CURLMOPT_PUSHDATA(3) Library Functions Manual CURLMOPT_PUSHDATA(3)
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_PUSHFUNC-
TION(3) 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(3) returns a CURLMcode indicating success or error.
CURLM_OK (0) means everything was OK, non-zero means an error occurred,
see libcurl-errors(3).
SEE ALSO
CURLMOPT_PIPELINING(3), CURLMOPT_PUSHFUNCTION(3), CURLOPT_PIPEWAIT(3),
RFC7540
libcurl 2026-07-12 CURLMOPT_PUSHDATA(3)
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