How can I output leading zeros in Ruby?

Question

I\'m outputting a set of numbered files from a Ruby script. The numbers come from incrementing a counter, but to make them sort nicely in the directory, I\'d like to use leading

Answer 1

If the maximum number of digits in the counter is known (e.g., n = 3 for counters 1..876), you can do

str = "file_" + i.to_s.rjust(n, "0")