is_writable
(PHP 4, PHP 5)
is_writable — Tells whether the filename is writable
Description
Returns TRUE if the filename exists and is writable. The filename argument may be a directory name allowing you to check if a directory is writable.
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.
Parameters
- filename
-
The filename being checked.
Return Values
Returns TRUE if the filename exists and is writable.
範例
Example#1 is_writable() example
<?php
$filename = 'test.txt';
if (is_writable($filename)) {
echo 'The file is writable';
} else {
echo 'The file is not writable';
}
?>
Notes
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.