(PHP 4, PHP 5, PHP 7, PHP 8)
is_readable — Tells whether a file exists and is readable
filenamePath to the file.
Returns true if the file or directory specified by
filename exists and is readable, false otherwise.
Під час збоїв буде видаватись E_WARNING.
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';
}
?>Keep in mind that PHP may be accessing the file as the user id that the web server runs as (often 'nobody').
Зауваження:
For local files, the result of this function is not cached and the file is checked again on every call. For paths using other wrappers the result is cached. See clearstatcache() for more details.
Починаючи з PHP 5.0.0, ця функція також може бути використана з деякими URL-обгортками. На сторінці Підтримувані протоколи та обгортки вказано, які обгортки підтримують сімейство функцій stat().
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.
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.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));
}
}
?>Note that is_readable() will return false for streams, eg, php://stdin.Do note that is_readable/is_writable evaluates permissions in an attempt to produce the result.
This WILL fail in certain situations, while the file is actually accessible to the user, but manual evaluation fails to connect the dots.
The only trusted way to detect if a file is readable is to actually open it for reading. The only trusted way to detect if a file is writable is to actually open it for writing. And catche the error in case of failure.This will return false on urls, even if file_get_contents() reads them. So, only for files.