Regular Expressions 101

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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

@"
"
gxmn

Test String

Code Generator

Language

Generated Code

use strict; my $str = '# Entry ## Definition A published announcement made by a trusted [[Emitter]], detailing an event that occurred on their platform. ## Specifications (3.0) #v3_0 A trustlist entry follows a basic structure, with parts being omitted during ingest, as these are filled by the receiving [[Directory]], responsible for the good tenure of this entry, and its correlation to existing data. As SocialGuard 1.0 to 3.0 tied its data to the [Discord](https://discord.com) [[Platform]], all data types are bound to that end. | Property | Type | Description | Requirement | | -------- | ---- | ----------- | ----------- | | `id` | Guid | ID of the entry. | Set by API | | `userId` | UInt64 | ID of the receiving [[User]]. | Required | | `entryAt` | DateTime | Date/Time at which the entry was emitted on the [[Directory]]. | Set by API | | `lastEscalated` | DateTime | Date/Time at which the entry was last escalated/edited. | Set by API | | `emitterId` | String | ID of the [[Emitter]] responsible for this Entry. | Set by API | | `emitter` | [[Emitter#Specifications (3.0)]] | Details of the [[Emitter]] responsible for this entry. | Set by API | | `escalationLevel` | [[#Range: Escalation level (3.0)]] | Escalation/Severity level of the events indicated by this entry. | Required | | `escalationNote` | String | Details of the event that led to this entry. | Required | ### Range: Escalation level (3.0) This range defines the severity of an event leading to an entry. It is ranged by severity level and ordered from lowest to highest severity : 1. **Suspicious** The [[User]] is marked as suspicious. Their behaviour should be monitored. 2. **Untrusted** The [[User]] is marked as untrusted. It is advised to exercise caution when interacting with them. 3. **Blacklisted** The [[User]] is deemed dangerous. Banning this user is greatly advised. '; my $regex = qr/\[\[( # link, and optional anchor (?<link>[^\|\#\]]+)?(\#(?<anchor>[^\|\]]+))? # display title (optional) (\|(?<title>[^|\]]+))? # tooltip (optional) (\|(?<tooltip>[^|\]]+))? )\]\]/xmnp; 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