/*创建消息队列*/ msgid=msgget(IPC_PRIVATE,0666 | IPC_CREAT);

#include <stdlib.h>#include <stdio.h>#include <string.h>#include <errno.h>#include <unistd.h>#include <sys/types.h>#include <sys/ipc.h>#include <sys/msg.h>#define MAX_TEXT 512struct my_msg_st{    long int my_msg_type;char some_text[MAX_TEXT];};int main(void){    long int msg_to_receive=0;struct my_msg_st some_data;int msgid;char buffer[BUFSIZ];pid_t pid;/*创建消息队列*/msgid=msgget(IPC_PRIVATE,0666 | IPC_CREAT);if(msgid==-1){    fprintf(stderr,"msgget failed with error:%d\n",errno);exit(EXIT_FAILURE);    }/*向消息队列中添加消息*/pid=fork();if(pid<0){    fprintf(stderr,"fork failed with error:%d\n",errno);exit(EXIT_FAILURE);}else if(pid){    printf("Enter some text:");fgets(buffer,BUFSIZ,stdin);some_data.my_msg_type=1;strcpy(some_data.some_text,buffer);/*添加消息*/if(msgsnd(msgid,(void *)&some_data,MAX_TEXT,0)==-1){    fprintf(stderr,"msgsed failed\n");exit(EXIT_FAILURE);}wait(NULL);}else{sleep(2);/*读取消息*/    if(msgrcv(msgid,(void *)&some_data,BUFSIZ,msg_to_receive,0)==-1){    fprintf(stderr,"msgrcv failed with error: %d\n",errno);exit(EXIT_FAILURE);}printf("You wrote: %s",some_data.some_text);/*从系统内核中移走消息队列*/if(msgctl(msgid,IPC_RMID,0)==-1){    fprintf(stderr,"msgctl(IPC_RMID) failed\n");exit(EXIT_FAILURE);}}return 0;}