Rc

Website: doc.cat-v.org/plan_9/4th_edition/papers/rc

Designed by: Tom Duff

rc (for “run commands”) is the command line interpreter for Version 10 Unix and Plan 9 from Bell Labs operating systems.

It resembles the Bourne shell, but its syntax is somewhat simpler.

It was created by Tom Duff, who is better known for an unusual C programming language construct (“Duff’s device”).A port of the original rc to Unix is part of Plan 9 from User Space.

A rewrite of rc for Unix-like operating systems by Byron Rakitzis is also available but includes some incompatible changes.

Rc uses C-like control structures instead of the original Bourne shell’s ALGOL-like structures, except that it uses an if not construct instead of else, and has a Bourne-like for loop to iterate over lists.

In rc, all variables are lists of strings, which eliminates the need for constructs like “$@”.

Variables are not re-split when expanded.

The language is described in Duff’s paper.