如何在Ruby中对数组进行块

In Ruby 1.8.6, I have an array of, say, 100,000 user ids, each of which is an int. I want to perform a block of code on these user ids but I want to do it in chunks. For example, I want to process them 100 at a time. How can I easily achieve this as simply as possible?In Ruby 1.8.6, I have an array of, say, 100,000