a question that maybe has nothing to do with AIX, but on AIX it causes me to do two commands, while i can do it on linux in one command.

why are files always compressed in .tar.gz ???
i don't see the benefit over just compressing it to .tar

on linux i can decompress .tar.gz files with tar -zxvf file.tar.gz

on Aix i have to to first gunzip file.tar.gz, and thereafter tar -xvf file.tar. is there a way to do it in one command on aix???

.tar is not compressed at all, it is just an archive format.

Linux (GNU tar) has non-standard extensions added to tar that other implmentations of tar do not have. If the extra typing is a problem write a short shell script to do it.

Exactly. A tar file is like a "package" but not compressed at all.
A .tar.gz (or .tgz in some cases) is just a gzip compressed tar file.
In this case, that extension is the "z" flag. Have a look to gtar man pages.
For instance, in one line:
gzip -c myfile.tar.gz | tar xvf -
or
tar cvf - whatever | gzip -c > myfile.tar.gz
Regards.

I would like to add that archiving and compressing are two distinct independent tasks. It is not very "UNIX-like" to combine distinct tasks into one tool, so GNU-tar, as handy as it may be, is a little bit against the cultural tradition of UNIX.

bakunin

I agreed GNU-tar is "against the cultural tradition of UNIX" but assume if we need to ftp many directory from one server into another every hours ??
1: maintain the dir
2: reduce the size so that FTP faster
By using GNU-tar it save us a lot of time,i believe.
In my environment we need to sync data between server in different country, this work the best.