CURLOPT_DNS_SERVERS.3 2.5 KB

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  25. .TH CURLOPT_DNS_SERVERS 3 "January 02, 2023" "libcurl 7.88.1" "curl_easy_setopt options"
  26. .SH NAME
  27. CURLOPT_DNS_SERVERS \- DNS servers to use
  28. .SH SYNOPSIS
  29. .nf
  30. #include <curl/curl.h>
  31. CURLcode curl_easy_setopt(CURL *handle, CURLOPT_DNS_SERVERS, char *servers);
  32. .fi
  33. .SH DESCRIPTION
  34. Pass a char * that is the list of DNS servers to be used instead of the system
  35. default. The format of the dns servers option is:
  36. host[:port][,host[:port]]...
  37. For example:
  38. 192.168.1.100,192.168.1.101,3.4.5.6
  39. The application does not have to keep the string around after setting this
  40. option.
  41. .SH DEFAULT
  42. NULL - use system default
  43. .SH PROTOCOLS
  44. All
  45. .SH EXAMPLE
  46. .nf
  47. CURL *curl = curl_easy_init();
  48. if(curl) {
  49. curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/foo.bin");
  50. curl_easy_setopt(curl, CURLOPT_DNS_SERVERS, "192.168.1.100:53,192.168.1.101");
  51. ret = curl_easy_perform(curl);
  52. curl_easy_cleanup(curl);
  53. }
  54. .fi
  55. .SH AVAILABILITY
  56. This option requires that libcurl was built with a resolver backend that
  57. supports this operation. The c-ares backend is the only such one.
  58. Added in 7.24.0
  59. .SH RETURN VALUE
  60. Returns CURLE_OK if the option is supported, CURLE_UNKNOWN_OPTION if not,
  61. CURLE_NOT_BUILT_IN if support was disabled at compile-time,
  62. CURLE_BAD_FUNCTION_ARGUMENT when given an invalid server list, or
  63. CURLE_OUT_OF_MEMORY if there was insufficient heap space.
  64. .SH "SEE ALSO"
  65. .BR CURLOPT_DNS_LOCAL_IP4 "(3), " CURLOPT_DNS_CACHE_TIMEOUT "(3), "