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

/
/
gim

Test String

Code Generator

Language

Generated Code

use strict; my $str = 'Herbst, D. M., Griffith, N. R., & Slama, K. M. (2014). Rodeo cowboys: Conforming to masculine norms and help-seeking behaviors for depression. Journal of Rural Mental Health, 38, 20–35. http://dx.doi.org/10.1037/rmh0000008 Herbst, D. M., Griffith, N. R., & Slama, K. M. (2014). Rodeo cowboys: Conforming to masculine norms and help- seeking behaviors for depression. Journal of Rural Mental Health, 38, 20–35. doi:10.1037/rmh0000008 Example: https://doi.org/10.5468/ogs.2016.59.1.1 "Quantum tomography: Measured measurement", Markus Aspelmeyer, nature physics January 2009, Volume 5, No 1, pp11-12; [doi:10.10.1038/nphys1170] Held, Gilbert. Internetworking LANs and WANs (Second Edition), John Wiley & Sons, 1998, Published Online 05 Oct 2001. Chapter 1, Network Concepts (p 1-30) [doi:10.1002/0470841559.ch1] Irino, T; Tada, R (2009): Chemical and mineral compositions of sediments from ODP Site 127-797. Geological Institute, University of Tokyo. [doi:10.1594/PANGAEA.726855] Earthquake Event, Authored by Automated System: Geofon operator (2009): GEOFON event gfz2009kciu (NW Balkan Region) GeoForschungsZentrum Potsdam(GFZ). [doi:10.1594/GFZ.GEOFON.gfz2009kciu] Kraus, Stefan; del Valle, Rodolfo (2008): Geological map of Potter Peninsula (King George Island, South Shetland Islands, Antarctic Peninsula). Instituto Antártico Chileno, Punta Arenas, Chile & Instituto Antártico Argentino, Buenos Aires, Argentina. [doi:10.1594/PANGAEA.667386] B. Kirchhof (2009) Silicone oil bubbles entrapped in the vitreous base during silicone oil removal, Video Journal of Vitreoretinal Surgery. [doi: 10.3207/2959859860]'; my $regex = qr/\b(10\.[0-9]{4,}(?:\.[0-9]+)*\/(?:(?![\"&\'])\S)+)\b/imp; 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