One cannot live without introduction…

Two weeks ago I had a presentation about importance of writing test prior to its code impementation. I talk about testing and why its very important, why everybody should do it and what happens if not…but in this blog post I would like to share one interesting perk that might help you with preparing presentation slides.

Search, search, search

Occasionally, I would put source-code in my presentation slides, and I’ve been doing it in a number of ways over the last 8 years:

1. screen shot
2. copy & paste and manually arrange spaces
3. 2) + manually apply syntax highlight
4. open terminal during presentation and show great hacker skills 🙂

All methods above have clear benefits and drawbacks. Personally, when preparing presentation slides I try to improve visuals and overall positive impressions from the point of view of spectators.
With this idea in mind I decided to invest some time into searching for better ways of presenting source-code.
After few attempts to google for source-code and presentation,
I found this gist: https://gist.github.com/jimbojsb/1630790, which completely made my day.

Let’s roll!

With this approach it is very easy to copy & paste source code with indents and syntax highlight preserved. In my case, I had to adjust styling, because I usually have bright background for slides and black boxes for source-code. It is also possible to select specific syntax highlight for certain language.
I will put some samples below. Note: even though ‘highlight’ might be available on other platforms, but in this blog post I would focus mainly on OS X.

To highlight bash script with darkness theme:

$: highlight --style darkness -S bash -O rtf script.sh | pbcopy

then with `Cmd + V` one can paste nicely looking source-code to the presentation.

As a real example, let’s consider this simple fibonacci sequence calculation:

#!/usr/bin/env ruby

def fibonacci(num)
	return 0 if (num == 0)
	return 1 if (num == 1 or num == 2) 
	return fibonacci(num - 1) + fibonacci(num - 2)
end

def benchmark
	t1 = Time.now
	yield
	t2 = Time.now

	return t2-t1
end

arr		=[]
items_num	=40

time = benchmark do 
	items_num.times do |t|
		arr << fibonacci(t)
	end
end

puts "Elapsed time: #{time}"
puts
puts "First #{items_num} numbers in Fibonacci sequence:\n#{arr.inspect}"

Changing the last command like follows:

$: highlight --style darkness -S ruby -O rtf fibonacci.rb | pbcopy

we can enjoy nicely rendered code in the presentation slides like follows:

Example of Syntax highlight in Keynote