/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(2) requests supported by the device that
tty refers to, the ioctl(2) request
TIOCNOTTY is supported.
Detach the calling process from its controlling
If the process
is the session leader, then SIGHUP and SIGCONT
signals are sent to the foreground process group and all
processes in the current session lose their controlling
ioctl(2) call works only on file descriptors
connected to /dev/tty. It 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.
mknod(1), ioctl(2), termios(3),
console(4), tty_ioctl(4), ttyS(4),
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