figuring out some things regarding directories

unlink-dir.c

#include <err.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <unistd.h>

int main(void)
{
	const char *outer_path = "tmpdir";
	const char *inner_path = "inner";
	const char *file_path = "file";
	struct stat sb = {};
	int dirfd = 0;
	int error = 0;

	error = stat(outer_path, &sb);
	if(error != 0 && errno == ENOENT)
	{
		fprintf(stderr, "stat: ENOENT\n");
		if(mkdir(outer_path, 0750))
		{
			err(1, "mkdir");
		}
		fprintf(stderr, "mkdir: ok\n");
		error = stat(outer_path, &sb);
	}
	if(error != 0)
	{
		err(1, "stat");
	}
	fprintf(stderr, "stat: ok\n");

	if(!(sb.st_mode&S_IFDIR))
	{
		errx(1, "dir is not a directory: %s", outer_path);
	}
	fprintf(stderr, "directory: ok\n");

	dirfd = open(outer_path, O_DIRECTORY);
	if(dirfd < 0)
	{
		err(1, "open");
	}
	fprintf(stderr, "open: ok\n");

	/*
	// if this is enabled the unlinkat call fails with "directory not empty" on this box
	if((error = openat(dirfd, file_path, O_CREAT|O_APPEND)) < 0)
	{
		err(1, "creat");
	}
	close(error);
	fprintf(stderr, "creat: ok\n");
	//*/

	if(unlinkat(AT_FDCWD, outer_path, AT_REMOVEDIR))
	{
		err(1, "unlink");
	}
	fprintf(stderr, "unlink: ok\n");

	printf("waiting, press enter to continue\n");
	getchar();

	//*
	// this fails with "no such file or directory"
	// likely because the directory does have neither `.` nor `..` after the unlinkat, therefore ceasing to exist
	if(mkdirat(dirfd, inner_path, 0))
	{
		err(1,"mkdirat");
	}
	fprintf(stderr, "mkdirat: ok\n");
	//*/

	printf("waiting, press enter to continue\n");
	getchar();

	return 0;
}