dnslookup-1.py 文件源码

def dnslookup(str):
    """ Perform DNS lookup on str.  If first character of digit is numeric,
        assume that str contains an IP address.  Otherwise, assume that str
        contains a hostname."""
    if str == '': str = ' '
    if str[0] in string.digits:
        try:
            value = socket.gethostbyaddr(str)[0]
        except:
            value = 'Lookup failed'
    else:
        try:
            value = socket.gethostbyname(str)
        except:
            value = 'Lookup failed'
    return value