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
설명
bool is_readable
( string $filename
)
Tells whether a file exists and is readable.
인수
- filename
-
Path to the file.
반환값
Returns TRUE if the file or directory specified by filename exists and is readable, FALSE otherwise.
예제
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';
}
?>
오류/예외
Upon failure, an E_WARNING is emitted.
주의
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: 이 함수의 결과는 캐시에 저장합니다. 자세한 설명은 clearstatcache()를 참고하십시오.
Tip
PHP 5.0.0부터 이 함수는 몇몇 URL 래퍼를 사용할 수 있습니다. 기능적으로 stat() 패밀리를 지원하는 래퍼 목록은 Supported Protocols and Wrappers를 참고하십시오.
Note:
The check is done using the real UID/GID instead of the effective one.
참고
- 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 01:13
jascha át gmx dót com
06-Nov-2006 11:58
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 02:15
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 03:22
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 01:08
Sometimes in situations where file_exists fails (returns false even though the file does exist) stat will work.