curl(1) -6 -s -L -o /dev/null -w "%{http_code}\n" pansift.com
transfer a URL
-6, --ipv6
       If  libcurl  is  capable  of  resolving  an  address to multiple IP versions (which it is if it is
       IPv6-capable), this option tells libcurl  to  resolve  names  to  IPv6  addresses  only.   default
       statistics.
-s, --silent
       Silent or quiet mode. Don't show progress meter or error messages.  Makes Curl mute.
-L, --location
       (HTTP/HTTPS) If the server reports that the requested page  has  moved  to  a  different  location
       (indicated  with  a Location: header and a 3XX response code), this option will make curl redo the
       request on the new place. If used together with -i, --include or  -I,  --head,  headers  from  all
       requested pages will be shown. When authentication is used, curl only sends its credentials to the
       initial host. If a redirect takes curl to a different host, it won't  be  able  to  intercept  the
       user+password.  See  also  --location-trusted  on  how to change this. You can limit the amount of
       redirects to follow by using the --max-redirs option.

       When curl follows a redirect and the request is not a plain GET (for example POST or PUT), it will
       do  the  following  request  with a GET if the HTTP response was 301, 302, or 303. If the response
       code was any other 3xx code, curl will re-send the following request  using  the  same  unmodified
       method.
-o, --output <file>
       Write  output  to <file> instead of stdout. If you are using {} or [] to fetch multiple documents,
       you can use '#' followed by a number in the <file> specifier. That variable will be replaced  with
       the current string for the URL being fetched. Like in:

         curl http://{one,two}.site.com -o "file_#1.txt"

       or use several variables like:

         curl http://{site,host}.host[1-5].com -o "#1_#2"

       You may use this option as many times as the number of URLs you have.
-w, --write-out <format>
       Defines  what  to  display  on  stdout after a completed and successful operation. The format is a
       string that may contain plain text mixed with any number of variables. The string can be specified
       as  "string",  to  get  read from a particular file you specify it "@filename" and to tell curl to
       read the format from stdin you write "@-".
source manpages: curl