is_link
Note that is_readable() will return false for streams, eg, php://stdin.
is_readable
(PHP 4, PHP 5)
is_readable — Tells whether a file exists and is readable
Opis
bool is_readable
( string $filename
)
Tells whether a file exists and is readable.
Parametry
- filename
-
Path to the file.
Zwracane wartości
Returns TRUE if the file or directory specified by filename exists and is readable, FALSE otherwise.
Przykłady
Przykład #1 is_readable() example
<?php
$filename = 'test.txt';
if (is_readable($filename)) {
echo 'The file is readable';
} else {
echo 'The file is not readable';
}
?>
Notatki
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.
Informacja: Wyniki działania tej funkcji są buforowane. Zobacz opis funkcji clearstatcache() aby uzyskać więcej informacji.
Wskazówka
Od PHP 5.0.0 ta funkcja może być użyta także z niektórymi nakładkami URL. Zobacz List of Supported Protocols/Wrappers aby uzyskać listę nakładek, które obsługują funkcjonalność z rodziny stat().
Informacja: The check is done using the real UID/GID instead of the effective one.
Zobacz też:
- is_writable() - Tells whether the filename is writable
- file_exists() - Sprawdza czy plik lub katalog istnieje
- fgets() - Pobiera linię ze wskaźnika pliku
add a note
User Contributed Notesis_readable
pgl at yoyo dot org
31-Jul-2009 02:13
31-Jul-2009 02:13
jascha át gmx dót com
07-Nov-2006 02:58
07-Nov-2006 02:58
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 05:15
30-Jan-2006 05:15
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 04:22
13-Oct-2005 04:22
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.
27-Jul-2005 02:08
Sometimes in situations where file_exists fails (returns false even though the file does exist) stat will work.
php dot 5 dot ce at spamgourmet dot com
12-Jan-2005 02:32
12-Jan-2005 02:32
If you are using ACL, watch out for Bug #30931 (now open without any reaction for about 2 month, alltough an solution exists.)