    MESG(I)                      3/15/72                      MESG(I)

    NAME
         mesg  -  permit or deny messages

    SYNOPSIS
         mesg [ n ] [ y ]

    DESCRIPTION
         Mesg  with argument n forbids messages via write by revoking
         non-user write permission on the  user's  typewriter.   Mesg
         with  argument y reinstates permission.  All by itself, mesg
         reverses the current permission.  In all cases the  previous
         state is reported.

    FILES
         /dev/tty?

    SEE ALSO
         write(I)

    DIAGNOSTICS
         `?' if the standard input file is not a typewriter

    BUGS

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