Use separate if statements or change your existance check to &&.

my $file_name = "files.txt";
if (-e $file_name) {
    unlink $file_name or die "Unable to unlink $file_name: $!";
}

my $filename = "data.txt";
if (-e $filename) {
    unlink $filename or die "Unable to unlink $filename: $!";
}
[download]