Easy cURL interface

easy-curl.c

#include <curl/curl.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>

typedef struct EasyCurlString {
	int size;
	char **str;
	
} EasyCurlString;

static size_t counter(char *str)
{
	size_t commas = 0;
	int string = 0;
	
	if (strcmp(str, "\"\"") == 0) return 0;
	if (strcmp(str, "NULL") == 0) return 0;
	if (*str == '0') return 0;
	
	while (*str) {
		
		if (*str == '"' && *(str - 1) != '\\') string = !string;
		
		if (string == 0)
			if (*str == ',') commas++;
		str++;
	}
	
	return commas + 1;
}

static size_t _easycurl_callback(char *ptr, size_t size, size_t nitems, void *user_data)
{
	EasyCurlString *r = (EasyCurlString*)user_data;
	
	if (r->str == NULL) return size * nitems;
	
	if (r->size == 0)
	{
		r->size = nitems * size;
		*r->str  = (char*)malloc(r->size + 1);
		**r->str = 0;
	}
	else
	{
		int len = size * nitems + r->size;
		char *aux = (char*)malloc(len + 1);
		*aux = 0;
		
		strcpy(aux, *r->str);
		free(*r->str);
		
		*r->str = aux;
		r->size = len;
	}
	
	strcat(*r->str, ptr);
	
	return size * nitems;
}

void GO(char *method, char *url, char *data, char **response, char **header, int *code, unsigned int count, ...)
{
	unsigned int i;
	va_list args;
	CURL *curl;
	CURLcode res;
	struct curl_slist *chunk = NULL;
	EasyCurlString r = {0}, h = {0};
	
	curl_global_init(CURL_GLOBAL_ALL);
	
	if ((curl = curl_easy_init()) == NULL)
	{
		fprintf(stderr, "CURL ERROR: curl_easy_init() failed.\n");
		return;
	}
	
	va_start(args, count);
	
	for (i=0; i<count; i++)
	{
		chunk = curl_slist_append(chunk, va_arg(args, char*));
	}
	
	if (data)
	{
		curl_easy_setopt(curl, CURLOPT_POSTFIELDS, data);
	}
	
	if (response)
	{
		r.str = response;
	}
	
	if (header)
	{
		h.str = header;
		curl_easy_setopt(curl, CURLOPT_HEADERFUNCTION, _easycurl_callback);
		curl_easy_setopt(curl, CURLOPT_HEADERDATA, &h);
	}
	
	if (count)
	{
		curl_easy_setopt(curl, CURLOPT_HTTPHEADER, chunk);
	}
	
	curl_easy_setopt(curl, CURLOPT_CUSTOMREQUEST, method);
	curl_easy_setopt(curl, CURLOPT_URL, url);
	curl_easy_setopt(curl, CURLOPT_CAINFO , "cacert.pem");
	curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, _easycurl_callback);
	curl_easy_setopt(curl, CURLOPT_WRITEDATA, &r);
	
	if ((res = curl_easy_perform(curl)) != CURLE_OK)
	{
		fprintf(stderr, "CURL ERROR: %s\n", curl_easy_strerror(res));
	}
	
	if (chunk) curl_slist_free_all(chunk);
	if (code) curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE, code);
	
    curl_easy_cleanup(curl);
    curl_global_cleanup();
}

#define GO(method, url, data, response_ptr, header_ptr, code_ptr, ...) \
	GO(method, url, data, response_ptr, header_ptr, code_ptr, counter(#__VA_ARGS__), __VA_ARGS__)

/*///////////////////////////////////
	
		Testing:
		
///////////////////////////////////*/

int main(void) {
	int code;
	char *body = NULL;
	char *header = NULL;
	
	GO("GET", "https://github.com", "", &body, &header, &code, "");
	
	printf("code: %i\n\n", code);
	
	if (header)
	{
		printf("%s\n", header);
		free(header);
	}
	
	if (body)
	{
		printf("%s\n", body);
		free(body);
	}
	
	return 0;
}