is_link
Note that is_readable() will return false for streams, eg, php://stdin.
is_readable
(PHP 4, PHP 5)
is_readable — بررسی وجود و قابلیت خواندن فایل
Description
bool is_readable
( string $filename
)
بررسی وجود و قابلیت خواندن فایل.
Parameters
- filename
-
مسیر فایل.
Return Values
بازگرداندن TRUE اگر فایل یا دایرکتوری مشخص شده توسط filename وجود دارد و قابل خواندن است FALSE در غیر این صورت.
Examples
Example #1 مثال is_readable()
<?php
$filename = 'test.txt';
if (is_readable($filename)) {
echo 'The file is readable';
} else {
echo 'The file is not readable';
}
?>
Notes
توجه داشته باشید که PHP ممکن است به فایل به عنوان کاربر id اجرای وب سرور (معمولا 'nobody') دسترسی پیدا کند. محدودیتهای حالت امن پیش از PHP 5.1.5 در نظر گرفته نشده است.
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 for a listing of which wrappers support stat() family of functionality.
Note:
بررسی با استفاده از UID/GID واقعی به جای شیوه موثر انجام میشود.
See Also
- is_writable() - Tells whether the filename is writable
- file_exists() - Checks whether a file or directory exists
- fgets() - Gets line from file pointer
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User Contributed Notes
is_readable
pgl at yoyo dot org
31-Jul-2009 07:13
jascha át gmx dót com
07-Nov-2006 06:58
Safe_mode restrictions ignored means:
cant read by read() so is_readable() = false.
even if safe_mode_include_dir is set and include does works, is_readable() is false to. :(
(php5)
jo at durchholz dot org
30-Jan-2006 09:15
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.
DrTebi at yahoo dot com
13-Oct-2005 09:22
Be careful when using is_readable on symbolic links.
is_readable will return true if the file the symbolic link is pointing to is readable.
The problem is that if the server does NOT allow to follow symbolic links, is_readable will still return true, but e.g. redirecting to the sybolic link will not work. For Apache, make sure that at the server, virtual host configuration level, or inside a directory container you have set
Options +FollowSymLinks
As an example, let's say you have at the document root directory:
index.php -- the script using is_readable
my_linked_page.html -- a regular HTML page
my_link -- a link pointing to my_linked_page.html
Now in index.php:
<?php
if (is_readable('my_link')) {
header('Location: /my_link');
}
?>
If FollowSymLinks is forbidden, this will not work, if allowed, it will.
26-Jul-2005 07:08
Sometimes in situations where file_exists fails (returns false even though the file does exist) stat will work.