freebsd-skq/lib/libc/gen/tcsetsid.3
ed f8170e41fe Add tcsetsid(3).
The entire world seems to use the non-standard TIOCSCTTY ioctl to make a
TTY a controlling terminal of a session. Even though tcsetsid(3) is also
non-standard, I think it's a lot better to use in our own source code,
mainly because it's similar to tcsetpgrp(), tcgetpgrp() and tcgetsid().

I stole the idea from QNX. They do it the other way around; their
TIOCSCTTY is just a wrapper around tcsetsid(). tcsetsid() then calls
into an IPC framework.
2009-05-07 13:49:48 +00:00

93 lines
2.8 KiB
Groff

.\" Copyright (c) 2009 Ed Schouten <ed@FreeBSD.org>
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.Dd May 4, 2009
.Dt TCSETSID 3
.Os
.Sh NAME
.Nm tcsetsid
.Nd set session ID associated with a controlling terminal
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In sys/types.h
.In termios.h
.Ft int
.Fn tcsetsid "int fd" "pid_t pid"
.Sh DESCRIPTION
The
.Fn tcsetsid
function sets associates a session identified by
.Fa pid
with a controlling terminal specified by
.Fa fd .
.Pp
This implementation only allows the controlling terminal to be changed
by the session leader itself.
This implies that
.Fa pid
always has to be equal to the process ID.
.Pp
It is unsupported to associate with a terminal that already has an
associated session.
Conversely, it is also unsupported to associate to a terminal when
the session is already associated with a different terminal.
.Sh ERRORS
If an error occurs,
.Fn tcsetsid
returns -1 and the global variable
.Va errno
is set to indicate the error, as follows:
.Bl -tag -width Er
.It Bq Er EBADF
The
.Fa fd
argument is not a valid file descriptor.
.It Bq Er ENOTTY
The file descriptor represented by
.Fa fd
is not a terminal.
.It Bq Er EINVAL
The
.Fa pid
argument is not equal to the session ID of the calling process.
.It Bq Er EPERM
The calling process is not a session leader.
.It Bq Er EPERM
The session already has an associated terminal or the terminal already
has an associated session.
.El
.Sh SEE ALSO
.Xr getsid 2 ,
.Xr setsid 2 ,
.Xr tcgetpgrp 3 ,
.Xr tcgetsid 3
.Sh HISTORY
A
.Fn tcsetsid
function first appeared in QNX.
It does not comply to any standard.