diff options
Diffstat (limited to 'share/man/man4/tty.4')
| -rw-r--r-- | share/man/man4/tty.4 | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/share/man/man4/tty.4 b/share/man/man4/tty.4 index d47a5d510cce..b3b9f67db35d 100644 --- a/share/man/man4/tty.4 +++ b/share/man/man4/tty.4 @@ -28,7 +28,7 @@ .\" @(#)tty.4 8.3 (Berkeley) 4/19/94 .\" $FreeBSD$ .\" -.Dd January 11, 2017 +.Dd November 27, 2019 .Dt TTY 4 .Os .Sh NAME @@ -194,7 +194,6 @@ Simulate typed input. Pretend as if the terminal received the character pointed to by .Fa cp . .It Dv TIOCNOTTY Fa void -This call is obsolete but left for compatibility. In the past, when a process that did not have a controlling terminal (see .Em The Controlling Terminal in @@ -203,7 +202,7 @@ first opened a terminal device, it acquired that terminal as its controlling terminal. For some programs this was a hazard as they did not want a controlling terminal in the first place, and this -provided a mechanism to disassociate the controlling terminal from +provides a mechanism to disassociate the controlling terminal from the calling process. It .Em must @@ -228,6 +227,14 @@ system call which will place the process into its own session - which has the effect of disassociating it from the controlling terminal. This is the new and preferred method for programs to lose their controlling terminal. +.Pp +However, environmental restrictions may prohibit the process from being able to +.Fn fork +and call the +.Fn setsid +system call to disassociate it from the controlling terminal. +In this case, it must use +.Dv TIOCNOTTY . .It Dv TIOCSTOP Fa void Stop output on the terminal (like typing ^S at the keyboard). .It Dv TIOCSTART Fa void |