---
name: "curl_mime_data"
section: "3"
platform: "linux"
package: "curl"
version: "8.23.0-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux", "macos"]
url: "https://new.carta.tech/curl_mime_data"
---

# curl\_mime\_data(3)

set a mime part's body data from memory

## NAME

curl\_mime\_data - set a mime part's body data from memory

## SYNOPSIS

```
#include <curl/curl.h>
CURLcode curl_mime_data(curl_mimepart *part, const char *data,
                        size_t datasize);
```

## DESCRIPTION

*[curl\_mime\_data(3)](/curl_mime_data/3.md)* sets a mime part's body content from memory data.

*part* is the mime part to assign contents to, created with *[curl\_mime\_addpart(3)](/curl_mime_addpart/3.md)*.

*data* points to the data that gets copied by this function. The storage may safely be reused after the call.

*datasize* is the number of bytes *data* points to. It can be set to *CURL\_ZERO\_TERMINATED* to indicate *data* is a null-terminated character string.

Setting a part's contents multiple times is valid: only the value set by the last call is retained. It is possible to unassign part's contents by setting *data* to NULL.

Setting large data is memory consuming: one might consider using *[curl\_mime\_data\_cb(3)](/curl_mime_data_cb/3.md)* in such a case.

## PROTOCOLS

This functionality affects http, imap and smtp

## EXAMPLE

```
int main(void)
{
  curl_mime *mime;
  curl_mimepart *part;
  CURL *curl = curl_easy_init();
  if(curl) {
    /* create a mime handle */
    mime = curl_mime_init(curl);
    /* add a part */
    part = curl_mime_addpart(mime);
    /* add data to the part */
    curl_mime_data(part, "raw contents to send", CURL_ZERO_TERMINATED);
  }
}
```

## AVAILABILITY

Added in curl 7.56.0

## RETURN VALUE

This function returns a CURLcode indicating success or error.

CURLE\_OK (0) means everything was OK, non-zero means an error occurred, see *[libcurl-errors(3)](/libcurl-errors/3.md)*. If *[CURLOPT\_ERRORBUFFER(3)](/CURLOPT_ERRORBUFFER/3.md)* was set with *[curl\_easy\_setopt(3)](/curl_easy_setopt/3.md)* there can be an error message stored in the error buffer when non-zero is returned.

## SEE ALSO

[**curl\_mime\_addpart**(3)](/curl_mime_addpart/3.md), [**curl\_mime\_data\_cb**(3)](/curl_mime_data_cb/3.md), [**curl\_mime\_name**(3)](/curl_mime_name/3.md), [**curl\_mime\_type**(3)](/curl_mime_type/3.md)