(PHP 4, PHP 5, PHP 7, PHP 8)
readfile — Outputs a file
$filename
, bool $use_include_path
= false
, ?resource $context
= null
): int|falseReads a file and writes it to the output buffer.
filename
The filename being read.
use_include_path
You can use the optional second parameter and set it to true
, if
you want to search for the file in the include_path, too.
context
A context stream resource.
Returns the number of bytes read from the file on success,
or false
on failure
Upon failure, an E_WARNING
is emitted.
Example #1 Forcing a download using readfile()
<?php
$file = 'monkey.gif';
if (file_exists($file)) {
header('Content-Description: File Transfer');
header('Content-Type: application/octet-stream');
header('Content-Disposition: attachment; filename="'.basename($file).'"');
header('Expires: 0');
header('Cache-Control: must-revalidate');
header('Pragma: public');
header('Content-Length: ' . filesize($file));
readfile($file);
exit;
}
?>
The above example will output something similar to:
Note:
readfile() will not present any memory issues, even when sending large files, on its own. If you encounter an out of memory error ensure that output buffering is off with ob_get_level().
A URL can be used as a filename with this function if the fopen wrappers have been enabled. See fopen() for more details on how to specify the filename. See the Supported Protocols and Wrappers for links to information about what abilities the various wrappers have, notes on their usage, and information on any predefined variables they may provide.