/*
 * Sendpacket.c 
 *
 * An invaluable addition to your Amiga.lib file. This code sends a packet the
 * given message port. This makes working around DOS lots easier. 
 *
 * Note, I didn't write this, those wonderful folks at CBM did. I do suggest
 * however that you may wish to add it to Amiga.Lib, to do so, compile it and
 * say 'oml lib:amiga.lib -r sendpacket.o' 
 */

#include <exec/types.h>
#include <exec/ports.h>
#include <exec/memory.h>
#include <libraries/dos.h>
#include <libraries/dosextens.h>

/*
 * Function - SendPacket written by Phil Lindsay, Carolyn Scheppner, and Andy
 * Finkel. This function will send a packet of the given type to the Message
 * Port supplied. 
 */

long
SendPacket(pid, action, args, nargs)
    struct MsgPort *pid;	/* process indentifier ... (handlers message
				 * port ) */
    long            action,	/* packet type ... (what you want handler to
				 * do )   */
                    args[],	/* a pointer to a argument list */
                    nargs;	/* number of arguments in list  */
{
    struct MsgPort *replyport;
    struct StandardPacket *packet;

    long            count, *pargs, res1;

    replyport = (struct MsgPort *) CreatePort(NULL, 0);
    if (!replyport)
	return (0);

    /* Allocate space for a packet, make it public and clear it */
    packet = (struct StandardPacket *)
	AllocMem((long) sizeof(struct StandardPacket), MEMF_PUBLIC | MEMF_CLEAR);
    if (!packet) {
	DeletePort(replyport);
	return (0);
    }
    packet->sp_Msg.mn_Node.ln_Name = (char *) &(packet->sp_Pkt);
    packet->sp_Pkt.dp_Link = &(packet->sp_Msg);
    packet->sp_Pkt.dp_Port = replyport;
    packet->sp_Pkt.dp_Type = action;

    /* copy the args into the packet */
    pargs = &(packet->sp_Pkt.dp_Arg1);	/* address of first argument */
    for (count = 0; count < nargs; count++)
	pargs[count] = args[count];

    PutMsg(pid, packet);	/* send packet */

    WaitPort(replyport);
    GetMsg(replyport);

    res1 = packet->sp_Pkt.dp_Res1;

    FreeMem(packet, (long) sizeof(struct StandardPacket));
    DeletePort(replyport);

    return (res1);
}