TTY
Section: Linux Programmer's Manual (4)
Updated: 2019-03-06
Page Index
NAME
tty - controlling terminal
DESCRIPTION
The file
/dev/tty
is a character file with major number 5 and
minor number 0, usually with mode 0666 and ownership 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.
TIOCNOTTY
Detach the calling process from its controlling terminal.
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 tty.
This
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.
FILES
/dev/tty
SEE ALSO
chown(1),
mknod(1),
ioctl(2),
ioctl_console(2),
ioctl_tty(2),
termios(3),
ttyS(4),
vcs(4),
pty(7),
agetty(8),
mingetty(8)
COLOPHON
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man-pages
project.
A description of the project,
information about reporting bugs,
and the latest version of this page,
can be found at
https://www.kernel.org/doc/man-pages/.