#include <unistd.h>
#include <fcntl.h>
#include <stdlib.h> #define BUFFERSIZE 4096
#define COPYMODE 0644 void oops(char *, char *); int main(int argc, char *argv[])
{
int in_fd, out_fd, n_chars;
char buf[BUFFERSIZE]; if (argc != 3)
{
fprintf(stderr, "Usage: %s source destination\n", *argv);
exit(1);
} if ((in_fd = open(argv[1], O_RDONLY)) == -1)
oops("Cannot open ", argv[1]); if ((out_fd = creat(argv[2], COPYMODE)) == -1)
oops("Cannot creat ", argv[2]); while ((n_chars = read(in_fd, buf, BUFFERSIZE)) > 0)
{
if (write(out_fd, buf, n_chars) != n_chars)
{
oops("Write error to ", argv[2]);
}
} if (n_chars == -1)
oops("Read error from ", argv[1]); if (close(in_fd) == -1 || close(out_fd) == -1)
oops("Error closing files", "");
return 0;
}
void oops(char *s1, char *s2)
{
fprintf(stderr, "Error: %s", s1);
perror(s2);
exit(1);
}