CURLOPT_WRITEDATA3
Pointer passed to the write callback
Usage
#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_WRITEDATA, void *pointer);
Overview
A data pointer to pass to the write callback. If you use the CURLOPT_WRITEFUNCTION(3) option, this is the pointer you get in that callback's fourth and last argument. If you do not use a write callback, you must make pointer a 'FILE ' (cast to 'void ') as libcurl passes this to fwrite(3) when writing data.
The internal CURLOPT_WRITEFUNCTION(3) writes the data to the FILE * given with this option, or to stdout if this option has not been set.
If you are using libcurl as a Windows DLL, you MUST use a CURLOPT_WRITEFUNCTION(3) if you set this option or you might experience crashes.
Default
By default, this is a FILE * to stdout.
Protocols
Used for all protocols.
Examples
A common technique is to use the write callback to store the incoming data into a dynamically growing allocated buffer, and then this CURLOPT_WRITEDATA(3) is used to point to a struct or the buffer to store data in. Like in the getinmemory example: https://curl.se/libcurl/c/getinmemory.html
Return value
This returns CURLE_OK.
Releases
79 releases since OS X 10.10; the text changed 14 times.