[TUHS] RUNCOM and Multics: the origin of "rc" file

Michelangelo De Simone michel at ngelo.eu
Mon Jul 25 13:44:05 AEST 2022


long time lurker here. Today I ended up on an article by Christian Lee Seibold about the origin of shells [1].

Coincidentally the article explained how the “rc” files came to be and why they’re called “rc”: everything started with RUNCOM and Multics. An excerpt from the article:

Unix Shells have had a very long history, and it all starts with a program written by Louis Pouzin for the MIT CTSS Operating System, called RUNCOM (which stood for “run commands”). It executed commands from a file, called “a runcom”. According to Kernighan and Ritchie[1], “rc” configuration files from Unix descended from this. Tom Van Vleck also gives origins of Unix’s use of “rc” to RUNCOM [2], and notes that the first time he read the term “shell” was from Multics documentation created by Doug Eastwood. According to Louis Pouzin, he coined the word “shell”.

Well, now I know…

[1] https://portal.mozz.us/gemini/auragem.space/~krixano/ShellHistory-Unix.pdf

— Michelangelo

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