Question

So given this simple example:

<?php
$memory = fopen('php://memory', 'r+');

fwrite($memory, 'asdf', 4);

$value = fread($memory, 3);

var_dump($value);

I was expecting $value to contain the string "asd" but instead I get an empty string. Is there anything obvious about this example that needs to change? Is my expectation incorrect? If $value should indeed contain "asd" what might cause this to happen (a configuration/php.ini issue perhaps)?

Answer 1

Since the internal pointer of the stream is at index 4 after you write the data, you need to fseek back to the beginning of your stream:

// fwrite
fseek($memory, 0);  // same as rewind($memory);
// fread