Tribblix: manual page: CURLOPT_MIME

CURLOPT_MIME_OPTIONS(3) Introduction to Library Functions

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 CURLMIMEOPT_* defines. 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) {
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 */
curl_easy_perform(curl);
}
}

curl_easy_cleanup(curl);
curl_mime_free(form);
}
}

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).