问题
I know Rake stands for Ruby Make, and I know Make is a unix build utility. Now, I come from working in Xcode building iPhone apps to Ruby, so I have never used Make before, and the only time I use rake is when in rails or installing some third party package and I type a command like rake db:migrate. The things I don't understand are ... What exactly is a build utility? What is the purpose of rake? What does it let me do? So if anyone can help answer any of these questions for me, it would be much appreciated.
回答1:
Rake lets you script certain tasks on a per-project basis, much as a Makefile allows a Unix developer to script their compile and build process. The defined tasks you've used Rake with so far were included with the packages they came with (e.g. rake db:migrate comes with Rails, or at least with ActiveRecord) and automate certain tasks related to those packages (e.g. installing required gems for a Rails project).
If your project has certain tasks which are performed repeatedly, you can write a rake task to run those tasks which gets included in the SCM tree for the project and runs in the context of that project; in Rails they're in lib/tasks. You could write a Rake task to purge stale session records from your database, for example, and then set up a cron job to run it.
来源：https://stackoverflow.com/questions/3669400/what-is-the-purpose-of-rake