www.LinuxHowtos.org

CURLOPT_WRITEDATA

Section: C Library Functions (3)
Updated: 202-0-19
Index Return to Main Contents

NAME

CURLOPT_WRITEDATA - pointer passed to the write callback

SYNOPSIS

#include <curl/curl.h>

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

DESCRIPTION

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 callbackaqs fourth and last argument. If you do not use a write callback, you must make pointer a aqFILE aq (cast to aqvoid aq) 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 also use CURLOPT_WRITEFUNCTION(3) if you set this option or you might experience crashes.

DEFAULT

stdout

PROTOCOLS

This functionality affects all supported protocols

EXAMPLE

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

HISTORY

This option was formerly known as CURLOPT_FILE, the name CURLOPT_WRITEDATA(3) was added in 7.9.7.

AVAILABILITY

Added in curl 7.9.7

RETURN VALUE

This returns CURLE_OK.