LINUX msgget and ftok - linux

Question

Hello I'm trying IPC practice. But I have problem... Here is the code
Send_process.c (path : /home/John/h1/send_process.c)
struct mymsgbuf {
long mtype;
char mtext[80];
};
int main(void) {
key_t key;
int msgid;
struct mymsgbuf mesg;
char inputmsg[80];
if(msgid = msgget((key_t)123, IPC_CREAT | 0666) == -1) {
perror("Failed to create new MessageQueue");
exit(1);
}
printf("%d\n", msgid);
mesg.mtype = 1;
while(1) {
printf("Enter Sending Message. (Input exit, programm terminate) : ");
scanf("%s", inputmsg);
strcpy(mesg.mtext, inputmsg);
if(msgsnd(msgid, (void *)&mesg, sizeof(mesg.mtext), IPC_NOWAIT) == -1) {
perror("msgsnd");
exit(1);
}
if(strcmp(inputmsg, "exit") == 0) {
printf("Sending Process Terminated\n");
break;
}
}
return 0;
}
Receive_process.c (path : /home/John/h1/send_process.c)
struct mymsgbuf {
long mtype;
char mtext[80];
};
int main(void) {
struct mymsgbuf inmsg;
key_t key;
int msgid;
key = ftok("/home/John/h1/receive_process.c", 123);
if((msgid = msgget(key,0666)) < 0 ) { //here is error
perror("msgget");
exit(1);
}
printf("%d\n", msgid);
while(1) {
if(msgrcv(msgid, &inmsg, sizeof(inmsg.mtext), 0,0) == -1) {
perror("Message Receive");
exit(1);
}
printf("Received Message. Message is [%s]\n", inmsg.mtext);
if(strcmp(inmsg.mtext, "exit") == 0 ) {
printf("Receive_process end\n");
exit(0);
}
}
return 0;
}
Send_process is works very well, but Receive_process not works well. What is the problem?