Mesg controls the access to your terminal by others. Its typically used to
allow or disallow other users to write to your terminal (see write(1)).
Allow write access to your terminal.
Disallow write access to your terminal.
If no option is given, mesg prints out the current access state of your
Mesg assumes that its standard input is connected to your
terminal. That also means that if you are logged in multiple times,
you can get/set the mesg status of other sessions by using redirection.
For example "mesg n < /dev/pts/46".