There's a Cat in My Linux Computer!

Some days ago, Mechatotoro taught me steganography (how to hide compressed files into images.) 

I was impressed to see how easy and fun that was!

Also, I learned that for doing it in Linux, you use the command "cat".

To be honest, I had used the command "cat" before.  However, my use of this command has been mainly to play jokes.  The one of the talking cat is my favorite.  Basically, children (and some adults) get amazed to see this little feline talking from my CLI.

1. You type "cat hello" and you get this:

2. You type "cat identify_yourself" and the cat responds this:

3. You tell something nice to the cat by typing "cat you_are_cute" and the feline answers:

So much for cat humbleness, huh? Cats are like that!

4. Finally, it's time to say good-bye. You type "cat bye" and you get this:

It's quite fun!

What's the trick? For those who haven't figured it out by now, the trick is basically creating four simple text files named "hello", "identify_yourself", "you_are_cute", and "bye", all without specifying any extension for the files.  You draw the ASCII cat in each file and type whatever you want the "cat" to say. Whenever you type "cat" in the terminal, the command displays the content of each file. That's it!

The command "cat" can do very important tasks...but little things like this, besides providing some fun, help people lose their fear of the command line. Who knows? A kid might get interested in programming because of this!

How to Turn up Sound with AlsaMixer

Some distros have problems enabling sound on various equipments.  An old trick I learned recently is using AlsaMixer to check how the sound is handled.

To use AlsaMixer, you just have to open a terminal and type "alsamixer" (without the quotation marks.)

Then, you will see something like this:

That is AlsaMixer.  All you have to do is using the cursors to set the different bars!

Looking for Windows Drivers and don't Know Your Hardware? TUX will Help!

Some time ago, a colleague asked me to find the drivers for her XP laptop. She didn't have the rescue discs, her recovery partition didn't work, and her knowledge of the computer's hardware was equal to zero.

The driver hunt took me some time...especially because first I had to find out what hardware that computer was using and the owner of the pc didn't help.

Today at the Mepis Forum, a fellow Mepis user named Uncle Mark posted a similar experience. However, he had a better idea than just going the painful "Windows way": He used Linux!

He booted a Mepis 11 Live DVD, and once on Mepis, he opened the command line and typed:

lspci

Following that, in his own words:

"And there it was, pretty as you please, a list of all the hardware with vendor names and model numbers. Copied it to a text file, then onto a thumb drive, and went back to my desktop."

Back in my Windows days, if I had witnessed someone doing anything like that, I'd have told that person: "forget about Windows and install that magic system instead, please!" :P

Too bad too many people in the same situation won't notice and will go with the Win installation anyway...

Still, this is a very fine trick I'll make sure to remember! Thanks, Uncle Mark; thanks, Tux!

How to Create a Live USB Key Using Syslinux

I learned this trick from Anticapitalista at the MEPIS Forums. It lets you create a bootable USB key quite easily by means of iso hybridization.

You'll need:

1. To download and install Syslinux. You'll find information about it here.

2. To have an iso of your distro and a spare USB key with enough room available. Well, this one was to be expected...

3. To lose your fear of the CLI/terminal/Console. You will have to type in two commands as root. :P

4. To test your patience. The process may take some time, especially the part of copying the files to the USB Key. During that time you either wait or do something else while you let the terminal be.

PREPARATION

1. Place a copy of your iso into a folder and note its location. Also, insert your USB key and note how it shows on your system. You'll need that information. I placed my MEPIS 11 iso on the desktop, in a folder I named "Distro." Thus, the location is:


/home/myName/Desktop/Distro/

My USB shows as sdb1, so I must remember "sdb" (without the 1.)

2. Open a terminal and make sure you are located into that folder. In my case, the prompt looks like this:

MyName@NakBlack:~/Desktop/Distro$


3. Become root. In my case, I did it by typing "su" and then my root password when prompted. Now, my prompt looks like this:

root@NakBlack:/home/myName/Desktop/Distro#


HOW TO DO THE TRICK

1. WARNING: this step will turn your original iso into a hybrid one. If you want to keep your original iso, then work with a copy. Making sure you are root, type "isohybrid" (without the quotation marks) and add the name of your iso. In my case, it was this:

isohybrid MEPIS11.iso

The conversion was fast! However, I got this warning:

"Warning: more than 1024 cylinders (1336).
Not all BIOSes will be able to boot this device."

2. WARNING: this step will delete all the contents of your USB key and will render it unusable as a storage device. As root, copy the contents of the now hybrid iso to the USB key by following this model:

dd if=/path-to-iso-file/nameofdistro.iso of=/dev/sdx

In this model, "if=" means input file and "of=" means output file. Likewise, "sdx" represents the name of your USB key.

Again, in my case, it was like this:

dd if=/home/myName/Desktop/Distro/MEPIS11.iso of=/dev/sdb

This step will take a while. Wait until your terminal finishes. If everything goes well, it will give you some technical details. This is what I got:

"2736128+0 records in
2736128+0 records out
1400897536 bytes (1.4 GB) copied, 1248.62 s, 1.1 MB/s"

That's it! As you can see, my live USB creation took 20 minutes (1248 seconds.)

Please note that this trick does not guarantee success. So far, I've tested it with MEPIS 11, antiX M-11, and Mandriva 2011 alpha. All of them worked, but I cannot be certain that it will work with any distro. I'll keep experimenting with other distros, though.

Good luck!

A couple of useful? tips I've learned...

This is just a short list of useful and not so useful bits of knowledge I've managed to collect this week:


1. Configuring GRUB
Some Linux distros come with a GUI that lets you configure GRUB (the menu at the start that lets you choose which system to boot.) Mepis doesn't include that GUI. However, it is easy to configure GRUB manually with Kedit (as root). Just go to /boot/grub/menu.lst and cut and paste the system you want to boot as default right below the line "gfxmenu /boot/grub/message" (see the illustration).


You can also edit the language of the menu by editing the lines beginning with the word "title." To edit the boot menu timeout, simply change the value after the word "timeout."

2. Virtual command shells
In the case you want to go from a graphical session to a text session, simply press CTRL + ALT + F1. That will open a virtual command shell that will let you pass commands...and it may be a great boss key, too! :P To return to a graphical session, press CTRL + ALT + F7 (your windows and programs will be unaltered!) Also, in the case of frozen windows (I've never experienced such case on Mepis), you may press CTRL + ALT + Backspace instead of rebooting. I've heard it helps sometimes.

3. Fun with Konsole
Open your terminal and enter the following commands:

$ cal -3 : It will display a pretty nice and handy calendar

$ uname -a : It will display some useful info about your system (the kernel, the OS, the processor) and also the date and time

$ date --date='xx yyy' +%A (xx represents a number and yyy represents a month) : It will tell you which day your birthday will be this year! Mine will be on a Thursday! :P