消息队列函数 msgsnd 出现Invalid argument错误的解决办法

直接看代码：

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




#define MAX_MSG 128


struct mssgbuf
{
long type;
char buf[MAX_MSG];
};


int main()
{
int msqid;
int err;


key_t key;
key = ftok(".",'b');
if(key < 0)
{
printf("fait to creat value\n");
return -1;
}


msqid = msgget(key,IPC_CREAT|0666);
if(msqid < 0)
{
perror("failse to masgget");
return -1;
}
printf("success to get msqid %d\n",msqid);
system("ipcs -q");


struct mssgbuf sendbuf;
printf("enter your message:\n");
fgets(sendbuf.buf,MAX_MSG,stdin);
sendbuf.type = 1;


err = msgsnd(msqid,(void *)&sendbuf,strlen(sendbuf.buf)+1,0);
if(err < 0)
{
perror("write message fail");
return -1;
}
printf("success to write message\n");
printf("err = %d\n", err);


system("ipcs -q");


err = msgctl(msqid,IPC_RMID,NULL);
if(err < 0)
{
printf("fail to delete message queue\n");
return -1;
}
system("ipcs -q");
return 0;




}

以上是修改过的代码， 重点在sendbuf.type = 1这句，不加上这句的话 就会出现如题所说的错误。