#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
#include <errno.h>

int main(int argc, char** argv) {

	int fd = open("test.txt", O_WRONLY|O_CREAT|O_TRUNC, S_IRUSR|S_IWUSR);
	if (fd < 0) {
		fprintf(stderr, "return from open %d\n", fd);
		return 1;
	}

	char txt[] = "Hello World\n";

	int r = write(fd, txt, sizeof(txt));
	if (r != sizeof(txt)) {
		fprintf(stderr, "return from write unexpected -- %d -- %s\n", 
			r, strerror(errno));
		return 1;
	}

	close(fd);
	return 0;
}