CURLOPT_NOPROXY man page
CURLOPT_NOPROXY — disable proxy use for specific hosts
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_NOPROXY, char *noproxy);
Pass a pointer to a zero terminated string. The string consists of a comma separated list of host names that do not require a proxy to get reached, even if one is specified. The only wildcard available is a single * character, which matches all hosts, and effectively disables the proxy. Each name in this list is matched as either a domain which contains the hostname, or the hostname itself. For example, example.com would match example.com, example.com:80, and www.example.com, but not www.notanexample.com or example.com.othertld.
The application does not have to keep the string around after setting this option.
Added in 7.19.4
Returns CURLE_OK if the option is supported, CURLE_UNKNOWN_OPTION if not, or CURLE_OUT_OF_MEMORY if there was insufficient heap space.