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mesg(1)								      mesg(1)



NAME

  mesg - Permits or refuses write messages

SYNOPSIS

  mesg	[y | n ]

  [Tru64 UNIX]	The following format is	supported for backward compatibility:

  mesg [[-]y[es] | [-]n[o] ]

STANDARDS

  Interfaces documented	on this	reference page conform to industry standards
  as follows:

  mesg:	 XCU5.0

  Refer	to the standards(5) reference page for more information	about indus-
  try standards	and associated tags.

OPERANDS

  y   Grants permission	to other users to send messages	to the terminal	dev-
      ice.

      [Tru64 UNIX]  You	can optionally include a - (hyphen) before y, include
      es after y, or both.

  n   Denies permission	to other users to send messages	to the terminal	dev-
      ice.

      [Tru64 UNIX]  You	can optionally include a - (hyphen) before n, include
      o	after n, or both.

DESCRIPTION

  The mesg command controls whether other users	on the system can send mes-
  sages	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), .cshrc (csh), or	.login (csh) file.








				     Note

       [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 terminal.

  The terminal device affected is determined by	searching for the first	ter-
  minal	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 com-
  mand.	 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 talk com-
  mand.

  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


  [Tru64 UNIX]	In the trusted configuration of	the system, all	terminal dev-
  ices 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.

NOTES

  [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	.profile file.

EXIT STATUS

  The following	exit values are	returned:

  0   Message reception	is allowed.

  1   Message reception	is denied.

  >>1  An error occurred.

EXAMPLES

   1.  To allow	only appropriately authorized users to send messages to	your
       terminal, enter:
	    mesg no

   2.  To allow	everyone the permission	to send	messages to your terminal,
       enter:
	    mesg yes

   3.  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

  The following	environment variables affect the execution of mesg:

  LANG
      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.

  LC_ALL
      If set to	a non-empty string value, overrides the	values of all the
      other internationalization variables.

  LC_CTYPE
      Determines the locale for	the interpretation of sequences	of bytes of
      text data	as characters (for example, single-byte	as opposed to multi-
      byte characters in arguments).

  LC_MESSAGES
      Determines the locale for	the format and contents	of diagnostic mes-
      sages written to standard	error.

  NLSPATH
      Determines the location of message catalogues for	the processing of
      LC_MESSAGES.

FILES

  $HOME/.profile
      User profile

  .cshrc
      User profile (csh)

  .login
      User profile (csh)

  /dev/tty*
      Your current terminal

SEE ALSO

  Commands:  chmod(1), csh(1), Bourne shell sh(1b), POSIX shell	sh(1p),
  stty(1), talk(1), wall(1), write(1)

  Functions:  chmod(2)

  Standards:  standards(5)