is_readable
(PHP 4, PHP 5)
is_readable — Tells whether the filename is readable
Description
Tells whether the filename is readable.
Parameters
- filename
-
Path to the file.
Return Values
Returns TRUE if the file or directory specified by filename exists and is readable, FALSE otherwise.
範例
Example#1 is_readable() example
<?php
$filename = 'test.txt';
if (is_readable($filename)) {
echo 'The file is readable';
} else {
echo 'The file is not readable';
}
?>
Notes
Keep in mind that PHP may be accessing the file as the user id that the web server runs as (often 'nobody'). Safe mode limitations are not taken into account before PHP 5.1.5.
Note: 此函數的結果會被快取。詳細資訊請參考 clearstatcache()。
As of PHP 5.0.0 this function can also be used with some URL wrappers. Refer to List of Supported Protocols/Wrappers for a listing of which wrappers support stat() family of functionality.
Note: The check is done using the real UID/GID instead of the effective one.