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no warnings 'uninitialized';
if ($_[$i] =~ /^(.+?)\.(zip|t?gz|tar|bz2?|tbz)$/i) {
 ...
}

for (my $i = 0; $i <= $#_; $i++) {
  next unless
    defined $_[$i] and
            $_[$i] =~ /^(.+?)\.(zip|t?gz|tar|bz2?|tbz)$/i
         or $_[$i] =~ .... and so on