shell.lua

-- Quick and dirty lua shell in lua.
-- This may prove useful in testing/debugging.

function lua_shell(greet)
   local command, next_line, chunk, error
   io.write((greet and greet..'/' or ''),'Lua shell:\n')
   repeat
      io.write('Lua> ')
      next_line, command = io.read '*l', ''
      if next_line then
	 next_line, print_it = next_line:gsub('^=(.*)$', 'return %1')
	 repeat
	    command = command..next_line..'\n'
	    chunk, error = loadstring(command, '')
	    if chunk then
	       (function (success, ...)
		     if not success then error = ...
		     elseif print_it ~= 0 then print(...)
	       end end)(pcall(chunk))
	       break
	    end
	    if not error:find('<eof>') then break end
	    io.write('>> ')
	    next_line = io.read '*l'
	 until not next_line
	 if error then print((error:gsub('^[^:]*:(.*)$', 'stdin:%1'))) end
      end
   until not next_line
   io.write 'Goodbye\n'
end