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.\" Copyright (c) 1996 Joerg Wunsch
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.Dd May 10, 2020
.Dt LOGIN_TTY 3
.Os
.Sh NAME
.Nm login_tty
.Nd prepare a tty for a new login session
.Sh LIBRARY
.Lb libutil
.Sh SYNOPSIS
.In libutil.h
.Ft int
.Fn login_tty "int fd"
.Sh DESCRIPTION
The function
.Fn login_tty
prepares a terminal for a new login session.
The file descriptor
.Ar fd
passed to
.Fn login_tty
must be opened for reading and writing on a terminal device.
It will be
made the controlling terminal for the calling process, after allocating
a new session with
.Xr setsid 2 .
This terminal device will also be made the standard input, standard output,
and standard error output of the calling process.
.Sh RETURN VALUES
The
.Fn login_tty
function returns -1 if it could not make the device referenced by
.Ar fd
the controlling terminal of the calling process, and 0 otherwise.
.Sh SEE ALSO
.Xr dup2 2 ,
.Xr ioctl 2 ,
.Xr setsid 2 ,
.Xr tty 4
.Sh HISTORY
The function
.Fn login_tty
first appeared in
.Bx 4.4 .