:50:50+01:00 localhost testSyslogXds SOAP_KSW-RI-Z1_100000000000023_000000000000011 IHE+RFC-3881 [origin swVersion="4.7.0" software="Orchestra"] <?xml version="1.0" encoding="UTF-8"?><AuditMessage><EventIdentification EventActionCode="C" EventDateTime="2020-11-16T09:50:50.755+01:00" EventOutcomeIndicator="0"><EventID codeSystemName="DCM" csd-code="110110" originalText="Patient Record"/><EventTypeCode codeSystemName="IHE Transactions" csd-code="ITI-44" originalText="Patient Identity Feed"/></EventIdentification><ActiveParticipant AlternativeUserID="11000000000506150000169" NetworkAccessPointID="10.70.65.176" NetworkAccessPointTypeCode="2" UserID="2.16.756.5.30.1.107|2.16.756.5.30.1.107.4.2" UserIsRequestor="true"><RoleIDCode codeSystemName="DCM" csd-code="110153" originalText="Source Role ID"/></ActiveParticipant><ActiveParticipant NetworkAccessPointID="https://api.test.xad.ch/mpi/ws/iti44Service" NetworkAccessPointTypeCode="2" UserID="2.16.756.5.30.1.194|2.16.756.5.30.1.194.3.1" UserIsRequestor="false"><RoleIDCode codeSystemName="DCM" csd-code="110152" originalText="Destination Role ID"/></ActiveParticipant><AuditSourceIdentification AuditEnterpriseSiteID="2.16.756.5.30.1.107.4" AuditSourceID="KSW ddag Navision TEST"><AuditSourceTypeCode csd-code="4"/></AuditSourceIdentification><ParticipantObjectIdentification ParticipantObjectID="1069851^^^&amp;2.16.756.5.30.1.107.4.2.1&amp;ISO" ParticipantObjectTypeCode="1" ParticipantObjectTypeCodeRole="1"><ParticipantObjectIDTypeCode codeSystemName="RFC-3881" csd-code="2" originalText="Patient Number"/><ParticipantObjectDetail type="II" value="Mi4xNi43NTYuNS4zMC4xLjEwNy40LjIuMTA5MDM0MDQ3MDQ2MDE5MDQxLjE2MDU1MTY2NTAyMzkuMjE="/></ParticipantObjectIdentification></AuditMessage> Ereignisaktionen'; my $regex = qr/ActiveParticipant.*?\sUserID=\"+?(?<atnaUserID>[^\"]+)\".+?UserIsRequestor=\"true\"/sp; if ( $str =~ /$regex/g ) { print "Whole match is ${^MATCH} and its start/end positions can be obtained via \$-[0] and \$+[0]\n"; # print "Capture Group 1 is $1 and its start/end positions can be obtained via \$-[1] and \$+[1]\n"; # print "Capture Group 2 is $2 ... and so on\n"; } # ${^POSTMATCH} and ${^PREMATCH} are also available with the use of '/p' # Named capture groups can be called via $+{name}

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 Perl, please visit: http://perldoc.perl.org/perlre.html