ruby - Rake 中的常规任务和文件任务有什么区别

Question

我目前正在研究使用 Rake 来部署我的项目，并且我正在努力学习 Ruby/Rake。但是有人可以向我解释常规任务和文件任务之间的区别吗？这一直被提及，但我不知道两者之间的区别，我找不到定义？

Answer 1

Martin Fowler 对这些特性做了很好的解释。

• http://martinfowler.com/articles/rake.html#RakeTasks
• http://martinfowler.com/articles/rake.html#FileTasks

File Tasks

The tasks I talked about above are similar to tasks in ant. Rake also supports a slightly different kind of task called a file task which is closer to the notion of tasks in make. Here's another example, slightly simplified, from my web site rakefile.

file 'build/dev/rake.html' => 'dev/rake.xml' do |t|
  require 'paper'
  maker = PaperMaker.new t.prerequisites[0], t.name
  maker.run
end

With a file you are referring to actual files rather than task names. So 'build/dev/rake.html' and 'dev/rake.xml' are actual files. The html file is the output of this task and the xml file is the input. You can think of a file task as telling the build system how to make the output file - indeed this is exactly the notion in make - you list the output files you want and tell make how to make them.