zcat won’t unzip files properly
Your school’s system still has the old “compress” style utilities rather than the newer GNU “gzip” based ones. You need to use gzcat rather than zcat, assuming that it’s available.
zcat
How to get few lines from a .gz compressed file without uncompressing
zcat(1) can be supplied by either compress(1) or by gzip(1). On your system, it appears to be compress(1) — it is looking for a file with a .Z extension. Switch to gzip -cd in place of zcat and your command should work fine: gzip -cd CONN.20111109.0057.gz | head Explanation -c –stdout –to-stdout Write output on … Read more