c++ socket http json post

main.cpp

#include <iostream>
#include <arpa/inet.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <errno.h>
#include <netinet/in.h>
#include <stdio.h>
#include <netdb.h>
#include <unistd.h>

#define SA struct sockaddr
#define MAX_LINE 4096
#define MAX_SUB 1024

#define JSON_TEMPLATE "{\"key1":\"%s\"}"

extern int h_errno;

ssize_t process_http(int socketfd, char *host, char *page, char *poststr) {
    char sendline[MAX_LINE + 1], recvline[MAX_LINE +1];
    ssize_t n;
    snprintf(sendline, MAX_SUB,
                             "POST %s HTTP/1.0\r\n"
                             "Host: %s\r\n"
                             "Content-type: application/json\r\n"
                             "Content-length: %d\r\n\r\n"
                             "%s", page, host, (int)strlen(poststr), poststr);
    write(socketfd, sendline, strlen(sendline));

    while((n = read(socketfd, recvline, MAX_LINE))> 0) {
        recvline[n] = '\0';
        printf("%s", recvline);
    }

    return n;
}

int main() {

  if ((hptr = gethostbyname(SERVER_BASE_URL)) == NULL) {
    fprintf(stderr, " gethostbyname error for host: %s: %s", SERVER_BASE_URL, hstrerror(h_errno));
  }

  char str[50];

  if (hptr->h_addrtype == AF_INET && (pptr = hptr->h_addr_list) != NULL) {
    printf("address: %s\n", inet_ntop(hptr->h_addrtype, *pptr, str, sizeof(str)));
  } else {
    fprintf(stderr, "Error call inet_stop\n");
  }

  sockfd = socket(AF_INET, SOCK_STREAM, 0);
  bzero(&serveraddr, sizeof(serveraddr));
  serveraddr.sin_family = AF_INET;
  serveraddr.sin_port = htons(80);
  inet_pton(AF_INET, str, &serveraddr.sin_addr);
  connect(sockfd, (SA *) &serveraddr, sizeof(serveraddr));
        char *postContents = new char[128];
        sprintf(postContents,
                JSON_TEMPLATE,
                "val1")
        process_http(postContents);
        delete []postContents;
  return 0;
}