#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <curl/curl.h>
// Function to perform HTTP GET request using libcurl
size_t write_callback(void contents, size_t size, size_t nmemb, void userp) {
size_t realsize = size * nmemb;
char response_ptr = (char )userp;
response_ptr = realloc(response_ptr, realsize + 1);
if (*response_ptr == NULL) {
fprintf(stderr, "Failed to allocate memory.\n");
exit(EXIT_FAILURE);
}
memcpy(&(*response_ptr)[0], contents, realsize);
(*response_ptr)[realsize] = 0;
return realsize;
}
int main(void) {
CURL *curl;
CURLcode res;
// Elasticsearch URL with date filter
const char *url = "http://your_elasticsearch_server/your_index/_search?q=@timestamp:[2023-01-01 TO 2023-12-31]";
// Initialize libcurl
curl_global_init(CURL_GLOBAL_DEFAULT);
curl = curl_easy_init();
// Set the URL for the request
curl_easy_setopt(curl, CURLOPT_URL, url);
// Set the callback function to handle the response
curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_callback);
// Buffer to store the response data
char *response_data = NULL;
// Set the userp parameter for the callback function
curl_easy_setopt(curl, CURLOPT_WRITEDATA, &response_data);
// Perform the HTTP GET request
res = curl_easy_perform(curl);
// Check for errors
if (res != CURLE_OK) {
fprintf(stderr, "curl_easy_perform() failed: %s\n", curl_easy_strerror(res));
} else {
// Print the response data
printf("%s\n", response_data);
}
// Clean up resources
curl_easy_cleanup(curl);
curl_global_cleanup();
// Free the allocated memory for the response data
free(response_data);
return 0;
}