#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

int main(int argc, char *argv[])
{
	int in;
	int out;
	int pagesize; 
	void *buf;
	off_t pos;

	if (argc != 3) {
		printf("Usage: %s <src> <dest>\n", argv[0]); 
		return EXIT_FAILURE;
	}

	in = open(argv[1], O_RDONLY, 0);
	out = open(argv[2], O_CREAT | O_WRONLY | O_TRUNC, 0666);

	posix_fadvise(in, 0, 0, POSIX_FADV_SEQUENTIAL);
	posix_fadvise(out, 0, 0, POSIX_FADV_SEQUENTIAL);

	pagesize = getpagesize();
	buf = malloc(pagesize);

	pos = 0;

	for (;;) {
		ssize_t count;

		count = read(in, buf, pagesize);
		if (!count || count == -1)
			break;

		write(out, buf, count);

		/* right usage pattern? */
		posix_fadvise(in, pos, count, POSIX_FADV_NOREUSE);
		posix_fadvise(out, pos, count, POSIX_FADV_NOREUSE);

		pos += count;
	}

	free(buf);
	close(in);
	close(out);

	return EXIT_SUCCESS;
}