> I got a file which was double compressed: filename.tar.gz I know
> how to uncompress tar file but not gz file (uncompress is not >
Any file with a .gz suffix is compressed with GNU gzip. You can
uncompress it with gunzip or gzip -d (both available by ftp from the
GNU program archive at ftp://prep.ai.mit.edu), or if you have a recent
version of tar you can uncompress is automatically while untarring it
by giving tar the -z option (i.e. tar -zxvf filename.tar.gz).
BTW, a tar.gz suffix does NOT mean your file is "double compressed".
Tar just collects a bunch of files into one file; it does NOT, by
default, compress them. (Tar is NOT like most DOS archivers like ZIP
and ARJ which both collect and compress files in one step.) However,
because compression is such a common requirement, recent versions of
tar have support for gzip built-in. See "man tar" for details.