CURLOPT_TFTP_BLKSIZE(3)

CURLOPT_TFTP_BLKSIZE3

Tftp block size

Usage

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

Overview

Specify blocksize to use for TFTP data transmission. Valid range as per RFC 2348 is 8-65464 bytes. The default of 512 bytes is used if this option is not specified. The specified block size is only used if supported by the remote server. If the server does not return an option acknowledgment or returns an option acknowledgment with no block size, the default of 512 bytes is used.

Default

512

Protocols

This functionality affects tftp only

Examples

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode result;
    curl_easy_setopt(curl, CURLOPT_URL, "tftp://example.com/bootimage");
    /* try using larger blocks */
    curl_easy_setopt(curl, CURLOPT_TFTP_BLKSIZE, 2048L);
    result = curl_easy_perform(curl);
    curl_easy_cleanup(curl);
  }
}

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).

Releases

7 releases since Debian 8 (Jessie); the text changed 6 times.

  1. 8
  2. 9
  3. 10
  4. 11
  5. 12
  6. 13
  7. Arch

Availability

Added in curl 7.19.4

From curl 8.23.0-1 in Arch Linux 2026-11-01. Parsed by carta from the page's man source.