In the Linux command line shell, moving around from directory to directory, adding new directories, and deleting old directories is easy once you know the proper commands. Again, with Linux, you are limited only by your brain! If you know all the commands, then you weild great power. But if you know only a few commands, it’s like you are standing in the airport in Tokyo and want to know where the bathroom is, but only know how to say hi and bye in Japanese.
If you want to move a file from one place to another, use the mv, or move command. Now, the mv tool can send a file from one directory to another, but it also can rename a file. If you simply want to change the name of a file, say, from joo.txt to joe.txt, you can do that with mv also. Here are a few examples to get you going.
mv joe joe1
The file joe is simply renamed joe1
mv joe /Documents/joe
The file joe is moved to the Documents directory.
Now, what if we wanted to move joe.txt to the Documents directory and at the same time rename it to joe2?
mv joe Documents/joe2
This would move the file joe to the Documents directory and would change the name to joe2.
This is similar to cp, but the original file is changed. With cp we get a new file and the original file is unchanged.
If you’d like to see the contents of a file, use the cat command. cat stands for concatenate. cat will display the contents of a file and also join, or concatenate several files.
This command will output the contents of joe.
What if you’d like to view the contents of two or more files?
cat joe bob
Will output the contents of joe and then bob.
Ok. Now let’s play around with cat and two new commands: touch and echo.
Which will create new text file called jj.txt.
echo “Hi there” >> jj.txt
This adds the text “Hi there!” to jj.txt.
You can append some more text to the end of jj.txt with another echo command and two greater than signs “>>” like this:
echo “How are you?” >> jj.txt
Now take a look at the contents of jj.txt via:
One thing to know when using cat, if you use only one greater than sign “>”, it will overwrite the contents of the file. Be careful!
Let’s overwrite jj.txt on purpose.
echo “See you later.” > jj.txt
Now view the contents via cat:
… and you should see only the “See you later.” line.
I hope this helped you become a little more familiar with the Linux command line. Have fun and experiment. Remember, while playing around, it’s best to create a new directory and make new files specifically to experiment with so you don’t lose any important data. Soon you’ll be using the command line like a programs.
I am mohanchen read mathematics at Stanford and remained there for his MS. From 1998-1999 on researched in Evolution and in Animal Behavior in Camrbidge, UK. I was was then a professor in the departments of Anthropology and Biology, New Jersy College, USA. Now teaches at the department of Zoology. Carried out research in several areas of evolutionary biology, particularly in sexual selection and the comparative method.