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