CURLOPT_UPLOAD_FLAGS(3) Introduction to Library Functions

NAME

CURLOPT_UPLOAD_FLAGS - upload flags for IMAP

SYNOPSIS

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_UPLOAD_FLAGS, long bitmask);

DESCRIPTION

Pass a long as parameter, which is set to a bitmask, to tell libcurl
which flags to send the server relating to uploaded files. The
currently supported flags are:

CURLULFLAG_ANSWERED
Sets the Answered flag for IMAP uploads. Indicates that the
message has been replied to.

CURLULFLAG_DELETED
Sets the Deleted flag for IMAP uploads. Marks the message for
deletion rather than immediately removing it.

CURLULFLAG_DRAFT
Sets the Draft flag for IMAP uploads. Marks the message as an
uncompleted composition.

CURLULFLAG_FLAGGED
Sets the Flagged flag for IMAP uploads. Marks the message for
special attention.

CURLULFLAG_SEEN
Sets the Seen flag for IMAP uploads. Marks the message as
read.

DEFAULT

A bitmask with only the CURLULFLAG_SEEN flag set.

PROTOCOLS

This functionality affects imap and imaps

EXAMPLE

static size_t read_cb(char *ptr, size_t size, size_t nmemb, void *userdata)
{
FILE *src = userdata;
/* copy as much data as possible into the 'ptr' buffer, but no more than
'size' * 'nmemb' bytes */
size_t retcode = fread(ptr, size, nmemb, src);

return retcode;
}

int main(void)
{
CURL *curl;
FILE *src = fopen("local-file", "r");
if(!src)
return 1;

curl = curl_easy_init();
if(curl) {
CURLcode result;
curl_off_t fsize = 9876; /* set this to the size of the input file */

/* we want to use our own read function */
curl_easy_setopt(curl, CURLOPT_READFUNCTION, read_cb);

/* enable uploading */
curl_easy_setopt(curl, CURLOPT_UPLOAD, 1L);

/* specify target */
curl_easy_setopt(curl, CURLOPT_URL, "imap://example.com:993/mailbox");

/* provide username */
curl_easy_setopt(curl, CURLOPT_USERNAME, "user@example.com");

/* provide password */
curl_easy_setopt(curl, CURLOPT_PASSWORD, "password");

/* specify that uploaded mail should be considered flagged */
curl_easy_setopt(curl, CURLOPT_UPLOAD_FLAGS, CURLULFLAG_FLAGGED);

/* now specify which pointer to pass to our callback */
curl_easy_setopt(curl, CURLOPT_READDATA, src);

/* Set the size of the file to upload */
curl_easy_setopt(curl, CURLOPT_INFILESIZE_LARGE, (curl_off_t)fsize);

/* perform the upload */
result = curl_easy_perform(curl);
curl_easy_cleanup(curl);
}
fclose(src);
}

AVAILABILITY

Added in curl 8.13.0

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_UPLOAD(3)

libcurl 2026-04-29 CURLOPT_UPLOAD_FLAGS(3)