Exercise 14: Prompting And Passing

Let's do one exercise that uses ARGV and gets.chomp() together to ask the user something specific. You will need this for the next exercise where we learn to read and write files. In this exercise we'll print a simple > prompt. This is similar to a game like Zork or Adventure.

user = ARGV.first
prompt = '> '

puts "Hi #{user}, I'm the #{$0} script."
puts "I'd like to ask you a few questions."
puts "Do you like me #{user}?"
print prompt
likes = STDIN.gets.chomp()

puts "Where do you live #{user}?"
print prompt
lives = STDIN.gets.chomp()

puts "What kind of computer do you have?"
print prompt
computer = STDIN.gets.chomp()

puts <<MESSAGE
Alright, so you said #{likes} about liking me.
You live in #{lives}.  Not sure where that is.
And you have a #{computer} computer.  Nice.
MESSAGE

Important: Also notice that we're using STDIN.gets instead of plain 'ol gets. That is because if there is stuff in ARGV, the default gets method tries to treat the first one as a file and read from that. To read from the user's input (i.e., stdin) in such a situation, you have to use it STDIN.gets explicitly.

What You Should See

When you run this, remember that you have to give the script your name for the ARGV arguments.

$ ruby ex14.rb Zed
Hi Zed, I'm the ex/ex14.rb script.
I'd like to ask you a few questions.
Do you like me Zed?
> Yes
Where do you live Zed?
> America
What kind of computer do you have?
> Tandy
Alright, so you said Yes about liking me.
You live in America.  Not sure where that is.
And you have a Tandy computer.  Nice.

Extra Credit

1. Find out what Zork and Adventure were. Try to find a copy and play it.
2. Change the prompt variable to something else entirely.
3. Add another argument and use it in your script.
4. Make sure you understand how I combined a <<SOMETHING style multi-line string with #{ } string interpolation as the last print.