is_link
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)
is_readable
(PHP 4, PHP 5)
is_readable — 判断给定文件名是否可读
说明
bool is_readable
( string $filename
)
如果由 filename 指定的文件或目录存在并且可读则返回 TRUE。
记住 PHP 也许只能以运行 webserver 的用户名（通常为 'nobody'）来访问文件。不计入安全模式的限制。
Example#1 is_readable() 例子
<?php
$filename = 'test.txt';
if (is_readable($filename)) {
echo 'The file is readable';
} else {
echo 'The file is not readable';
}
?>
Note: 本函数的结果会被缓存。更多信息参见 clearstatcache()。
Tip
自 PHP 5.0.0 起本函数也可被某些 URL wrapper 使用。参考支持的协议／封装协议列表 来看哪些 wrapper 支持 stat() 系列函数的功能。
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User Contributed Notesis_readable
jascha át gmx dót com
07-Nov-2006 10:58
07-Nov-2006 10:58
jo at durchholz dot org
31-Jan-2006 01:15
31-Jan-2006 01:15
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
14-Oct-2005 12:22
14-Oct-2005 12:22
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 10:08
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 10:32
12-Jan-2005 10:32
If you are using ACL, watch out for Bug #30931 (now open without any reaction for about 2 month, alltough an solution exists.)