Joomla User Manual

File Permissions: Linux

Introduction¶

The following information is for Linux based servers. If your web server is a Microsoft Windows based server(IIS), you should see Permissions: Windows.

Depending on the security configuration of your Web server the recommended default permissions are:

755 for directories
644 for files
444 for the configuration.php file (when a Global Configuration change is saved Joomla first changes the permission to 644, saves the change and then changes the permission back to 444)

Warning!

Never use 777 unless you know what you are doing! Do not use extensions that require 777 permissions!

How to Locate the Permissions¶

There are a variety of methods available to view and change the permissions of website files or folders. The host control panel file browser or a common File Transfer Protocol (FTP) program should each provide a method to see and change file and folder permissions. The command line is good for those who have terminal access and familiarity with system commands.

Depending on what you are using, you should see something like this image of part of the Joomla root file system as seen in cPanel:

verifying permissions in cpanel

The permissions are at the far right and preceded by a zero to indicate that they are octal numbers. There should be a form to change the permissions of one or more selected items:

changing permissions in cpanel

In a terminal window, file and folder permissions are displayed as letter groups rather than numbers (the leading d indicates the item is a directory):

drwxr-xr-x   20 ceford  staff     640 14 Oct 22:23 components
-r--r--r--    1 ceford  staff    3485 27 Oct 06:56 configuration.php
drwxr-xr-x    2 ceford  staff      64 20 Oct 14:21 files
-rw-r--r--    1 ceford  staff    6899 30 Sep 09:27 htaccess.txt
drwxr-xr-x   15 ceford  staff     480 24 Oct 12:19 images

Permission Numbers¶

In a permissions display of the form 777, each octal digit corresponds to three letters for three different user groups:

First digit = owner (the item owner - ceford in the command line list above)
Second digit = group (the group allowed access - staff in the list above)
Third digit = others (everyone else on this computer)

Meaning of the numbers¶

Each octal digit is the sum of the permissions granted:

     r = Read    = 4
     w = Write   = 2
     x = Execute = 1

Add the numbers for each permission required for a given user group:

"Octal" #	(r)ead	(w)rite	e(x)ecute	User or Group or Others
0	no	no	no	`---` 0+0+0 = 0
1	no	no	yes	`--x` 0+0+1 = 1
2	no	yes	no	`-w-` 0+2+0 = 2
3	no	yes	yes	`-wx` 0+2+1 = 3
4	yes	no	no	`r--` 4+0+0 = 4
5	yes	no	yes	`r-x` 4+0+1 = 5
6	yes	yes	no	`rw-` 4+2+0 = 6
7	yes	yes	yes	`rwx` 4+2+1 = 7

Examples¶

755 is rwx (owner), r-x (group) and r-x (others) or in other words everyone may read and execute (run) but only the owner(you) may make changes to the file. It would look like this when it is all put together: -rwxr-xr-x. This is the normal setting for folders.
644 is rw-, r--, r-- or EVERYONE can read the file but only the owner may write to the file or -rw-r--r--. This is the normal setting for files.
777 or -rwxrwxrwx means EVERYONE can read, write and execute ANY file
This is something you **NEVER** want to allow on your server/website unless you are absolutely sure you know what you are doing.

Permissions are used for directories as well as files, which is why you might see this drwxr-xr-x where the d is for directory.

For a complete explanation read the Wikipedia article on Filesystem permissions

Previous Next