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       mesg - permit or deny messages


       mesg  [-s]  [-v]  [y|n|ye|ne|Y|N|NE]  [d]  [-p[w|t|k|a]]  [-x[w|t|k|n]]
       [-m[l|c|a]] [-h[Y|y|n]] [-r[y|n]] [-b[y|n]]


       This is the "Orville write" verison of the standard Unix mesg  command.

       Mesg  with  argument  n forbids messages via write(1), ojot(1), tel(1),
       and talk(1)  by  revoking  non-user  write  permission  on  the  user’s
       terminal.   Mesg with argument y reinstates permission.  All by itself,
       mesg reports the current state without changing it.

       The ne and ye settings mean  ‘‘no  with  exceptions’’  and  ‘‘yes  with
       exceptions’’  respectively.   If  ne  is  set,  and there is file named
       .yeswrite in your home directory,  then  the  users  whose  logins  are
       listed  there  may  still write you.  If ye is set, and there is a file
       named .nowrite in your home directory, then the users whose logins  are
       listed  there  may  not  write  you.  These files have no effect if the
       permissions are set to n or y.  The .nowrite and .yeswrite files do not
       need  to  be  permitted to anyone else, and almost any plausible format
       will be understood (listing one login name per line is a good default).
       Lines may be commented out with a # sign in the first column.

       The upper case Y and N do all that the lower case ones do, but may have
       some additional affects depending on the installation.

       The N argument, if  enabled,  will  attempt  to  disconnect  any  write
       sessions  currently directed at your tty.  This is meant to allow users
       to slam the door on unwelcome writers.  Note that a simple  ‘‘mesg  n’’
       will  not  stop anyone who is already writing you from continuing to do
       so, it only prevents new connections from being made.  The  NE  setting
       also  causes  a disconnect, but turns your settings to ne instead of n.
       The d argument causes a disconnect, just like ‘‘mesg N’’, but does  not
       change your message permissions.

       Normally  mesg  always  depermits  your  tty device, so you can only be
       written through write and similar programs.   This  prevents  arbitrary
       stuff  from  being redirected to your tty.  When you do ‘‘mesg Y’’ your
       tty is  write  permitted  to  others.   This  is  rarely  necessary  or

       Mesg  can  also  be  used  to  set  other  switches that affect Orville
       write(1).  The -p flag lets you  set  preferences  to  (w)  write,  (t)
       telegrams, (k) talk, or (a) any.  The default is ‘‘any.’’  If you set a
       preference to write, then people will not be able to send telegrams  or
       talk  requests  to  you.   If  they try to send telegrams, they will be
       asked if they want to write  you  instead.   Similarly  if  you  prefer
       telegrams,  people will not be able to write or talk to you, and if you
       prefer talk, people will not be able to write  or  tel  you.   You  can
       designate  two  preferences,  like  ‘‘mesg -pt -pw’’ to allow people to
       write or telegram you, but not make talk requests to you.  Alternately,
       you  can  use  the  -x flag to block particular programs.  Doing ‘‘mesg
       -xk’’ blocks only the talk program, and is  equivalent  to  ‘‘mesg  -pt
       -pw’’.   Similarly  the  ‘‘-xn’’  flag  excludes  no  programs  and  is
       equivalent to ‘‘-pa’’.  Trying to block all  programs  just  turns  you
       permissions off.

       The  -m flag lets you set modes to (l) line, (c) character, or (a) any.
       The default is ‘‘any.’’  If you set a mode, then all writes to you will
       be  done  in that mode.  If you leave it as ‘‘any,’’ the choice is left
       to the writer.  This will not affect connections already  in  progress,
       only future ones.

       The  -r flag lets you turn on or off the recording to telegrams sent to
       you.  If it is enabled, everytime you are sent a telegram (or  a  write
       with  input  taken from a file), the text of the messages is saved in a
       file named .lastmesg in  your  home  directory.   This  allows  you  to
       redisplay  the last message sent to you using the huh(1) command.  If a
       screen clear ate a telegram message before you had  time  to  read  it,
       then  the  huh  command lets you see it again.  Note that only the last
       message sent is stored.  The file is permitted to be  readable  to  you

       The -b flag lets you tell the write and talk programs whether or not to
       beep when a person writes you or sends you a telegram.  The default  is
       to beep.

       The  -h  flag  lets  you turn on or off your helper status.  People who
       designate themselves as helpers are  announcing  their  willingness  to
       help  out  lost  users.  Their accounts will be marked on the output of
       the finger(1) command, and  if  anyone  does  a  write  or  ojot(1)  to
       ‘‘help’’  they  automatically  get  connected to someone who has a help
       flag set.  Normally, turning  your  permissions  off  also  turns  your
       helper-status  off,  but  if  you  set  the -h flag to Y, then you will
       remain a helper even when your message permissions are off.  This means
       you can receive help requests, but not normal messages.

       On some systems there is a restricted list of users who may be helpers.
       This is usually kept in the file /etc/helpers, one login name per line.
       If  such  a  file exists then you will have to get the operators to add
       your name to it to be able to designate yourself as a helper.

       If no new settings are given to mesg,  then  it  just  reports  on  the
       current settings.  Normally it prints the message permissions, but if a
       -h, -p, -r, or -m flag was given without a new value after it, then the
       current  status of that switch will be printed instead.  If you use the
       -s flag, then this  output  will  be  suppressed.   The  command  still
       reports the status of the selected switch with its numeric return code.

       If you use the -v flag, all switch  settings  will  be  reported  in  a
       verbose mode.

       The  numeric  values  returned  as return codes (see below) can also be
       used to set switches.  Thus ‘‘mesg 0 -m2’’ sets permissions on, and the
       mode  to any.  This makes it easy for shell scripts to restore settings
       that were stored previously.

       The argument syntax is actually a lot looser than mentioned above.  The
       dashes  before  options  may be omitted, Spaces may be added or omitted
       anywhere in the argument list.




       write(1), amin(1), finger(1), huh(1), helpers(1), talk(1)


       Exit status is -1 on an error.  Otherwise a code is returned  reporting
       the  status  of one of the settings.  If the arguments included -h, -p,
       or -m flags without a new value after it, then the last of these listed
       will  be  reported.   Otherwise,  if  any options were set, the last of
       those listed in the argument list will be reported.  And if nothing was
       set, then message permissions are reported.

       When  message  permissions,  record  settings,  or  helper settings are
       reported, 0 indicates ’y’, and 1 indicates ’n’.  When  preferences  are
       reported,  1  indicates  ’w’, 2 indicates ’t’, and 4 indicates ’k’, and
       any combinations are returned as sums of these values.  When modes  are
       reported, 0 indicates ’l’, 1 indicates ’c’, and 2 indicates ’a’.


       Turning off ’talk’ permissions will only work if you have a talkd which
       has been modified to understand Orville write’s permission.