Often it would be nice to make a file smaller—say, to download it
faster, or so it takes up less space on your disk. The program to do
this is called gzip (GNU zip). Here’s how it works:
$ cd; cp /etc/profile ./mysamplefile
This switches to your home directory and copies an arbitrarily
chosen file (/etc/profile) to your current directory, in the process
renaming it mysamplefile. This gives you a file to play with when
using gzip.
$ ls -l
Lists the contents of the current directory. Note the size of
mysamplefile.
$ gzip mysamplefile
Compresses mysamplefile.
$ ls -l
Observe the results of this command: mysamplefile is now called
mysamplefile.gz . It’s also a good bit smaller.
$ gunzip mysamplefile.gz; ls -l
This uncompresses the file. Observe that mysamplefile has returned
to its original state. Notice that to uncompress, one uses gunzip,
not gzip.
$ rm mysamplefile
Use this command to remove the file, since it was just to practice
with.