- if (FD_ISSET(selectable_fd, &setread))
- printf("readable, ");
- else
- printf("not readable, ");
- if (FD_ISSET(selectable_fd, &setexcept))
- printf("exceptional condition\n");
- else
- printf("no exceptional condition\n");
+ if (selectable_fd == -1)
+ printf("couldn't do select() on FD\n");
+ else {
+ if (FD_ISSET(selectable_fd, &setread))
+ printf("readable, ");
+ else
+ printf("not readable, ");
+ if (FD_ISSET(selectable_fd, &setexcept))
+ printf("exceptional condition\n");
+ else
+ printf("no exceptional condition\n");
+ }