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

`
`
gm

Test String

Code Generator

Language

Generated Code

use strict; my $str = '### rgmz example @----__-2as-2:password@----__-2as-2.com ### From test cases var ( validPattern = " https://kaNydBSAodo87dSAFtsd7.com:1234@qYY3SylY7fHP " validPattern2 = `<p><a href="http://username:password@127.0.0.1">http://username:password@127.0.0.1</a></p>` invalidPattern = "https://kaNydBSAodo87dsm9asuiSAFtsd7.com.1234@qYY3SylY7fHP" keyword = "uri" ) ### examples from chatgpt 1. `https://user.name:pa$$word123@sub.example.com` 2. `http://u$er_name:my%p@$$word@api.dev.localhost` 3. `https://12345:67890@my-app.server123.co.uk` 4. `http://user~!name:pass.word@some-long-subdomain.example.org` 5. `https://_:__@localhost` 6. `https://admin:admin123@192.168.1.1` 7. `http://test-user:complex!password#123@server.example.io` 8. `https://valid_user:!valid-password@simple-host.co` 9. `http://username_with.dots:password_with-dashes@domain.with.subdomain.net` 10. `https://username:password@127.0.0.1:8080` 11. `http://user:pass@----__-2as-2` 12. `https://user@localhost` 13. `http://user:pass@:invalidhost` 14. `https://:passwordonly@hostname.com` 15. `ftp://username:password@hostname.com` 16. `https://user:password@hostname_with_underscores.com` 17. `http://user@:missingpassword.com` 18. `https://missingcolonpassword@hostname.com` 19. `http://user:password@-invalid-hostname.com` 20. `https://user:password@host..com` '; my $regex = qr`\b(?:https?:\/\/)?[\w-\.$~!&'()*+,;=:%-]{3,50}:([\w-\.%$^#&'()*+,;=:%-]{3,50})@[a-zA-Z0-9.-]+(?:\.[a-zA-Z]{2,})?\b`mp; 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