01. Your first Unix command

  Wurm lab

It’s important to note that you will always be inside a single directory when using the terminal. The default behavior is that when you open a new terminal you start in your own home directory (containing files and directories that only you can modify). To see what files and directories are in our home directory, we need to use the ls command. This command lists the contents of a directory. If we run the ls command we should see something like:

learner@:~$ ls
a_directory another_directory

There are three things that you should note here:

  1. The learner@:~$ text that you see is the Unix command prompt. In this case, it contains a user name (‘learner’) and the name of the current directory (‘~’, more on that later). Note that the command prompt might not look the same on different Unix systems. In this case, the $ sign marks the end of the prompt.
  2. The output of the ls command lists two things. In this case, they are both directories, but they could also be files. We’ll learn how to tell them apart later on.
  3. After the ls command finishes it produces a new command prompt, ready for you to type your next command.

The ls command is used to list the contents of any directory, not necessarily the one that you are currently in. Try the following:

learner@:~$ ls /
bin  data  dev  etc  home  lib  media  mnt  opt  
proc  root  run  sbin   srv  sys  tmp  usr  var

learner@:~$ ls /etc/modprobe.d/
aliases.conf  blacklist.conf  i386.conf  kms.conf