which.lua
local List = require 'pl.List'
local path = require 'pl.path'
local app = require 'pl.app'
local pathl = List.split(os.getenv 'PATH',path.dirsep)
local function which (file)
local res = pathl:map(path.join,file)
res = res:filter(path.exists)
if res then return res[1] end
end
local _,lua = app.lua()
local file = arg[1] or lua local try
if not file then return print 'must provide a filename' end
if path.extension(file) == '' and path.is_windows then
try = which(file..'.exe')
else
try = which(file)
end
if try then print(try) else print 'cannot find on path' end