calling exec in a pthread

pthread_exec.c

#include <stdio.h>
#include <unistd.h>
#include <pthread.h>

void *thread_func(void *data)
{
	execlp("/bin/ls", "ls", "-l", NULL);
}

int main(void) {
	int ret;
	pthread_t tid;

	ret = pthread_create(&tid, NULL, thread_func, NULL);
	if (ret < 0) {
		return -1;
	}

	while (1) {
		printf(".... \n");
		sleep(1);
	}

	return 0;
}