php is_file 总是返回 false

Question

php is_file always return false

[apache@h185 default]$ ls -l /home/www/default/p.php
-rwxr-xr-x. 1 zhouhh zhouhh 50837 Aug 28 19:02 /home/www/default/p.php
[apache@h185 default]$ ls -l /usr/bin/rrdtool
-rwxr-xr-x. 1 root root 24688 Aug 21  2010 /usr/bin/rrdtool
[apache@h185 default]$ ls -l /root/my.cnf
ls: cannot access /root/my.cnf: Permission denied
[apache@h185 default]$ ls -l /usr/bin/ld
-rwxr-xr-x. 1 root root 594968 Jun 22 22:06 /usr/bin/ld
[apache@h185 default]$ ls -l /usr/bin/php
-rwxr-xr-x. 1 root root 3224944 Jul  4 00:57 /usr/bin/php
[apache@h185 default]$ vi test.php
[apache@h185 default]$ cat test.php
<?php
#if(is_file('/home/www/default/p.php'))

#if(is_file('/usr/bin/rrdtool'))
#if(is_file('/root/my.cnf'))
#if(is_file('/usr/bin/ld'))
#if(file_exists('/usr/bin/ld'))
if(is_file('/usr/bin/php'))
{
print 'ok';
}
else
{
print 'no ok';
}
?>
[apache@h185 default]$

except first line returns true, other line always returns false. but this file all exist. /root/my.cnf can't access, other files can execute and read.

how to solve this problem?

Answer 1

Note that is_file() returns false if the parent directory doesn't have +x (running permissions) set for the user running the php file.

This make sense, but other functions such as readdir() don't seem to have this limitation. The end result is that you can loop through a directory's files but is_file() will always fail.

Quoted from here

Answer 2

请注意，www-data 或 web 服务器用户必须具有访问目录的权限，而文件是，以 webserver 用户身份登录（linux 中的 su www-data）并检查您是否可以通过您用来访问的所有路径进行访问文件。

Answer 3

You can also use !is_dir which doesn't suffer from running permissions issue.

if(!is_dir($filename)) {
  //remove a file
  unlink($filename);
} else {
  //remove a directory
}

Answer 4

is_file() returns if a file is regular file .

when you do a ls -l if the first column of the file permissions is a -, then that file is a regular file.

so use file_exists() function. It returns if a file/directory exists.

Answer 5

I had the same problem. The issue was an incorrect file path.

Always make sure that eg is_file($dir.$file) is pointing to the correct location.

Output your recent location by: var_dump($dir.$file);

Output if the correct file path is set (must be true): var_dump(is_file($dir.$file));

Answer 6

As a general rule check your file permissions in accordance with previous answers.

In a Docker build environment, files copied as a result of host:container directory mappings may not have copied correctly. If you see -?????????? for your file's permissions, manually copy the file(s) with docker cp .