一个消息队列例子，第一次运行正确，第二次运行就提示消息发送失败了

[sin816]

第一次运行还能正确发送消息，第二次运行就无法发出消息，请大家指点下，谢谢。

#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/msg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main(void)
{
	key_t unique_key;
	int msgid;
	int status;
	char str1[] = {"test message:hello!"};
	char str2[] = {"test message:goodbye!"};
	struct msgbuf
	{
		long msgtype;
		char msgtext[1024];
	}sndmsg,rcvmsg;

	if(msgid = msgget(IPC_PRIVATE, 0666) == -1)
	{
		printf("msgget error!\n");
		exit(254);
	}

	sndmsg.msgtype = 111;
	sprintf(sndmsg.msgtext, "%s", str1);

	if(msgsnd(msgid, (struct msgbuf *)&sndmsg, sizeof(str1)+1, 0) == -1)
	{
		printf("msgtype 111 send error!\n");
		exit(254);
	}

	if(status = msgrcv(msgid, (struct msgbuf *)&rcvmsg,80,111,IPC_NOWAIT) == -1)
	{
		printf("msgrcv error!\n");
		exit(254);
	}

	printf("The received message:%s\n",rcvmsg.msgtext);
	msgctl(msgid, IPC_RMID, 0);

	exit(0);
}

[jcback]

改成if( ( msgid=(msgget(IPC_PRIVATE, 0660))) == -1)

ipcs -qa 就发现异常了，一下子多了那么多队列

[qq120848369]

sizeof(str1)+1 这不对哦，不需要+1，不过你这里是先拷贝过去的，多发也不是越界而已。

[justkk]

嗯，典型的C语法错误
if((msgid = msgget(IPC_PRIVATE, 0666)) == -1)

[wenzheng101]

if(msgid = msgget(IPC_PRIVATE, 0666) == -1)
少加了括号，应该是if((msgid = msgget(IPC_PRIVATE, 0666)) == -1)