CURLMOPT_PUSHDATA explained

Name

CURLMOPT_PUSHDATA - pointer to pass to push callback

Synopsis

#include <curl/curl.h>
 
CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_PUSHDATA, void *pointer);

Description

Set a pointer to pass as the last argument to the CURLMOPT_PUSHFUNCTION callback. The pointer is not touched or used by libcurl itself, only passed on to the callback function.

Default

NULL

Protocols

This functionality affects http only

Example

#include <string.h>
 
/* only allow pushes for filenames starting with "push-" */
int push_callback(CURL *parent,
                  CURL *easy,
                  size_t num_headers,
                  struct curl_pushheaders *headers,
                  void *clientp)
{
  char *headp;
  int *transfers = (int *)clientp;
  FILE *out;
  headp = curl_pushheader_byname(headers, ":path");
  if(headp && !strncmp(headp, "/push-", 6)) {
    fprintf(stderr, "The PATH is %s\n", headp);
 
    /* save the push here */
    out = fopen("pushed-stream", "wb");
 
    /* write to this file */
    curl_easy_setopt(easy, CURLOPT_WRITEDATA, out);
 
    (*transfers)++; /* one more */
 
    return CURL_PUSH_OK;
  }
  return CURL_PUSH_DENY;
}
 
int main(void)
{
  int counter;
  CURLM *multi = curl_multi_init();
  curl_multi_setopt(multi, CURLMOPT_PUSHFUNCTION, push_callback);
  curl_multi_setopt(multi, CURLMOPT_PUSHDATA, &counter);
}

Availability

Added in curl 7.44.0

Return value

curl_multi_setopt returns a CURLMcode indicating success or error.

CURLM_OK (0) means everything was OK, non-zero means an error occurred, see libcurl-errors.