NAME
        DoPkt -- Send a dos packet and wait for reply (V36)

   SYNOPSIS
        result1 = DoPkt(port,action,arg1,arg2,arg3,arg4,arg5)
        D0               D1    D2    D3   D4   D5   D6   D7

        long dopkt(struct msgport *,long,long,long,long,long,long)

   FUNCTION
        Sends a packet to a handler and waits for it to return.  Any secondary
        return will be available in D1 AND from ioerr().  dopkt() will work
        even if the caller is an exec task and not a process; however it will
        be slower, and may fail for some additional reasons, such as being
        unable to allocate a signal.  DoPkt() uses your pr_MsgPort for the
        reply, and will call pr_PktWait.  (See BUGS regarding tasks, though).

        Only allows 5 arguments to be specified.  For more arguments (packets
        support a maximum of 7) create a packet and use sendpkt()/waitpkt().

   INPUTS
        port    - pr_MsgPort of the handler process to send to.
        action  - the action requested of the filesystem/handler
        arg1, arg2, arg3, arg4,arg5 - arguments, depend on the action, may not
                   be required.

   RESULT
        result1 - the value returned in dp_Res1, or FALSE if there was some
                  problem in sending the packet or recieving it.
        result2 - Available from ioerr() and in register d1.

   BUGS
        Using DoPkt() from tasks doesn't work in V36. Use allocdosobject(),
        putmsg(), and waitport()/getmsg() for a workaround, or you can call
        createnewproc() to start a process to do dos i/o for you.  in v37,
        DoPkt() will allocate, use, and free the msgport required.

   NOTES
        Callable from a task (under V37 and above).

   SEE ALSO
        allocdosobject(), freedosobject(), sendpkt(), waitpkt(),
        createnewproc(), abortpkt()