CURLOPT_WRITEDATA
Section: curl_easy_setopt options (3)
Updated: November 04, 2020
Page Index
NAME
CURLOPT_WRITEDATA - custom 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'll get in that
callback's 4th argument. If you don't use a write callback, you must make
pointer a 'FILE *' (cast to 'void *') as libcurl will pass this to
fwrite(3) when writing data.
The internal CURLOPT_WRITEFUNCTION(3) will write the data to the FILE *
given with this option, or to stdout if this option hasn't been set.
If you're using libcurl as a win32 DLL, you MUST use a
CURLOPT_WRITEFUNCTION(3) if you set this option or you will experience
crashes.
DEFAULT
By default, this is a FILE * to stdout.
PROTOCOLS
Used for all 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
AVAILABILITY
Available in all libcurl versions. This option was formerly known as
CURLOPT_FILE, the name
CURLOPT_WRITEDATA(3) was introduced in
7.9.7.
RETURN VALUE
This will return CURLE_OK.
SEE ALSO
CURLOPT_WRITEFUNCTION(3),
CURLOPT_READDATA(3),