def head(phenny, input):
    """Provide HTTP HEAD information."""
    uri = input.group(2)
    uri = (uri or '')
    if ' ' in uri:
        uri, header = uri.rsplit(' ', 1)
    else: uri, header = uri, None

    if not uri and hasattr(phenny, 'last_seen_uri'):
        try: uri = phenny.last_seen_uri[input.sender]
        except KeyError: return phenny.say('?')

    if not uri.startswith('htt'):
        uri = 'http://' + uri
    # uri = uri.replace('#!', '?_escaped_fragment_=')

    start = time.time()

    try:
        info = web.head(uri)
        info['status'] = '200'
    except urllib.error.HTTPError as e:
        return phenny.say(str(e.code))
    except http.client.InvalidURL:
        return phenny.say("Not a valid URI, sorry.")
    except IOError:
        return phenny.say("Can't connect to %s" % uri)

    resptime = time.time() - start

    if header is None:
        data = []
        if 'Status' in info:
            data.append(info['Status'])
        if 'content-type' in info:
            data.append(info['content-type'].replace('; charset=', ', '))
        if 'last-modified' in info:
            modified = info['last-modified']
            modified = time.strptime(modified, '%a, %d %b %Y %H:%M:%S %Z')
            data.append(time.strftime('%Y-%m-%d %H:%M:%S UTC', modified))
        if 'content-length' in info:
            data.append(info['content-length'] + ' bytes')
        data.append('{0:1.2f} s'.format(resptime))
        phenny.reply(', '.join(data))
    else:
        headerlower = header.lower()
        if headerlower in info:
            phenny.say(header + ': ' + info.get(headerlower))
        else:
            msg = 'There was no %s header in the response.' % header
            phenny.say(msg)
head.commands = ['head']
head.example = '.head http://www.w3.org/'

r_title = re.compile(r'(?ims)<title[^>]*>(.*?)</title\s*>')
r_entity = re.compile(r'&[A-Za-z0-9#]+;')