File/folder Permission

Note that mode is 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 prefix mode with a zero (0):

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 mode parameter 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.

// 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);

Change File Permission Owner

// File name and username to use
$file_name= "foo.php";
$path = "/home/sites/public_html/sandbox/" . $file_name ;
$user_name = "root";

// Set the user
chown($path, $user_name);

// Check the result
$stat = stat($path);
print_r(posix_getpwuid($stat['uid']));