MESG(1) General Commands Manual MESG(1)

mesg — display (do not display) messages from other users

mesg [n | y]

The mesg utility is invoked by a user to control write access others have to a terminal device. Write access is allowed by default, and programs such as talk(1) and write(1) may display messages on the terminal.

The first terminal device in the sequence of devices associated with standard input, standard output and standard error is affected.

The following options are available:

Disallow messages.
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.
An error has occurred.

Disallow messages from other users to the current terminal:

mesg n

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.

biff(1), talk(1), wall(1), write(1)

The mesg utility conforms to IEEE Std 1003.1-2001 (“POSIX.1”).

A mesg command appeared in Version 1 AT&T UNIX.

May 5, 2002 Mac OS X 12