CURLOPT_READDATA(3) Introduction to Library Functions CURLOPT_READDATA(3)

CURLOPT_READDATA - pointer passed to the read callback

#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_READDATA, void *pointer);

Data pointer to pass to the file read function. If you use the CURLOPT_READFUNCTION(3) option, this is the pointer you get as input in the fourth argument to the callback.

If you do not specify a read callback but instead rely on the default internal read function, this data must be a valid readable FILE * (cast to 'void *').

If you are using libcurl as a DLL on Windows, you must use the CURLOPT_READFUNCTION(3) callback if you set this option, otherwise you might experience crashes.

By default, this is a FILE * to stdin.

This is used for all protocols when sending data.

struct MyData {

void *custom; }; int main(void) {
CURL *curl = curl_easy_init();
struct MyData this;
if(curl) {
curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
/* pass pointer that gets passed in to the
CURLOPT_READFUNCTION callback */
curl_easy_setopt(curl, CURLOPT_READDATA, &this);
curl_easy_perform(curl);
} }

This option was once known by the older name CURLOPT_INFILE, the name CURLOPT_READDATA(3) was introduced in 7.9.7.

This returns CURLE_OK.

CURLOPT_HEADERDATA(3), CURLOPT_READFUNCTION(3), CURLOPT_WRITEDATA(3), CURLOPT_WRITEFUNCTION(3)

March 12 2024 libcurl