CURLOPT_XFERINFODATA(3) Library Functions Manual CURLOPT_XFERINFODATA(3)
NAME
CURLOPT_XFERINFODATA - pointer passed to the progress callback
SYNOPSIS
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_XFERINFODATA, void *pointer);
DESCRIPTION
Pass a pointer that is untouched by libcurl and passed as the first ar-
gument in the progress callback set with CURLOPT_XFERINFOFUNCTION(3).
This is an alias for CURLOPT_PROGRESSDATA(3).
DEFAULT
NULL
PROTOCOLS
This functionality affects all supported protocols
EXAMPLE
struct progress {
char *private;
size_t size;
};
static int progress_cb(void *clientp,
curl_off_t dltotal,
curl_off_t dlnow,
curl_off_t ultotal,
curl_off_t ulnow)
{
struct progress *memory = clientp;
printf("private ptr: %p\n", memory->private);
/* use the values */
return 0; /* all is good */
}
int main(void)
{
CURL *curl = curl_easy_init();
if(curl) {
struct progress data;
/* pass struct to callback */
curl_easy_setopt(curl, CURLOPT_XFERINFODATA, &data);
curl_easy_setopt(curl, CURLOPT_XFERINFOFUNCTION, progress_cb);
}
}
AVAILABILITY
Added in curl 7.32.0
RETURN VALUE
curl_easy_setopt(3) returns a CURLcode indicating success or error.
CURLE_OK (0) means everything was OK, non-zero means an error occurred,
see libcurl-errors(3).
SEE ALSO
CURLOPT_NOPROGRESS(3), CURLOPT_VERBOSE(3), CURLOPT_XFERINFOFUNCTION(3)
libcurl 2026-07-12 CURLOPT_XFERINFODATA(3)
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