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 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  sup-
       ported.

   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 only works 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), termios(3), console(4), tty_ioctl(4), ttyS(4), agetty(8), mingetty(8)

COLOPHON
       This  page  is  part of release 3.25 of the Linux man-pages project.  A description of the project, and information about
       reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.



Linux                                                      2003-04-07                                                     TTY(4)