functions that don't return

[Joseph S. D. Yao]

In article <86900066 at haddock> karl at haddock writes:
>if you supersede exit() with a function that returns, how do you get out of
>the program?  Send yourself a signal?

Most crt0.s's or the like contain code similar to:

	store-args	argc, argv, envp
	call-function	_main
	call-function	_exit
	system-call	exit
	halt

If exit() is re-defined to return, the system call will exit after
a return from main().  The 'halt' usually causes a trap if neither
works.

Using 'return' from main() is the preferred way to exit according
to System V lint (which complains otherwise).  I've preferred it
myself, for years before, because I've viewed exit() as a glitch
in a smooth mental model of the invocation and return of routines.
THIS (latter) IS PURELY PERSONAL PREFERENCE, NO FLAMES DESIRED,
but comments on s5lint's and others' mental models welcome.
-- 

	Joe Yao		hadron!jsdy at seismo.{CSS.GOV,ARPA,UUCP}
			jsdy at hadron.COM (not yet domainised)