如何从 Ruby 中的特定相对路径加载文件? [英] How do I load files from a specific relative path in Ruby?

问题描述

我正在制作一个供内部使用的宝石.在其中，我从另一个目录加载了一些 YAML:

I'm making a gem for internal use. In it, I load some YAML from another directory:

# in <project_root>/bin/magicwand
MagicWand::Configuration::Initializer.new(...)

# in <project_root>/lib/magicwand/configuration/initializer.rb
root_yaml = YAML.load_file(
  File.expand_path("../../../../data/#{RootFileName}", __FILE__))

# in <project_root>/data/root.yaml
---
apple:   100
banana:  200
coconut: 300

我宁愿不依赖于 data/root.yaml 相对于 initializer.rb 的位置.相反，我宁愿获得对 <project_root> 的引用并依赖于那里的相对路径，这似乎是一个更明智的举动.

I'd rather not depend on the location of data/root.yaml relative to initializer.rb. Instead, I'd rather get a reference to <project_root> and depend on the relative path from there, which seems like a smarter move.

首先，这是最好的方法吗?其次，如果是这样，我该怎么做?我检查了各种 File 方法，但我认为没有类似的东西.我使用的是 Ruby 1.9.

First, is that the best way to go about this? Second, if so, how do I do that? I checked out the various File methods, but I don't think there's anything like that. I'm using Ruby 1.9.

现在，我创建了一个特殊的常量并依赖于它:

Right now, I create a special constant and depend on that instead:

# in lib/magicwand/magicwand.rb
module MagicWand
  # Project root directory.
  ROOT = File.expand_path("../..", __FILE__)
end

但我也不确定我是否喜欢这种方法.

but I'm not sure I like that approach either.

推荐答案

如果有一个您一直在运行的主文件，您可以使用该文件作为参考点.该文件的相对路径(当前目录和)将在 $0 中，因此要获取 data/root.yaml 的相对路径(假设这是相对路径)主文件和 root.yaml) 之间的路径

If there's a main file you always run you can use that file as a reference point. The relative path (between the current directory and) of that file will be in $0, so to get the relative path to data/root.yaml (assuming that is the relative path between the main file and root.yaml) you do

path_to_root_yaml = File.dirname($0) + '/data/root.yaml'

这篇关于如何从 Ruby 中的特定相对路径加载文件?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！