libcurl won't load contents of URL - c++

Question

I'm trying to load the contents of this URL in order to send an SMS;
https://app2.simpletexting.com/v1/send?token=[api key]&phone=[phone number]&message=Weather%20Alert!
Using this bit of code implementing libcurl:
std::string sendSMS(std::string smsMessage, std::string usrID) {
std::string simplePath = "debugOld/libDoc.txt";
std::string preSmsURL = "https://app2.simpletexting.com/v1/send?token=";
std::cout << "\n" << getFile(simplePath) << "\n";
std::string fullSmsURL = preSmsURL + getFile(simplePath) + "&phone=" + usrID + "&message=" + smsMessage;
std::cout << fullSmsURL;
//Outputs URL contents into a file
CURL *curl;
FILE *fd;
CURLcode res;
char newFile[FILENAME_MAX] = "debugOld/noSuccess.md";
curl = curl_easy_init();
if (curl) {
fd = fopen(newFile, "wb");
curl_easy_setopt(curl, CURLOPT_URL, fullSmsURL);
curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, NULL);
curl_easy_setopt(curl, CURLOPT_WRITEDATA, fd);
res = curl_easy_perform(curl);
curl_easy_cleanup(curl);
fclose(fd);
}
}
I've used pretty much this exact code before to save the JSON contents of a URL to a file, although I'm trying something a bit different here.
This URL will actually send an SMS when visited. When using curl in a cli, I have no problem doing this. Although from C++, it doesn't treat anything as a error, just perhaps the actual function to send the sms isn't being actuated in the same way it would had I visited the URL physically.
I've scoured google for some kind of a solution to no avail. Perhaps I'm too novice to curl to know exactly what to search for.
Edit #1: getFile function
//Read given file
std::string getFile(std::string path) {
std::string nLine;
std::ifstream file_(path);
if (file_.is_open()) {
while (getline(file_, nLine)) {
return nLine;
}
file_.close();
}
else {
std::cout << "file is not open" << "\n";
return "Error 0x000001: inaccesable file location";
}
return "Unknown error in function 'getFile()'"; //This should never happen
}

Answer 1

This line is wrong:
curl_easy_setopt(curl, CURLOPT_URL, fullSmsURL);
CURLOPT_URL expects a char* pointer to null-terminated C string, not a std::string object. You need to use this instead:
curl_easy_setopt(curl, CURLOPT_URL, fullSmsURL.c_str());
Also, you are not performing any error checking on the return values of getFile(), fopen(), or curl_easy_perform() at all. So, your code could be failing in any one of those places and you would never know it.