I stumbled on this feature on a SLES10 system yesterday... if you tar tf filename.tar.gz or tar xf filename.tar.gz it automatically gunzips the data for you. Has this feature been around for a while? I have 1.12 on my system, which doesn't, but the 1.20 manual mentions it...
I used this feature since i can remember and i've been starting with Suse Linux in 1996. It was alwas there. maybe there was a release that hasn't but i didn't recognize. I miss it on Solaris (such as many other basic linux features)
At least in version 1.15, GNU tar works fine on bz2 files as well. By doing an ltrace on it, I infer that after reading in the file's header, tar pipes the file in from the appropriate decompression program.
Thanks for satisfying my curiosity. I'm still using my SuSE 6.0 installation from about '95 (with manual updates to 2.6 kernel, etc), so some of the utilities are showing their age!