A lot of things can be done using just the command line.
In fact, Bash shell scripting language is a touring-complete language, so anything can be done!

One important feature is the ability to slice an array (i.e. select a contiguous subset of elements of a collection).
So let’s say for example we stored the list of installed packages into a variable PACKAGE_LIST as a bash array:

and for some reason we want to select elements from 4 to 10:

Let me explain. Here, we are using Bash parameter expansion:

• The [@] following the array name returns the whole content of the array.
• The :X:Y part is doing the slicing by taking a slice of length Y starting at position X. Note that if X is negative, that is we start at X elements from the end, we must put a space between the colon and the number.