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

void die(const char *what)
{
	fprintf(stderr,"Exiting because of a fatal error %s: %s\n",
		what, strerror(errno));
	exit(1);
}


void *child(void *p)
{
	printf("This is child %d, pid: %d, uid: %d\n", 
	       (int) p, getpid(), getuid());
	return 0;
}


int main(int argc, char **argv)
{
	pthread_t tid1,tid2,tid3;
	void* ret;

	pthread_create(&tid1, 0, child, (void *)1); /* stevens did this too */

	printf("Current pid: %d, current uid: %d\n", getpid(), getuid());
	if(setuid(2000)<0)
		die("setting uid");
	printf("uid now: %d\n",getuid());



	pthread_create(&tid2, 0, child, (void *)2);
	pthread_create(&tid3, 0, child, (void *)3);
	pthread_join(tid1, &ret);
	pthread_join(tid2, &ret);
	pthread_join(tid3, &ret);
	printf("Exiting.\n");
}