How to set control tty (Sys5)

[Walter Mecky]

In article <1990Jul06.015108.14622 at virtech.uucp> cpcahil at virtech.UUCP (Conor P. Cahill) writes:
< In article <483 at trux.UUCP> car at trux.UUCP (Chris Rende) writes:
< >However, I can't figure/find out how to set the control tty. I read in
< >TERMIO(7) something like "The first terminal file that gets opened becomes
< >the control terminal". When I wrote a program that disassociates itself from
< >the control terminal and then does a "fd=open("/dev/ttyi00",O_RDWR);"
< >it didn't work. I.e, a "ps -ef" shows "?" for the control tty.
< 
< The other requirement is that no other proces has that terminal as its 
< controlling terminal.  I would guess that your test is failing because
< the tty is the controlling terminal for another process.

The third requirement is that the proces is a process group leader.
According to my manual from SCO UNIX 3.2:
	                            The	very first terminal file
	  opened by the	process	group leader of	a terminal file	not
	  already associated with a process group becomes the for that
	  process group.  The control terminal plays a special role in
	  handling quit	and interrupt signals, as discussed below.
	  The control terminal is inherited by a child process during
	  a fork(S).  A	process	can break this association by changing
	  its process group using setpgrp(S).
-- 
Walter Mecky	[ walter at mecky	or  ...uunet!unido!mecky!walter ]