udp_short_sockaddr.c: In function 'udp_sock':
udp_short_sockaddr.c:36:33: warning: implicit declaration of function 'exit' [-Wimplicit-function-declaration]
  if (s < 0) { perror("socket"); exit(1); }
                                 ^~~~
udp_short_sockaddr.c:36:33: warning: incompatible implicit declaration of built-in function 'exit'
udp_short_sockaddr.c:36:33: note: include '<stdlib.h>' or provide a declaration of 'exit'
udp_short_sockaddr.c:30:1:
+#include <stdlib.h>
 
udp_short_sockaddr.c:36:33:
  if (s < 0) { perror("socket"); exit(1); }
                                 ^~~~
udp_short_sockaddr.c:43:19: warning: incompatible implicit declaration of built-in function 'exit'
   perror("bind"); exit(1);
                   ^~~~
udp_short_sockaddr.c:43:19: note: include '<stdlib.h>' or provide a declaration of 'exit'
BUILD-OK