How I made the terminal for MRTS and URTG
I highly reccomend reading about URTG and MRTS if you haven’t already
Welcome back to my blog!
I’ll try to start posting more regular updates on here. No promises!
So, what is this blog about?
If you haven’t heard me talk bout the terminal, please do what I said at the beggining of this post and read about URTG and MRTS
Without further ado, here is how I came up with the terminal, how I made it, etc
When I originally started MRTS I had no intention of making a terminal. Or even any sort of admin gui. So, what sparked my inspiration?
Well, it actually didn’t start with MRTS, it started with a side project I was working on called noob factory tycoon. I was trying to run something from roblox’s default command line, but it wasn’t working. I kept getting an error.
Then I realized 2 important things about roblox’s basic command line interface
- It’s really bad. There’s no syntax highlighting, you can only write code on 1 line, it’s just horrific
- I’m really bad at using it
So, I did what every roblox dev has done at least 4 billion times: I looked up my problem on google.
Answer to the devforum post ↓
loadstring my beloved.
There were quite a few problems with loadstring, however.
- It would make us vulnerable to exploits because of the remoteevents we’d need to use, meaning anyone with a script executer could literally run CODE on our game
- It couldn’t be used on the client
I’ll come back to these later. However, for now, loadstring it was!
After learning about loadstring and doing everything I needed to do to use it, I put together a small gui and added this server-sided code:
game.ReplicatedStorage.Remotes.RunCode.OnServerEvent:Connect(function(plr, text)
if table.find(require(game.ReplicatedStorage.Admins), plr.UserId) then
loadstring(text)()
end
end)
However, if someone typed in code that didn’t work and errored, EVERY OTHER server-sided thing I wanted the terminal to do would halt. So, I wrapped it in a pcall.
local Success, Error = pcall(function()
loadstring(text)()
end)
if Success then
print("Code ran successfully")
else
assert(false, Error)
end
What was the point of the pcall? Like, what would’ve been halted if the loadstring failed?
Our anticheat for the terminal.
You see, I knew when starting this project that exploiting would be a problem. So, I added an exploitation reporting system. If our system detected an exploiter, it would kick them and report them straight to us.
And now, the prototype of the terminal was done! It had no syntax highlighting, but had multi-line, and code execution!
Eventually, WhiteTurtle caught on to what I was doing. He found (and I still don’t know where) a syntax module.
I unfortunately do not know the original coding of the syntax module, and WhiteTurtle doesn’t remember where he found it. However, here is it’s current version:
local highlighter = {}
-- Define keywords for different categories
local keywords = {
lua = {
-- Lua keywords
"and", "break", "or", "else", "elseif", "if", "then", "until", "repeat", "while", "do", "for", "in", "end",
"local", "return", "function", "export", "type", "self", "not"
},
rbx = {
-- Roblox-specific keywords and global functions
"game", "workspace", "script", "math", "string", "table", "task", "wait", "select", "next", "Enum",
"error", "warn", "tick", "assert", "shared", "loadstring", "tonumber", "tostring", "type",
"typeof", "unpack", "print", "Instance", "CFrame", "Vector3", "Vector2", "Color3", "UDim", "UDim2", "Ray", "BrickColor",
"OverlapParams", "RaycastParams", "Axes", "Random", "Region3", "Rect", "TweenInfo",
"collectgarbage", "not", "utf8", "pcall", "xpcall", "_G", "setmetatable", "getmetatable", "os", "pairs", "ipairs", "require"
},
operators = {
-- Operators and punctuation
"#", "+", "-", "*", "%", "/", "^", "=", "~", "=", "<", ">", ",", ".", "(", ")", "{", "}", "[", "]", ";", ":"
};
SpecialSyntax = {
"--Client"
};
}
-- Define colors for different syntax elements
local colors = {
numbers = Color3.fromRGB(255, 198 ,22),
boolean = Color3.fromRGB(255, 198, 22),
lua = Color3.fromRGB(248, 99, 94),
rbx = Color3.fromRGB(117, 214, 216),
str = Color3.fromRGB(105, 209, 105),
comment = Color3.fromRGB(102, 102, 102),
call = Color3.fromRGB(253 ,251, 154),
local_property = Color3.fromRGB(97, 161, 241),
SpecialSyntax = Color3.fromRGB(104, 241, 0)
}
-- Create sets of keywords for faster lookup
local function createKeywordSet(keywords)
local keywordSet = {}
for _, keyword in ipairs(keywords) do
keywordSet[keyword] = true
end
return keywordSet
end
local luaSet = createKeywordSet(keywords.lua)
