Category: privacy

Any computer user with normal level skill set knows that any data removed from computer system can be recovered later with little bit of efforts. This is a good thing in the scenario when you have accidentally deleted your critical data. But in most cases, you don’t want your private data to be recovered easily. Whenever we remove anything, the operating system deletes just the index of the particular data. It means that data is still there somewhere on the disk, this method is insecure, as any smart computer hacker can use any good data recovery tool to easily recover your deleted data. Linux users utilizes the well know “rm” command to remove data from their operating system, but “rm” command works in the conventional fashion. Data removed using this command can be recovered by special file recovery tools.

Let’s see how we can safely and completely remove files/folders from our Linux system. The methods mentioned below remove data completely so it becomes very hard for recovery tools to find traces of the actual data and recover it.

Full article here:
4 Tools to Securely Delete Files from Linux (LinOxide)

The Unix operating system (and likewise, Linux) differs from other computing environments in that it is not only amultitasking system but it is also a multi-user system as well.

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In order to make this practical, a method had to be devised to protect the users from each other. After all, you could not allow the actions of one user to crash the computer, nor could you allow one user to interfere with the files belonging to another user.

This lesson will cover the following commands:

• chmod – modify file access rights
• su – temporarily become the superuser
• chown – change file ownership
• chgrp – change a file’s group ownership

Full article here:
Understanding Linux File Permissions (Project: Fenix)