chmod
(PHP 4, PHP 5)
chmod — Changes file mode
Description
$filename
, int $mode
)
Attempts to change the mode of the specified file to that given in
mode.
Parameters
-
filename -
Path to the file.
-
mode -
Note that
modeis not automatically assumed to be an octal value, so strings (such as "g+w") will not work properly. To ensure the expected operation, you need to prefixmodewith a zero (0):<?php
chmod("/somedir/somefile", 755); // decimal; probably incorrect
chmod("/somedir/somefile", "u+rwx,go+rx"); // string; incorrect
chmod("/somedir/somefile", 0755); // octal; correct value of mode
?>The
modeparameter consists of three octal number components specifying access restrictions for the owner, the user group in which the owner is in, and to everybody else in this order. One component can be computed by adding up the needed permissions for that target user base. Number 1 means that you grant execute rights, number 2 means that you make the file writeable, number 4 means that you make the file readable. Add up these numbers to specify needed rights. You can also read more about modes on Unix systems with 'man 1 chmod' and 'man 2 chmod'.<?php
// Read and write for owner, nothing for everybody else
chmod("/somedir/somefile", 0600);
// Read and write for owner, read for everybody else
chmod("/somedir/somefile", 0644);
// Everything for owner, read and execute for others
chmod("/somedir/somefile", 0755);
// Everything for owner, read and execute for owner's group
chmod("/somedir/somefile", 0750);
?>
Return Values
Returns TRUE on success or FALSE on failure.
Notes
Note:
The current user is the user under which PHP runs. It is probably not the same user you use for normal shell or FTP access. The mode can be changed only by user who owns the file on most systems.
Note: This function will not work on remote files as the file to be examined must be accessible via the server's filesystem.
Note:
When safe mode is enabled, PHP checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed. In addition, you cannot set the SUID, SGID and sticky bits.
See Also
- chown() - Changes file owner
- chgrp() - Changes file group
- fileperms() - Gets file permissions
- stat() - Gives information about a file
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Коментарии
In the previous post, stickybit avenger writes:
Just a little hint. I was once adwised to set the 'sticky bit', i.e. use 1777 as chmod-value...
Note that in order to set the sticky bit on a file one must use '01777' (oct) and not '1777' (dec) as the parameter to chmod:
<?php
chmod("file",01777); // correct
chmod("file",1777); // incorrect, same as chmod("file",01023), causing no owner permissions!
?>
Rule of thumb: always prefix octal mode values with a zero.
If you cannot chmod files/directories with PHP because of safe_mode restrictions, but you can use FTP to chmod them, simply use PHP's FTP-functions (eg. ftp_chmod or ftp_site) instead. Not as efficient, but works.Usefull reference:
Value Permission Level
400 Owner Read
200 Owner Write
100 Owner Execute
40 Group Read
20 Group Write
10 Group Execute
4 Global Read
2 Global Write
1 Global Execute
(taken from http://www.onlamp.com/pub/a/php/2003/02/06/php_foundations.html)
an update to 'neil at 11 out of 10's code for changing mode using FTP.
changes: proper array added within the function (better for those of us who only need to connect to one ftp server) so only the mode and directory name need to be passed.
the octal added, for completeness and predictable stability.
<?php
function changemode($xcite)
{
$ftp_details = array(
ftp_user_name => 'username',
ftp_user_pass => 'password',
ftp_user_root => '/public_html/',
ftp_server => 'ftp.something.org'
);
$path = "public";
$mod = intval($xcite, 8);
// extract ftp details (array keys as variable names)
extract ($ftp_details);
// set up basic connection
$conn_id = ftp_connect($ftp_server);
// login with username and password
$login_result = ftp_login($conn_id, $ftp_user_name, $ftp_user_pass);
// try to chmod $path directory
if (ftp_site($conn_id, 'CHMOD '.$mod.' '.$ftp_root.$path) !== false) {
$success=TRUE;
}
else {
$success=FALSE;
}
// close the connection
ftp_close($conn_id);
return $success;
}
?>
for those of you, like me, who were looking for a way to make an 'un-hackable' uploader, here's the closest i got, now for a field test, good luck!
