windsor - 5:28 am on Feb 3, 2002 (gmt 0)

To clarify a few things:

"rm -r" is a recursive rm(1) (e.g. "get subdirs also")
"rm -f" means "don't pester you about RO file permissions"
"rm -rf" merely combines these two
"rm -rf" means "read mail, really fast" if you want to play mean tricks on new users. :)

"ln -s" makes a symlink (pointed to anything: file, dir, nothing)
"ln -f" forces it (removes the target and drops a symlink in there)
"ln -sf" just combines the actions of the above two
While the term isn't proper, you won't be shot if you use the phrase "soft links" when referring to symbolic links. Everyone still knows that you mean "links that aren't 'hard links'". :)

tar(1) almost requires its own topic, but not quite. Here's the rundown:

action flags (unique per use, one required)
-x -- extract ("untar" as it is commonly called)
-c -- create (make a tar file)
-t -- list table (take a peek at what's inside, without extracting)

modifier flags (purely optional)
-v -- verbose
-p -- preserve permissions/ownership
-z -- compress or uncompress

special situation (you always need this, unless you're working with actual backup tapes)
-f <tar_file> -- we're going to work with <tar_file>

The verbose "-v" option to tar(1) often drowns out error messages, so I rarely use it unless I'm using "-t".

Common uses then become:

tar -cf foo.tar foo bar baz (make tarfile foo.tar and include foo bar baz)
tar -tf foo.tar (show you list of files/dirs in foo.tar)
tar -tvf foo.tar (show you what's inside foo.tar, perms and all)
tar -xf foo.tar (untar foo.tar)

tar -zcf foo.tar.gz foo bar baz (make gzipped tarfile foo.tar.gz to include foo bar and baz)
tar -ztf foo.tar.gz (show you the list of files/dirs in foo.tar.gz)
tar -ztvf foo.tar.gz (show you what's inside foo.tar.gz, perms and all)
tar -zxf foo.tar.gz (untar foo.tar.gz)
tar -zxpf foo.tar.gz (untar foo.tar.gz, keep perms)

You can verify everything above in the relevant manpages. If you need manpages for any of these, I can send them to you.

Hope this helps.

Rob++ (Senior UNIX Sysadmin, at large)