is_readable in PHP

is_readable — Tells whether a file exists and is readable
Syntax:

bool is_readable ( string $filename )
Tells whether a file exists and 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.



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';
}
?>
Errors/Exceptions ¶

Upon failure, an E_WARNING is emitted.



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: The results of this function are cached. See clearstatcache() for more details.
Tip
As of PHP 5.0.0, this function can also be used with some URL wrappers. Refer to Supported Protocols and Wrappers to determine which wrappers support stat() family of functionality.
Note:
The check is done using the real UID/GID instead of the effective one.
This function may return TRUE for directories. Use is_dir() to distinguish file and directory.