CURLOPT_USERNAME − user name to use in authentication
curl_easy_setopt(CURL *handle, CURLOPT_USERNAME,
Pass a char * as parameter, which should be pointing to the null-terminated user name to use for the transfer.
CURLOPT_USERNAME(3) sets the user name to be used in protocol authentication. You should not use this option together with the (older) CURLOPT_USERPWD(3) option.
When using Kerberos V5 authentication with a Windows based server, you should include the domain name in order for the server to successfully obtain a Kerberos Ticket. If you don’t then the initial part of the authentication handshake may fail.
When using NTLM, the user name can be specified simply as the user name without the domain name should the server be part of a single domain and forest.
To include the domain name use either Down-Level Logon Name or UPN (User Principal Name) formats. For example, EXAMPLE\user and firstname.lastname@example.org respectively.
Some HTTP servers (on Windows) support inclusion of the domain for Basic authentication as well.
To specify the password and login options, along with the user name, use the CURLOPT_PASSWORD(3) and CURLOPT_LOGIN_OPTIONS(3) options.
The application does not have to keep the string around after setting this option.
CURL *curl =
curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/foo.bin");
curl_easy_setopt(curl, CURLOPT_USERNAME, "clark");
ret = curl_easy_perform(curl);
Added in 7.19.1
Returns CURLE_OK if the option is supported, CURLE_UNKNOWN_OPTION if not, or CURLE_OUT_OF_MEMORY if there was insufficient heap space.
CURLOPT_USERPWD(3), CURLOPT_PASSWORD(3), CURLOPT_HTTPAUTH(3), CURLOPT_PROXYAUTH(3)