*nix `which` command on Windows (need Ruby).

which.bat

@echo off
rem setlocal
rem for %%t in (%1) do echo,%%~$path:t
rem for %%e in (%pathext%) do (
rem   for %%t in (%1%%e) do echo,%%~$path:t
rem )
rem endlocal
ruby -x %~f0 %*
@goto end

#!ruby
# encoding=utf-8
# `which` command in Windows.
# author: ne_Sachirou <utakata.c4se@gmail.com>
# date: 2013
# License: Public Domain

target = ARGV[0]
path = ENV['path'].split ';'
pathext = ',' + ENV['pathext'].split(';').join(',').downcase
path.each do |dir|
  Dir.chdir dir rescue next
  files = Dir["#{target}{#{pathext}}"]
  if files.any?
    puts "#{dir}#{dir =~ /\\$/ ? '' : '\\'}#{files.first}"
    break
  end
end

:end

Windos版whichコマンド (*nix which command on Windows (need Ruby).) - c4se記：さっちゃんですよ☆ http://c4se.hatenablog.com/entry/2013/03/24/061210