CURLOPT_OPENSOCKETDATA.3 3.0 KB

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  25. .TH CURLOPT_OPENSOCKETDATA 3 "May 17, 2022" "libcurl 7.85.0" "curl_easy_setopt options"
  26. .SH NAME
  27. CURLOPT_OPENSOCKETDATA \- pointer passed to open socket callback
  28. .SH SYNOPSIS
  29. .nf
  30. #include <curl/curl.h>
  31. CURLcode curl_easy_setopt(CURL *handle, CURLOPT_OPENSOCKETDATA, void *pointer);
  32. .fi
  33. .SH DESCRIPTION
  34. Pass a \fIpointer\fP that will be untouched by libcurl and passed as the first
  35. argument in the opensocket callback set with \fICURLOPT_OPENSOCKETFUNCTION(3)\fP.
  36. .SH DEFAULT
  37. The default value of this parameter is NULL.
  38. .SH PROTOCOLS
  39. All
  40. .SH EXAMPLE
  41. .nf
  42. /* make libcurl use the already established socket 'sockfd' */
  43. static curl_socket_t opensocket(void *clientp,
  44. curlsocktype purpose,
  45. struct curl_sockaddr *address)
  46. {
  47. curl_socket_t sockfd;
  48. sockfd = *(curl_socket_t *)clientp;
  49. /* the actual externally set socket is passed in via the OPENSOCKETDATA
  50. option */
  51. return sockfd;
  52. }
  53. static int sockopt_callback(void *clientp, curl_socket_t curlfd,
  54. curlsocktype purpose)
  55. {
  56. /* This return code was added in libcurl 7.21.5 */
  57. return CURL_SOCKOPT_ALREADY_CONNECTED;
  58. }
  59. curl = curl_easy_init();
  60. if(curl) {
  61. /* libcurl will internally think that you connect to the host
  62. * and port that you specify in the URL option. */
  63. curl_easy_setopt(curl, CURLOPT_URL, "http://99.99.99.99:9999");
  64. /* call this function to get a socket */
  65. curl_easy_setopt(curl, CURLOPT_OPENSOCKETFUNCTION, opensocket);
  66. curl_easy_setopt(curl, CURLOPT_OPENSOCKETDATA, &sockfd);
  67. /* call this function to set options for the socket */
  68. curl_easy_setopt(curl, CURLOPT_SOCKOPTFUNCTION, sockopt_callback);
  69. res = curl_easy_perform(curl);
  70. curl_easy_cleanup(curl);
  71. }
  72. .fi
  73. .SH AVAILABILITY
  74. Added in 7.17.1
  75. .SH RETURN VALUE
  76. Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.
  77. .SH "SEE ALSO"
  78. .BR CURLOPT_OPENSOCKETFUNCTION "(3), " CURLOPT_SOCKOPTFUNCTION "(3), "