is_readable

(PHP 4, PHP 5, PHP 7)

is_readableTells whether a file exists and is readable

Опис

bool is_readable ( string $filename )

Tells whether a file exists and is readable.

Параметри

filename

Path to the file.

Значення, що повертаються

Returns TRUE if the file or directory specified by filename exists and is readable, FALSE otherwise.

Приклади

Приклад #1 is_readable() example

<?php
$filename 
'test.txt';
if (
is_readable($filename)) {
    echo 
'The file is readable';
} else {
    echo 
'The file is not readable';
}
?>

Помилки/Винятки

При збоях, буде видаватись E_WARNING.

Примітки

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.

Зауваження: Рузультати цієї функції кешуються. Прогляньте clearstatcache() для більш детальної інформації.

Підказка

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.

Зауваження:

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.

Прогляньте Також

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User Contributed Notes 4 notes

up
10
jo at durchholz dot org
16 years ago
DrTebi at yahoo dot com is wrong. is_readable() checks whether you can do file_get_contents() or similar calls, no more, no less. If the location given returns a 500 or 403 error, you can still read() that (you'll simply get the error page), but it's still read()able. Using is_readable to check the validity of a URL is simply the wrong function.
up
0
pgl at yoyo dot org
12 years ago
Note that is_readable() will return false for streams, eg, php://stdin.
up
-1
arikan134 at gmail dot com
6 years ago
is readable recursively. Check all sub directories and files readable
<?php
function is_readable_r($dir) {
    if (
is_dir($dir)) {
        if(
is_readable($dir)){
           
$objects = scandir($dir);
            foreach (
$objects as $object) {
                if (
$object != "." && $object != "..") {
                    if (!
is_readable_r($dir."/".$object)) return false;
                    else continue;
                }
            }   
            return
true;   
        }else{
            return
false;
        }
       
    }else if(
file_exists($dir)){
        return (
is_readable($dir));
       
    }
}

?>
up
-38
Anonymous
16 years ago
Sometimes in situations where file_exists fails (returns false even though the file does exist) stat will work.
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