If my gz file does not exist, why doesn't it DIE?
$ cat test.pl
open(FILE, "zcat dummy.gz |") or die "DIE";
$ ./test.pl
zcat: dummy.gz: No such file or directory
If I read a file normally, it works as expected:
$ cat test2.pl
open(FILE, "dummy.gz") or die "DIE";
$ ./test2.pl
DIE at ./test.pl line 2.