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 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),    termios(3),    console_ioctl(4),
   tty_ioctl(4), ttyS(4), agetty(8), mingetty(8)

COLOPHON

   This page is part of release 4.09 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/.

---

Free and Open Source Software