Skip to content

Instantly share code, notes, and snippets.

@johntyree
Created January 15, 2015 19:16
Show Gist options
  • Save johntyree/c1bf0c4ec02deb4e6b4a to your computer and use it in GitHub Desktop.
Save johntyree/c1bf0c4ec02deb4e6b4a to your computer and use it in GitHub Desktop.
#include <stdio.h>
#include <unistd.h>
#include <string.h> /* for strncpy */
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <netinet/in.h>
#include <net/if.h>
#include <arpa/inet.h>
int main(int argc, char *argv[])
{
int fd;
struct ifreq ifr;
const char *interface = argc > 1 ? argv[1] : "eth0";
fd = socket(AF_INET, SOCK_DGRAM, 0);
/* I want to get an IPv4 IP address */
ifr.ifr_addr.sa_family = AF_INET;
/* I want IP address attached to "eth0" */
strncpy(ifr.ifr_name, interface, IFNAMSIZ-1);
ioctl(fd, SIOCGIFADDR, &ifr);
close(fd);
/* display result */
printf("%s\n", inet_ntoa(((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr));
return 0;
}
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment