Originally Posted by ctsgnb

Did you check the -f option ?

Code:

man compress

Originally Posted by bakunin

sea, what you quoted from is a Linux man page. This is the AIX board and the AIX tar works quite differently - POSIX-compatibly, that is.



Even if sea's suggestion was faulty his intention was right: read the man page (of compress, instead of GNU-tar) to find the following:

Code:

        -f or -F
            Forces compression. The -f and -F flags are interchangeable.
            Overwrites the File.Z file if it already exists.

How to use man

As you mentioned DOS i suppose you are not familiar with UNIX in general or AIX in specific. Here is a general advice: if you do not know how to use/configure a command you can always enter

Code:

man command

to get the "man[ual] page" of command. This works even for man itself, so man man will tell you how to use man. The works not only for commands but also standard configuration files. Enter, for instance,

Code:

man filesystems

to get information about the file /etc/filesystems, which denotes all the mountable filesystems in a system.

(Tip: the paginating program used in man is more which navigation keys match the ones of vi. Scroll down a line with "j", scroll up a line with "k", etc..)

If you are not sure which command to use you can search all the man pages for a specific term with the man -k keyword (or its more eponymic alias apropos keyword) command, which will list all the man pages containing keyword.

For instance:

Code:

# man -k users
bellmail(1)     - Sends messagesto system users and displays messages from system users.
chargefee(1)    - Charges endusers for the computer resources they use.
chpasswd(1)     - Changes password for users.
comsat(1)       - Notifies usersof incoming mail.
custom(1)       - Enables usersto customize X  applications.
[...]
# apropos users
bellmail(1)     - Sends messagesto system users and displays messages from system users.
chargefee(1)    - Charges endusers for the computer resources they use.
chpasswd(1)     - Changes password for users.
comsat(1)       - Notifies usersof incoming mail.
custom(1)       - Enables usersto customize X  applications.
[...]

I hope this helps.

bakunin