local rbxSet = createKeywordSet(keywords.rbx)
local operatorsSet = createKeywordSet(keywords.operators)
local SpecialSyntax = createKeywordSet(keywords.SpecialSyntax)
-- Determine the highlight color for a given token
local function getHighlight(tokens, index)
local token = tokens[index]
if colors[token .. "_color"] then
return colors[token .. "_color"]
end
if token:sub(1, 8) == "--Client" then
return colors.SpecialSyntax
elseif string.sub(token, 1, 2) == "--" then
return colors.comment
elseif luaSet[token] then
return colors.lua
elseif rbxSet[token] then
return colors.rbx
elseif token:sub(1, 1) == "\"" or token:sub(1, 1) == "\'" or token:sub(1, 2) == "\[[" or token:sub(1, 3) == "\[=[" then
return colors.str
elseif token == "true" or token == "false" or token == "nil" then
return colors.boolean
elseif tonumber(token) then
return colors.numbers
end
if tokens[index + 1] == "(" then
if table.find(keywords.rbx, tokens[index - 2]) and tokens[index - 1] ~= ":" then
return colors.rbx
end
return colors.call
end
if tokens[index - 1] == "." then
if tokens[index - 2] == "Enum" then
return colors.rbx
end
return colors.local_property
end
end
-- Main function to run the syntax highlighting
function highlighter.run(source)
local tokens = {}
local currentToken = ""
local inString = false
local stringPersist = false
local inComment = false
local isClient = false
local commentPersist = false
local StringPersistType = ""
-- Tokenize the source code
for i = 1, #source do
local character = source:sub(i, i)
if inComment then
-- Handle comments
if character == "\n" and not commentPersist then
table.insert(tokens, currentToken)
table.insert(tokens, character)
currentToken = ""
inComment = false
elseif source:sub(i - 1, i) == "]]" and commentPersist then
currentToken ..= "]"
table.insert(tokens, currentToken)
currentToken = ""
inComment = false
commentPersist = false
else
currentToken = currentToken .. character
end
elseif inString then
local function EndPersistingString(Type)
currentToken ..= "]"
table.insert(tokens, currentToken)
currentToken = ""
inString = false
stringPersist = false
end
-- Handle strings
if character == inString and source:sub(i-1, i-1) ~= "\\" or character == "\n" and not stringPersist then
table.insert(tokens, currentToken)
table.insert(tokens, character)
currentToken = ""
inString = false
elseif source:sub(i - 1, i) == "]]" or source:sub(i-2, i) == "]=]" and stringPersist then
-- if source:sub(i, i+1) == "[[" and source:sub(i-2, i) ~= "]=]" or source:sub(i, i+2) == "[=[" and source:sub(i-1, i) ~= "[[" then
if StringPersistType == "[[" and source:sub(i - 1, i) == "]]" then
EndPersistingString(StringPersistType)
elseif StringPersistType == "[=[" and source:sub(i-2, i) == "]=]" then
EndPersistingString(StringPersistType)
else
currentToken = currentToken .. character
end
else
currentToken = currentToken .. character
end
elseif isClient then
if character == "\n" then
table.insert(tokens, currentToken)
table.insert(tokens, character)
currentToken = ""
isClient = false
else
currentToken = currentToken .. character
end
else
-- Handle other tokens
if source:sub(i, i + 1) == "--" then
table.insert(tokens, currentToken)
currentToken = "-"
inComment = true
commentPersist = source:sub(i + 2, i + 3) == "[["
isClient = source:sub(i + 2, i + 7) == "Client"
if isClient then
inComment = false
end
elseif source:sub(i, i+1) == "[[" or source:sub(i, i+2) == "[=[" then
if source:sub(i, i+1) == "[[" then
StringPersistType = "[["
else
StringPersistType = "[=["
end
currentToken = "["
inString = true
stringPersist = true
elseif character == "\"" or character == "\'" then
table.insert(tokens, currentToken)
currentToken = character
inString = character
elseif operatorsSet[character] then
table.insert(tokens, currentToken)
table.insert(tokens, character)
currentToken = ""
elseif character:match("[%w_]") then
currentToken = currentToken .. character
else
table.insert(tokens, currentToken)
table.insert(tokens, character)
currentToken = ""
end
end
end
table.insert(tokens, currentToken)
local highlighted = {}
-- Apply highlighting to tokens
for i, token in ipairs(tokens) do
local highlight = getHighlight(tokens, i)
if highlight then
local syntax = string.format("<font color = \"#%s\">%s</font>", highlight:ToHex(), token:gsub("<", "<"):gsub(">", ">"))
if token == "true" or token == "false" or token == "nil" or luaSet[token] then
syntax = `<b>{syntax}</b>`
end
table.insert(highlighted, syntax)
else
table.insert(highlighted, token)
end
end
return table.concat(highlighted)
end
return highlighter
Ignore special syntax. I’ll talk about that more later.
