Iterate through every file in one directory

Question

How do i write a loop in ruby so that I can execute a block of code on each file?

I'm new to ruby, and I've concluded that the way to do this is a do each loop.

The ruby file will be executed from a different directory than the directory I want to loop through.

I've tried the Dir.foreach and I couldn't get it to work.

Answer 1

Dir.foreach("/home/mydir") do |fname|
  puts fname
end

Answer 2

Dir.new('/my/dir').each do |name|
  ...
end

Answer 3

As others have said, Dir.foreach is a good option here. However, note that Dir.entries and Dir.foreach will always show . and .. (the current and parent directories). You will generally not want to work on them, so you can do something like this:

Dir.foreach('/path/to/dir') do |item|
  next if item == '.' or item == '..'
  # do work on real items
end

Dir.foreach and Dir.entries also show all items in the directory - hidden and non-hidden alike. Often this is what you want, but if it isn't, you need to do something to skip over the hidden files and directories.

Alternatively, you might want to look into Dir.glob which provides simple wildcard matching:

Dir.glob('/path/to/dir/*.rb') do |rb_file|
  # do work on files ending in .rb in the desired directory
end

Answer 4

The find library is designed for this task specifically: http://stdlib.rubyonrails.org/libdoc/find/rdoc/index.html

require 'find'
Find.find(path) do |file|
  # process
end

This is a standard ruby library, so it should be available