A tarball is a file that contains an archive of a directory or file(s) created by the command tar (which stands for tape archive). It's commonly used in Unix-like systems and they are often compressed with gzip or bzip2.
More on the origins of the term at [L1 ]
Tcl supports tar filesystems with the vfs::tar module of the tclvfs.
Question: What would a Tcl script look like to access a tar file using tclvfs and accounting for the possible compression of the file?