#include 
#include 
#include 
#include 
#include 
int main(int argc, char **argv) {
 char buf[1024];
 int n, in, out;
 if(argc != 3) {
 fprintf(stderr, "Usage: append SOURCE TARGET\n");
 return 0;
 }
 /* open the first file for reading */
 in = open(argv[1], O_RDONLY);
 /* the second file for writing */
 out = open(argv[2], O_WRONLY|O_APPEND);
 /* copy data from the first file to the second file */
 while((n = read(in, buf, sizeof(buf))) > 0)
 write(out, buf, n);
 return 0;
}