return function(argv, con)

if argv[2] == '-v'
then
  con.println 'Er2Shell 0.5'
  return
end

local sh = require 'src.baseshell' (con)

function sh:prompt()
  return ('%d > '):format(self.env.code)
end

function sh:run(ln)
  local argv = self:parseArgs(ln)

  if not argv[1] then -- nothing

  elseif argv[1] == 'exit' then
    self.runs = false

  elseif argv[1] == 'which' then
    local fnd, snd = self:which(argv[2])
    if not fnd then self.env.code = 1
    else self.env.code = 0
      return fnd..snd
    end

  elseif argv[1] == 'env' then
    local ls = ''
    for k, v in pairs(self.env) do
      k, v = tostring(k), tostring(v)
      ls=ls.. ('$%s=%s\n')
      :format(k, v:match '%s' and '"'..v..'"' or v)
    end
    self.env.code = 0
    return ls:sub(1, -2)

  else
    local fnd, snd = self:which(argv[1])
    if not fnd then
      self.env.code = 127
      return argv[1].. ': command not found'
    else self.env.code = 0
      local succ, msg = pcall(select(2, pcall(loadfile, fnd..snd)))
      if not succ then
        print(msg)
        self.env.code = 126
        return argv[1].. ': file error'
      else
        local succ, msg = pcall(msg, argv, con, self.env)
        if not succ then
          self.env.code = self.env.code ~= 0 and self.env.code or 1
          return argv[1].. ': '.. tostring(msg)
        else self.env.code = tonumber(msg) or 0
        end
      end
    end
  end
end

sh:loop()

end