Challenge 1: "Count instances: Create a script that either reads standard
input or one or more files specified on the command-line. Count the number
of times and then print a summary, sorted by the count of each entry.

So with the following input in file example.txt

apple
banana
apple
cherry
cherry
apple

the script would display something like:

apple     3
cherry    2
banana    1

For extra credit, add a -csv option to your script, which would generate:

apple,3
cherry,2
banana,1

My notes: Straightforward use of a hash.


Challenge 2: "ASCII bar chart: Write a function that takes a hashref
where the keys are labels and the values are integer or floating point
values. Generate a bar graph of the data and display it to stdout.

The input could be something like:

$data = { apple => 3, cherry => 2, banana => 1 };
generate_bar_graph($data);

And would then generate something like this:

 apple | ############
cherry | ########
banana | ####

If you fancy then please try this as well: (a) the function could let you specify whether the chart should be ordered by (1) the labels, or (2) the values.

My notes: easy, especially using a histogram module I wrote recently.