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CURLOPT_IOCTLDATA(3) Library Functions Manual CURLOPT_IOCTLDATA(3)

NAME

CURLOPT_IOCTLDATA - 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 is 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

#include <unistd.h> /* for lseek */
struct data {

int fd; /* our file descriptor */ }; static curlioerr ioctl_callback(CURL *handle, int cmd, void *clientp) {
struct data *io = (struct data *)clientp;
if(cmd == CURLIOCMD_RESTARTREAD) {
lseek(io->fd, 0, SEEK_SET);
return CURLIOE_OK;
}
return CURLIOE_UNKNOWNCMD; } int main(void) {
struct data ioctl_data;
CURL *curl = curl_easy_init();
if(curl) {
curl_easy_setopt(curl, CURLOPT_IOCTLFUNCTION, ioctl_callback);
curl_easy_setopt(curl, CURLOPT_IOCTLDATA, &ioctl_data);
} }

AVAILABILITY

Added in 7.12.3. Deprecated since 7.18.0.

RETURN VALUE

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

SEE ALSO

CURLOPT_IOCTLFUNCTION(3), CURLOPT_SEEKFUNCTION(3)

February 24 2024 libcurl