bin.rb

#!/usr/bin/env ruby
path =  ENV['PATH'].split(':')

all = []
path.each do |p|
  all.push(Dir.entries(p))
end
puts all.flatten.select{ |a| a != '.' && a != '..' }

#!/usr/bin/env ruby
path =  ENV['PATH'].split(':')

all = []
path.each do |p|
  all.push(Dir.entries(p))
end
puts all.flatten.select{ |a| a != '.' && a != '..' }.sort

排序一下比较好...

puts ENV['PATH'].split(':').inject([]){|a,b| a.push(Dir.entries(b))}.flatten.select{ |a| a != '.' && a != '..' }.sort

恩,其实可以写成一行的

System getEnvironmentVariable("PATH") split(":") reduce(a,b,a push(Directory with(b) items reduce(a,b,a push(b name),list())), list()) flatten  select(a, a != "." and a != "..") sort

io语言版本...