[k33l0r]

> If you only care about headers use the -I flag and the response body will be hidden

That is actually wrong. The -I flag set the request method to HEAD. So in some cases it will return different headers than a normal get request (and some servers don't implement HEAD responses at all).

[eik3_de]

That's why I have this in the shell config and use it daily:

  alias h='curl -sIX GET -w "Total time: %{time_total} s\n"'

It issues a GET request, only prints the response headers and displays the time it took.

[markild]

Very true, but let's not forget that [0]

> The HEAD method is identical to GET except that the server MUST NOT return a message-body in the response.

and that

> 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.

[0]: http://www.w3.org/Protocols/rfc2616/rfc2616-sec9.html

[eli]

Yes, it should work the same. But it's not the same.

[KrisJordan]

Ah, great catch. Added a note about having to specify the method explicitly / that -I uses HEAD implicitly. Thanks!

[bonobo]

A better way to view only the header of a response is using the flags -o to redirect the body and -D to redirect the header of the response. When I want to print only the header to stdout I do

    curl -o/dev/null -D- http://www.example.com

-I does not work with methods other than GET. This does the job.

[KrisJordan]

So you can use -I with another method, but as soon as you add a body curl refuses. Went ahead and just took that scenario out of the post -- but your redirection snippet is great.

[brown9-2]

Why not just use -i?

[bonobo]

-i mixes the header and the body of the response into one stream. If you want only the header it won't help.

[brown9-2]

Note that -I and -i are different:

-i, --include (HTTP) Include the HTTP-header in the output. The HTTP-header includes things like server-name, date of the document, HTTP-version and more...

-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.