CURLINFO_CONTENT_TYPE man page

#include <curl/curl.h>

CURLcode curl_easy_getinfo(CURL *handle, CURLINFO_CONTENT_TYPE, char **ct);

Pass a pointer to a char pointer to receive the content-type of the downloaded object. This is the value read from the Content-Type: field. If you get NULL, it means that the server didn't send a valid Content-Type header or that the protocol used doesn't support this.

The ct pointer will be NULL or pointing to private memory you MUST NOT free it - it gets freed when you call curl_easy_cleanup(3) on the corresponding CURL handle.

HTTP(S)

CURL *curl = curl_easy_init();
if(curl) {
  curl_easy_setopt(curl, CURLOPT_URL, "http://example.com");

  res = curl_easy_perform(curl);

  if(!res) {
    /* extract the content-type */
    char *ct = NULL;
    res = curl_easy_getinfo(curl, CURLINFO_CONTENT_TYPE, &ct);
    if(!res && ct) {
      printf("Content-Type: %s\n", ct);
    }
  }
  curl_easy_cleanup(curl);
}

Added in 7.9.4

Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.

curl_easy_getinfo(3), curl_easy_setopt(3),

curl_easy_getinfo(3).