http://www.perlmonks.org?node_id=921034


in reply to Weird Regexes Stuff

Updated

this may help you

#!/usr/bin/perl -w

use strict;
use warnings;

my $input = 'All the following should be acceptable: 12:00am, 5:00pm, 
+8:30AM. These should probably not be accepted: 3:00,2:60am, 99:00am, 
+3:0pm, 29:00AM.';
while ($input =~ m/\W([1-9]|[01][0-2]|2[0-3]):[0-5][0-9][ap]m/gsi)
{
        print "This is a valid time!\t$&\n";
}
__END__
OUTPUT

This is a valid time!    12:00am
This is a valid time!    5:00pm
This is a valid time!    8:30AM

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Regards,
Velusamy R.

eval"print uc\"\\c$_\""for split'','j)@,/6%@0%2,`e@3!-9v2)/@|6%,53!-9@2~j';

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Re^2: Weird Regexes Stuff
by AnomalousMonk (Archbishop) on Aug 18, 2011 at 18:11 UTC 
    >perl -wMstrict -le
"my $input = '12:00AM 29:00AM';
 while ($input =~ m/\W(0|[0-2]?[0-9]):[0-5][0-9][ap]m/gsi)
 {
         print qq{This is a valid time!\t'$&'};
 }
"
This is a valid time!   ' 29:00AM'

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Re^2: Weird Regexes Stuff
by AnomalousMonk (Archbishop) on Aug 19, 2011 at 07:47 UTC

    The updated solution still has a problem, IMO, with that pesky  \W anchoring the start of the match. Is the following really what you intend? 

    >perl -wMstrict -le
"my $input = '12:00am, 5:00pm,8:30AM';
 while ($input =~ m/\W([1-9]|[01][0-2]|2[0-3]):[0-5][0-9][ap]m/gsi)
 {
         print qq{This is a valid time!\t$&};
 }
"
This is a valid time!    5:00pm
This is a valid time!   ,8:30AM

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