client.c

本代码是linux消息机制部分的示例

#include <stdio.h> 
#include <string.h> 
#include <stdlib.h> 
#include <errno.h> 
#include <sys/types.h> 
#include <sys/ipc.h> 
#include <sys/msg.h> 
#include <sys/stat.h>

#define MSG_FILE "server.c" 
#define BUFFER 255 
#define PERM S_IRUSR|S_IWUSR 

struct msgtype { 
	long mtype; 
	char buffer[BUFFER+1]; 
};

int main(int argc,char **argv) 
{ 
	struct msgtype msg; 
	key_t key; 
	int msgid;
       	
	if(argc!=2) 
	{ 
		fprintf(stderr,"Usage:%s string\n\a",argv[0]); 
		exit(1); 
	}
       	
	/* 创建关键字 */
	if((key=ftok(MSG_FILE,'a'))==-1) 
	{ 
		fprintf(stderr,"Creat Key Error:%s\a\n",strerror(errno)); 
		exit(1); 
	} 
	/* 创建信号量 */
	if((msgid=msgget(key,PERM))==-1) 
	{ 
		fprintf(stderr,"Creat Message Error:%s\a\n",strerror(errno)); 
		exit(1); 
	}
       	
	msg.mtype=1; 
	strncpy(msg.buffer,argv[1],BUFFER); 
	
	msgsnd(msgid,&msg,sizeof(struct msgtype),0);      // 发送消息 
	memset(&msg,'\0',sizeof(struct msgtype)); 
	msgrcv(msgid,&msg,sizeof(struct msgtype),2,0);    // 接受消息
	fprintf(stderr,"Client receive:%s\n",msg.buffer); // 显示消息
	
	exit(0); 
}