1--- 2c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. 3SPDX-License-Identifier: curl 4Title: CURLOPT_IOCTLDATA 5Section: 3 6Source: libcurl 7See-also: 8 - CURLOPT_IOCTLFUNCTION (3) 9 - CURLOPT_SEEKFUNCTION (3) 10Protocol: 11 - All 12Added-in: 7.12.3 13--- 14 15# NAME 16 17CURLOPT_IOCTLDATA - pointer passed to I/O callback 18 19# SYNOPSIS 20 21~~~c 22#include <curl/curl.h> 23 24CURLcode curl_easy_setopt(CURL *handle, CURLOPT_IOCTLDATA, void *pointer); 25~~~ 26 27# DESCRIPTION 28 29Pass the *pointer* that is untouched by libcurl and passed as the 3rd 30argument in the ioctl callback set with CURLOPT_IOCTLFUNCTION(3). 31 32# DEFAULT 33 34NULL 35 36# %PROTOCOLS% 37 38# EXAMPLE 39 40~~~c 41#include <unistd.h> /* for lseek */ 42 43struct data { 44 int fd; /* our file descriptor */ 45}; 46 47static curlioerr ioctl_callback(CURL *handle, int cmd, void *clientp) 48{ 49 struct data *io = (struct data *)clientp; 50 if(cmd == CURLIOCMD_RESTARTREAD) { 51 lseek(io->fd, 0, SEEK_SET); 52 return CURLIOE_OK; 53 } 54 return CURLIOE_UNKNOWNCMD; 55} 56int main(void) 57{ 58 struct data ioctl_data; 59 CURL *curl = curl_easy_init(); 60 if(curl) { 61 curl_easy_setopt(curl, CURLOPT_IOCTLFUNCTION, ioctl_callback); 62 curl_easy_setopt(curl, CURLOPT_IOCTLDATA, &ioctl_data); 63 } 64} 65~~~ 66 67# DEPRECATED 68 69Deprecated since 7.18.0. 70 71# %AVAILABILITY% 72 73# RETURN VALUE 74 75Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not. 76
