Linux XSI message Hello World (msgget msgsnd msgrcv)

main.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <sys/msg.h>

int main(){
	char* buf = "Hello world !";
	unsigned long len = strlen(buf);
	char* buf2 = alloca(len);

	key_t key = ftok("/tmp", rand()%100); // I don't think it actually needs to be random
	printf("key=%i\n", key);

	int qid = msgget(key, IPC_CREAT|0600);
	perror("msgget");
	printf("qid=%i\n", qid);

	msgsnd(qid, buf, len, 0);
	perror("msgsnd");

	msgrcv(qid, buf2, len, 0, 0);
	perror("rcvsnd");
	printf("RCV=%s\n", buf2);
}

Output :

key=1394868225
qid=32939
RCV=Hello world !
msgget: Success
msgsnd: Success
rcvsnd: Success