CURLOPT_MIME_OPTIONS(3)

NAME
CURLOPT_MIME_OPTIONS - set MIME option flags

SYNOPSIS
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_MIME_OPTIONS, long options);

DESCRIPTION
Pass a long that holds a bitmask of options. Each bit is a boolean flag used while encoding a MIME tree or multipart form data. Available bits are:

CURLMIMEOPT_FORMESCAPE
    Tells libcurl to escape multipart form field and filenames using the backslash-escaping algorithm rather than percent-encoding (HTTP only). Backslash-escaping consists in preceding backslashes and double quotes with a backslash. Percent encoding maps all occurrences of double quote, carriage return and line feed to %22, %0D and %0A respectively. Before version 7.81.0, percent-encoding was never applied. HTTP browsers used to do backslash-escaping in the past but have over time transitioned to use percent-encoding. This option allows one to address server-side applications that have not yet have been converted. As an example, consider field or filename strangename"kind. When the containing multipart form is sent, this is normally transmitted as strangename%22kind. When this option is set, it is sent as strangename"kind.

DEFAULT
0, meaning disabled.

PROTOCOLS
This functionality affects http, imap and smtp

EXAMPLE
int main(void)
{
  CURL *curl = curl_easy_init();
  curl_mime *form = NULL;
  if(curl) {
    CURLcode result = CURLE_OK;
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
    curl_easy_setopt(curl, CURLOPT_MIME_OPTIONS, CURLMIMEOPT_FORMESCAPE);
    form = curl_mime_init(curl);
    if(form) {
      curl_mimepart *part = curl_mime_addpart(form);
      if(part) {
        curl_mime_filedata(part, "strange\\file\\name");
        curl_mime_name(part, "strange\"field\"name");
        curl_easy_setopt(curl, CURLOPT_MIMEPOST, form);
        /* Perform the request */
        result = curl_easy_perform(curl);
      }
    }
    curl_easy_cleanup(curl);
    curl_mime_free(form);
  }
}

HISTORY
CURLMIMEOPT_FORMESCAPE macro became long type in 8.16.0, prior to this version a long cast was necessary when passed to curl_easy_setopt(3).

AVAILABILITY
Added in curl 7.81.0

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_HTTPPOST(3), CURLOPT_MIMEPOST(3)