Consider for example, the presence of the .spec file in the .tar.gz, so that you can build an RPM:
[leonid@home tmp]$ tar tzvf somefile.tar.gz | grep somefile.spec
Another need arises sometimes – to check if the archive will extract into a newly created directory or if it will mess up with the content of the current directory (some people still do it). Here is how the proper archive will look:
[leonid@home tmp]$ tar tzvf somefile.tar.gz
somefile/COPYING
somefile/README
somefile/Makefile
somefile/somefile.c
In the above example you can see, that you will extract the archive (tar xzvf somefile.tar.gz), then it will create a directory somefile and place all it’s content there. Below is the example of the bad archive which will mess up your current directory.
[leonid@home tmp]$ tar tzvf somefile.tar.gz
COPYING
README
Makefile
somefile.c
To extract this archive and be able to clean it up lately do the following:
[leonid@home tmp]$ mkdir somefile
[leonid@home tmp]$ mv somefile.tar.gz somefile/
[leonid@home tmp]$ cd somefile
[leonid@home somefile]$ tar xzvf somefile.tar.gz
That’s it.