expanding/uncompressing files

[wadada]

hi comerades,

could some please give me some info on how to expand (or uncompress) 
the file "sag-alpha-1.ps.gz". i have tried the following commands:
                uncompress
                unpack
but could not make any meaningful headway through. this file contains 
the system administrators guide for linux which i have downloaded 
from sunsite.unc.edu. any help would be much appreciated.

regards
eugene