All of a sudden, our terminal was looking snazzy!
After adding this script to our scrolling frame (which contains our textboxes):
local textArea = script.Parent:WaitForChild("TextBox")
local scrollFrame = script.Parent
textArea.AutomaticSize = "XY"
textArea:GetPropertyChangedSignal("TextBounds"):Connect(function()
local requiredWidth = textArea.TextBounds.X + 16
local requiredHeight = textArea.TextBounds.Y + 16
scrollFrame.CanvasSize = UDim2.new(0, requiredWidth, 0, requiredHeight)
local newXPosition = math.max(0, requiredWidth - scrollFrame.AbsoluteWindowSize.X)
local newYPosition = math.max(0, requiredHeight - scrollFrame.AbsoluteWindowSize.Y)
scrollFrame.CanvasPosition = Vector2.new(newXPosition, newYPosition)
end)
textArea:GetPropertyChangedSignal("Text"):Connect(function()
local requiredWidth = textArea.TextBounds.X + 16
local requiredHeight = textArea.TextBounds.Y + 16
scrollFrame.CanvasSize = UDim2.new(0, requiredWidth, 0, requiredHeight)
local newXPosition = math.max(0, requiredWidth - scrollFrame.AbsoluteWindowSize.X)
local newYPosition = math.max(0, requiredHeight - scrollFrame.AbsoluteWindowSize.Y)
scrollFrame.CanvasPosition = Vector2.new(newXPosition, newYPosition)
end)
now everything was almost perfect! Formatting code worked, long scripts looked good (with the script above), everything was chef’s kiss.
Everything… except client-sided code execution.
So, again, I looked it up.
Boom! All I needed now was to use vLua in a client-sided script and add a remote (and an anticheat, again)!
Until recently, this is how the terminal was, besides me adding premade scripts after I figured out client-sided stuff.
And then I quit MRTS.
And then I forgot about the terminal.
Until recently, when i remembered I had the terminal. I imported it into URTG, but my god was it bad.
Number one, vLua only supported lua. Not luau.
Number two is that any time I wanted to run client-sided code, I had to require lua and send a remote to the client with the code I wanted to run.
So ineficient.
But I kept it that way. Until I found this.
I was looking for an in-game file explorer, and I found one! Yippie!
It had it’s own console, it’s own property editor,
and it’s own command bar.
I already had the terminal, which was much better than a stinky command line, so I deleted the command line.
However I saw that instead of using vLua, which was what I was expecting it to use, it was using vLuau.
So, I looked it up, saw it supported not JUST lua, but ALSO LUAU, and replaced vLua (and my server-sided loadstring) with vLuau.
And now, my terminal is better than anything i’ve ever seen!
After finding vLuau it gave me a burst of inspiration to make client-sided code execution better. Now, if you type --Client (username) as the first line in the terminal, it runs code on that person’s client!
All of a sudden I was getting comments from not only Phoenix, but also all my other friends who are admins for Yimello who were saying this was a cool system. They were reccomending premade scripts, etc.
I will probably not ever open-source the terminal. There’s too much to loose if someone finds a way to exploit the code.
However, I’m not evil, so feel free to use the snippets I’ve provided and the advice I’ve found online to make your own!
Just please remember to add an anticheat.
One other thing I will share with you guys because I know a lot of you hate RegEx as much as me, is how to add the detector for the --Client stuff.
local lines = string.split(text, "\n")
local firstLine = lines[1]
local player = nil
local splitString = string.split(firstLine, " ")
if splitString[1] == "--Client" and splitString[2] then
local username = splitString[2]
username = string.gsub(username, "^%s*(.-)%s*$", "%1")
player = game.Players:FindFirstChild(username)
if player then
table.remove(lines, 1)
text = table.concat(lines, "\n")
else
text = "assert(false, 'Client \"" .. username .. "\" does not exist')"
end
end
What this does is detect if I’ve added a --Client (username) line at the beggining of my terminal code execution, and if so, it will set a variable, player, to their username. if the player I’ve attempted to run code on doesn’t exist, it sets text to that, as text will get ran by the loadstring. The line after this checks if player is nil, and if it is, it runs the vLuau loadstring on the server. otherwise, it runs it on the client that the player variable is set to.
Anyways, this has been my admin terminal that I created from scratch. Thanks to WhiteTurtle for finding the syntax module, the devs of vLuau, that random guy from 2020 who made a devforum post, and everyone else who led me to make this super awesome terminal.
goober