We'll start by using the ls (short for list) command to list the contents of the current directory:
The output will be similar to the following:
Desktop Icon Music Sites Documents Library Pictures Temporary Items Downloads Movies Public
We can tell that several items are in the current directory, but this output does not tell us whether these items are files or directories. To find out which of the items are files and which are directories, we can specify the -F option to ls. An option is an argument that starts with the hyphen or dash character, '-'.
The following example illustrates the use of the -F option of ls:
$ ls -F
Now the output for the directory is slightly different:
Desktop/ Icon Music/ Sites/ Documents/ ...