NAME

       CURLOPT_IOCTLDATA - custom pointer passed to I/O callback

SYNOPSIS

       #include <curl/curl.h>

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_IOCTLDATA, void *pointer);

DESCRIPTION

       Pass  the  pointer that will be untouched by libcurl and passed as the 3rd argument in the ioctl callback
       set with CURLOPT_IOCTLFUNCTION(3).

DEFAULT

       By default, the value of this parameter is NULL.

PROTOCOLS

       Used with HTTP

EXAMPLE

       static curlioerr ioctl_callback(CURL *handle, int cmd, void *clientp)
       {
         struct data *io = (struct data *)clientp;
         if(cmd == CURLIOCMD_RESTARTREAD) {
           lseek(fd, 0, SEEK_SET);
           current_offset = 0;
           return CURLIOE_OK;
         }
         return CURLIOE_UNKNOWNCMD;
       }
       {
         struct data ioctl_data;
         curl_easy_setopt(curl, CURLOPT_IOCTLFUNCTION, ioctl_callback);
         curl_easy_setopt(curl, CURLOPT_IOCTLDATA, &ioctl_data);
       }

AVAILABILITY

       Added in 7.12.3

RETURN VALUE

       Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.

SEE ALSO

       CURLOPT_IOCTLFUNCTION(3), CURLOPT_SEEKFUNCTION(3),

libcurl 7.68.0                                    May 31, 2017                              CURLOPT_IOCTLDATA(3)