Can I stop talking about myself in third person now? Good. Penguin Shell will come out once a week, hopefully chock full of tips and tricks and information that helps you take one more step toward being the Linux guru you always wanted to be. If you have nagging problems or favorite things you'd like to see covered, drop me a line at dee@lockergnome.com. I may not have a chance to respond personally to you right away, especially during the busy summer season, but you just might see your problem solved here in these pages.

Rather than yammering on, let's get right down to business!

See You at Gnomedex,              
Dee-Ann LeBlanc       

GnomeTWEAK

In this week's GnomeCORE, I talk about environment and shell variables. What if you want to have a new variable created and set every time you log into your account? You'd edit either the file ~/.bash_profile, or ~/.profile, depending on which your Linux distribution uses. Your starting file might look something like:

# .bash_profile

# Get the aliases and functions
if [ -f ~/.bashrc ]; then
        . ~/.bashrc
fi

# User specific environment and startup programs

PATH=$PATH:$HOME/bin

export PATH
unset USERNAME

In this case, I would start adding new variables directly beneath the line starting with PATH, just for the sake of keeping things nicely organized. I'll take the same example I use in the GnomeCORE section, where I created the environment variable MYNAME. I could make sure MYNAME was always set after I logged in by editing the file so that it looks like the following:

# .bash_profile

# Get the aliases and functions
if [ -f ~/.bashrc ]; then
        . ~/.bashrc
fi

# User specific environment and startup programs

PATH=$PATH:$HOME/bin
MYNAME="Bob R. Smith"

export PATH MYNAME
unset USERNAME

Notice the two changes here. I added the variable definition beneath PATH, and then I added the variable to the end of the export line - with a single space between the entries. This change won't take effect until I either log out and back into this account, or I type:

source ~/.bash_profile

If your file is ~/.profile, you'd type:

source ~/.profile

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GnomeCORE

Is all this Linux stuff overwhelming? Ease into Linux with an eBook from an expert. Dave Taylor, author of numerous books on Unix, lends his digital pen to this tutorial, giving you information on how to become functional with the command line interface and explore several Linux applications and capabilities. By the time you've covered all the material, you'll know how to process files, script some processes and get at-a-glance information on your system's performance. Learn the basics of editing config files with command line text editors and much more. Get into Unix today!

Ever try to install a piece of software and it starts complaining that you need to create a shell or environment variable before you can proceed? Both types of variables are held during your login session, containing information that your system uses in order to know important things about itself.

The main difference between the two is that an environment variable is considered universal, and is carried from login to login and shell to shell, if you've set it up properly in your login files. A shell variable is only used in a single shell, or login instance. Visually, there's a big difference. All environment variables are traditionally typed in UPPERCASE, while shell variables are usually lowercase.

To see all of your currently set environment variables, type:

env | more

You probably have over a screen's worth of environment variables. Piping this information through more ensures that you'll see it a screen at a time. To see all of your variables, both environment and shell, type:

set | more

To see only one of these variables' contents, type:

echo $VARIABLE

For example, to see where your home directory is (a universally used environment variable; don't change this), type:

echo $HOME

You can change either type of variable's settings (or even create a new one) at any time from the command line. Just be careful of what you change. Many of the environment variables are vital for half your software to work properly! Start by making up your own until you're familiar with the process of working with these.

For example, you could type:

MYNAME="Bob R. Smith"
echo $MYNAME
myage=105
echo $myage

Give it a try, and see what happens!

GnomeBOOKMARK

Knoppix

http://www.knoppix.org/

Do you want to try out Linux without having to install something onto your hard drive? Want to let a friend try it without having to hold their hand while they try to get the operating system working on their system? Try Knoppix. This is a single-CD distribution that you can run directly off the CD itself. Not only is this a great teaching tool, but if you're borrowing a PC from someone else, you can use Knoppix instead of having to use their Windows setup!

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GnomeVOICE

Since this is my first week on the job, there aren't any Gnomies to quote here in GnomeVOICE! Help me change that, would you? Write me at dee@lockergnome.com with your Linux thoughts, wishes, dreams, tips, and so on.

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GnomeMAN

Being new around here, I don't yet have any reader Q&A to include in this section. In the meantime, here's a handy utility you'll like if you use instant messaging:

Gaim

http://gaim.sourceforge.net/

If you like your instant messaging, but just haven't been able to move that part of your online life over to Linux yet, check out Gaim. This messaging client supports a wide variety of IM protocols. I'm typically connected (using Gaim) to ICQ, AIM, and MSN all at once, and there are certainly more I could use - it's just that I only need these three to stay connected to the folks I work with.

This software might actually come with your Linux distribution by default. If so, install Gaim using your distribution's package management system. If not, download Gaim at the site listed above. You'll find that there are a number of package formats available - everything from RPMs for specific distributions to the source (if you want to compile the software on your own).

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