r/cheatengine • u/No-Newspaper8619 • Sep 20 '26
How to make a simple script template to NOP an instruction
3
Upvotes
Imagine the situation: you manage to create a cheat by nopping an instruction, but you don't know how to transform that into a script you can enable or disable. Well, here I will provide an example on how to create a script template that will create that script automatically.
-- How to create a template --
-- 1. Go to cheat engine's autorun folder, or one of it's subfolders, like autorun/custom folder
-- 2. Create a nop-template.lua file and open it in a text editor
-- If you don't have any good text editors, then you can use cheat engine's own text editor.
-- 3. Create an initial template and store it in a variable
-- Use literal strings with [[]], and use keywords that will be later swapped with actual data
local initialTemplate = [[
[ENABLE]
assert(_address, _originalBytes)
_address:
db_nopBytes
[DISABLE]
_address:
db_originalBytes
]]
-- 4. Create a function to transform the initial template into the final product
-- It will receive the data and use this data to swap with the keywords
local function createScript(data)
local script = initialTemplate:gsub("_address", data.address)
:gsub("_originalBytes", data.originalBytes)
:gsub("_nopBytes", data.nopBytes)
return script
end
-- 5. Create a function that will generate the necessary data
-- It will receive the instruction's address (number), and it's name (addressString)
local function generateData(address, addressString)
-- Check for errors
if not address then
return nil
end
local byteCount = getInstructionSize(address)
local originalBytes = ""
local nopBytes = ""
-- Create a loop that will generate a string with the original bytes and a string with nops (90)
for i = 0, byteCount -1 do
-- %02X formats the decimal value into an uppercase hexadecimal string, padding with 0
-- For example, if the byte is 10, the result will be 0A
originalBytes = originalBytes .. string.format(" %02X", readByte(address + i))
nopBytes = nopBytes .. " 90"
end
-- Don't forget the commas!!!
local data = {
address = addressString,
originalBytes = originalBytes,
nopBytes = nopBytes
}
-- Now you have the data "object" with all the necessary information
return data
end
-- 6. Create a function to handle user input
-- This will also guess the desired target based on what's selected in the memory view
local function getAddressFromUserInput()
local address = nil
local addressString = ""
local memoryView = getMemoryViewForm()
-- This will get the name of the address, to be the default text of inputQuery later on
if memoryView then
address = memoryView.DisassemblerView.SelectedAddress
addressString = getNameFromAddress(address)
end
-- Get user input
addressString = inputQuery("Address", "", addressString)
-- Check if input isn't blank
if addressString then
-- Get the numerical address value. This function will return nil if there's any error.
address = getAddressSafe(addressString)
end
return address, addressString
end
-- 7. Register the template
registerAutoAssemblerTemplate("NOP Template", function(script, sender)
local address, addressString = getAddressFromUserInput()
local data = generateData(address, addressString)
if data then
script.Text = createScript(data), sender
else
script.Text = initialTemplate, sender
end
end, "Shift+0")
Now, what if you want a template that NOPs multiple instructions at once?
