what does r,c ,d in rc.d stand for ?

"rc.d" 中的r、c、d分别是什么意思？

The definative answer comes from


-

      rc (as in ".cshrc" or "/etc/rc" = "RunCom"

        "rc" derives from "runcom", from the MIT CTSS system, ca. 1965.

            'There was a facility that would execute a bunch of
            commands stored in a file; it was called "runcom" for "run
            commands", and the file began to be called "a runcom."

            "rc" in Unix is a fossil from that usage.'

-

So there you have it.  "rc" stands for "runcom", which in turn was a
shortening of "run commands".

So claiming it stands for "run commands" isn't far from the truth.