|y||Permit messages to be displayed.|
If no arguments are given, mesg displays the present message status to the standard 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.
Disallow messages from other users to the current terminal:
Allow messages from other users to ttyp1 (assuming you are also logged in on that terminal):
mesg y </dev/ttyp1
Previous versions of the mesg utility wrote the message status to the standard error output and affected the terminal attached to standard error without first trying the standard input or output devices.
The mesg utility conforms to -p1003.1-2001.
A mesg command appeared in AT&T v1 .