import socket
import fcntl
import string
import sys
import exceptions

def hexy(n):
	return "%02x" % (ord(n))

def getMAC(ifname):
	SIOCGIFHWADDR = 0x8927 # magic number
	s=socket.socket(socket.AF_INET,socket.SOCK_STREAM)
	ifname = string.strip(ifname)
	
	print ifname
	
	ifr = ifname + '\0' * (32-len(ifname))
	
	print ifr
	
	try:
		r= fcntl.ioctl(s.fileno(),SIOCGIFHWADDR,ifr)
		addr = map(hexy,r[18:24])
		ret = (':'.join(map(str, addr)))
	except IOError, e:
		ret = ''
	return ret

if __name__ == "__main__":
	print getMAC(sys.argv[1])