$ wall
-> press "ctrl+d" to send the message
$ echo "Hello World!" | wall
$ sudo wall message.txt
-> send content of message.txt file
$ write alper
-> press "crlt+c" to quit
$ write alper pts/0
-> run "who" to see terminal names like pts/0
-> press "ctrl+d" to send the message
$ echo "Hello World!" | wall
$ sudo wall message.txt
-> send content of message.txt file
$ write alper
-> press "crlt+c" to quit
$ write alper pts/0
-> run "who" to see terminal names like pts/0