#include <stdio.h>
#include <dirent.h>
#include <assert.h>

int main(int argc, char *argv[])
{
	DIR *dirp;
	struct dirent *dent;
	off_t dpos;

	if (argc < 2) {
		fprintf(stderr, "Usage: %s DIR\n", argv[0]);
		return 1;
	}

	dirp = opendir(argv[1]);
	assert(dirp);
	dpos = 0;

	for (;;) {
		seekdir(dirp, dpos);
		dent = readdir(dirp);
		if (!dent)
			break;
		assert(dpos != telldir(dirp));
		dpos = telldir(dirp);
	}

	return 0;
}