CURLOPT_PROXYUSERNAME (3) - Linux Manuals
CURLOPT_PROXYUSERNAME: user name to use for proxy authentication
NAME
CURLOPT_PROXYUSERNAME - user name to use for proxy authenticationSYNOPSIS
#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PROXYUSERNAME, char *username);
DESCRIPTION
Pass a char * as parameter, which should be pointing to the zero terminated user name to use for the transfer.CURLOPT_PROXYUSERNAME(3) sets the user name to be used in protocol authentication with the proxy.
To specify the proxy password use the CURLOPT_PROXYPASSWORD(3).