How to rewrite POST request from python to C++ with curl - c++

Question

I have POST request on python with a lot of settings, and I don't uderstand how their look like in curl.
data_str = '{' + '"username": "{}", "domain_id": {}, "password": {}'.format(login, domain_id, password) + '}'
try:
data = requests.post("https://example.com/v/session",
proxies=proxy,
verify=False,
data=data_str,
headers={"Content-Type": "application/json;charset=UTF-8",
"Accept": "application/json"})
if is_json(data.text):
print(data)
I find that url set parament CURLOPT_URL, headers - CURLOPT_HTTPHEADER. But how set proxy, verify, data ? How get json as in python ?
how to complete the code that it have the same result as in python:
CURL *curl = curl_easy_init();
struct curl_slist *list = NULL;
if(curl) {
curl_easy_setopt(curl, CURLOPT_URL, "http://example.com");
list = curl_slist_append(list, "Shoesize: 10");
list = curl_slist_append(list, "Accept:");
curl_easy_setopt(curl, CURLOPT_HTTPHEADER, list);
curl_easy_perform(curl);
curl_slist_free_all(list); /* free the list again */
}

Answer 1

In order to get the return data from the curl request, we need a callback function for the CURLOPT_WRITEFUNCTION option.
The proxy, data, verify parameters should be set as following :
#include <iostream>
#include <string>
#include <curl/curl.h>
size_t curlWriter(void *contents, size_t size, size_t nmemb, std::string *s)
{
size_t newLength = size*nmemb;
try
{
s->append((char*)contents, newLength);
}
catch(std::bad_alloc &e)
{
//memory problem
return 0;
}
return newLength;
}
int main()
{
CURL *curl;
CURLcode res;
curl_global_init(CURL_GLOBAL_DEFAULT);
curl = curl_easy_init();
if(curl)
{
std::string strResponse;
std::string strPostData = "my data post";
curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/v/session");
curl_easy_setopt (curl, CURLOPT_VERBOSE, 1L);
//set the proxy
curl_easy_setopt(curl, CURLOPT_PROXY, "http://proxy.net");
curl_easy_setopt(curl, CURLOPT_PROXYPORT, 8080L);
//verify=False. SSL checking disabled
curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0L);
curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0L);
//set the callback function
curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, curlWriter);
curl_easy_setopt(curl, CURLOPT_WRITEDATA, &strResponse);
/* size of the POST data */
curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE, strPostData.length() );
/* pass in a pointer to the data - libcurl will not copy */
curl_easy_setopt(curl, CURLOPT_POSTFIELDS, strPostData.c_str() );
/* Execute the request */
res = curl_easy_perform(curl);
/* Check for errors */
if(res != CURLE_OK)
{
std::cerr << "CURL error : " << curl_easy_strerror(res) << std::endl;
}else {
std::cout << "CURL result : " << strResponse << std::endl;
}
curl_easy_cleanup(curl);
}
}