authentication then you can tell curl to select the user name and password
from your environment by specifying a single colon with this option: "-U :".
+On systems where it works, curl will hide the given option argument from
+process listings. This is not enough to protect credentials from possibly
+getting seen by other users on the same system as they will still be visible
+for a brief moment before cleared. Such sensitive data should be retrieved
+from a file instead or similar and never used in clear text in a command line.
+
If this option is used several times, the last one will be used.
impossible to use a colon in the user name with this option. The password can,
still.
+On systems where it works, curl will hide the given option argument from
+process listings. This is not enough to protect credentials from possibly
+getting seen by other users on the same system as they will still be visible
+for a brief moment before cleared. Such sensitive data should be retrieved
+from a file instead or similar and never used in clear text in a command line.
+
When using Kerberos V5 with a Windows based server you should include the
Windows domain name in the user name, in order for the server to successfully
obtain a Kerberos Ticket. If you don't then the initial authentication