write(1)                 USER COMMANDS                   write(1)



NAME
     write - write to another user

SYNOPSIS
     write user [line]

DESCRIPTION
     write copies lines from your terminal  to  that  of  another
     user.  When first called, it sends the message:

          Message from yourname (tty??)  [ date ]...

     to the person you want to talk to.  When it has successfully
     completed  the  connection,  it also sends two bells to your
     own terminal to indicate that what you are typing  is  being
     sent.

     The recipient of the  message  should  write  back  at  this
     point.  Communication continues until an end of file is read
     from the terminal, an interrupt is sent,  or  the  recipient
     has  executed  "mesg  n".  At that point write writes EOT on
     the other terminal and exits.

     If you want to write to a user who is logged  in  more  than
     once,  the  line argument may be used to indicate which line
     or terminal to send to (e.g., term/12); otherwise, the first
     writable  instance  of  the  user  found in /var/adm/utmp is
     assumed and the following message posted:

          user is logged on more than one place.
          You are connected to "terminal".
          Other locations are:
          terminal

     Permission to write may be denied or granted by use  of  the
     mesg  command.   Writing  to  others  is normally allowed by
     default.  Certain commands, such as the pr command, disallow
     messages in order to prevent interference with their output.
     However, if the user has  super-user  permissions,  messages
     can be forced onto a write-inhibited terminal.

     If the character ! is found at  the  beginning  of  a  line,
     write  calls  the shell to execute the rest of the line as a
     command.

     write runs setgid() [see setuid(2)] to the group ID tty,  in
     order to have write permissions on other user's terminals.

     write will detect non-printable  characters  before  sending
     them to the user's terminal.  Control characters will appear
     as a `^' followed by the appropriate ASCII character;  char-
     acters  with  the  high-order  bit  set  will appear in meta



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write(1)                 USER COMMANDS                   write(1)



     notation. For example,  `\003'  is  displayed  as  `^C'  and
     `\372' as `M-z'.

     The following protocol is suggested for using  write:   when
     you first write to another user, wait for them to write back
     before starting to send.  Each person should end  a  message
     with  a  distinctive signal (i.e., (o) for ``over'') so that
     the other person knows when to reply.  The signal (oo)  (for
     ``over  and  out'')  is suggested when conversation is to be
     terminated.

FILES
     /var/adm/utmp
               to find user
     /usr/bin/sh
               to execute !

SEE ALSO
     mail(1), mesg(1), pr(1), sh(1), who(1), setuid(2).

DIAGNOSTICS
     user is not logged on                  if the person you
                                            are trying to write
                                            to is not logged on.
     Permission denied                      if the person you
                                            are trying to write
                                            to denies that per-
                                            mission (with mesg).
     Warning: cannot respond, set mesg -y   if your terminal is
                                            set to mesg n and
                                            the recipient cannot
                                            respond to you.
     Can no longer write to user            if the recipient has
                                            denied permission
                                            (mesg n) after you
                                            had started writing.



















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