curl/docs/libcurl/opts/CURLOPT_DNS_USE_GLOBAL_CACHE.md
Daniel Stenberg e694c8284a
docs/libcurl/opts: clarify the return values
Expand a little.

- mention the type name of the return code
- avoid stating which exact return codes that might be returned, as that
  varies over time, builds and conditions
- avoid stating some always return OK
- refer to the manpage documenting all the return codes

Closes #15900
2025-01-02 17:13:33 +01:00

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_DNS_USE_GLOBAL_CACHE 3 libcurl
CURLOPT_DNS_CACHE_TIMEOUT (3)
CURLOPT_SHARE (3)
All
7.9.3

NAME

CURLOPT_DNS_USE_GLOBAL_CACHE - global DNS cache

SYNOPSIS

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_DNS_USE_GLOBAL_CACHE,
                          long enable);

DESCRIPTION

Has no function since 7.62.0. Do not use.

Pass a long. If the enable value is 1, it tells curl to use a global DNS cache that survives between easy handle creations and deletions. This is not thread-safe and this uses a global variable.

See CURLOPT_SHARE(3) and curl_share_init(3) for the correct way to share DNS cache between transfers.

DEFAULT

0

%PROTOCOLS%

EXAMPLE

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode ret;
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
    /* switch off the use of a global, thread unsafe, cache */
    curl_easy_setopt(curl, CURLOPT_DNS_USE_GLOBAL_CACHE, 0L);
    ret = curl_easy_perform(curl);
    curl_easy_cleanup(curl);
  }
}

DEPRECATED

Deprecated since 7.11.1. Functionality removed in 7.62.0.

%AVAILABILITY%

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).