tty port changing owner and permissions after reboot

Posted on 2006-06-02
Last Modified: 2013-12-16
SCO OpenServer 5.0.6

My software vendor set up a serial port originally for a dumb terminal (3 years ago), but about 6 months ago I had them change the port to support a serial printer.   They made the change and everything works fine except that any time I have to reboot the box (OK, not very often), when it comes back up the port ownership and permissions change back to the following (to support a terminal)

crw-------   1 bin      terminal 120,155 Jun  2 09:12 ttyb14

I need them to stay as below to work with the printer

crw-rw-rw-   1 root     sys      120,156 Jun  2 11:02 ttyb13

What is changing it back during reboot and how can I change it to keep the correct settings?
Question by:andersen58
    LVL 61

    Expert Comment

    Just add chown command in startup script of your program.
    LVL 39

    Expert Comment

    see to it that during booting of the system you execute the commands:

    chown root:sys /dev/ttyb13
    chmod 666 /dev/ttyb13

    Is possible that in inittab a getty is started?
    Or during initialisation some vendor supplied script
    setup these security settings.

    LVL 16

    Accepted Solution

    Terminal ports are frequently being changed to allow specific processes for their required permissions.
    It looks like some process (a getty or something the like?) is changing the perms as soon as it gets started. Therefore, if you have a process for this port, it will change the perms avery time it starts up. In case of a getty or something else being started from inittab (with "respawn"), it will automaticall restart and reset the perms when killed (or died).

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