| Long: user | 
 | Short: u | 
 | Arg: <user:password> | 
 | Help: Server user and password | 
 | --- | 
 | Specify the user name and password to use for server authentication. Overrides | 
 | --netrc and --netrc-optional. | 
 |  | 
 | If you simply specify the user name, curl will prompt for a password. | 
 |  | 
 | The user name and passwords are split up on the first colon, which makes it | 
 | impossible to use a colon in the user name with this option. The password can, | 
 | still. | 
 |  | 
 | 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 | 
 | handshake may fail. | 
 |  | 
 | When using NTLM, the user name can be specified simply as the user name, | 
 | without the domain, if there is a single domain and forest in your setup | 
 | for example. | 
 |  | 
 | To specify the domain name use either Down-Level Logon Name or UPN (User | 
 | Principal Name) formats. For example, EXAMPLE\\user and user@example.com | 
 | respectively. | 
 |  | 
 | If you use a Windows SSPI-enabled curl binary and perform Kerberos V5, | 
 | Negotiate, NTLM or Digest 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 :". | 
 |  | 
 | If this option is used several times, the last one will be used. |