curl/docs/libcurl/opts/CURLOPT_TELNETOPTIONS.md
Daniel Stenberg c4ab33370a
CURLOPT_*-docs: provide additional details
Went through CURLOPTTYPE_STRINGPOINT and CURLOPTTYPE_SLISTPOINT options
and clarified:

- what happens when setting the option *again*

- setting to NULL disables/restores to default

- libcurl does not copy the slist for options using a such

Closes #14846
2024-09-10 13:48:42 +02:00

1.5 KiB

c SPDX-License-Identifier Title Section Source See-also Protocol Added-in
Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. curl CURLOPT_TELNETOPTIONS 3 libcurl
CURLOPT_HTTPHEADER (3)
CURLOPT_QUOTE (3)
TELNET
7.7

NAME

CURLOPT_TELNETOPTIONS - set of telnet options

SYNOPSIS

#include <curl/curl.h>

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

DESCRIPTION

Provide a pointer to a curl_slist with variables to pass to the telnet negotiations. The variables should be in the format <option=value>. libcurl supports the options TTYPE, XDISPLOC and NEW_ENV. See the TELNET standard for details.

Using this option multiple times makes the last set list override the previous ones. Set it to NULL to disable its use again.

libcurl does not copy the list, it needs to be kept around until after the transfer has completed.

DEFAULT

NULL

%PROTOCOLS%

EXAMPLE

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode res;
    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);
    res = curl_easy_perform(curl);
    curl_easy_cleanup(curl);
    curl_slist_free_all(options);
  }
}

%AVAILABILITY%

RETURN VALUE

Returns CURLE_OK if TELNET is supported, and CURLE_UNKNOWN_OPTION if not.