Thanks for your code, "imoldgreg at o2 dot co dot uk". I am using it for an instalation script that has to CHMOD a bunch of files. I have found it faster to use the same connectino for each, as shown below.
<?php
// Thanks to "imoldgreg at o2 dot co dot uk" for the base 'CHMOD via FTP' script.
function chmod_open()
{
// Use your own FTP info
$ftp_user_name = 'chmod@XXXXXXXXX.com';
$ftp_user_pass = 'XXXXXXXXXX';
$ftp_root = '/';
$ftp_server = 'localhost';
$conn_id = ftp_connect($ftp_server);
$login_result = ftp_login($conn_id, $ftp_user_name, $ftp_user_pass);
return $conn_id;
}
function chmod_file($conn_id, $permissions, $path)
{
if (ftp_site($conn_id, 'CHMOD ' . $permissions . ' ' . $ftp_root . $path) !== false)
{
return TRUE;
}
else
{
return FALSE;
}
}
function chmod_close($conn_id)
{
ftp_close($conn_id);
}
// CHMOD the required setup files
// Connect to the FTP
$conn_id = chmod_open();
// CHMOD each file and echo the results
echo chmod_file($conn_id, 777, 'master/cache/') ? 'CHMODed successfully!' : 'Error';
echo chmod_file($conn_id, 777, 'master/files/') ? 'CHMODed successfully!' : 'Error';
echo chmod_file($conn_id, 777, 'master/store/') ? 'CHMODed successfully!' : 'Error';
echo chmod_file($conn_id, 766, 'master/config.php') ? 'CHMODed successfully!' : 'Error';
echo chmod_file($conn_id, 777, 'master/images/avatars/upload/') ? 'CHMODed successfully!' : 'Error';
// Close the connection
chmod_close($conn_id);
?>
Here, the same FTP connection is used for each CHMOD command, making the execute time lower. This is essential for me, since my script is also copying a bunch of files.
<?php
error_reporting(E_ERROR | E_PARSE);
/* Makes is so Directories are not browseable to the public,
removing only the Public = Read permission, while leaving
the other chmod permissions for the file in tact.
If you have exectue already on, and read off, public viewers will only
be able to view files through links, but not browse
around to see what's inside of directories and see what
you've got laying around. */
//-------------------------------------------------------
// Get file mode
// Get file permissions supported by chmod
function getmod($filename) {
$val = 0;
$perms = fileperms($filename);
// Owner; User
$val += (($perms & 0x0100) ? 0x0100 : 0x0000); //Read
$val += (($perms & 0x0080) ? 0x0080 : 0x0000); //Write
$val += (($perms & 0x0040) ? 0x0040 : 0x0000); //Execute
// Group
$val += (($perms & 0x0020) ? 0x0020 : 0x0000); //Read
$val += (($perms & 0x0010) ? 0x0010 : 0x0000); //Write
$val += (($perms & 0x0008) ? 0x0008 : 0x0000); //Execute
// Global; World
$val += (($perms & 0x0004) ? 0x0004 : 0x0000); //Read
$val += (($perms & 0x0002) ? 0x0002 : 0x0000); //Write
$val += (($perms & 0x0001) ? 0x0001 : 0x0000); //Execute
// Misc
$val += (($perms & 0x40000) ? 0x40000 : 0x0000); //temporary file (01000000)
$val += (($perms & 0x80000) ? 0x80000 : 0x0000); //compressed file (02000000)
$val += (($perms & 0x100000) ? 0x100000 : 0x0000); //sparse file (04000000)
$val += (($perms & 0x0800) ? 0x0800 : 0x0000); //Hidden file (setuid bit) (04000)
$val += (($perms & 0x0400) ? 0x0400 : 0x0000); //System file (setgid bit) (02000)
$val += (($perms & 0x0200) ? 0x0200 : 0x0000); //Archive bit (sticky bit) (01000)
return $val;
}
//-------------------------------------------------------
// Find out if file has mode
function hasmod($perms, $permission) {
# User Read = 0400 (256), Write = 0200 (128), Execute = 0100 (64)
# Group Read = 0040 (32), Write = 0020 (16), Execute = 0010 (8)
# Public Read = 0004 (4), Write = 0002 (2), Execute = 0001 (1)
return (($perms & $permission) == $permission);
}
//-------------------------------------------------------
// Take the read option off of all the subdirectories of the included path
function pathlock($dir, $listall = false, $testrun = true) {
echo "START @ " . date("F j, Y, h:i:s A") . "<br><br>";
echo ($testrun ? '**Test Run Activated (no changes will be made).**<br><br>' : '**Live Run Activated.**<br><br>');
echo $dir . " is our directory.<br><br>\n";
echo "[...IN PROGRESS...]<br><br>";
$file_list = '';
$stack[] = $dir;
while ($stack) {
$current_dir = array_pop($stack);
if ($dh = opendir($current_dir)) {
while (($file = readdir($dh)) !== false) {
if ($file !== '.' AND $file !== '..') {
$current_file = "{$current_dir}/{$file}";
if (is_dir($current_file)) {
// BEG ADD PATH
$mode = getmod($current_file); //Get the mode
$HasPubRead = hasmod($mode,4);
if ($HasPubRead || $listall) { // Can the public read this dir?
