修改一个目录中所有文件名，只取数字

require 'fileutils'
require 'pathname'
require 'find'
def proc(dir_name)
dir = Dir.open(dir_name)
dir.each do  |file|
next if file =='.' or file == '..'
if File.ftype(dir_name + "//" + file) == "directory"
puts "#{dir_name}//#{file}"
proc(dir_name + "//" + file)
else
if file=~/.+([j|J][P|p][G|g])$/
numstr=''
file.gsub(//w/)  do |s|
numstr+=s
end
File.rename(dir_name + "//" + file,dir_name + "//" + numstr+".JPG")
end
end
end
end

proc("D://缺照片//")