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);
?>
fileperms
(PHP 4, PHP 5, PHP 7)
fileperms — Gets file permissions
설명
int fileperms
( string
$filename
)Gets permissions for the given file.
인수
-
filename -
Path to the file.
반환값
Returns the file's permissions as a numeric mode. Lower bits of this mode
are the same as the permissions expected by chmod(),
however on most platforms the return value will also include information on
the type of file given as filename. The examples
below demonstrate how to test the return value for specific permissions and
file types on POSIX systems, including Linux and Mac OS X.
For local files, the specific return value is that of the st_mode member of the structure returned by the C library's stat() function. 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.
예제
Example #1 Display permissions as an octal value
<?php
echo substr(sprintf('%o', fileperms('/tmp')), -4);
echo substr(sprintf('%o', fileperms('/etc/passwd')), -4);
?>
위 예제의 출력:
1777 0644
Example #2 Display full permissions
<?php
$perms = fileperms('/etc/passwd');
switch ($perms & 0xF000) {
case 0xC000: // socket
$info = 's';
break;
case 0xA000: // symbolic link
$info = 'l';
break;
case 0x8000: // regular
$info = 'r';
break;
case 0x6000: // block special
$info = 'b';
break;
case 0x4000: // directory
$info = 'd';
break;
case 0x2000: // character special
$info = 'c';
break;
case 0x1000: // FIFO pipe
$info = 'p';
break;
default: // unknown
$info = 'u';
}
// Owner
$info .= (($perms & 0x0100) ? 'r' : '-');
$info .= (($perms & 0x0080) ? 'w' : '-');
$info .= (($perms & 0x0040) ?
(($perms & 0x0800) ? 's' : 'x' ) :
(($perms & 0x0800) ? 'S' : '-'));
// Group
$info .= (($perms & 0x0020) ? 'r' : '-');
$info .= (($perms & 0x0010) ? 'w' : '-');
$info .= (($perms & 0x0008) ?
(($perms & 0x0400) ? 's' : 'x' ) :
(($perms & 0x0400) ? 'S' : '-'));
// World
$info .= (($perms & 0x0004) ? 'r' : '-');
$info .= (($perms & 0x0002) ? 'w' : '-');
$info .= (($perms & 0x0001) ?
(($perms & 0x0200) ? 't' : 'x' ) :
(($perms & 0x0200) ? 'T' : '-'));
echo $info;
?>
위 예제의 출력:
-rw-r--r--
오류/예외
실패 시, E_WARNING이 발생합니다.
주의
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.
참고
- chmod() - Changes file mode
- is_readable() - Tells whether a file exists and is readable
- stat() - Gives information about a file
add a note
User Contributed Notes 9 notes
coolmic at example dot com ¶
11 years ago
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", $perm);
?>
MartinAngermeier at gmx dot net ¶
16 years ago
An easy way to calculate fileperms to chmod is this:
substr(decoct(fileperms("test.html")),3);
Displays 666 or 777 (depends on chmod set).
substr(decoct(fileperms("test.html")),2);
Displays 0666 or 0777 and refers immediately to the number set with chmod();
paul2712 at gmail dot com ¶
17 years ago
Do not forget: clearstatcache();
==============================
When ever you make a:
mkdir($dstdir, 0770 ))
or a:
chmod($dstdir, 0774 );
You have to call:
clearstatcache();
before you can call:
fileperms($dstdir);
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)
sviscaino123 at hotmail dot fr ¶
14 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 $filename ] ] )
Returns permissions given a string in literal format and a filename.
If the file name is omitted, the permissions that the function will return are based on 000-permissions.
If return_as_string is set to true, the result will be output as a 644 format string. Otherwise it will return a string converted to base-10 for chmod.
Examples:
<?php
echo mkperms('u+r', true), "\n"; // 400
echo mkperms('u+rwx,g+rw,o+x', true), "\n"; // 761
touch('myfile.txt'); // Create a file with any permissions
chmod('myfile.txt', mkperms('u=rwx,g=x,o=rw')); // myfile.txt is now at -rwx--xrw-
// Make a file and give it full permissions
touch('somefile.txt');
chmod('somefile.txt', 0777);
echo mkperms('g-w,o-rw', true, 'somefile.txt'); // 751
echo mkperms('u=rwx,g-r,o=-', true, 'somefile.txt'); // 730
// This way you can apply permissions to files
chmod('somefile.txt', mkperms('u=rwx,g-r,o=-', false, 'somefile.txt')); // somefile.txt is now at -rwx-wx---
?>
PS : sorry I had to put it on pastebin, or else it just made the note way too long.
Dominic ¶
10 years ago
A small function for the last 3 digits (777/755 ect.)
<?php
function getFilePermission($file) {
$length = strlen(decoct(fileperms($file)))-3;
return substr(decoct(fileperms($file)),$length);
}
?>
jchris dot fillionr at kitware dot com ¶
15 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);
?>
chinello at gmail dot com ¶
17 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
?>
