Perl version:
#!/usr/bin/perl
use warnings;
use strict;
use 5.010;
use feature "switch";
use Data::Dumper;
while (<DATA>) {
chomp;
if (m/^(?:(\d+)mins,)?(\d+)sec$/) {
my $min = $1 ? $1 : 0;
my $sec = $2 ? $2 : 0;
print $min * 60 + $sec, "\n";
}
}
__DATA__
16sec
16sec
1mins,36sec
19mins,34sec
43sec
6mins,38sec