| MESG(1) | General Commands Manual | MESG(1) | 
mesg —
| mesg | [ n|y] | 
mesg utility is invoked by a user to control write
  access others have to the terminal device associated with the standard error
  output. Write access is allowed by default, and programs such as
  talk(1) and
  write(1) may display messages on
  the terminal.
Options available:
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:
mesg command appeared in
  Version 1 AT&T UNIX.
| September 1, 2019 | NetBSD 10.0 |