ComputerCraft Tutorial: modify_editcmd0_1

-- ##########################
-- modify_editcmd
-- version 0.1
-- http://hevohevo.hatenablog.com/
-- This program modifies "/rom/programs/edit"
-- to convert acces menu key (ctrl_key) into alt_key.

input_file = "/rom/programs/edit"
output_file = "edit2"

trans = {}
trans['local sStatus = "Press Ctrl to access menu"'] = 'local sStatus = "Press Alt to access menu"'
trans['     elseif param == keys.leftCtrl or param == keys.rightCtrl then'] = '     elseif param == keys.leftAlt or param == keys.rightAlt then'

if fs.exists(output_file) then
  print("Error: output file exists")
else
  print("input file: ",input_file)
  local tmp = {}
  for line in io.lines(input_file) do
    table.insert(tmp,(trans[line] or line))
  end

  local fh = fs.open(output_file,"w")
  for _,l in ipairs(tmp) do
    fh.writeLine(l)
  end
  fh.close()

  print("output file: ",output_file)
end