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MESG(1) User Commands MESG(1)

mesg - display (or do not display) messages from other users

mesg [option] [n|y]

The mesg utility is invoked by a user to control write access others have to the terminal device associated with 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.

The mesg utility silently exits with error status 2 if not executed on terminal. In this case execute mesg is pointless. The command line option --verbose forces mesg to print a warning in this situation. This behaviour has been introduced in version 2.33.

n
Disallow messages.
y
Allow messages to be displayed.

If no arguments are given, mesg shows the current message status on standard error output.

-v, --verbose
Explain what is being done.
-V, --version
Display version information and exit.
-h, --help
Display help text and exit.

The mesg utility exits with one of the following values:
 0
Messages are allowed.
 1
Messages are not allowed.
>1
An error has occurred.

/dev/[pt]ty[pq]?

login(1), talk(1), write(1), wall(1), xterm(1)

A mesg command appeared in Version 6 AT&T UNIX.

The mesg command is part of the util-linux package and is available from https://www.kernel.org/pub/linux/utils/util-linux/.
July 2014 util-linux