This probably comes as no surprise to most Unix or Linux administrators out there (at least this first thing), but I find it's always interesting how rarely the "last" command is used to determine anything other than the users logged in "now" and the "last" time a user logged in.

Now it’s time to discuss one of the most mysterious and confusing parts of Linux to a Windows user: the command line. To most Windows users the prospect of typing in what you want your computer to do is completely foreign and thus intimidating.

On Ubuntu I have a user account "administrator" which is in the admin group. It has a complicated password for security. OpenSSH by default allows all users to attempt to login remotely. Since user accounts often have weak passwords it's unsafe to allow this.

This tutorial will explain how to Add,Modify and Delete Users,Groups in Ubuntu.Linux users can login to the system and use with the provided previliges. Linux groups are a mechanism to manage a collection of computer system users. All Linux users have a user ID and a group ID and a unique numerical identification number called a userid (UID) and a groupid (GID) respectively.

Sudo which is su “do” allows a system administrator to delegate authority to give certain users (or groups of users) the ability to run some (or all) commands as root or another user while providing an audit trail of the commands and their arguments.sudo allows a permitted user to execute a command as the superuser or another user, as specified in the sudoers file.

A week ago I published a boring little post on this blog about the command line and the average user. The essence of it was that non-geeks considering switching to Linux shouldn't even be shown the command line, as it may scare them away.

User management on Fedora 15 is just as easy as on any other distribution or operating system. And the graphical user management tools (there are two) are very intuitive to use. There are two types of user accounts on Fedora 15 – Standard and Administrator. The Administrator has root or super user privileges. During installation, the user created may be added to the Administrators group.

GUI calculators may be user-friendly, but they don't offer much comfort for a command-line power user. Fortunately, console-based tools such as bc, Genius, and Calc offer distinct advantages over their GUI counterparts.

What if you want one user to run a command as an another system user without exchanging passwords. For example, you may want an user john to run a find command or custom bash shell script as an user greg or even as a user root ( superuser ) without password exchange. In this case a sudo utility with its /etc/sudoers configuration file will be your friend.