Bug in csh? (exec v. job control)

Greg Noel greg at ncr-tp.UUCP
Wed Apr 24 08:28:26 AEST 1985


> From: anton at ucbvax.ARPA (Jeff Anton)
> For those few who understand how the "process group" has been abused
> in the name of job control this should be understud.
>
> The new csh changed the process group of the terminal then the
> csh execs foobar and the process dies.  The vi wakesup [sic] from the
> forked process dying and tries to print something.  The vi's [sic] process
> group now does not match the terminals so the system sends the process
> group a SIGTOUT stopping is.

I'm not sure this is a complete explanation since I don't have "stty tostop"
set, meaning that there should be no inhibition to "vi" writing its output.
However, I have a strong feeling that the death of the process leader may
cause something significant and subtle within the tty routines that would
give an equivalent effect.

In any event, I have sent the problem on to my vendor (Pyramid) as a bug
and suggested that the cure may be to not create a new process group when
execing a program, but to continue to use the current one.  Would this
cause any problems?  Is this a reasonable solution?
-- 
-- Greg Noel, NCR Torrey Pines       Greg at ncr-tp.UUCP or Greg at nosc.ARPA



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