# Bash 的 mesg 命令

mesg [OPTION]... [n|y]

$ mesg        # 查看是否允许显示来自其它用户的消息
is y
$ mesg n      # 禁止显示来自其它用户的消息
$ mesg
is n

MESG(1)                          User Commands                         MESG(1)

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

SYNOPSIS
       mesg [option] [n|y]

DESCRIPTION
       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
       a terminal. In this case executing 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.

ARGUMENTS
       n
           Disallow messages.

       y
           Allow messages to be displayed.

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

OPTIONS
       -v, --verbose
           Explain what is being done.

       -h, --help
           Display help text and exit.

       -V, --version
           Print version and exit.

EXIT STATUS
       The mesg utility exits with one of the following values:

       0
           Messages are allowed.

       1
           Messages are not allowed.

       >1
           An error has occurred.

FILES
       /dev/[pt]ty*, /dev/pts/[0-9]*

HISTORY
       mesg (I) appears in the UNIX Programmer’s Manual. It used to invert the
       current state with no argument before Version 7 AT&T UNIX.

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

REPORTING BUGS
       For bug reports, use the issue tracker at
       https://github.com/util-linux/util-linux/issues.

AVAILABILITY
       The mesg command is part of the util-linux package which can be
       downloaded from Linux Kernel Archive
       <https://www.kernel.org/pub/linux/utils/util-linux/>.

util-linux 2.39.3                 2023-11-21                           MESG(1)