| .\" Copyright (c) 1993 Michael Haardt (michael@moria.de), |
| .\" Fri Apr 2 11:32:09 MET DST 1993 |
| .\" |
| .\" This is free documentation; you can redistribute it and/or |
| .\" modify it under the terms of the GNU General Public License as |
| .\" published by the Free Software Foundation; either version 2 of |
| .\" the License, or (at your option) any later version. |
| .\" |
| .\" The GNU General Public License's references to "object code" |
| .\" and "executables" are to be interpreted as the output of any |
| .\" document formatting or typesetting system, including |
| .\" intermediate and printed output. |
| .\" |
| .\" This manual is distributed in the hope that it will be useful, |
| .\" but WITHOUT ANY WARRANTY; without even the implied warranty of |
| .\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| .\" GNU General Public License for more details. |
| .\" |
| .\" You should have received a copy of the GNU General Public |
| .\" License along with this manual; if not, write to the Free |
| .\" Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, |
| .\" USA. |
| .\" |
| .\" Modified 1993-07-24 by Rik Faith (faith@cs.unc.edu) |
| .\" Modified 2003-04-07 by Michael Kerrisk |
| .\" |
| .TH TTY 4 2003-04-07 "Linux" "Linux Programmer's Manual" |
| .SH NAME |
| tty \- controlling terminal |
| .SH DESCRIPTION |
| The file \fI/dev/tty\fP 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. |
| .LP |
| In addition to the |
| .BR ioctl (2) |
| requests supported by the device that |
| \fBtty\fP refers to, the |
| .BR ioctl (2) |
| request \fBTIOCNOTTY\fP is supported. |
| .SS TIOCNOTTY |
| Detach the calling process from its controlling terminal. |
| .sp |
| If the process is the session leader, |
| then |
| .B SIGHUP |
| and |
| .B SIGCONT |
| signals are sent to the foreground process group |
| and all processes in the current session lose their controlling tty. |
| .sp |
| This |
| .BR ioctl (2) |
| call only works on file descriptors connected |
| to \fI/dev/tty\fP. |
| It is used by daemon processes when they are invoked |
| by a user at a terminal. |
| The process attempts to open \fI/dev/tty\fP. |
| If the open succeeds, it |
| detaches itself from the terminal by using \fBTIOCNOTTY\fP, while if the |
| open fails, it is obviously not attached to a terminal and does not need |
| to detach itself. |
| .SH FILES |
| /dev/tty |
| .SH "SEE ALSO" |
| .BR chown (1), |
| .BR mknod (1), |
| .BR ioctl (2), |
| .BR termios (3), |
| .BR console (4), |
| .BR tty_ioctl (4), |
| .BR ttyS (4), |
| .BR agetty (8), |
| .BR mingetty (8) |