Tech Volta

Probably the best class I have ever talken, as in I learned a whole bunch of stuff from, was a UNIX class. We used the book Guide to UNIX using Linux and installed Fedora Core 4 to learn all the amazing things about Linux/UNIX or *NIX. This book has a lot of bad reviews on Amazon, but for getting your feet wet with Linux/UNIX this is a really great book. The book was required by the department and we had to read the book on our own time. In class the teacher, typical UNIX guy, would bring lots of print-out from other books. Truly, I can say this was one of my most educational experiences in school and has stayed with me till this day. I’m running Ubuntu Feisty Fawn 7.04 at home and couldn’t be happier!

Overall in the class I developed a much greater appreciation for the command line, GUI is nice, but the command line is more powerful. So here is my list of helpful command line… commands…

CAL

Displays a simple calendar of the current month of the screen. Great for a quick lookup for dates. I usually go into the clock on the desktop, which requires a few clicks. Simply type, cal

CAT

What a great command, especially useful if you are working with a lot of TXT files. Simply displays the contents of a file to the screen. cat file.txt

CLEAR

Clears the screen, simple yet elegant. clear

LOCATE

Finding things is one of the more difficult things to do on Linux systems. Directories are cryptically named and stored in many locations. The locate command can save you a great deal of time. locate file.txt

ECHO

Echo command will echo things to the screen, this is definitely a great tool. Say you want to know your working directory echo $PWD , or lets say your home directory echo $HOME , or the type of shell you are using echo $SHELL

TAR

When working with Linux you will, without a doubt, run into TAR archives. The easily to untar them is to use the TAR command. The easiest way: tar -xzvf file.tar

HOSTNAME

Need to know the name of the computer you are using? HOSTNAME will give you that information. This also works in the Windows world and is very useful. hostname

HEAD/TAIL

The head and tail commands are similar to CAT as they let you see inside of files. Head, by default, gives you the first 10 lines of a file. Tail, by default, gives you the last 10 lines of a file. This is especially useful for log files and things of that natural. head file.log

SHUTDOWN

The shutdown commands, well, shuts down your computer. You can halt the system with the -h flag, the system can be rebooted with the -r, or you can cancel the shutdown with -c flag. The really great thing about this command is the ability to specify when the shutdown occurs… You can do it now (really use the word now) or specify the number of minutes +N, or you can specify the precise time hh:mm to shutdown the system. shutdown -h now

UPTIME

I really like the uptime command because it is so simple, yet so informative. It displays the current time, length of time the user has been logged in, how many users are logged in, and system usage over the last 1, 5, and 15 minutes. A lot of desklets (desktop goodies) incorporate this type of display and this command is where it all came from. uptime

TOP

Top is a lot like Window’s Task Manager, or Gnome’s Task Manager (if you have that installed). This will tell you what’s going on in your system processor usage, memory usage, and as well, Process IDs, which can also be killed via the command line using the kill <PID(Process ID)>. top

This is only a small fraction of the many, many, many different command-line commands that are offered in today’s distros. These are among some of the widely used ones and most useful.

The command-line is such a great tool. Many high profile companies still use UNIX scripts to automate many processes that are used today. The future is looking bright for Linux/UNIX. It is a lot of work to use, but it is also a lot of fun.