mesg—Display (do not display) messages from other users
The mesg utility is invoked by a users to control write access others have to the terminal device associated with the standard error output. If write access is allowed, then programs such as talk(1) and write(1) may display messages on the terminal.
Traditionally, write access is allowed by default. However, as users become more conscious of various security risks, there is a trend to remove write access by default, at least for the primary login shell. To make sure your ttys are set the way you want them to be set, mesg should be executed in your login scripts.
|y||Permits messages to be displayed|
|If no arguments are given, mesg displays the present message status to the standard error output.
The mesg utility exits with one of the following values:
|\0||Messages are allowed.|
|\1||Messages are not allowed.|
|1||An error has occurred.|