[net.sources] on.1 -- manual page for on.c

CSvax:cak (10/09/82)

	.PU
	.TH ON 1
	.SH NAME
	on \- enable logins on a tty line
	.br
	off \- disable logins on a tty line
	.SH SYNOPSIS
	.B on
	[
	.RB \- n
	]
	[
	.I ttyname
	]
	.br
	.B off
	[
	.RB \- n 
	]
	[
	.RB \- f
	]
	[
	.I ttyname
	]
	.SH DESCRIPTION
	.I On
	and
	.I off
	are used to enable or disable logins on a particular tty line, respectively.
	This is done by rewriting 
	.I /etc/ttys
	and signalling 
	.I init
	(process 1) to re-read it and set up the 
	lines appropriately.
	The 
	.I ttyname
	should be specified as it appears in
	.IR /etc/ttys ,
	.IR i.e. ,
	the full pathname with the 
	.I /dev/
	stripped off.
	.PP
	If someone is logged in when a line is
	.IR off ed,
	.I off
	will modify 
	.IR /etc/ttys ,
	but will not signal
	.IR init ,
	allowing the user to finish up,
	and print a message to this effect.
	The 
	.RB \- f
	flag will force a logoff.
	.PP
	The
	.RB \- n
	flag will cause 
	.IR on / off
	to modify 
	.IR /etc/ttys ,
	but
	not signal
	.IR init .
	.PP
	Invoking
	.I on
	or
	.I off
	without arguments will cause 
	.I init
	to be signalled, with no change to 
	.IR /etc/ttys .
	.SH NOTES
	.I Off
	is really just a link to 
	.IR on ;
	the different functions are determined by looking at
	the last character of the name the program was invoked by.
	.br
	Since these programs manipulate 
	.I /etc/ttys
	and
	.IR init,
	they must be run as
	.B root 
	to do any good.
	.SH FILES
	/etc/ttys
	to signify which lines have logins enabled
	.br
	/etc/utmp
	to see if anyone is logged in on the specified line
	.SH "EXIT CODES"
	Negative on error; 0 if the operation was successful and no 
	one was logged onto the tty; 1 if someone was logged in.
	.SH AUTHOR
	Christopher A. Kent