For various reasons, I have to look from time to time at one particular IP and try to find out some information about it. Until I have found out about geoiplookup, this was something like: nslookup to get the reverse of the IP, and then whois to find out more details (maybe also traceroute/mtr, etc.). But now I will always start with geoiplookup as it instantly shows me the location (read country) of the respective IP.

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Installing lshw on a Debian system is very easy since it is packaged and can be found in the official debian repositories:
http://packages.debian.org/lshw

Installation:

aptitude install lshw

That’s it… You might want to return to the main article on lshw.

There are many situations when you will need regular users to have more privileges than the normal user account they have. What situations? This will depend very much on a case by case basis but believe me there will be such cases… For example if a regular user needs to run a program that will change some some protected folder or file, or just a special root command (like shutdown for example).
What can be done in such situations? Well this depends: if you can go around it by assigning proper file/folder permission then this is great. But if not:

• you can give them the root password and place them in the group allowed to ’su’ and you are done. I never liked this option as it will allow them to do anything on the system, and this is not what we were trying to achieve.

• you can use a program like sudo, to fine tune the proper commands that you will allow the user to run. This is more likely what I would do in this situation…

So the magical solution to this problem is sudo (superuser do), a program that allows a system administrator to give certain users (or groups of users) the ability to run some (or all) commands as root or another user. And all the commands will be logged for your reference.

The installation, in case you don’t already have sudo on the system, is very simple, but in case you want it you can check out some simple details about installing sudo on Debian, or Rhel, Fedora, Centos, and some details about the configuration files location and default state.
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If you are using RHEL (any version of Redhat from what I know, but if I am wrong please let me know) Fedora or Centos, you don’t have to do anything special. sudo is installed by default and you will already have it on the system.

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In case you don’t have sudo installed already the installation is very simple as it is part of the official debian package repository:
http://packages.qa.debian.org/s/sudo.html

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Even if the Debian package system works extremely well, after running a system and keeping it updated for some longer time, there will remain some orphaned packages. What I am interested is to clean up the remaining orphaned libraries that are no longer in use.

This is exactly what the deborphan package does. From its description:
“deborphan finds “orphaned” packages on your system. It determines which packages have no other packages depending on their installation, and shows you a list of these packages. It is most useful when finding libraries, but it can be used on packages in all sections.”

Just install it:

aptitude install deborphan

Normally I use it by simply typing:

deborphan

and this will show a list of the libraries that are obsolete and then I clean them using aptitude with purge. I prefer to use it like this, because it will give me the control on future actions (it will only report the orphaned packages without taking any action). If I choose, I can remove, if not they can stay.

There are many other options that can be used (just check the man page or help for full usage). Read the rest of this entry »

Well this is the first tool I would install on any new server. What is MC? It is a text-mode full-screen file manager. It uses a two panel interface and a subshell for command execution. It includes an internal editor with syntax highlighting and an internal viewer with support for binary files. Also included is Virtual Filesystem (VFS), that allows files on remote systems (e.g. FTP, SSH, SMB servers) and files inside archives to be manipulated like real files.

Even if I consider that MC should be installed by default on any system, for some reason, not all the distributions install it by default. In fact some don’t provide a package for it at all… Here I will show you how easy it can be installed.

Debian
As any debian package this is very easy to install. Just use:

aptitude install mc

and you are all set.

RHEL4/Centos4
We can install MC with up2date as long as it is available in the packages (as it is for rhel4, cetos4):

up2date mc

Fedora
If you don’t have up2date, we can use yum to retrieve the package:

yum install mc

Others
You can always install it from sources on any linux distribution. Still I would prefer to have it in the package system that will provide the advantage of automatically updates. Anyway if anyone is interested on details on how this can be done, just let me know.

On some older distributions like RHEL3 for example the MC package is missing.
Update 20060605: In case you are looking on how to install MC on RHEL3, please see this post: “Install Mc (Midnight Commander) on RHEL3/Centos3″.