I've got a ruby script run-this.rb that outputs live calculations to a text file when I run
ruby run-this.rb > output.txt
However, I need to load this same procedure onto a web server where the Ruby script will run on page load and the web page will read the result from the txt file.
My question is two part,
1) How do you tell the web page to run this script on load?
and
2) How do I output the results of run-this.rb to output.txt on page refresh?
Thanks!
You can build a simple web application with the Sinatra framework that will
I would however advise you to encapsulate your script in a Ruby class, which makes it easier to run from another file. For example, in run-this.rb:
class FooRunner
def self.run!
# write to string instead of printing with puts
result = ''
# do your computations and append to result
result << 'hello, world!'
# return string
result
end
end
# maintain old functionality: when running the script
# directly with `ruby run-this.rb`, simply run the code
# above and print the result to stdout
if __FILE__ == $0
puts FooRunner.run!
end
In the same directory, you can now have a second file server.rb, which will perform the steps outlined in the list above:
require 'sinatra'
require './run-this'
get '/' do
# run script and save result to variable
result = FooRunner.run!
# write result to output.txt
File.open('output.txt','w') do |f|
f.write result
end
# return result to be written to HTTP response
content_type :text
result
end
After installing Sinatra with gem install sinatra, you can start the server with ruby server.rb. The output will tell you where to point your browser:
[2014-01-08 07:06:58] INFO WEBrick 1.3.1
[2014-01-08 07:06:58] INFO ruby 2.0.0 (2013-06-27) [x86_64-darwin12.3.0]
== Sinatra/1.4.4 has taken the stage on 4567 for development with backup from WEBrick
[2014-01-08 07:06:58] INFO WEBrick::HTTPServer#start: pid=92108 port=4567
This means your page is now available at http://127.0.0.1:4567, so go ahead and type this in your browser. Et voilá!
After you have displayed the page, the directory will also contain output.txt with the same contents.
