This program to retrieve the nodes and ways returns some extra garbage values…

#include <iostream>
#include <string>
#include <vector>
#include <cstdio>
#include <stdlib.h>
#include <winsock2.h>
#define SIZE 10000

using namespace std;

const std::string host  = "81.19.81.199"; // IP of overpass.osm.rambler.ru
const int port          = 80;

//(lower lat, usually lower lon, higher lat, usually higher lon).
const std::string query = "GET /cgi/interpreter?data=[out:json];(node(18.51507,73.87276,18.53597,73.90142);way(18.51507,73.87276,18.53597,73.90142);node(w)->.x;);out; HTTP/1.1\r\n"
                          "Host: overpass.osm.rambler.ru\r\n"
                          "User-Agent: SteveC\r\n"
                          "Accept: */*\r\n"
                          "Connection: close\r\n"
                          "\r\n";

int main(int argc, char* argv[]) {

    FILE *fp = fopen ("d://test.txt", "r+");

    // Initialize Winsock.
    WSADATA wsadata;
    int iResult = WSAStartup (MAKEWORD(2,2), &wsadata );
    if (iResult !=NO_ERROR )
        printf("\nmyERROR at WSAStartup()\n");

    int sock = socket(AF_INET, SOCK_STREAM, 0);
    if (sock == -1) {
        perror("error opening socket"); return -1;
    }

    struct sockaddr_in sin;
    sin.sin_port = htons(port);
    sin.sin_addr.s_addr = inet_addr(host.c_str());
    sin.sin_family = AF_INET;

    if (connect(sock, (struct sockaddr *)&sin, sizeof(sin)) == -1) {
        perror("error connecting to host"); return -1;
    }

    const int query_len = query.length() + 1; // trailing '\0'
    if (send(sock, query.c_str(), query_len, 0) != query_len) {
        perror("error sending query"); return -1;
    }

    const int buf_size = 1024 * 1024;
    while (true) {
        std::vector<char> buf(buf_size, '\0');
        const int recv_len = recv(sock, &buf[0], buf_size - 1, 0);

        if (recv_len == -1) {
            perror("error receiving response"); return -1;
        } else if (recv_len == 0) {
            std::cout << std::endl; break;
        } else {
            std::cout << &buf[0];
            fprintf(fp, "%s", &buf[0]);
        }
    }

    return 0;
}

In this program some extra garbage values are inserted like :

{
  "type": "node",
  "id": 245647473,
  "lat": 18.5289245,
  "lon": 73.9019677,
  "tags": {
    "source": "AND"
  }
},
{

1000                         // garbage...

"type": "node",
  "id": 245647482,
  "lat": 18.5301753,
  "lon": 73.8676588,
  "tags": {
    "source": "AND"
  }
},

While executing the query in browser gives no problem. Earlier I thought there is some problem while writing to file, but the output by /std::cout << &buf[0];/ also gives the same result. Also the garbage value gets inserted in the same place every time I run the program. Why does it happen ?