[newbie] Tar files

[Dennis Podein]

I can't seem to install any tar files . I get to the folder
that contains the file  , then type in tar xvfprog.tar.gz , or
zxvf or xzf . To no avail . All I get is an error message -
Old option `f ', or `g ' , or `a' , etc requires an argument ,
try `tar --help ' for more info . I tried tar help , and
mantar , and niether will function . They just don't open .
Help please , newbie at the helm .