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

#define FILE_SIZE 325443890
#define WRT_BYTES 4096

int main(void)
{
	struct stat stat_buf;
	int fd = 0, flag = 0;
	const size_t cnt = FILE_SIZE / WRT_BYTES;
	char arr[WRT_BYTES];
	
	fd = open("this_file_name.mp4",
		O_RDWR|O_CREAT, 0666);
	
	fstat(fd, &stat_buf);
	
	flag = fcntl(fd, F_GETFD);
	fcntl(fd, F_SETFD, flag | FD_CLOEXEC);
	
	lseek(fd, 0, SEEK_CUR);
	
	ftruncate(fd, FILE_SIZE);
	
	lseek(fd, 0, SEEK_SET);
	
	for (int i = 0; i < cnt; ++i) {
		write(fd, arr, WRT_BYTES);
	}
	
	write(fd, arr, FILE_SIZE - (WRT_BYTES * cnt));
	
	close(fd);
	
	return 0;
}