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);
?>
(PHP 4, PHP 5, PHP 7, PHP 8)
fileperms — Gets file permissions
filenamePath to the file.
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 macOS.
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.
Returns false on failure.
Upon failure, an E_WARNING is emitted.
Example #1 Display permissions as an octal value
<?php
echo substr(sprintf('%o', fileperms('/tmp')), -4);
echo substr(sprintf('%o', fileperms('/etc/passwd')), -4);
?>The above example will output:
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 $info;
?>The above example will output:
-rw-r--r--
Note: The results of this function are cached. See clearstatcache() for more details.
As of PHP 5.0.0, this function can also be used with some URL wrappers. Refer to Supported Protocols and Wrappers to determine which wrappers support stat() family of functionality.
Don't use substr, use bit operator
<?php
decoct(fileperms($file) & 0777); // return "755" for example
?>
If you want to compare permission
<?php
0755 === (fileperms($file) & 0777);
?>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", $perm);
?>An easy way to calculate fileperms to chmod is this:
substr(decoct(fileperms("test.html")),3);
Displays 666 or 777 (depends on chmod set).
substr(decoct(fileperms("test.html")),2);
Displays 0666 or 0777 and refers immediately to the number set with chmod();Do not forget: clearstatcache();
==============================
When ever you make a:
mkdir($dstdir, 0770 ))
or a:
chmod($dstdir, 0774 );
You have to call:
clearstatcache();
before you can call:
fileperms($dstdir);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)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 $filename ] ] )
Returns permissions given a string in literal format and a filename.
If the file name is omitted, the permissions that the function will return are based on 000-permissions.
If return_as_string is set to true, the result will be output as a 644 format string. Otherwise it will return a string converted to base-10 for chmod.
Examples:
<?php
echo mkperms('u+r', true), "\n"; // 400
echo mkperms('u+rwx,g+rw,o+x', true), "\n"; // 761
touch('myfile.txt'); // Create a file with any permissions
chmod('myfile.txt', mkperms('u=rwx,g=x,o=rw')); // myfile.txt is now at -rwx--xrw-
// Make a file and give it full permissions
touch('somefile.txt');
chmod('somefile.txt', 0777);
echo mkperms('g-w,o-rw', true, 'somefile.txt'); // 751
echo mkperms('u=rwx,g-r,o=-', true, 'somefile.txt'); // 730
// This way you can apply permissions to files
chmod('somefile.txt', mkperms('u=rwx,g-r,o=-', false, 'somefile.txt')); // somefile.txt is now at -rwx-wx---
?>
PS : sorry I had to put it on pastebin, or else it just made the note way too long.A small function for the last 3 digits (777/755 ect.)
<?php
function getFilePermission($file) {
$length = strlen(decoct(fileperms($file)))-3;
return substr(decoct(fileperms($file)),$length);
}
?>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);
?>