Why this .vbs script retrieve null value?
Option Explicit
On Error Resume Next
Dim h: Set h = CreateObject("MSXML2.XMLHTTP")
h.Open "HEAD", "http://google.com/", False
h.send
Dim GetLocation: Set GetLocation = h.getResponseHeader("Location")
MsgBox GetLocation
Almost all HTTP libraries follow redirects by default.
Therefore you can not get Location header as long as you follow the redirects, so you need to stop following redirects.
I recommend two different solutions.
#1 Achieving the final url would be the easiest way instead of getting Location header.
Option Explicit
Dim GetLocation
Const SXH_OPTION_URL = -1
Dim h
Set h = CreateObject("MSXML2.ServerXMLHTTP")
h.Open "HEAD", "http://google.com/", False
h.send
GetLocation = h.getOption(SXH_OPTION_URL) 'final URL even if redirected
MsgBox GetLocation
#2 If you want to make sure you get the first Location header (not the last link in the chain of redirects), you should use WinHttpRequest by disabling redirects, so you can get the header if available.
Option Explicit
Dim GetLocation
Const WHR_EnableRedirects = 6
Dim h
Set h = CreateObject("WinHttp.WinHttpRequest.5.1")
h.Option(WHR_EnableRedirects) = False 'disable redirects
h.Open "HEAD", "http://google.com/", False
h.Send
GetLocation = h.GetResponseHeader("Location") 'an error occurs if not exist
MsgBox GetLocation
Not sure off hand why you don't get the Location HTTP header, but you can debug by adjusting your code
Option Explicit
On Error Resume Next
Dim h: Set h = CreateObject("MSXML2.XMLHTTP")
h.Open "HEAD", "http://google.com/", False
h.send
Dim headers: headers = h.getAllResponseHeaders()
MsgBox headers
Example output
Date: Fri, 18 Sep 2015 15:33:41 GMT Expires: -1 Cache-Control: private, max-age=0 Content-Type: text/html; charset=UTF-8 Server: gws X-XSS-Protection: 1; mode=block X-Frame-Options: SAMEORIGIN Alternate-Protocol: 443:quic,p=1 Alt-Svc: quic=":443"; p="1"; ma=604800 Transfer-Encoding: chunked
Thinking about it not sure if Location is included unless the server is redirecting from a URL.
If the location isn't provided, it is because the winhttp service isn't registered to the server to connect to. So you can change the user-agent option with objWinhttpReq.Option(0) = "curl" since it works well with curl tool.
Option Explicit
Dim GetLocation
Const WHR_UserAgent = 0
Dim h
Set h = CreateObject("WinHttp.WinHttpRequest.5.1")
h.Option(WHR_UserAgent ) = "curl"
h.Open "HEAD", "http://google.com/", False
h.Send
GetLocation = h.GetResponseHeader("Location") 'an error occurs if not exist
MsgBox GetLocation
