Why Doesn't Relative_Require Work on Ruby 1.8.6

Why doesn't relative_require work on Ruby 1.8.6?

Edit:

Back in the days where this question was asked it referred to Ruby 1.8.6 where there was no require_relative. By now Ruby 1.8.6 is outdated and shouldn't be used anymore.

Original:

There is simply no method name require_relative. You can use require there aswell.

The require_relative function is included in an extension project to the Ruby core libraries, found here: http://www.rubyforge.org/projects/extensions

You should be able to install them with gem install extensions.
Then in your code add the following line before the require_relative:

require 'extensions/all'

Why relative path doesn't work in Ruby require

Relative path is based on working dir. I assume that there is main file on the same directory. If you run ruby ./shapes/main.rb on project root, ruby try to find {project_root}/shape.rb, not {project_root}/shapes/shape.rb. It doesn't work.

You need to use require_relative like below.

# {project_root}/shapes/main.rb
require_relative './shape'
require_relative './rectangle'
require_relative './square'

Why doesn't Ruby 'require' allow relative paths?

tl;dr: IRB is special and has some odd rules. Ruby in general works just fine with relative paths.

require will search the load path (which you can see by inspecting $: or $LOAD_PATH). This will not include the directory that you launched IRB from:

> $:
 => ["/usr/local/rvm/rubies/jruby-head/lib/ruby/2.2/site_ruby", "/usr/local/rvm/rubies/jruby-head/lib/ruby/stdlib"]

So there's no joy there, unless you explicitly add your directory to the load path. This is what Rubygems and Bundler spends most of their time doing - they manage the load paths for gems so you don't have to worry about it. However, this doesn't help you with single files.

Additionally, require_relative will search from the directory that __FILE__ is in, but in IRB, this is a non-directory (irb) value! This is why you get the "can't infer basepath" issue when trying require_relative from IRB; since the currently executing file, __FILE__, isn't a proper path, require_relative can't figure out where to start from.

When you are not running from IRB, this isn't really an issue; require_relative 'mytest.so' should work just fine when you execute it in a script, since the currently-executing script will populate __FILE__. That is, if you have loader.rb and mytest.so and execute loader via ruby loader.rb, require_relative should work just fine.

If you want to run this in IRB, consider something like:

require "#{__dir__}/mytest.so"

which will expand out to the current working directory, which should by default be the directory you've launched it from. I would recommend that you not do this in a script, though, since it depends on __dir__ not having been changed, and that may be difficult to guarantee.

Ruby 'require' error: cannot load such file

I just tried and it works with require "./tokenizer". Hope this helps.

What is the difference between require_relative and require in Ruby?

Just look at the docs:

require_relative complements the builtin method require by allowing you to load a file that is relative to the file containing the require_relative statement.

For example, if you have unit test classes in the "test" directory, and data for them under the test "test/data" directory, then you might use a line like this in a test case:

require_relative "data/customer_data_1"

How to make node.js require absolute? (instead of relative)

Here is the actual way I'm doing for more than 6 months. I use a folder named node_modules as my root folder in the project, in this way it will always look for that folder from everywhere I call an absolute require:

• node_modules
  
  
  • myProject
    
    
    • index.js I can require("myProject/someFolder/hey.js") instead of require("./someFolder/hey.js")
    • someFolder which contains hey.js

This is more useful when you are nested into folders and it's a lot less work to change a file location if is set in absolute way. I only use 2 the relative require in my whole app.

Initialize env.rb from unit test in ruby

Assuming that the Test::Unit script directory and the cucumber project are siblings, you can use relative require to require env.rb. For example:

/cucumber_project/features/support/env.rb

require 'logger'
$LOG = Logger.new(STDOUT)

hello_world.rb

class HelloWorld
  def say_hi
    greeting = 'Hello World'
    $LOG.info greeting
    greeting
  end
end

test.rb

require_relative 'hello_world'
require_relative '../cucumber_project/features/support/env'
require 'test/unit'

class TC_HelloWorld < Test::Unit::TestCase

  def test_say_hi
    assert_equal('Hello World', HelloWorld.new.say_hi)
  end

end

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