curl_easy_duphandle(3) Library Functions Manual curl_easy_duphandle(3)

curl_easy_duphandle - Clone a libcurl session handle

#include <curl/curl.h>
CURL *curl_easy_duphandle(CURL *handle);

This function returns a new curl handle, a duplicate, using all the options previously set in the input curl handle. Both handles can subsequently be used independently and they must both be freed with curl_easy_cleanup(3).

Any options that the input handle has been told to point to (as opposed to copy) with previous calls to curl_easy_setopt(3), are pointed to by the new handle as well. You must therefore make sure to keep the data around until both handles have been cleaned up.

The new handle does not inherit any state information, no connections, no SSL sessions and no cookies. It also does not inherit any share object states or options (created as if CURLOPT_SHARE(3) was set to NULL).

If the source handle has HSTS or alt-svc enabled, the duplicate gets data read data from the main filename to populate the cache.

In multi-threaded programs, this function must be called in a synchronous way, the input handle may not be in use when cloned.


int main(void)
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode res;
    CURL *nother;
    curl_easy_setopt(curl, CURLOPT_URL, "");
    nother = curl_easy_duphandle(curl);
    res = curl_easy_perform(nother);

Added in 7.9

If this function returns NULL, something went wrong and no valid handle was returned.

curl_easy_cleanup(3), curl_easy_init(3), curl_easy_reset(3), curl_global_init(3)

2024-05-22 libcurl