s/fileno\(stdin\)/STDIN_FILENO/g

s/fileno\(stdout\)/STDOUT_FILENO/g

libbb/dump.c

@@ -311,7 +311,7 @@ static void do_skip(char *fname, int statok)
 	struct stat sbuf;
 
 	if (statok) {
-		if (fstat(fileno(stdin), &sbuf)) {
+		if (fstat(STDIN_FILENO, &sbuf)) {
 			bb_perror_msg_and_die("%s", fname);
 		}
 		if ((!(S_ISCHR(sbuf.st_mode) ||

libbb/print_file.c

@@ -28,7 +28,7 @@ extern void bb_xprint_and_close_file(FILE *file)
 	bb_xfflush_stdout();
 	/* Note: Do not use STDOUT_FILENO here, as this is a lib routine
 	 *       and the calling code may have reassigned stdout. */
-	if (bb_copyfd_eof(fileno(file), fileno(stdout)) == -1) {
+	if (bb_copyfd_eof(fileno(file), STDOUT_FILENO) == -1) {
 		/* bb_copyfd outputs any needed messages, so just die. */
 		exit(bb_default_error_retval);
 	}