/*********************************************************************************
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* Copyright: (C) 2025 LingYun IoT System Studio
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* All rights reserved.
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*
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* Filename: mq_recv.c
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* Description: This file is Message Queue(receiver) example program.
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*
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* Version: 1.0.0(11/10/2025)
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* Author: Guo Wenxue <guowenxue@gmail.com>
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* ChangeLog: 1, Release initial version on "11/10/2025 10:06:53 AM"
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*
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********************************************************************************/
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#include <stdio.h>
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#include <string.h>
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#include <errno.h>
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#include <unistd.h>
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#include <stdlib.h>
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#include <sys/types.h>
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#include <sys/ipc.h>
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#include <sys/msg.h>
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#define FTOK_PATH "/dev/zero"
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#define FTOK_PROJID 0x22
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typedef struct msg_s
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{
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long mtype;
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char mtext[512];
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} msg_t;
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int main(int argc, char **argv)
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{
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key_t key;
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msg_t msg;
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int msgid;
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int msgtype=2;
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int i;
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if( (key=ftok(FTOK_PATH, FTOK_PROJID)) < 0 )
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{
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printf("ftok() get IPC token failure: %s\n", strerror(errno));
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return -1;
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}
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msgid = msgget(key, IPC_CREAT|0666);
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if( msgid < 0)
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{
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printf("shmget() create shared memroy failure: %s\n", strerror(errno));
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return -2;
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}
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printf("key[%d] msgid[%d] msgypte[%d]\n", (int)key, msgid, msgtype);
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printf("Waiting for messages...\n");
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while(1)
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{
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memset(&msg,0,sizeof(msg));
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if( msgrcv(msgid, &msg, sizeof(msg.mtext), msgtype, 0) < 0 )
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{
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printf("msgsnd() receive message failure: %s\n", strerror(errno));
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break;
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}
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printf("Received: %s", msg.mtext);
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if (strncasecmp(msg.mtext, "exit", 4) == 0)
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break;
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}
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msgctl(msgid, IPC_RMID, NULL);
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return 0;
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}
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