pointer to json parse vector

[kessero]

My main:

int main(int argc, char *argv[])
{
  // read a JSON file
  std::stringstream ss;
  std::ifstream i("filee.json");
  json j_complete = json::parse(i);
  std::vector < int > data_send_to_LED;
  for (int i =0; i<j_complete["tablica"].size(); i++){
    data_send_to_LED.push_back(j_complete["tablica"][i].get<int>());
  }
  for (int i =0; i<data_send_to_LED.size(); i++){
    cout <<"data send: "<< data_send_to_LED[i]<<endl;
  }
  json j_vec(data_send_to_LED);
  long int pv = j_vec.get_ptr<json::number_integer_t*>();
  cout << j_vec.size() << endl;
  cout << j_vec << endl;
  cout << pv << endl;
...
n = write(sockfd,pv, j_vec.size()+1);

In general I want to send the contents of the file.json file to the server which accepts data in json format.
J_vec shows - [192,0,0,1,0,0,1,0,84,76,126]
Pv.size shows 11 elements and this is OK
pv shows 0
and n returns bad address?
I can skip the vector in the program and send the data directly form file.

[nlohmann]

long int pv = j_vec.get_ptr<json::number_integer_t*>(); is weird: you store a pointer to json::number_integer_t inside a long int variable.

[theodelrieu]

First, you could use j_complete.at("tablica").get<std::vector<int>>() to avoid a loop, but to fix your problem, try to use j_vec.get_ptr<json::array_t*>().

[kessero]

Now:

std::vector < int > data_send_to_LED;
  for (int i =0; i<j_complete["tablica"].size(); i++){
    data_send_to_LED.push_back(j_complete["tablica"][i].get<int>());
  }
  //j_complete.at("tablica").get<std::vector<int>>();
  for (int i =0; i<data_send_to_LED.size(); i++){
    cout <<"data send: "<< data_send_to_LED[i]<<endl;
  }
  json j_vec(data_send_to_LED);
  auto pv = j_vec.get_ptr<json::array_t*>();
  cout << j_vec.size() << endl;
  cout << pv << endl;

I don't have errors in this program but server shows mi error:

what(): [json.exception.parse_error.101] parse error at 1: syntax error - invalid literal; last read: 'p'
pBg�� Cg

[nlohmann]

Your input to the parse function seems corrupted. Can you make sure you pass proper JSON?

[kessero]

I'm not sure what you mean but my json file looks like this:

{
  "tablica": [192, 0, 0, 1, 0, 0, 1, 0,84, 76, 126]
}

[nlohmann]

Well the parser exception says the first read character is p.

[kessero]

On server side bafore json error:

bufor: p��{:

So some ^%&(( are sending.

[gregmarr]

As Niels and Theo have pointed out, it is most likely that pv is not of the proper data type. What does the receiving side think is the format of the data being received?

[gregmarr]

If it's expecting json, you probably want:

int main(int argc, char *argv[])
{
  // read a JSON file
  std::ifstream i("filee.json");
  json j_complete = json::parse(i);
  json j_vec = j_complete["tablica"];
  cout << j_vec.size() << endl;
  cout << j_vec << endl;
  std::string json = j_vec.dump();
  n = write(sockfd, json.data(), json.size());

[nlohmann]

@kessero Any news on this?

[kessero]

Thnx gregmarr solve my problem i have to read what dump do in doc but works. Sorry for late response