- (void) xwrite (sock, lenbuf, 4);
- (void) xwrite (sock, buf, len);
+ if (xwrite (sock, lenbuf, 4) == -1) {
+ fprintf (stderr, "xwrite failed\n");
+ exit (1);
+ }
+ if (xwrite (sock, buf, len) == len) {
+ fprintf (stderr, "xwrite failed\n");
+ exit (1);
+ }