Accessing text file in ruby gem

Question

I am using ruby version 2.0.0 , I made some custom logo in text file named logo.txt like this:

  _____
 |     |
 |_____|
 |
 |
 |

Now i made a gem with name of "custom" and placed this file under lib/logo.txt . Now i wants to print this file in my script under ruby gem so i wrote in this way.

file = File.open("lib/logo.txt")
contents = file.read
puts "#{contents}"

But above code produce errors, like:

/usr/local/rvm/rubies/ruby-2.0.0-p451/lib/ruby/gems/2.0.0/gems/custom-0.0.1/lib/custom/custom.rb:1551:in `initialize': No such file or directory - lib/logo.txt (Errno::ENOENT)

I include this logo.txt file in gemspec as per below:

Gem::Specification.new do |s| 
s.name         = "custom"
s.version      =  VERSION
s.author       = "Custom Wear"
s.email        = "[email protected]"
s.homepage     = "http://custom.com"
s.summary      = "custom wera"
s.description  = File.read(File.join(File.dirname(__FILE__), 'README'))
s.license      = 'ALL RIGHTS RESERVED'
s.files         = [""lib/custom.rb", "lib/custom/custom.rb", "lib/custom /version.rb","lib/logo.txt"]
s.test_files    = Dir["spec/**/*"]
s.executables   = [ 'custom' ]
s.require_paths << 'lib/'

Answer 1

The file is opened relative to the current working directory, unless you specify the full path.

In order to avoid hard-coding full paths, you can get the full path of the current file from Ruby using __FILE__. In fact you can see in the custom.gemspec file something very similar going on:

File.join( File.dirname(__FILE__), 'README')

I think you can get to your logo file like this:

logo_path = File.join( File.dirname(__FILE__), '../logo.txt' )
file = File.open( logo_path )

In Ruby 2.0, you also have __dir__ (which can replace File.dirname(__FILE__)) but that would not be compatible with Ruby 1.9. Generally you are safer using backward-compatible syntax in gems in case you are not sure what someone has when they run your library.