在C中查找机器的IP地址？

Question

How do I get the IP address of the local machine in C on Windows? I was not able to get the IP address of my machine in the following code:

#include <ifaddrs.h>
#include <stdio.h>

int main()
{
    struct ifaddrs *id;
    int val;
    val = getifaddrs(&id);
    printf("Network Interface Name :- %s\n",id->ifa_name);
    printf("Network Address of %s :- %d\n",id->ifa_name,id->ifa_addr);
    printf("Network Data :- %d \n",id->ifa_data);
    printf("Socket Data : -%c\n",id->ifa_addr->sa_data);
    return 0;
}

I am facing an error while compiling:

fatal error C1083: Cannot open include file: 'net/if.h': No such file or directory.

I cannot use #include <net/if.h> as it is only available on Linux.

Answer 1

The code you showed does not compile because it is designed for Linux, not Windows. There is no <net/if.h> header on Windows.

getifaddrs() returns a linked list of local interface addresses. But getifaddrs() does not exist on Windows at all (unless you find a custom 3rd party implementation).

The equivalent on Windows is to use the Win32 GetAdaptersInfo() function on XP and earlier, or the GetAdaptersAddresses() function on Vista and later. Both functions return a linked list of detailed adapter information (much more than just addresses).

C examples are provided in their documentation on MSDN.

Answer 2

The structure

struct ifaddrs *id;

is a linked list. You have to loop through it and check the existence of the address

if(id->fa_addr)
   // print statements