How to kill user's processes and logout the user

The other day a friend of mine was asking me how to stop all users' processes and then logout him.

Well maybe the first thing you need is to send a message to the user, so he can actually save his work.

to do that you may use the command wall to let your users know you are about to log them out.

Now at the given time end all of your users' applications, using pkill

sudo pkill -u username

replace username with every username you have in your system, you can also use.

who | awk '{ printf ("%s",$1 "\n"); }'| grep -v root | xargs -I {} -t pkill -u $1{}

This way you will all all users' processes, be careful using this.

You can also use the command skill but in its man page it says it is obsolete.

skill -KILL -u username

Use this command carefully, as you may make your users loose their jobs.