contemporary operating systems may seem baroque in their complexity, but almost every one of them – except for Windows, natch – are based on the idea of simplicity and modularity. This is the lesson that UNIX taught us, explained completely in a bit film from Bell Labs in 1982 starring giants of computation, [Dennis Ritchie], [Ken Thompson], [Brian Kernighan], and others.
At the time this film was made, UNIX had been around for about 10 years. in that time, it had moved far from an OS cloistered in huge mainframes connected to teletypes to somewhat smaller minicomputers wired as much as video terminals. Yes, smallish computers like the Apple II and the VIC-20 were around by this time, but they were toys compared to the hulking racks inside Bell Labs.
The film describes the core concept of UNIX by demonstrating modularity with a terrific example by [Brian Kernighan]. He took a short passage from a paper he composed and found spelling errors by piping his paper though different commands from the shell. first the words in the paper were separated line by line, made lowercase, and sorted alphabetically. All the special words were extracted from this list, and compared to a dictionary. A spell checker in one line of code, given you by the power of UNIX.