Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!uunet!husc6!uwvax!rutgers!ucla-cs!zen!ucbvax!decvax!hanauma!stew
From: stew@hanauma.UUCP (Stewart Levin)
Newsgroups: comp.unix.wizards
Subject: Re: Using argv to show process status
Message-ID: <116@hanauma.UUCP>
Date: Thu, 27-Aug-87 12:13:06 EDT
Article-I.D.: hanauma.116
Posted: Thu Aug 27 12:13:06 1987
Date-Received: Sat, 29-Aug-87 12:55:28 EDT
References: <7166@ism780c.UUCP>
Organization: Stanford U. Geophysics
Lines: 14

Instead of having the interpreter try to rewrite argv, have it
initially popen() a tiny program which has the name RUN, say.
Then when the interpreter wants to show it is now performing
MULT, say, it fprintf's the name MULT to the pipe and the
tiny program links the name MULT to its own executable and
execl's itself under that new name.  Standard input remains
open and the new copy waits for the next process name to
come down the pipe so it can repeat the link/exec.  And unlink
the name MULT also, unless there are only a fixed set of
possibilities.  

The logic of doing it with a child is that a fork and load of a tiny
program is minor, asynchronous overhead, forking the interpreter is major,
synchronous overhead.