#include <bbs.h>intf_cp (src, dst, mode)char *src, *dst;int mode;			/* O_EXCL / O_APPEND / O_TRUNC */{  int fsrc, fdst, ret = 0;  if ((fsrc = open (src, O_RDONLY)) >= 0) {    ret = -1;    if ((fdst = open (dst, O_WRONLY | O_CREAT | mode, 0600)) >= 0) {      char pool[BLK_SIZE];      do {	ret = read (fsrc, pool, BLK_SIZE);	if (ret <= 0)	  break;      } while (write (fdst, pool, ret) > 0);      close (fdst);    }    close (fsrc);  }  return ret;}