//======================================
$ch = true;
$take = 0;
// Change the mode:
if ($HasPubRead) {
$take = 4; // Value for Public Read. 4 is the same in octal and decimal.
if (!$testrun) {
$ch = chmod($current_file, $mode-$take);
}
}
echo $current_file . ",current=" . decoct($mode) .
(($mode!==$mode-$take) ? ",new=" . decoct($mode-$take) : '') .
($ch ? '' : ',FAILED') . "<br>\n";
} // end if hasmod
// END ADD PATH
$stack[] = $current_file;
} // if if_dir
} //if ($file !== '.' AND $file !== '..')
} //while (($file = readdir($dh)) !== false)
} //if ($dh = opendir($current_dir))
} // while ($stack)
echo "<br>COMPLETE @ " . date("F j, Y, h:i:s A") . "<br>\n";
return;
//return $path_list;
} // end function
//-------------------------------------------------------
//listall Show all folders, even one's we're not going to process?
//testrun Do a test run without making any changes
pathlock($_SERVER["DOCUMENT_ROOT"],false,true); // listall?=false, testrun?=true
?>
Note that info at rvgate dot nl's chmodnum function produces INCORRECT results. The resutls are base-10 numbers that only LOOK like they are octal numbers. The function also ignores setuid, setgid and sticky bits, and will produce incorrect numbers if such a file is encountered. Instead, this brute-force code works. Maybe there is something more slick, but this isn't too CPU-intensive (note that it assumes you've error-checked that you indeed have a 10-character string!):
<?php
$permissions = 'drwxr-xr-x'; // or whatever
$mode = 0;
if ($permissions[1] == 'r') $mode += 0400;
if ($permissions[2] == 'w') $mode += 0200;
if ($permissions[3] == 'x') $mode += 0100;
else if ($permissions[3] == 's') $mode += 04100;
else if ($permissions[3] == 'S') $mode += 04000;
if ($permissions[4] == 'r') $mode += 040;
if ($permissions[5] == 'w') $mode += 020;
if ($permissions[6] == 'x') $mode += 010;
else if ($permissions[6] == 's') $mode += 02010;
else if ($permissions[6] == 'S') $mode += 02000;
if ($permissions[7] == 'r') $mode += 04;
if ($permissions[8] == 'w') $mode += 02;
if ($permissions[9] == 'x') $mode += 01;
else if ($permissions[9] == 't') $mode += 01001;
else if ($permissions[9] == 'T') $mode += 01000;
printf('Mode is %d decimal and %o octal', $mode, $mode);
?>
I use the code of haasje@welmers.net, but have a lite alteration. (linux symlink)
<?php
function chmod_R($path, $filemode) {
if (!is_dir($path))
return chmod($path, $filemode);
$dh = opendir($path);
while (($file = readdir($dh)) !== false) {
if($file != '.' && $file != '..') {
$fullpath = $path.'/'.$file;
if(is_link($fullpath))
return FALSE;
elseif(!is_dir($fullpath))
if (!chmod($fullpath, $filemode))
return FALSE;
elseif(!chmod_R($fullpath, $filemode))
return FALSE;
}
}
closedir($dh);
if(chmod($path, $filemode))
return TRUE;
else
return FALSE;
}
?>
thanks alls
Changes file mode recursive in $pathname to $filemode
<?php
$iterator = new RecursiveIteratorIterator(new RecursiveDirectoryIterator($pathname));
foreach($iterator as $item) {
chmod($item, $filemode);
}
?>
if you want to chmod directories too, use this
<?php
$iterator = new RecursiveIteratorIterator(new RecursiveDirectoryIterator($pathname), RecursiveIteratorIterator::SELF_FIRST);
foreach($iterator as $item) {
chmod($item, $filemode);
}
?>
BEWARE using quotes around the second parameter...
