Linux消息队列编程示例_LINUX_操作系统_

struct haha{
long mtype;
char data[max];
};

int main(int argc,char *argv[]){
int pid;
if(argc!=2){
printf("Usage: msg [Message]\n");
return -1;
}
key_t key;
if((key=ftok("/tmp",'g'))<0){ //这里文件夹必须存在，有t属性并且上级目录也要有t属性
printf("Getting key error! \n");
return -1;
}
int mgsid;
if((mgsid=msgget(key,IPC_CREAT|0666))==-1){ //key值随便写一个数也能用
printf("mgs queue create error\n");
return -1;
}
pid=fork();
if(pid <0){
printf("fork create error!\n");
_exit(1);
}
if(pid == 0){
printf("welcome in child process\n Sending the message......\n");
sleep(1);
struct haha hehe;
hehe.mtype=getppid();
strcpy(hehe.data,argv[1]);
if(msgsnd(mgsid,&hehe,sizeof(hehe.data),0)<0){ //此处注意长度
printf("Sending error!!!\n");
_exit(1);
}else {
printf("Sending complete!\n");
_exit(0);
}
}else{
wait(NULL);
printf("welcome in parents process\n Receiving the message......\n");
sleep(1);
struct haha gaga;
if(msgrcv(mgsid,&gaga,max,getpid(),0)<0){
printf("Receiving error!!!\n");
_exit(1);
}else {
printf("Receiving complete!\n");
printf("The message is %s \n",gaga.data);
}
}
return 0;
}