Why does Ruby seem to access files in a directory randomly?

问题

Is this by design?

Here's the code:

class FileRenamer
    def RenameFiles(folder_path)    
        files = Dir.glob(folder_path + "/*")
    end
end

puts "Renaming files..."

renamer = FileRenamer.new()
files = renamer.RenameFiles("/home/papuccino1/Desktop/Test")
puts files

puts "Renaming complete."

It seems to be fetching the files is random order, not as they are displayed in Nautilus.

Is this by design? I'm just curious.

回答1:

The order should be the same every time on a particular OS, however it is different across operating systems.

The behaviour or Dir.glob can not be relied upon to be the same across different OSs. Not sure if this is by design, but rather an artefact of the filesystems.

On Windows and Linux the results are sorted by hierarchy, and then alphabetically; On Mac OS X the results are sorted alphabetically.

You could mitigate the effect by calling sort on your results e.g.:

files = Dir.glob("./*").sort

or if you wanted it case insensitive, perhaps:

 files = Dir.glob("./*").sort {|a,b| a.upcase <=> b.upcase}

来源：https://stackoverflow.com/questions/5529895/why-does-ruby-seem-to-access-files-in-a-directory-randomly