If you use quotes eg
chmod (file, "0644");
php will not complain but will do an implicit conversion to an int before running chmod. Unfortunately the implicit conversion doesn't take into account the octal string so you end up with an integer version 644, which is 1204 octal
BEWARE, a couple of the examples in the comments suggest doing something like this:
chmod(file_or_dir_name, intval($mode, 8));
However, if $mode is an integer then intval( ) won't modify it. So, this code...
$mode = 644;
chmod('/tmp/test', intval($mode, 8));
...produces permissions that look like this:
1--w----r-T
Instead, use octdec( ), like this:
chmod(file_or_dir_name, octdec($mode));
See also: function.octdec
I was trying to change permissions of a folder with chmod command with FTP connection. (I needed a writable folder to upload pictures with php)
I got the following respond:
"SITE CHMOD 777 uploads: command not understood"
The reason: Server is running under Windows system that does not allow to set file permissions via FTP. Conversely, the UNIX-running servers allow that.
Solutions:
1. If your web hosting provider has a web-based control panel that lets you set file permissions, then you need to login there and make changes.
2. It is possible to contact the hosting provider and ask them about this issue; maybe they can make the changes.
3. It is possible to change the hosting provider that has servers run on UNIX, and keep the site there.
For recursive chmod'ing both files and directories in one step you can use the function below. Note that this function has one argument for directory permissions and one for file permissions.
In this way you can apply the 'x' permission on directories, and skip it on directories. This function also skips links.
Example usage :
chmod_R( 'mydir', 0666, 0777);
Makes all files and directories within mydir/ directory accessible for everyone, but doesn't make the files executable.
I guess for very deeply nested directories the recursion with php can become problematic, but I can be wrong because I never investigated this.
<?php
function chmod_R($path, $filemode, $dirmode) {
if (is_dir($path) ) {
if (!chmod($path, $dirmode)) {
$dirmode_str=decoct($dirmode);
print "Failed applying filemode '$dirmode_str' on directory '$path'\n";
print " `-> the directory '$path' will be skipped from recursive chmod\n";
return;
}
$dh = opendir($path);
while (($file = readdir($dh)) !== false) {
if($file != '.' && $file != '..') { // skip self and parent pointing directories
$fullpath = $path.'/'.$file;
chmod_R($fullpath, $filemode,$dirmode);
}
}
closedir($dh);
} else {
if (is_link($path)) {
print "link '$path' is skipped\n";
return;
}
if (!chmod($path, $filemode)) {
$filemode_str=decoct($filemode);
print "Failed applying filemode '$filemode_str' on file '$path'\n";
return;
}
}
}
?>
Windows has a very different file permission model to Unix and integrates them only minimally.
On Windows, all this function can do is to change the "read only" flag, which is turned on if $mode & 0200 does not pass.
i.e. it only checks if u+w is missing from the bitmask, and if it is, it sets the read only flag.
The executable flag cannot be set as Windows determines it based on file extension.
The write flag cannot be set as Windows determines write access based on ACLs, which are not integrated here.
Just an update of the solution with octdec. You have to give octdec the string as a parameter.
$mode = '644';
chmod(file_or_dir_name, octdec($mode));
See also: function.octdec
use a stored string for the mask is a painex: $mask contains a string 0755
int($mask) not work (return 755)
the only way i found is use octdec($mask)