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.

Today, I did a fresh installation of Ubuntu 9.04 inside virtual box. My original idea was to play with sudoers and sudo command. I edited /etc/sudoers and logged out. Next time I tried to sudo , I go some parse error in /etc/sudoers. I was stuck . I needed sudo for modifying the file. But sudo was preventing me because of the error.

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.

But what if, as a system administrator, you add a new user and want to give them similar sudo rights? How do you go about doing this?

Have you ever attempted to do something with a file on a Linux machine and been given the error "permission denied"? For some people this isn't a problem, either su to the root user or use the sudo command to help you along. For some users, however, this can be very frustrating.

If you are using GNOME and a distribution that supports either sudo or su, then we have a quick tip for you.

Ubuntu's use of sudo to simplify Linux administration is ingenious, but barely scratches the surface of what sudo can do. Follow along as Yvo Van Doorn of Likewise Software unlocks the powers of sudo.

You can change the owner and group of a file or a directory with the chown command. Please, keep in mind you can do this only if you are the root user or the owner of the file. Set the file's owner: $ chown username somefile After giving this command, the new owner of a file called somefile will be the user username. The file's group owner will not change.

As most of you already know, Dolphin is the new KDE 4 default file manager. The KDE 3 version introduced a new way for file management on KDE. It introduced, for the first time in KDE world, a simple KDE file manager, easy to follow and use. Let's see how Dolphin looks, and how it's an improvement of file management.