CURLOPT_INFILESIZE - size of the input file to send off

Added in curl 7.1

Unset

When uploading a file to a remote site, filesize should be used to tell libcurl what the expected size of the input file is. This value must be passed as a long. See also CURLOPT_INFILESIZE_LARGE(3) for sending files larger than 2GB. For uploading using SCP, this option or CURLOPT_INFILESIZE_LARGE(3) is mandatory. To unset this value again, set it to -1. Using CURLOPT_UPLOAD(3) to an HTTP/1.1 server and this value set to -1, makes libcurl do a chunked transfer-encoded upload. When sending emails using SMTP, this command can be used to specify the optional SIZE parameter for the MAIL FROM command. This option does not limit how much data libcurl actually sends, as that is controlled entirely by what the read callback returns, but telling one value and sending a different amount may lead to errors.

#define FILE_SIZE 12345L int main(void) { CURL *curl = curl_easy_init(); if(curl) { long uploadsize = FILE_SIZE; curl_easy_setopt(curl, CURLOPT_URL, "ftp://example.com/destination.tar.gz"); curl_easy_setopt(curl, CURLOPT_UPLOAD, 1L); curl_easy_setopt(curl, CURLOPT_INFILESIZE, uploadsize); curl_easy_perform(curl); } }

SMTP support added in 7.23.0

CURLOPT_INFILESIZE - size of the input file to send off

This functionality affects all supported protocols

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).

CURLINFO_CONTENT_LENGTH_UPLOAD_T(3), CURLOPT_INFILESIZE_LARGE(3), CURLOPT_UPLOAD(3) libcurl 2025-06-16 CURLOPT_INFILESIZE(3)

#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_INFILESIZE, long filesize);