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

#define  MYSIZE      10000

int copy_file(char destination[], char source[])        
{
//  ATTEMPT TO OPEN source FOR READ-ONLY ACCESS
    int fd0    = open(source, O_RDONLY);
//  ENSURE THE FILE COULD BE OPENED
    if(fd0 == -1) {
        return -1;
    }

//  ATTEMPT TO OPEN destination FOR WRITE-ONLY ACCESS
    int fd1    = open(destination, O_WRONLY);
//  ENSURE THE FILE COULD BE OPENED
    if(fd1 == -1) {
        close(fd0);
        return -1;
    }

//  DEFINE A CHARACTER ARRAY TO HOLD THE FILE'S CONTENTS
    char   buffer[MYSIZE];
    size_t got;

//  PERFORM MULTIPLE READs OF FILE UNTIL END-OF-FILE REACHED  
    while((got = read(fd0, buffer, sizeof buffer)) > 0) {  
        if(write(fd1, buffer, got)) != got) {  
            close(fd0); close(fd1);
            return -1;
        }
    }

    close(fd0); close(fd1);
    return 0;
}