利用C语言获取设备的MAC address

利用C语言获取设备的MAC address

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MAC address --> Medium Access Control layer address

//
// http://www.binarytides.com/c-program-to-get-mac-address-from-interface-name-on-linux/

#include <stdio.h>	//printf
#include <string.h>	//strncpy
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>	//ifreq
#include <unistd.h>	//close

void getmacaddr(char *macaddr, const char *interface)
{
	int fd;
	struct ifreq ifr;
	const char *iface = interface;
	unsigned char *mac;

	fd = socket(AF_INET, SOCK_DGRAM, 0);

	ifr.ifr_addr.sa_family = AF_INET;
	strncpy(ifr.ifr_name , iface , IFNAMSIZ-1);

	ioctl(fd, SIOCGIFHWADDR, &ifr);

	close(fd);

	mac = (unsigned char *)ifr.ifr_hwaddr.sa_data;

	sprintf(macaddr, "%.2x:%.2x:%.2x:%.2x:%.2x:%.2x" , mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);

}

int main()
{
	char macaddress[17]={'0'};
	getmacaddr(macaddress, "eth0");

	int i=0;
	for(i=0;i<sizeof(macaddress);i++)
	{
		printf("%c", macaddress[i]);
	}
	printf("\n");

	return 0;
}

这里有一个需要玩味的是，函数getmacaddr()同样可以使用二维字符之称char **作为参数，但是需要注意的是，不能直接拿参数来操作，需要设置临时变量。

void _getmacaddr(char **macaddr, const char *interface)
{
	int fd;
	struct ifreq ifr;
	const char *iface = interface;
	unsigned char *mac;
	char **newaddress = macaddr;

	fd = socket(AF_INET, SOCK_DGRAM, 0);

	ifr.ifr_addr.sa_family = AF_INET;
	strncpy(ifr.ifr_name , iface , IFNAMSIZ-1);

	ioctl(fd, SIOCGIFHWADDR, &ifr);

	close(fd);

	mac = (unsigned char *)ifr.ifr_hwaddr.sa_data;

	sprintf( *newaddress, "%.2x:%.2x:%.2x:%.2x:%.2x:%.2x" , mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);

}

参考：

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1、Get MAC Address

2、How to get mac address