Linux CLI - How to broadcast a message to all users - using wall

1. As the main input of wall is a file, we will first create our message file.Type :

$ echo 'Please note that in two more hours, and for one hour, you will not be able to use the SQL database, please save all your job before, and quit any application using it'> message.txt

2. OK, now we have our message ready, it is time to send it to the users

$ wall < message.txt

 Try yourself!!!