1. 使用头文件<sys/msg.h>
2. ftok函数获取key，内核使用key作为唯一标识创建消息队列
3. msgsnd, msgrcv函数，发送/接收消息
4. 消息结果第一个字段要为long type
ipc-msg.h
//
// Created by gxf on 2020/2/13.
//
#ifndef UNTITLED_IPC_MSGQUEUE_H
#define UNTITLED_IPC_MSGQUEUE_H
#define FTOK_FILE "/etc/passwd"
const int ftok_pro = ‘z‘;
typedef struct{
long type;
char content[256];
} msginfo;
#endif //UNTITLED_IPC_MSGQUEUE_H
server.c
//
// Created by gxf on 2020/2/13.
//
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/msg.h>
#include "ipc-msgqueue.h"
int main() {
key_t ftokRes = ftok(FTOK_FILE, ftok_pro);
if (ftokRes < 0) {
printf("ftok err\n");
return 1;
}
int msgId = msgget(ftokRes, IPC_CREAT | 0777);
if (msgId < 0) {
perror("msgget fail");
return 1;
}
msginfo recveivMsgInfo;
while (1) {
msgrcv(msgId, &recveivMsgInfo, 256, 123, 0);
printf("receive from client msg:%s\n", recveivMsgInfo.content);
recveivMsgInfo.type = 124;
msgsnd(msgId, &recveivMsgInfo, 256, 0);
}
return 0;
}
client.c
//
// Created by gxf on 2020/2/13.
//
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/msg.h>
#include "ipc-msgqueue.h"
int main() {
key_t ftokRes = ftok(FTOK_FILE, ftok_pro);
if (ftokRes < 0) {
perror("ftok fail");
return 1;
}
msginfo msginfo2Send;
msginfo2Send.type = 123;
sprintf(msginfo2Send.content, "hello I am client pid:%d", getpid());
int msgId = msgget(ftokRes, IPC_CREAT | 777);
if (msgId < 0) {
perror("msgget fail");
return 0;
}
int res = msgsnd(msgId, &msginfo2Send, 256, 0);
printf("msgsnd res:%d\n", res);
res = msgrcv(msgId, &msginfo2Send, 256, 124, 0);
printf("receive from msgserver:%s\n", msginfo2Send.content);
printf("msgrcv res:%d\n", res);
return 0;
}
原文：https://www.cnblogs.com/luckygxf/p/12303142.html