TTY
Section: Linux Programmer's Manual (4)
Updated: January 21, 1992
NAME
tty - controlling terminal
DESCRIPTION
The file /dev/tty is a character file with major number 5 and
minor number 0, usually of mode 0666 and owner.group root.tty. It is a
synonym for the controlling terminal of a process, if any.
In addition to the ioctl() requests supported by the device that
tty refers to, the following ioctl() request is supported:
- TIOCNOTTY
-
Detach the current process from its controlling terminal, and remove it
from its current process group, without attaching it to a new process
group (that is, set its process group ID to zero). This ioctl()
call only works on file descriptors connected to /dev/tty; this is
used by daemon processes when they are invoked by a user at a terminal.
The process attempts to open /dev/tty; if the open succeeds, it
detaches itself from the terminal by using TIOCNOTTY, while if the
open fails, it is obviously not attached to a terminal and does not need
to detach itself.
FILES
/dev/tty
SEE ALSO
mknod(1), chown(1), getty(1), termios(2),
console(4), ttys(4)