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
Processing...

Test String

Code Generator

Language

Generated Code

use strict; my $str = 'VA ADVISORY STATUS: EXER DTG: 20211116/0600Z VAAC: LONDON VOLCANO: EYJAFJALLAJOKULL 372020 PSN: N6338 W01938 AREA: ICELAND SUMMIT ELEV: 1651M ADVISORY NR: 2021/009 INFO SOURCE: ICELAND MET OFFICE AVIATION COLOUR CODE: RED ERUPTION DETAILS: EXERCISE VOLCEX21 - EYJAFJALLAJOKULL ERUPTION OBS VA DTG: 16/0600Z OBS VA CLD: SFC/FL200 N4550 W04415 - N6356 W01927 - N7353 E05847 - N4025 E05735 - N4550 W04415 MOV SE 15KT FL200/350 N5343 W03145 - N6355 W01932 - N7446 E05944 - N6250 E05925 - N5255 W02531 - N5343 W03145 MOV SE 40KT FCST VA CLD +6 HR: 16/1200Z SFC/FL200 N4517 W04623 - N6356 W01924 - N7750 E07729 - N3856 E06031 - N4517 W04623 FL200/350 N4839 W04904 - N7025 E01017 - N7505 E07954 - N6139 E06549 - N4839 W04904 FCST VA CLD +12 HR: 16/1800Z SFC/FL200 N4010 E03817 - N4900 W04529 - N7112 W00641 - N7617 E09941 - N4010 E03817 FL200/350 N4919 W05700 - N7300 E03329 - N7732 E09626 - N5936 E09143 - N4919 W05700 FCST VA CLD +18 HR: 17/0000Z SFC/FL200 N4901 W05420 - N7235 E00056 - N7558 E09708 - N3934 E05131 - N4901 W05420 FL200/350 N4933 W03842 - N5436 W04127 - N7433 E03732 - N7935 E11430 - N6503 E10238 - N4933 W03842 RMK: EXERCISE VOLCEX21 - EYJAFJALLAJOKULL ERUPTION CONTINUES, RECENTLY INCREASING TO APPROX 8KM NXT ADVISORY: NO LATER THAN 20211116/1200Z'; my $regex = qr/([\d]+/[\d\w]+\s)(([\w\d]+/[\w\d]+)\s((?:[\w]{1}[\d]{4}\s[\w]{1}[\d]{5}\s\-\s)+[\w]{1}[\d]{4}\s[\w]{1}[\d]{5}\s))+/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