I want to store the result of this curl function in a variable, how can I do so?
#include <stdio.h>
#include <curl/curl.h>
int main(void)
{
CURL *curl;
CURLcode res;
curl = curl_easy_init();
if(curl) {
curl_easy_setopt(curl, CURLOPT_URL, "curl.haxx.se");
res = curl_easy_perform(curl);
/* always cleanup */
curl_easy_cleanup(curl);
}
return 0;
}
thanks, I solved it like this:
#include <stdio.h>
#include <stdlib.h>
#include <curl/curl.h>
function_pt(void *ptr, size_t size, size_t nmemb, void *stream){
printf("%d", atoi(ptr));
}
int main(void)
{
CURL *curl;
curl = curl_easy_init();
if(curl) {
curl_easy_setopt(curl, CURLOPT_URL, "curl.haxx.se");
curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, function_pt);
curl_easy_perform(curl);
curl_easy_cleanup(curl);
}
system("pause");
return 0;
}
Answer
You can set a callback function to receive incoming data chunks using curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, myfunc);
The callback will take a user defined argument that you can set using curl_easy_setopt(curl, CURLOPT_WRITEDATA, p)
Here's a snippet of code that passes a buffer struct string {*ptr; len} to the callback function and grows that buffer on each call using realloc().
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <curl/curl.h>
struct string {
char *ptr;
size_t len;
};
void init_string(struct string *s) {
s->len = 0;
s->ptr = malloc(s->len+1);
if (s->ptr == NULL) {
fprintf(stderr, "malloc() failed\n");
exit(EXIT_FAILURE);
}
s->ptr[0] = '\0';
}
size_t writefunc(void *ptr, size_t size, size_t nmemb, struct string *s)
{
size_t new_len = s->len + size*nmemb;
s->ptr = realloc(s->ptr, new_len+1);
if (s->ptr == NULL) {
fprintf(stderr, "realloc() failed\n");
exit(EXIT_FAILURE);
}
memcpy(s->ptr+s->len, ptr, size*nmemb);
s->ptr[new_len] = '\0';
s->len = new_len;
return size*nmemb;
}
int main(void)
{
CURL *curl;
CURLcode res;
curl = curl_easy_init();
if(curl) {
struct string s;
init_string(&s);
curl_easy_setopt(curl, CURLOPT_URL, "curl.haxx.se");
curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, writefunc);
curl_easy_setopt(curl, CURLOPT_WRITEDATA, &s);
res = curl_easy_perform(curl);
printf("%s\n", s.ptr);
free(s.ptr);
/* always cleanup */
curl_easy_cleanup(curl);
}
return 0;
}