CURLOPT_TELNETOPTIONS(3)

💅 CURLOPT_TELNETOPTIONS(3) — set of telnet options

Okay bestie, so you're poking at libcurl's manual, and this little icon is all about telling telnet what's up 🦋

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✨ SYNOPSIS ✨

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_TELNETOPTIONS,
                          struct curl_slist *cmds);

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🌸 DESCRIPTION 🌸

So what you do is hand over a pointer to a curl_slist stuffed with variables that get passed to the telnet negotiations. The variables gotta be in the format <option=value> — that's the whole vibe, no cap.

libcurl supports these options: TTYPE, XDISPLOC and NEW_ENV. For the details, go read the TELNET standard, iykyk 📖

If you use this option multiple times, the last set list overrides the previous ones — it's giving main character energy, last one wins 💅

Set it to NULL to disable its use again.

⚠️ Lowkey important: libcurl does not copy the list. You have to keep it around until after the transfer has completed. Don't let it get freed on you, bestie 😭

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🎀 DEFAULT 🎀

NULL

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🦋 PROTOCOLS 🦋

This functionality affects telnet only. Periodt.

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⭐ EXAMPLE ⭐

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode result;
    struct curl_slist *options;
    options = curl_slist_append(NULL, "TTTYPE=vt100");
    options = curl_slist_append(options, "USER=foobar");
    curl_easy_setopt(curl, CURLOPT_URL, "telnet://example.com/");
    curl_easy_setopt(curl, CURLOPT_TELNETOPTIONS, options);
    result = curl_easy_perform(curl);
    curl_easy_cleanup(curl);
    curl_slist_free_all(options);
  }
}

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🌈 AVAILABILITY 🌈

Added in curl 7.7 — vintage, honestly 👑

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💖 RETURN VALUE 💖

curl_easy_setopt(3) returns a CURLcode indicating success or error.

CURLE_OK (0) means everything was OK 🫶 — a non-zero value means an error occurred, so go check libcurl-errors(3), bestie.

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👀 SEE ALSO 👀

• CURLOPT_HTTPHEADER(3)
• CURLOPT_QUOTE(3)

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Okay that's the whole page, mwah 💋 This lil' gem comes to you from the libcurl manual, dated 2026-10-12 — go forth and negotiate your telnet options, icon ✨