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CURLOPT_WRITEDATA(3) libcurl CURLOPT_WRITEDATA(3)
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 will 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 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 has not been set.
If you are 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),
ibcurl 8.1.2 April 26, 2023 CURLOPT_WRITEDATA(3)