C/C ++ obtains the IP address of the local machine.

/* Compiling environment: Visual C ++ */

1. # Include <stdio. h>
2. # Include <winsock2.h>
3. # Pragma comment (Lib, "ws2_32.lib ")
5. Int doit (INT, char **)
6. {
7. Char host_name [2, 255];
8. // Obtain the local host name
9. If (gethostname (host_name, sizeof (host_name) = socket_error ){
10. Printf ("error % d when getting local host name./N", wsagetlasterror ());
11. Return 1;
12. }
13. Printf ("host name is: % s/n", host_name );
15. // Obtain the corresponding "host" from the host name database"
16. Struct hostent * Phe = gethostbyname (host_name );
17. If (PHE = 0 ){
18. Printf ("yow! Bad host lookup .");
19. Return 1;
20. }
22. // Cyclically obtain all IP addresses of the Local Machine
23. For (INT I = 0; phe-> h_addr_list [I]! = 0; ++ I ){
24. Struct in_addr ADDR;
25. Memcpy (& ADDR, Phe-> h_addr_list [I], sizeof (struct in_addr ));
26. Printf ("address % d: % s/n", I, inet_ntoa (ADDR ));
27. }
29. Return 0;
30. }
32. Int main (INT argc, char * argv [])
33. {
34. Wsadata;
35. If (wsastartup (makeword (1, 1), & wsadata )! = 0 ){
36. Return 255;
37. }
39. Int retval = doit (argc, argv );
41. Wsacleanup ();
43. Return retval;
44. }