startup call code, rewrite

for sPath in shell.getEnvVar("startup", "", true).readAll():gmatch('([^:]+)') do
  if fs.isDir(sPath) then
    local list = fs.list(sPath)
    for i=1, #list do
      local s, m = shell.run(sPath..list[i])
      if not s then
        printError("Failed to run "..sPath..". error: "..m)
      end
    end
  else
    local s, m = shell.run(sPath)
    if not s then
      printError("Failed to run "..sPath..". error: "..m)
    end
  end
end