unlink ($input);
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What's that suppose to do? It doesn't look like $input holds a file name. Perhaps you meant

 undef ($input);
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but that's totally useless since the variable is destroyed when the scope ends at the end of the script, the next line.

Another consideration is that split(',', ...) is misleading since the first argument must be a regexp. I prefer always specifying a regexp: split(/,/, ...).

Finally,
my $ts;
foreach $ts (...) { ... }
can be written as simply
foreach my $ts (...) { ... }