Index for Section 1

Alphabetical listing for M

mesg(1)
NAME
  mesg - Permits or refuses write messages

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

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

  mesg:	 XPG4, XPG4-UNIX

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

OPTIONS
  [-]y[es]
      This permits other users to send messages to your terminal.

      [Compaq]	The leading - (dash) is optional.  Only the initial letter is
      required, but the full word is accepted.

  [-]n[o]
      This denies other users permission to send messages to your terminal.
      Disables incoming write messages, except by appropriately authorized
      users.

      [Compaq]	The leading - (dash) is optional.  Only the initial letter is
      required, but the full word is accepted.

  If no option is specified, mesg reports the current state of message
  acceptance.

OPERANDS
  [Compaq]  There are no operands to mesg, but if the optional (-) hyphen is
  omitted with the option, then the option becomes the operand as described
  in the XPG4, XPG4-UNIX standard.

DESCRIPTION
  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.

  [Compaq]  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

       [Compaq]	 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.

  [Compaq]  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
  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.)

  [Compaq]  Message permission has no effect on messages delivered through
  the electronic mail system.

  [Compaq]  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 talk
  command.

  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


  [Compaq]  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.

NOTES
  [Compaq]  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
      multibyte characters in arguments).

  LC_MESSAGES
      Determines the locale for the format and contents of diagnostic
      messages 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)