3h4m            11040      3h4m      
1h2m3s          3723       1h2m3s    
1h5s            3605       1h5s      
3m4s            184        3m4s      
1d2h3m4s        93784      1d2h3m4s  
3x              -1                   
2m2m            -1                   
23h59m59s       86399      23h59m59s 

##</code><code>##

my @time_values = qw [ d h m s ];
my %time_value  = ( d => 86400, h => 3600, m => 60, s => 1 );

sub string_to_time
{
        my ($time) = @_;
        my $value  = 0;

        foreach my $letter (@time_values)
        {
                if ($time =~ s/(\d+)$letter//)
                {
                        $value += $1 * $time_value{$letter};
                }
        }

        return -1 if length $time;

        return $value;
}

sub time_to_string
{
        my ($time) = @_;
        my $value  = '';

        foreach my $letter (@time_values)
        {
                my $time_value = $time_value{$letter};

                if ($time > $time_value)
                {
                        $value .= int($time/$time_value).$letter;
                        $time %= $time_value;
                }
        }

        return $value;
}

##</code><code>##

#!/usr/bin/perl -w

use strict;
my @test = qw [ 3h4m 1h2m3s 1h5s 3m4s 1d2h3m4s 3x 2m2m 23h59m59s ];

foreach (@test)
{
        my $s2t = string_to_time($_);
        my $t2s = time_to_string($s2t);
        printf ("%-15s %-10s %-10s\n", $_, $s2t, $t2s);
}