mesg - Permits or refuses write messages
mesg [y | n ]
[Tru64 UNIX] The following format is supported for backward
compatibility: mesg [[-]y[es] | [-]n[o] ]
Interfaces documented on this reference page conform to
industry standards as follows:
Refer to the standards(5) reference page for more information
about industry standards and associated tags.
Grants permission to other users to send messages to the
[Tru64 UNIX] You can optionally include a -
(hyphen) before y, include es after y, or both.
Denies permission to other users to send messages
to the terminal device.
[Tru64 UNIX] You can optionally include a -
(hyphen) before n, include o after n, or both.
The mesg command controls whether other users on the system
can send messages to you with the talk and write commands.
Called without arguments, mesg displays the current
terminal message permission setting.
[Tru64 UNIX] The shell start-up procedure disallows messages
by default. You can override this default action by
including the line mesg y in your $HOME/.profile (sh),
(csh), or (csh) file.
[Tru64 UNIX] This default setting described for the shell
start-up procedure message permissions assumes that the
shell is one started as part of a login session. If the
shell got started by some other means, the default depends
on what that other program has done.
[Tru64 UNIX] Any user can send messages with write if the
receiving user has enabled messages. A user with the
sysadmin command authorization can send messages to any
The terminal device affected is determined by searching
for the first terminal in the sequence of devices associated
with standard input, standard output, and standard
error, respectively. (In other words, the affected device
is not the same as the controlling terminal for the session.)
[Tru64 UNIX] Message permission has no effect on messages
delivered through the electronic mail system.
[Tru64 UNIX] If you add mesg y to your $HOME/.profile,
you will be able to receive messages from other users via
the write command or the talk command. If you add mesg n
to your $HOME/.profile, you will not be able to receive
messages from other users via the write command or the
The mesg command also accepts the current locale's equivalent
of yes and no. These equivalents are determined by
the setting of the LC_MESSAGES environment variable. The
usage message displays the current locale's equivalent of
yes and no.
Security Restrictions [Toc] [Back]
[Tru64 UNIX] In the trusted configuration of the system,
all terminal devices have owner set to the login user and
group set to the pseudogroup tty. The login command sets
terminal modes to 0600 at login time, so you must explicitly
use mesg y to enable access from unauthorized users.
[Tru64 UNIX] If your current locale defines settings
other than yes or no, the mesg command does not accept yes
or no as arguments. This causes an error if you use a yes
or no argument to mesg in your file.
The following exit values are returned: Message reception
is allowed. Message reception is denied. An error
To allow only appropriately authorized users to send messages
to your terminal, enter: mesg no To allow everyone
the permission to send messages to your terminal, enter:
mesg yes To determine the state of message acceptance of
your terminal, enter: mesg
This will give one of the following responses, as
appropriate: is yes is no
ENVIRONMENT VARIABLES [Toc] [Back]
The following environment variables affect the execution
of mesg: Provides a default value for the internationalization
variables that are unset or null. If LANG is unset
or null, the corresponding value from the default locale
is used. If any of the internationalization variables
contain an invalid setting, the utility behaves as if none
of the variables had been defined. If set to a non-empty
string value, overrides the values of all the other internationalization
variables. Determines the locale for the
interpretation of sequences of bytes of text data as characters
(for example, single-byte as opposed to multibyte
characters in arguments). Determines the locale for the
format and contents of diagnostic messages written to
standard error. Determines the location of message catalogues
for the processing of LC_MESSAGES.
User profile User profile (csh) User profile (csh) Your
Commands: chmod(1), csh(1), Bourne shell sh(1b), POSIX
shell sh(1p), stty(1), talk(1), wall(1), write(1)
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