http head

Accept	HTTP_ACCEPT
Accept-Charset	HTTP_ACCEPT-CHARSET
Accept-Encoding	HTTP_ACCEPT-ENCODING
Accept-Language	HTTP_ACCEPT-LANGUAGE
Accept-Ranges	HTTP_ACCEPT-RANGES
Age	HTTP_AGE
Allow	HTTP_ALLOW
Authorization	HTTP_AUTHORIZATION
Cache-Control	HTTP_CACHE-CONTROL
Connection	HTTP_CONNECTION
Content-Base	HTTP_CONTENT-BASE
Content-Disposition	HTTP_CONTENT-DISPOSITION
Content-Encoding	HTTP_CONTENT-ENCODING
Content-Language	HTTP_CONTENT-LANGUAGE
Content-Length	HTTP_CONTENT-LENGTH
Content-Location	HTTP_CONTENT-LOCATION
Content-MD5	HTTP_CONTENT-MD5
Content-Range	HTTP_CONTENT-RANGE
Content-Type	HTTP_CONTENT-TYPE
Cookie	HTTP_COOKIE
Date	HTTP_DATE
ETag	HTTP_ETAG
Expires	HTTP_EXPIRES
From	HTTP_FROM
Host	HTTP_HOST
If-Match	HTTP_IF-MATCH
If-Modified-Since	HTTP_IF-MODIFIED-SINCE
If-None-Match	HTTP_IF-NONE-MATCH
If-Range	HTTP_IF-RANGE
Last-Modified	HTTP_LAST-MODIFIED
Link	HTTP_LINK
Location	HTTP_LOCATION
Max-Forwards	HTTP_MAX-FORWARDS
Mime-Version	HTTP_MIME-VERSION
Pragma	HTTP_PRAGMA
Proxy-Authenticate	HTTP_PROXY-AUTHENTICATE
Proxy-Authentication-Info	HTTP_PROXY-AUTHENTICATION-INFO
Proxy-Authorization	HTTP_PROXY-AUTHORIZATION
Proxy-Connection	HTTP_PROXY-CONNECTION
Public	HTTP_PUBLIC
Range	HTTP_RANGE
Referer	HTTP_REFERER
Request-Range	HTTP_REQUEST-RANGE
Retry-After	HTTP_RETRY-AFTER
Server	HTTP_SERVER
Set-Cookie	HTTP_SET-COOKIE
Title	HTTP_TITLE
Transfer-Encoding	HTTP_TRANSFER-ENCODING
Upgrade	HTTP_UPGRADE
User-Agent	HTTP_USER-AGENT
Vary	HTTP_VARY
Via	HTTP_VIA
Warning	HTTP_WARNING
WWW-Authenticate	HTTP_WWW-AUTHENTICATE
Authentication-Info	HTTP_AUTHENTICATION-INFO
X-Cache	HTTP_X-CACHE
X-Cache-Lookup	HTTP_X-CACHE-LOOKUP
X-Forwarded-For	HTTP_X-FORWARDED-FOR
X-Request-URI	HTTP_X-REQUEST-URI
X-Squid-Error	HTTP_X-SQUID-ERROR
Negotiate	HTTP_NEGOTIATE
X-Accelerator-Vary	HTTP_X-ACCELERATOR-VARY
Other:	HTTP_OTHER: