transfer a URL

-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

-u, --user <user:password>
       Specify the user name and password to use for server authentication.  Overrides  -n,  --netrc  and
       --netrc-optional.

       If you just give the user name (without entering a colon) curl will prompt for a password.

       If  you  use an SSPI-enabled curl binary and do NTLM authentication, you can force curl to pick up
       the user name and password from your environment by simply specifying a  single  colon  with  this
       option: "-u :".

       If this option is used several times, the last one will be used.

-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.