I have a Rails task: should I use script/runner or rake?

The difference between them is that script/runner boots Rails whereas a Rake task doesn't unless you tell it to by making the task depend on :environment, like this:

task :some_useful_task => :environment do  # do some useful taskend

Since booting Rails is expensive, it might be worth skipping if you can avoid it.

Other than that, they are roughly equivalent. I use both, but lately I've used script/runner executing a script separately more.

Passing parameters to a rake task is a pain in the butt, to say the least. You either need to resort to environment variables or a very hackish parameter system that is not intuitive and has lots of caveats.

If your task needs to handle command line arguments gracefully then writing a script is the way to go.

Luke Francl mentions script/runner booting up Rails. That's true. But if you don't want to boot up rails then just run the script as is without script/runner. So the only real difference between scripts and rake tasks are their aesthetics. Choose whatever feels right to you.

I use rake tasks for little tasks (one or two lines). Anything more complicated goes into the script/ directory. I'll break this rule if I think other developers will expect the code to live in one place over another.

FWIW there seems to be some movement away from using script runner in favor of rake:

Update (4/25/2009): I recommend using rake tasks as opposed to script/runner for recurring tasks.

Also, as per this post you can use rake for recurring tasks just fine:

If I then wanted this to run nightly on my production database at midnight, I might write a cronjob that looks something like this:

0 0 * * * cd /var/www/apps/rails_app/ && /usr/local/bin/rake RAILS_ENV=production utils:send_expire_soon_emails