fileperms

Gets file permissions

Description

int fileperms ( string $filename )

Gets permissions for the given file.

Parameters

filename: Path to the file.

Return Values

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.

Examples

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--

Errors/Exceptions

Upon failure, an E_WARNING is emitted.

Notes

Note: The results of this function are cached. See clearstatcache for more details.

Tip

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.