Question

I want to glob a directory to post-process header files. Yet I want to exclude some directories in the project. Right now the default way is…

Dir["**/*.h"].each { |header|
    puts header
}

Seems inefficient to check each header entry manually if it’s in an excluded directory.

Answer 1

Don’t use globbing, instead use Find. Find is designed to give you access to the directories and files as they’re encountered, and you programmatically decide when to bail out of a directory and go to the next. See the example on the doc page.

If you want to continue using globbing this will give you a starting place. You can put multiple tests in reject or’d together:

Dir['**/*.h'].reject{ |f| f['/path/to/skip'] || f[%r{^/another/path/to/skip}] }.each do |filename|
  puts filename
end

You can use either fixed-strings or regex in the tests.