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

# [NAME](#NAME)

CURLOPT\_PRIVATE - store a private pointer

# [SYNOPSIS](#SYNOPSIS)

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

# [DESCRIPTION](#DESCRIPTION)

Pass a void * as parameter, pointing to data that should be associated with this curl handle. The pointer can subsequently be retrieved using [*curl\_easy\_getinfo(3)*](/man/os/curl/curl_easy_getinfo.3) with the [*CURLINFO\_PRIVATE(3)*](/man/os/curl/CURLINFO_PRIVATE.3) option. libcurl itself never does anything with this data.

# [DEFAULT](#DEFAULT)

NULL

# [PROTOCOLS](#PROTOCOLS)

This functionality affects all supported protocols

# [EXAMPLE](#EXAMPLE)

```
struct private_data {


  void *custom;
};
int main(void)
{


  CURL *curl = curl_easy_init();


  struct private_data secrets;


  if(curl) {


    CURLcode result;


    struct private_data *extracted;


    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");


    /* store a pointer to our private_data struct */


    curl_easy_setopt(curl, CURLOPT_PRIVATE, &secrets);


    result = curl_easy_perform(curl);


    /* we can extract the private_data pointer again too */


    curl_easy_getinfo(curl, CURLINFO_PRIVATE, &extracted);


    curl_easy_cleanup(curl);


  }
}
```

# [AVAILABILITY](#AVAILABILITY)

Added in curl 7.10.3

# [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)

[**CURLINFO\_PRIVATE**(3)](/man/os/curl/CURLINFO_PRIVATE.3), [**CURLOPT\_STDERR**(3)](/man/os/curl/CURLOPT_STDERR.3), [**CURLOPT\_VERBOSE**(3)](/man/os/curl/CURLOPT_VERBOSE.3)

2026-09-24 libcurl

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Document: CURLOPT_PRIVATE(3) from curl 8.22.0-r3 (Chainguard OS)
Source: https://github.com/curl/curl.git