Linux下C语言获取本机IP地址

1. #include <sys/ioctl.h>

2. #include <net/if.h>

3. #include <arpa/inet.h>

4.  

5. char* GetLocalIp()

6. {

7. int MAXINTERFACES=16;

8. char *ip = NULL;

9. int fd, intrface, retn = 0;

10. struct ifreq buf[MAXINTERFACES];

11. struct ifconf ifc;

12.  

13. if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) >= 0)

14. {

15. ifc.ifc_len = sizeof(buf);

16. ifc.ifc_buf = (caddr_t)buf;

17. if (!ioctl(fd, SIOCGIFCONF, (char *)&ifc))

18. {

19. intrface = ifc.ifc_len / sizeof(struct ifreq);

20.  

21. while (intrface-- > 0)

22. {

23. if (!(ioctl (fd, SIOCGIFADDR, (char *) &buf[intrface])))

24. {

25. ip=(inet_ntoa(((struct sockaddr_in*)(&buf[intrface].ifr_addr))->sin_addr));

26. break;

27. }

28. }

29. }

30. close (fd);

31. return ip;

32. }

33. }