Question

I’m new to Ruby and I’m writing a pure Ruby script, not Rails.

This script is trivial:

require 'progressbar'

bar = ProgressBar.new("Example progress", 50)
total = 0
until total >= 50
  sleep(rand(2)/2.0)
  increment = (rand(6) + 3)
  bar.inc(increment)
  total += increment
end

When I run it, I get this:

./progressbar.rb:3: uninitialized constant ProgressBar (NameError)
from progressbar.rb:1:in `require'
from progressbar.rb:1

The gem is installed. What am I doing wrong?

Answer 1

Assuming you are on Ruby 1.8, I would rename the file you’ve in the question from progressbar.rb to pg_test.rb or anything other than progressbar.rb.

require 'rubygems'
require 'progressbar'

bar = ProgressBar.new("Example progress", 50)
total = 0
until total >= 50
  sleep(rand(2)/2.0)
  increment = (rand(6) + 3)
  bar.inc(increment)
  total += increment
end

In the shell:

$ ruby ./pg_test.rb