For php://input fread() writes temp files

Description

The following code:

<?php
// index.php

$postBodyResource = fopen("php://input", 'rb');
while (!feof($postBodyResource)) {
    $data = fread($postBodyResource, 5 * 1024);
}
fclose($postBodyResource);

and Apache 2.4 config

Alias "/api" "${SRVROOT}/htdocs/Api"
<Directory "${SRVROOT}/htdocs/Api">
    RewriteEngine On 
    RewriteCond %{REQUEST_FILEaNAME} !-f
    RewriteCond %{REQUEST_FILENAME} !-d
    RewriteRule ^ index.php [QSA,L]

    Script POST "index.php"
    Script PUT "index.php"

    php_value enable_post_data_reading Off
</Directory>

Resulted in this output:
If I do a HTTP POST (Content-Type: application/octet-stream) at http://localhost/api with a body larger than 16 kB, PHP creates a temp file at sys_temp_dir or upload_dir that stores the whole content of the stream php://input while doing fread().

But I expected this output instead:
At least there should be a configuration option to disable writing the temp files.

See temp file writing so caused by php_fopen_wrapper.c#L231.

Please, see Stackoverflow for some discussion.

PHP Version

PHP 7.4+

Operating System

Windows 10 21H2

从链接行处的 ext/standard/php_fopen_wrapper.c 开始，使用提供的脚本、Apache 配置以及 Windows 上超过 16 kB 的 POST 请求体，复现 PHP 7.4+ 的行为。追踪 php://input 将完整流写入临时文件的原因；当所报告的行为或其配置控制得到处理，并由回归测试覆盖时，即视为完成。