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

int main(void)
{
        char c;
        int src, dst;
        int count;

        src = open("src", O_RDONLY);
        if (src < 0) {
                perror("src");
                exit(1);
        }

        dst = open("dst", O_WRONLY | O_CREAT | O_TRUNC, 0666);
        if (dst < 0) {
                perror("dst");
                close(src);
                exit(1);
        }

        while ((count = read(src, &c, 1)) > 0) {
                if (write(dst, &c, count) < 0) {
                        perror("write");
                        exit(1);
                }
        }

        if (count < 0) {
                perror("read");
                exit(1);
        }

        close(src);
        close(dst);

        return 0;
}