CURLOPT_TFTP_BLKSIZE(3)

💖 CURLOPT_TFTP_BLKSIZE(3) 💖

okay so this is the CURLOPT_TFTP_BLKSIZE(3) page from the Library Functions Manual, and it is literally all about setting the TFTP block size. bestie, it's niche but iconic. 💅

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🌸 NAME 🌸

• CURLOPT_TFTP_BLKSIZE — TFTP block size. that's the vibe. 🎀

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✨ SYNOPSIS ✨

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_TFTP_BLKSIZE, long blocksize);

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🦋 DESCRIPTION 🦋

So you use this to specify blocksize 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. periodt. 🔥

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🎀 DEFAULT 🎀

512

that's the default, and that's the whole section. slay. ✨

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🌈 PROTOCOLS 🌈

This functionality affects tftp only. that's it. only tftp. no cap. 🫶

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🍓 EXAMPLE 🍓

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);
  }
}

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👑 AVAILABILITY 👑

Added in curl 7.19.4. vintage but still cute. 💜

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🌸 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). bestie, check the error code. no guessing. 💅

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🧚 SEE ALSO 🧚

• CURLOPT_MAXFILESIZE(3)

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xoxo, libcurl 💖 — dated 2026-10-12, bestie. ✨