23 Sep
2017
23 Sep
'17
1:08 a.m.
On 9/22/17 2:14 PM, Chris Torek wrote:
Job control ought to be independent of tty devices:
each shell
pipeline is a "job", and the shell should group them by having the
kernel create an initial empty(ish -- the shell is a member of
both its original pgroup and this one it just created, until it
detaches from it) job, then pushing each process it forks into
that pgroup.
In that sense, job control and process groups *are* independent of
the terminal device.
The complication arises when you have to multiplex one terminal
between several different jobs in an interactive shell. Setting
the terminal process group correctly -- the only way to accomplish
that -- is fragile and the consequences of setting it to the wrong
value are inconvenient, to say the least.
Chet
--
``The lyf so short, the craft so long to lerne.'' - Chaucer
``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU chet(a)case.edu http://cnswww.cns.cwru.edu/~chet/