transfer a URL

-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 a FTP or FILE file,  curl  displays  the
       file size and last modification time only.

-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.

-k, --insecure
       (SSL)  This option explicitly allows curl to perform "insecure" SSL connections and transfers. All
       SSL connections are attempted to be made secure by using the CA certificate  bundle  installed  by
       default. This makes all connections considered "insecure" fail unless -k, --insecure is used.

       See this online resource for further details: http://curl.haxx.se/docs/sslcerts.html