Understanding Linux Permissions
The Mathematical Sciences web server runs on the Linux operating system. Before going further, read Viewing Linux File and Directory Permissions and make sure that you understand the information on that page.
Permissions and Security
Permissions on web files and directories have security issues. Before you change permissions on a web file or directory, read Web Permissions and Security!
Minimal Permissions for Web Directories and Files
At a minimum, your web directory and all subdirectories of your web directory that you want to be accessible on the web, must have execute permission for other.
Any file that you would like to be accessible via the Web must be located in your web directory or some directory under your web directory, and the file must have at least read permission for other.
Enabling Web Features with Permissions
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Server-Side Includes
You can enable server-side includes by giving execute permission to user for any file under your web directory. Server-side includes allow you to create more feature-filled web pages.
Directory IndexingIf one of your web directories has both read and execute permission for other, and if the directory does not contain a file named index.html, index.htm, index.shtml, or index.php, then the web server will display a list of all files and directories in that directory. This is called directory autoindexing. Be sure you understand the security issues involved with autoindexing before you enable this feature!
Fixing Permissions
If you suspect you have the wrong permissions on some of your Web files and directories, you can use the fixpub command to fix all of them. To use fixpub, just execute the command:
fixpub
Running fixpub this way will break directory autoindexing. If you want to use directory autoindexing, then you must run fixpub with the -o command-line argument:
fixpub -o
You can also use the chmod command to change permissions on files and directories. For information about chmod, execute man chmod.
