#http response

From this brilliant blog post...  https://blog.josephscott.org/2011/10/14/timing-details-with-curl/

cURL supports formatted output for the details of the request (see the cURL manpage for details, under -w, –write-out <format>). For our purposes we’ll focus just on the timing details that are provided.

1. Create a new file, curl-format.txt, and paste in:

   time_namelookup:  %{time_namelookup}\n       time_connect:  %{time_connect}\n    time_appconnect:  %{time_appconnect}\n   time_pretransfer:  %{time_pretransfer}\n      time_redirect:  %{time_redirect}\n time_starttransfer:  %{time_starttransfer}\n                    ----------\n         time_total:  %{time_total}\n

2. Make a request:

curl -w "@curl-format.txt" -o /dev/null -s "http://wordpress.com/"

Or on Windows, it's...

curl -w "@curl-format.txt" -o NUL -s "http://wordpress.com/"

What this does:

-w "@curl-format.txt" tells cURL to use our format file -o /dev/null redirects the output of the request to /dev/null -s tells cURL not to show a progress meter "http://wordpress.com/" is the URL we are requesting. Use quotes particularly if your URL has "&" query string parameters

And here is what you get back:

Clean http response header

What are the required http response header fields to sent from server to the client?

I working to optimize the http response header to minimize the http response overhead. I know “overhead” is somewhat exaggerated, but i like a clean output.

I see a lot of website’s, which sends IMHO redundant cache headers:

e.g. It is redundant to specify both Expires and Cache-Control: max-age, or to specify…