How to determine the HTTP status without downloading the complete page?

Question

I want to know the HTTP Status of the websites using Ubuntu. I have used curl and wget command for that purpose. But the problem is these commands download the complete website page and then search for the header and display it on the screen. For example:

$ curl -I trafficinviter.com
HTTP/1.1 200 OK
Date: Mon, 02 Jan 2017 14:13:14 GMT
Server: Apache
X-Pingback: http://trafficinviter.com/xmlrpc.php
Link: <http://trafficinviter.com/>; rel=shortlink
Set-Cookie: wpfront-notification-bar-landingpage=1
Content-Type: text/html; charset=UTF-8

Same thing happens with Wgetcommand where the complete page is getting downloaded and unnecessarily consuming my bandwidth.

What I am looking for is: how to get the HTTP status code without actually downloading any page so that I can save my bandwidth consumption. I had tried using curl but not sure is I am downloading complete page or just a header to my system to get the status code.

Answer 1

curl -I fetches only the HTTP headers; it does not download the whole page. From man curl:

-I, --head
      (HTTP/FTP/FILE) Fetch the HTTP-header only! HTTP-servers feature
      the command HEAD which this uses to get nothing but  the  header
      of  a  document. When used on an FTP or FILE file, curl displays
      the file size and last modification time only.

Another option is to install lynx and use lynx -head -dump.

The HEAD request is specified by the HTTP 1.1 protocol (RFC 2616):

9.4 HEAD

   The HEAD method is identical to GET except that the server MUST NOT
   return a message-body in the response. The metainformation contained
   in the HTTP headers in response to a HEAD request SHOULD be identical
   to the information sent in response to a GET request. This method can
   be used for obtaining metainformation about the entity implied by the
   request without transferring the entity-body itself. This method is
   often used for testing hypertext links for validity, accessibility,
   and recent modification.

Answer 2

With wget, you need to use the --spider option to send a HEAD request like curl:

$ wget -S --spider https://google.com
Spider mode enabled. Check if remote file exists.
--2017-01-03 00:08:38--  https://google.com/
Resolving google.com (google.com)... 216.58.197.174
Connecting to google.com (google.com)|216.58.197.174|:443... connected.
HTTP request sent, awaiting response... 
  HTTP/1.1 302 Found
  Cache-Control: private
  Content-Type: text/html; charset=UTF-8
  Location: https://www.google.co.jp/?gfe_rd=cr&ei=...
  Content-Length: 262
  Date: Mon, 02 Jan 2017 15:08:38 GMT
  Alt-Svc: quic=":443"; ma=2592000; v="35,34"
Location: https://www.google.co.jp/?gfe_rd=cr&ei=... [following]
Spider mode enabled. Check if remote file exists.
--2017-01-03 00:08:38--  https://www.google.co.jp/?gfe_rd=cr&ei=...
Resolving www.google.co.jp (www.google.co.jp)... 210.139.253.109, 210.139.253.93, 210.139.253.123, ...
Connecting to www.google.co.jp (www.google.co.jp)|210.139.253.109|:443... connected.
HTTP request sent, awaiting response... 
  HTTP/1.1 200 OK
  Date: Mon, 02 Jan 2017 15:08:38 GMT
  Expires: -1
  Cache-Control: private, max-age=0
  Content-Type: text/html; charset=Shift_JIS
  P3P: CP="This is not a P3P policy! See https://www.google.com/support/accounts/answer/151657?hl=en for more info."
  Server: gws
  X-XSS-Protection: 1; mode=block
  X-Frame-Options: SAMEORIGIN
  Set-Cookie: NID=...; expires=Tue, 04-Jul-2017 15:08:38 GMT; path=/; domain=.google.co.jp; HttpOnly
  Alt-Svc: quic=":443"; ma=2592000; v="35,34"
  Transfer-Encoding: chunked
  Accept-Ranges: none
  Vary: Accept-Encoding
Length: unspecified [text/html]
Remote file exists and could contain further links,
but recursion is disabled -- not retrieving.