CURLOPT_DOH_URL(3)

1CURLOPT_DOH_URL(3)         curl_easy_setopt options         CURLOPT_DOH_URL(3)
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NAME

6       CURLOPT_DOH_URL - provide the DNS-over-HTTPS URL
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SYNOPSIS

9       #include <curl/curl.h>
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11       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_DOH_URL, char *URL);
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DESCRIPTION

14       Pass  in  a pointer to a URL for the DOH server to use for name resolv‐
15       ing. The parameter should be a char * to a null-terminated string which
16       must  be URL-encoded in the following format: "https://host:port/path".
17       It MUST specify a HTTPS URL.
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19       libcurl doesn't validate the syntax or  use  this  variable  until  the
20       transfer  is  issued. Even if you set a crazy value here, curl_easy_se‐
21       topt(3) will still return CURLE_OK.
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23       curl sends POST requests to the given DNS-over-HTTPS URL.
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25       To find the DOH server itself, which might be specified using  a  name,
26       libcurl  will  use  the default name lookup function. You can bootstrap
27       that by providing the address  for  the  DOH  server  with  CURLOPT_RE‐
28       SOLVE(3).
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30       Disable DOH use again by setting this option to NULL.
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32       Advanced: The DOH lookups use SSL so some SSL settings from your trans‐
33       fer are inherited. The hostname and peer certificate verification  set‐
34       tings  are  not  inherited  and  can  be controlled separately via CUR‐
35       LOPT_DOH_SSL_VERIFYHOST(3)  and  CURLOPT_DOH_SSL_VERIFYPEER(3).    Note
36       CURLOPT_SSL_CTX_FUNCTION(3) is inherited.
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DEFAULT

39       NULL  -  there is no default DOH URL. If this option isn't set, libcurl
40       will use the default name resolver.
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PROTOCOLS

43       All
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EXAMPLE

46       CURL *curl = curl_easy_init();
47       if(curl) {
48         curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
49         curl_easy_setopt(curl, CURLOPT_DOH_URL, "https://dns.example.com");
50         curl_easy_perform(curl);
51       }
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AVAILABILITY

54       Added in 7.62.0
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RETURN VALUE

57       Returns CURLE_OK on success or CURLE_OUT_OF_MEMORY if there was  insuf‐
58       ficient heap space.
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60       Note  that curl_easy_setopt(3) won't actually parse the given string so
61       given a bad DOH URL, curl will not detect a problem until it  tries  to
62       resolve a name with it.
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