In our “Advanced Console Tricks” series we have already covered subjects like Getting help and Processes management. Now it’s time to understand how the file permissions work. In this article we’re going to cover topics such as the basics of Linux file access rights, useful commands that allow you to manage file permissions, as well as numerical and special access modes.

Going all control-freak on a Samba share and trying to finely slice-and-dice file permissions is the path to madness. Charlie Schluting has some sensible ideas on managing file permissions on your fileserver.

In Windows they are used for a long time already, but most Linux-users probably don't even know that their system supports them too. Access Control Lists (ACLs) extend the regular permissions we all know with the possibility to give permissions for specific users/groups.

Yesterday I wrote about PCMan File Manager, which among other things offers better control over file permissions. Commenter Gavintlgold pointed out that’s it’s possible to get a similar dialog in Nautilus by changing a hidden setting in GNOME.

You may be faced with a situation in which you must figure out who has permissions to a file or directory and what those permissions are. This sounds simple enough. It really is not as simple as it may sound, here is an example. You view the contents of the /var/www (/var/www/html in CentOS) directory where your web site content is found and you see a directory that looks like this:
Ubuntu

A guide to understanding file permissions in gnu/linux.

The traditional file permission model, where read, write, and execute permissions are set on each file for the user, group, and others (UGO) has one drawback: It can't be used to define per-user or per-group permissions. For that, you need to employ access control lists (ACL). Eiciel is a graphical tool that integrates with the Nautilus file manager and allows for easy ACL management.

Still deeper into the dot (.) with an dive into access permissions. Study up because there’s going to be a quiz.

Recently on Tombuntu there's a post which tells you how to Enable the Advanced File Permissions Dialog in Nautilus by issuing the command in a terminal. If you feel more comfortable to achieve the goal through a GUI way. Here you go: