CURLOPT\_XFERINFODATA(3) Library Functions Manual CURLOPT\_XFERINFODATA(3)

# [NAME](#NAME)

CURLOPT\_XFERINFODATA - pointer passed to the progress callback

# [SYNOPSIS](#SYNOPSIS)

```
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_XFERINFODATA, void *pointer);
```

# [DESCRIPTION](#DESCRIPTION)

Pass a *pointer* that is untouched by libcurl and passed as the first argument in the progress callback set with [*CURLOPT\_XFERINFOFUNCTION(3)*](/man/os/curl/CURLOPT_XFERINFOFUNCTION.3).

This is an alias for [*CURLOPT\_PROGRESSDATA(3)*](/man/os/curl/CURLOPT_PROGRESSDATA.3).

# [DEFAULT](#DEFAULT)

NULL

# [PROTOCOLS](#PROTOCOLS)

This functionality affects all supported protocols

# [EXAMPLE](#EXAMPLE)

```
struct progress {


  char *private_data;


  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", (void *)memory->private_data);


  /* 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](#AVAILABILITY)

Added in curl 7.32.0

# [RETURN VALUE](#RETURN_VALUE)

[*curl\_easy\_setopt(3)*](/man/os/curl/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)*](/man/os/curl/libcurl-errors.3).

# [SEE ALSO](#SEE_ALSO)

[**CURLOPT\_NOPROGRESS**(3)](/man/os/curl/CURLOPT_NOPROGRESS.3), [**CURLOPT\_VERBOSE**(3)](/man/os/curl/CURLOPT_VERBOSE.3), [**CURLOPT\_XFERINFOFUNCTION**(3)](/man/os/curl/CURLOPT_XFERINFOFUNCTION.3)

2026-10-19 libcurl

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Document: CURLOPT_XFERINFODATA(3) from curl 8.23.0-r1 (Chainguard OS)
Source: https://github.com/curl/curl.git