docs/libcurl/opts/CURLOPT_READDATA.3

.\" **************************************************************************
.\" *                                  _   _ ____  _
.\" *  Project                     ___| | | |  _ \| |
.\" *                             / __| | | | |_) | |
.\" *                            | (__| |_| |  _ <| |___
.\" *                             \___|\___/|_| \_\_____|
.\" *
.\" * Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
.\" *
.\" * This software is licensed as described in the file COPYING, which
.\" * you should have received as part of this distribution. The terms
.\" * are also available at https://curl.se/docs/copyright.html.
.\" *
.\" * You may opt to use, copy, modify, merge, publish, distribute and/or sell
.\" * copies of the Software, and permit persons to whom the Software is
.\" * furnished to do so, under the terms of the COPYING file.
.\" *
.\" * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
.\" * KIND, either express or implied.
.\" *
.\" **************************************************************************
.\"
.TH CURLOPT_READDATA 3 "November 04, 2020" "libcurl 7.78.0" "curl_easy_setopt options"

.SH NAME
CURLOPT_READDATA \- custom pointer passed to the read callback
.SH SYNOPSIS
#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_READDATA, void *pointer);
.SH DESCRIPTION
Data \fIpointer\fP to pass to the file read function. If you use the
\fICURLOPT_READFUNCTION(3)\fP option, this is the pointer you'll get as
input in the 4th argument to the callback.

If you don't 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're using libcurl as a win32 DLL, you \fBMUST\fP use a
\fICURLOPT_READFUNCTION(3)\fP if you set this option or you will experience
crashes.
.SH DEFAULT
By default, this is a FILE * to stdin.
.SH PROTOCOLS
This is used for all protocols when sending data.
.SH EXAMPLE
.nf
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);
}
.fi
.SH AVAILABILITY
This option was once known by the older name CURLOPT_INFILE, the name
\fICURLOPT_READDATA(3)\fP was introduced in 7.9.7.
.SH RETURN VALUE
This will return CURLE_OK.
.SH "SEE ALSO"
.BR CURLOPT_READFUNCTION "(3), " CURLOPT_WRITEDATA "(3), "