stty -F does not use specified device
 

I have a java program that opens /dev/tty6 and writes vt100 escape sequences and characters. The problem is that the terminal is echoing the control keys that are typed on the screen. I have tried to use "stty -F /dev/tty6 -echoctl to turn it off but this does not work - "stty -a -F /dev/tty6" shows echoctl is still in force. If I try the stty command in another terminal without -F "stty -a" properly reports -echoctl. It just seems that the -F parameter is not getting the setting to the proper tty. There is another note that I reduced the number of mgettys so that /dev/tty6 has no bash running in it. It's just a blank screen when I ctl-alt-f6 to it before writing to it with my program. Any help would be appreciated. Thanks. Buddy

Hi
just a guess but how about the environment variable TERM?
Is it set to "vt100" when you start your Java program?

There is no environment associated with tty6 since it is not being controlled by bash in this case. Thanks.

Are you running a POSIX system? The ctlecho (or echoctl, your choice) directives are listed as "NON-POSIX" in the info file.

I am using Fedora 14. My googleing on this aspect seems to indicate it is POSIX compliant but I am not 100% sure. When I open a normal terminal window on my gui desktop and it has bash running in it I can sucessfully use the the stty command with no -F parameter to change the state of echoctl but not in my non bash tty6 vt. Thanks.

The POSIX compliance is optional in most Fedora systems, so that's probably not the problem.

I just glanced at /dev, and noted that my Fedora 14 system defines 64 /dev/tty<n> devices, which suggests that they are not intended for what I think you're trying to accomplish. (If I understand Linux setup, those devices are for remote user login, not use by programs. Fedora starts "root" on tty1 during boot, and then starts the first X-server on tty1. Subsequent X-server are started on tty[7-9], and tty[2-6] are started by a initctl call: initctl start tty TTY=/dev/tty2, etc. So those terminals are already in use. (Look at /etc/init/start-ttys.conf for details.)

Have you looked at the master/slave terminal setup? (See man pty - Note the single "t") That set-up sounds much more like what you need to accomplish (what I understand to be) your goal.