Discord HTTPS POST with C - c

Question

I'm trying to build a Discord API with C (libdiscord it's constantly crashing).
I have found this promosing code (found here):
#include <stdio.h> /* printf, sprintf */
#include <stdlib.h> /* exit */
#include <unistd.h> /* read, write, close */
#include <string.h> /* memcpy, memset */
#include <sys/socket.h> /* socket, connect */
#include <netinet/in.h> /* struct sockaddr_in, struct sockaddr */
#include <netdb.h> /* struct hostent, gethostbyname */
void error(const char *msg) { perror(msg); exit(0); }
int main(int argc,char *argv[])
{
/* first what are we going to send and where are we going to send it? */
int portno = 80;
char *host = "api.somesite.com";
char *message_fmt = "POST /apikey=%s&command=%s HTTP/1.0\r\n\r\n";
struct hostent *server;
struct sockaddr_in serv_addr;
int sockfd, bytes, sent, received, total;
char message[1024],response[4096];
if (argc < 3) { puts("Parameters: <apikey> <command>"); exit(0); }
/* fill in the parameters */
sprintf(message,message_fmt,argv[1],argv[2]);
printf("Request:\n%s\n",message);
/* create the socket */
sockfd = socket(AF_INET, SOCK_STREAM, 0);
if (sockfd < 0) error("ERROR opening socket");
/* lookup the ip address */
server = gethostbyname(host);
if (server == NULL) error("ERROR, no such host");
/* fill in the structure */
memset(&serv_addr,0,sizeof(serv_addr));
serv_addr.sin_family = AF_INET;
serv_addr.sin_port = htons(portno);
memcpy(&serv_addr.sin_addr.s_addr,server->h_addr,server->h_length);
/* connect the socket */
if (connect(sockfd,(struct sockaddr *)&serv_addr,sizeof(serv_addr)) < 0)
error("ERROR connecting");
/* send the request */
total = strlen(message);
sent = 0;
do {
bytes = write(sockfd,message+sent,total-sent);
if (bytes < 0)
error("ERROR writing message to socket");
if (bytes == 0)
break;
sent+=bytes;
} while (sent < total);
/* receive the response */
memset(response,0,sizeof(response));
total = sizeof(response)-1;
received = 0;
do {
bytes = read(sockfd,response+received,total-received);
if (bytes < 0)
error("ERROR reading response from socket");
if (bytes == 0)
break;
received+=bytes;
} while (received < total);
if (received == total)
error("ERROR storing complete response from socket");
/* close the socket */
close(sockfd);
/* process response */
printf("Response:\n%s\n",response);
return 0;
}
But I need to send a header and data, according to this post (in Python):
import requests
import json
channelID = "your_id_goes_here" # enable dev mode on discord, right-click on the channel, copy ID
botToken = "your_token_here" # get from the bot page. must be a bot, not a discord app
baseURL = "https://discordapp.com/api/channels/{}/messages".format(channelID)
headers = { "Authorization":"Bot {}".format(botToken),
"User-Agent":"myBotThing (http://some.url, v0.1)",
"Content-Type":"application/json", }
message = "hello world"
POSTedJSON = json.dumps ( {"content":message} )
r = requests.post(baseURL, headers = headers, data = POSTedJSON)
I'm sorry, I don't know the protocols in detail.
I'd like to read messages too, but for now I'm OK just writing they.
UPDATE:
My new code (error 400, bad request).
#include <stdio.h>
#include <curl/curl.h>
int main(void)
{
CURL *curl = NULL;
CURLcode res;
const char *data = "{\"content\": \"data to send\"}";
const char *ID = "...";
const char *token = "...";
char tmp[1024];
curl = curl_easy_init();
if(curl != NULL) {
struct curl_slist *headers = NULL;
/* Remove a header curl would otherwise add by itself */
headers = curl_slist_append(headers, "Accept:");
/* Add a custom header */
sprintf(tmp, "Host: https://discordapp.com/api/channels/%s/messages", ID);
headers = curl_slist_append(headers, tmp);
sprintf(tmp, "Authorization: Bot %s", token);
headers = curl_slist_append(headers, tmp);
headers = curl_slist_append(headers, "User-Agent: myBotThing (http://some.url, v0.1)");
headers = curl_slist_append(headers, "Content-Type: application/json");
/* set our custom set of headers */
curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);
sprintf(tmp, "https://discordapp.com/api/channels/%s/messages", ID);
curl_easy_setopt(curl, CURLOPT_URL, tmp);
curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
// POST
curl_easy_setopt(curl, CURLOPT_CUSTOMREQUEST, "POST");
curl_easy_setopt(curl, CURLOPT_POSTFIELDS, data);
res = curl_easy_perform(curl);
/* Check for errors */
if(res != CURLE_OK) printf("curl_easy_perform() failed: %s\n", curl_easy_strerror(res));
curl_easy_cleanup(curl);
curl_slist_free_all(headers);
}
return 0;
}