Is there a way to send a message to all logged-in users on an OS X (Snow Leopard) server? Sometimes I need to reboot the server and would like to give everyone a notice of the impending reboot that gives them five minutes to log-out before I proceed.
If you have OS X server and your users are using AFP, you can send them a message in the AFP section of the Server Admin tools. Also, if you are using Apple Remote Desktop and have it authorized for all computers, you can send a message even if users don't use AFP.
In BSD the command would be
wall
and OS X is based on BSD, you might give it a try.If the system has "Remote Management" enabled and you have ARD (Apple Remote Desktop), you can select Interact->Send Message to send a message to one or more users.
Unfortunately, if you are using the Screen Sharing service instead (which allows multiple desktop logins) you won't be able to also have Remote Management enabled, which is what led me to this post.