Programmatical determination of Network card MAC

You can also do that programmatically, by parsing the output of ifconfig.

The code you need to read it directly is found in the source for ethtool and ifconfig too for that matter. But it's simple enough. Email me and I will give you a sourcecode snippet (I'm not on my Linux box right now).

Poke around in /proc/net if you feel like saving the cost of a popen() or system(). Frankly, though, this routine will probably run so seldom that time spent optimising it is time wasted.

Kelly

I didn't want to suggest /proc because it's possible in an embedded system (in particular) that there may be no /proc filesystem.

Just ripped out the following from an older project...

#ifndef FAKED_IDENTITY // set an default mac... memcpy (my_mac, fake_mac, sizeof (my_mac)); success = 0;

if ((sockfd = socket (AF_INET, SOCK_DGRAM, 0)) >= 0) { strncpy (ifr.ifr_name, "eth0", IFNAMSIZ); memset (&ifr.ifr_hwaddr, 0, sizeof (struct sockaddr)); if (ioctl (sockfd, SIOCGIFHWADDR, &ifr) >= 0) { memcpy (&hwaddr, &ifr.ifr_hwaddr, sizeof (hwaddr)); memcpy (&my_mac, &hwaddr.sa_data, sizeof (my_mac)); success = 1; }

close (sockfd); }

if (success) log (SLOG_BASE+1, "hwaddr(%s): %02x:%02x:%02x:%02x:%02x:%02x", ifr.ifr_name, my_mac[0], my_mac[1], my_mac[2], my_mac[3], my_mac[4], my_mac[5]); else log (SLOG_ERR, "failed to determine hw addr"); #endif

Hope you've got sockets ;-)

HTH. Salut, Jörg

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