tty

TTY(4)                      Linux Programmer's Manual                     TTY(4)



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
       This page is part of release 5.09 of the Linux 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/.



Linux                              2019-03-06                             TTY(4)