It is possible to list the contents of tar files without needing to extract them. To do this with a tar file, you will do the following.
tar -tvf file.tar
To show the contents of a tar.gz file, you can do this.
tar -ztvf file.tar.gz
And you can also show a tar.bz2 file with the following.
tar -jtvf file.tar.bz2
