Programming :: PING Using Raw Sockets In C?

Is there any way to implement a simple ping script in C (unix)? I'm programming simple OpenWRT scripts.

I have found some examples of ping in C:

[URL]

However, nothing happens, nothing is sent.

When I look at the code, in the portion where the socket is created, I can see that the socket is not binding to any interface:

Code:
if ((sockfd = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP)) == -1)
{
perror("socket");
exit(EXIT_FAILURE);
}
setsockopt(sockfd, IPPROTO_IP, IP_HDRINCL, &optval, sizeof(int));

Instead, it uses "setsockopt" to set some options.

My guess is that it is trying to send packets over the eth0 interface instead over the wl0 (wireless) interface (which is the one I want to use to send pings).

Now, my question is: Is there any other way to send pings in C by binding to an interface?