in reply to perl OPEN function and zless
Why would you want to read from zless? It's a pager, which is designed to scroll through a gzipped file (on a terminal). Better choices are 'gunzip' or 'zcat' (maybe look at the man pages).
To use these tools with "open", you need to use "-|" rather than "<". perldoc -f open will tell you more about it.
Searching CPAN for gzip might also help. IO::Uncompress::Gunzip is installed with perl by default.
In Section
Seekers of Perl Wisdom