How To Utilize Your New Multimedia Keyboard Under Linux

Xbindkeys is a program that allows you to launch shell commands with your keyboard or your mouse under X Window. It links commands to keys or mouse buttons, using its configuration file. It does not depend on the window manager and can capture all keyboard keys.

Create Users And Change Passwords With A Bash Script

These two scripts are very important for the system admin who regularly works with mail servers and somehow forgets to backup his system username and password! Let’s say somehow we lost the usernames and passwords of the mail server. In this case the admin has to manually create all the users and then change the passwords for all the users. Tedious job. Let’s make our life easier.

Setting the SUID/SGID bits: Giving a program YOUR permissions when it runs

Normally, when a program runs under Linux, it inherits the permissions of the user who is running it, thus if I run a program under my account, the program runs with the same permissions that I would have if that program were me. Thus, if I cannot open a certain file, the program I am running also cannot open the file in question. If I set the SUID or SGID bit for a file, this causes any persons or processes that run the file to have access to system resources as though they are the owner of the file.

Using TAR with Bunzip2 files

Bunzipping and then unTARring in two steps is not convenient.

It is not necessary to use Bunzip2 and then TAR to unzip a file in two separate steps.

Tar will do the job on its own if the -j switch is used, thus:

tar xjvf linux-source<version>.tar.bz2

By the same token, you may use the -z switch with a gzipped file, e.g.

tar zxvf linux-source<version>.tar.gz

Cisco 350 Series And Kismet

This tutorial is describing how to configure a Cisco Aironet wireless card and how to set up kismet in order to run with it.

Step-By-Step Configuration of NAT with iptables

This tutorial shows how to set up network-address-translation (NAT) on a Linux system with iptables rules so that the system can act as a gateway and provide internet access to multiple hosts on a local network using a single public IP address. This is achieved by rewriting the source and/or destination addresses of IP packets as they pass through the NAT system.

To start the X server from a text mode session, execute the command:

startx

You can use ping to see if the system is alive:

ping -c4 <system's IP address>

To see if a certain service is still alive, use the telnet command:

telnet <system's IP address> 25 (for SMTP)

telnet <system's IP address> 80 (for HTTP)

telnet <system's IP address> 110 (for POP3)

You can login to the system using SSH (port 22) (use PuTTY if you are on a Windows PC; PuTTY is an SSH client for Windows), and when you are on the system, you have a few useful tools to gather more information:

Either with chkrootkit or with rkhunter.

chkrootkit

Either install the package that comes with your distribution (on Debian you would run

apt-get install chkrootkit

), or download the sources from www.chkrootkit.org and install manually:

wget --passive-ftp ftp://ftp.pangeia.com.br/pub/seg/pac/chkrootkit.tar.gz
tar xvfz chkrootkit.tar.gz
cd chkrootkit-<version>/
make sense

Afterwards, you can move the chkrootkit directory somewhere else, e.g. /usr/local/chkrootkit:

repquota -avug

shows a list for both users and groups.

repquota -au

shows a list for users,

repquota -ag

a list for groups.