If no args are provided, the program displays the text X Gone along with the time. If args are provided, then the concatenation of the arguments, separated by spaces, is displayed instead of the default string.
To leave xgone, press any mouse key. It will prompt you for your password, which will not be echoed on the display. End the password with ``Return.'' As an accelerator, you may simply type your password.
Xgone can be run from any system that has access to the user's workstation. It was designed this way so that it could be used by X terminal users. Because of this there is a possibility of malicious users locking other people's displays (or simple mistakes via setting the "DISPLAY" environment variable to the wrong display name). In order to avoid this problem, xgone tries to verify that the display in question actually belongs to the user running the program. Since there is no easy way of doing this verification under X11, xgone uses the following algorithm:
if (we were invoked as root) then
go ahead and lock the display;
else if (the display is "unix:0" or "unix:0.0"
and the invoking user is actually logged into
the console of this machine) then
go ahead and lock the display;
else {
Find the oldest xterm or rlogin from
the display we're trying to lock;
if (the user found above is the user invoking
this program) then
go ahead and lock the display;
}
By using the above algorithm, a user would have to do a little work in order to lock someone else's display. It mostly likely wouldn't happen by accident. There are lots of way to getting around the above restrictions, however until something better comes along this is the best that can be done.