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fileperms

(PHP 4, PHP 5, PHP 7, PHP 8)

fileperms获取文件权限

说明

fileperms(string $filename): int|false

获取指定文件权限。

参数

filename

文件的路径。

返回值

以数字模式返回文件权限。此模式的低位与 chmod() 期望权限相同,然而在大多数平台上,返回值还将会包含指定 filename 的文件类型信息。下面的示例示范了如何在 POSIX 系统上测试特定权限和文件类型的返回值。

对于本地文件,特定的返回值是通过 C 库的 stat() 函数返回结构中的 st_mode 成员的值。Exactly which bits are set can vary from platform to platform, and looking up your specific platform's documentation is recommended if parsing the non-permission bits of the return value is required.

失败时返回 false

错误/异常

失败时抛出 E_WARNING 警告。

示例

示例 #1 以八进制的形式显示文件的权限

<?php
echo substr(sprintf('%o', fileperms('/tmp')), -4);
echo
substr(sprintf('%o', fileperms('/etc/passwd')), -4);
?>

以上示例会输出:

1777
0644

示例 #2 输出全部权限

<?php
$perms
= fileperms('/etc/passwd');

switch (
$perms & 0xF000) {
case
0xC000: // 套接字
$info = 's';
break;
case
0xA000: // 符号链接
$info = 'l';
break;
case
0x8000: // regular
$info = 'r';
break;
case
0x6000: // 块设备
$info = 'b';
break;
case
0x4000: // 目录
$info = 'd';
break;
case
0x2000: // 字符设备
$info = 'c';
break;
case
0x1000: // FIFO 管道
$info = 'p';
break;
default:
// 位置
$info = 'u';
}

// 所有者
$info .= (($perms & 0x0100) ? 'r' : '-');
$info .= (($perms & 0x0080) ? 'w' : '-');
$info .= (($perms & 0x0040) ?
((
$perms & 0x0800) ? 's' : 'x' ) :
((
$perms & 0x0800) ? 'S' : '-'));

// 组
$info .= (($perms & 0x0020) ? 'r' : '-');
$info .= (($perms & 0x0010) ? 'w' : '-');
$info .= (($perms & 0x0008) ?
((
$perms & 0x0400) ? 's' : 'x' ) :
((
$perms & 0x0400) ? 'S' : '-'));

// 其它
$info .= (($perms & 0x0004) ? 'r' : '-');
$info .= (($perms & 0x0002) ? 'w' : '-');
$info .= (($perms & 0x0001) ?
((
$perms & 0x0200) ? 't' : 'x' ) :
((
$perms & 0x0200) ? 'T' : '-'));

echo
$info;
?>

以上示例会输出:

-rw-r--r--

注释

注意: 此函数的结果会被缓存。参见 clearstatcache() 以获得更多细节。

小技巧

自 PHP 5.0.0 起, 此函数也用于某些 URL 包装器。请参见 支持的协议和封装协议以获得支持 stat() 系列函数功能的包装器列表。

参见

add a note

User Contributed Notes 9 notes

up
35
coolmic at example dot com
10 years ago
Don't use substr, use bit operator
<?php
decoct
(fileperms($file) & 0777); // return "755" for example
?>

If you want to compare permission
<?php
0755
=== (fileperms($file) & 0777);
?>
up
6
admin at torntech dot com
12 years ago
This may not be immediately apparent to some, but you can use octdec( $octal_value ) to match the permissions retrieved by file perms

<?php

//assumes file has 2770 permissions
$perm= fileperms( __FILE__ );
$bit = "102770";

printf( "%s\n", octdec( $bit ) );
printf( "%s\n", $perm);

?>
up
3
MartinAngermeier at gmx dot net
15 years ago
An easy way to calculate fileperms to chmod is this:

substr(decoct(fileperms("test.html")),3);

Displays 666 or 777 (depends on chmod set).

substr(decoct(fileperms("test.html")),2);

Displays 0666 or 0777 and refers immediately to the number set with chmod();
up
4
paul2712 at gmail dot com
16 years ago
Do not forget: clearstatcache();
==============================

When ever you make a:

mkdir($dstdir, 0770 ))

or a:

chmod($dstdir, 0774 );

You have to call:

clearstatcache();

before you can call:

fileperms($dstdir);
up
1
chris at ocproducts dot com
4 years ago
Windows has a very different file permission model to Unix and integrates them only minimally.

Here's how Windows calculates the bitmask...

u+w/g+w/o+w is set based on whether the file has the read only flag.

u+r/g+w/o+w is always set.

u+x/g+x/o+x is set based on whether $filename is an inherently executable file (e.g. bat) or a directory.

Windows isn't integrating its ACLs at all.

Here's the source of all this: https://docs.microsoft.com/en-us/cpp/c-runtime-library/reference/stat-functions?view=vs-2019 (but it doesn't provide many details)
up
-1
sviscaino123 at hotmail dot fr
13 years ago
Here is a small function I made : http://pastebin.com/iKky8Vtu
I was bored and I thought it could be useful.

mixed mkperms( string $perms [, bool return_as_string = false [, string $filename ] ] )
Returns permissions given a string in literal format and a filename.
If the file name is omitted, the permissions that the function will return are based on 000-permissions.
If return_as_string is set to true, the result will be output as a 644 format string. Otherwise it will return a string converted to base-10 for chmod.

Examples:

<?php
echo mkperms('u+r', true), "\n"; // 400
echo mkperms('u+rwx,g+rw,o+x', true), "\n"; // 761

touch('myfile.txt'); // Create a file with any permissions
chmod('myfile.txt', mkperms('u=rwx,g=x,o=rw')); // myfile.txt is now at -rwx--xrw-

// Make a file and give it full permissions
touch('somefile.txt');
chmod('somefile.txt', 0777);
echo
mkperms('g-w,o-rw', true, 'somefile.txt'); // 751
echo mkperms('u=rwx,g-r,o=-', true, 'somefile.txt'); // 730
// This way you can apply permissions to files
chmod('somefile.txt', mkperms('u=rwx,g-r,o=-', false, 'somefile.txt')); // somefile.txt is now at -rwx-wx---
?>

PS : sorry I had to put it on pastebin, or else it just made the note way too long.
up
-4
Dominic
10 years ago
A small function for the last 3 digits (777/755 ect.)

<?php
function getFilePermission($file) {
$length = strlen(decoct(fileperms($file)))-3;
return
substr(decoct(fileperms($file)),$length);
}
?>
up
-5
jchris dot fillionr at kitware dot com
14 years ago
Since the output of decoct( fileperms('.') ) is of the form: 40644

It seems the previous example is wrong, instead you should understand:

To get permissions formatted as "644":
<?php
echo substr(decoct( fileperms('.') ), 2);
?>

To get permissions formatted as "0644":
<?php
echo substr(decoct( fileperms('.') ), 1);
?>
up
-10
chinello at gmail dot com
16 years ago
On Linux (not tested on Windows), if you want a chmod-like permissions, you can use this function:

<?php
function file_perms($file, $octal = false)
{
if(!
file_exists($file)) return false;

$perms = fileperms($file);

$cut = $octal ? 2 : 3;

return
substr(decoct($perms), $cut);
}
?>

Using it:

$ touch foo.bar
$ chmod 0754 foo.bar
<?php
echo file_perms('foo.bar'); // prints: 754
echo file_perms('foo.bar', true); // prints 0754
?>
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