BSD & Sys5 Job Control

[Lars Pensj|]

In article <1055 at sfsup.UUCP> dcm at sfsup.UUCP (David C. Miller, consultant) writes:
>... So, no, there is no great shell that works with shell layers
>and (sigh) nothing quite like BSD job controls.  The dmd however is really
>a lot of fun.
>

It is quite possible to make csh use the sxt devices. We have done
such an implementation, and are now using csh in place of sh.

Result:

++++	Possibilities to switch between 7 jobs and let them
	run in the background.

-	Csh doesn't modify tty name in wtmp. We "hacked" getlogin() to
	do it another way, and relinking all programs using it.

-	Csh have problems handling type ahead, because typed characters
	are associated to the sxt device attached to the current
	process. When the process exits, csh has to read them back from
	this device.

-	A process can not know whether it is blocked or not.

+!	Processes are not stopped, they are blocked (terminal i/o).

*	When any process (e.g. stty) changes the baudrate, the
	current sxt device gets another baud rate than all other
	jobs (very fun, but fixed nowadays).

-	The modifications are not public domain.

We also implemented this in tcsh.