Unix is user-friendly — it's just choosy about who its friends are.

The Art of UNIX Programming (2003) by Eric S. Raymond

Created in 1969 at AT&T Bell Labs to run on departmental computers for the PDP-11. It used 16-bit words and had 64KiB/128KiB RAM.

It was initially written in ASM, but sparked the creation of C which was designed to make Unix development easier.

Unix gives you just enough rope to hang yourself -- and then a couple of more feet, just to be sure.

Eric Allman



Environment Variables

Environment variables are defined by the system and will be will be passed to the shell.

More environment variables can be setup in the ~/.profile executable.