ncb.c 715 B

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  1. #include <stdlib.h>
  2. #include <unistd.h>
  3. #include <sys/socket.h>
  4. #include <linux/in.h>
  5. int main (int argc, char *argv[])
  6. {
  7. int s, len, o, port = 6666;
  8. char buf[512];
  9. struct sockaddr_in addr;
  10. int addr_len = sizeof addr;
  11. if (argc > 1)
  12. port = atoi (argv[1]);
  13. s = socket (PF_INET, SOCK_DGRAM, IPPROTO_UDP);
  14. o = 1;
  15. len = 4;
  16. setsockopt (3, SOL_SOCKET, SO_REUSEADDR, &o, len);
  17. addr.sin_family = AF_INET;
  18. addr.sin_port = htons (port);
  19. addr.sin_addr.s_addr = INADDR_ANY; /* receive broadcasts */
  20. bind (s, (struct sockaddr *) &addr, sizeof addr);
  21. for (;;) {
  22. len = recvfrom (s, buf, sizeof buf, 0, (struct sockaddr *) &addr, &addr_len);
  23. if (len < 0)
  24. break;
  25. write (1, buf, len);
  26. }
  27. return 0;
  28. }