man(1) Manual page archive

     WRITE(1)                                                 WRITE(1)

          write  -  write to another user

          write user [ ttyname ]

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

               Message from yourname yourttyname...

          The recipient of the message should write back at this
          point.  Communication continues until an end of file is read
          from the terminal or an interrupt is sent.  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 ttyname argument may be used to indicate the
          appropriate terminal name.

          Permission to write may be denied or granted by use of the
          mesg command.  At the outset writing is allowed.  Certain
          commands, in particular nroff and pr(1) disallow messages in
          order to prevent messy output.

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

          The following protocol is suggested for using write: when
          you first write to another user, wait for him to write back
          before starting to send.  Each party should end each message
          with a distinctive signal-(o) for `over' is conventional-
          that the other may reply.  (oo) for `over and out' is sug-
          gested when conversation is about to be terminated.

          /etc/utmp to find user
          /bin/sh        to execute `!'

          mesg(1), who(1), mail(1)