////  Copyright (C) 2002 Brad Wasson <bard@systemtoolbox.com>////  This file is part of 3ddesktop.////  3ddesktop is free software; you can redistribute it and/or modify it//  under the terms of the GNU General Public License as published by//  the Free Software Foundation; either version 2, or (at your option)//  any later version.////  3ddesktop is distributed in the hope that it will be useful, but//  WITHOUT ANY WARRANTY; without even the implied warranty of//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the//  GNU General Public License for more details.////  You should have received a copy of the GNU General Public License//  along with 3ddesktop; see the file COPYING.   If not, write to//  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.//#include <stdio.h>#include <stdlib.h>#include <unistd.h>#include <sys/types.h>#include <sys/ipc.h>#include <sys/msg.h>// used in message passing with 3ddesktop daemon typedef struct threedeedesk_command {    long mtype;    char view[50];    int goto_column;    int goto_row;    int zoom;    FaceType_t face_type;    int acquire_sleep;    int reload;    float face_change_steps;    float zoom_steps;} threedeedesk_command_t;// This class is supposed to encapsulate the messaging functionality// between the client (3ddesk) and the daemon (3ddeskd).  If the// messaging mechanism should ever be changed its easy to change cause// its all here.  This "manager" is used by both client and daemon// (one to send and the other to recieve).class MessageManager {private:    int msqid;public:    // modified directly by client and daemon    threedeedesk_command_t  msg;    enum msgtype_t {        WAIT = 0,        NOWAIT,        CREATE,        NOCREATE,    };    // Can't use msgout or end_program because this is used by both the    // client and daemon.    MessageManager() {        msqid = -1;        msg.mtype = MTYPE_ACTIVATE;        msg.view[0] = 0;        msg.goto_column = NO_GOTO;        msg.goto_row = NO_GOTO;        msg.zoom = -1;        msg.face_type = FACE_TYPE_NONE;        msg.acquire_sleep = 0;        msg.reload = 0;        msg.face_change_steps = 0;        msg.zoom_steps = 0;    };    int open (msgtype_t t = NOCREATE) {        key_t key;        key = ftok("/bin/sh", 222);        if (key == (key_t)-1)            return -1;                int o = 0666;        if (t == CREATE)            o |= IPC_CREAT;        msqid = msgget(key, o);        if (msqid == -1)            return -1;        if (t == CREATE)            // clear the queue            while (recieve(NOWAIT) == 0 && errno != ENOMSG)                ;        return msqid;    };    int close () {        if (msqid != -1)            if (msgctl(msqid, IPC_RMID, NULL) == -1)                 return -1;        return 0;    };    int send () {        return msgsnd(msqid, (struct msgbuf *)&msg, sizeof(msg) - sizeof(long), 0);    };    // returns -1 for error or 0 for success or NOMSG    int recieve (msgtype_t t = WAIT) {        errno = 0;        int rc = msgrcv(msqid, (struct msgbuf *)&msg, sizeof(msg)- sizeof(long), 0,                         t == NOWAIT ? IPC_NOWAIT : 0);        if (rc < 0 && errno != ENOMSG) {            //msgout (ERROR, "msgrcv failed: %s\n", strerror(errno));            return -1;        }        return 0;    };};