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
- PHP Руководство
- Функции по категориям
- Индекс функций
- Справочник функций
- Расширения для работы с файловой системой
- Функции для работы с файловой системой
- basename
- chgrp
- chmod
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- disk_free_space
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Коментарии
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)
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
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.