BAL: A Tool to Synchronize Document Collections Between Computers

The enormous growth of computer networks and declining hardware prices allow people to have more than one computer, e.g., to use a primary computer at work, a laptop or notebook as a secondary computer for 'on the road' and maybe a third computer at home.

One non- trivial problem that users face when using more than one computer alternately is the difficulty of keeping multiple, distributed copies of their files up to date and in sync, if they can't permanently share resources between their machines, e.g., when using a notebook computer off-line for some time.

System administrators of Unix sites who need to automatically distribute files between machines have known such problems for years and have come up with various tools to solve their specific needs. But tools which help Unix administrators are not always adequate for their users too.

This paper describes Bal, a tool which enables Unix users to more easily keep distributed copies of their files in sync. Bal is written in Perl and keeps two directory trees in sync.