multiple options?

I have searched the forums and the wiki and I cant find anything. What I'm looking for is the option to make multiple choices. Example

What would you like to do?
[1] shut down
[2] reboot
[3] open door

Any hints?

Huh. Actually now that I've looked around in the tutorials section, I'm not seeing anything that's very simple to follow while at the same time making use of good coding habits. I myself have made a tutorial on menus, but it's more for intermediate-advanced Lua programmers than for those new to programming.

Anyway, here's how I would go about it (note - please read the comments and don't just copy/paste! :)/>)

local termX, termY = term.getSize() --Get the terminal size
local function centerPrint(text, y) --Pretty self explanatory: just writes text to the center of the screen
  term.setCursorPos(termX/2-#text/2, y)
  term.write(text)
end

local menu_options = { --Our menu options: you can increase or decrease this list as you wish
[1] = "menu option 1";
[2] = "menu option 2";
[3] = "menu option 3";
}
term.clear() --Just clear the screen first
local startY = termY/2-#menu_options/2 --This is the starting position that we'll draw at.
for i=1, #menu_options do --A for loop which will write our menu options to the screen.
  centerPrint("["..i.."] "..menu_options[i], startY)
  startY = startY + 1
end

term.setCursorPos(1, termY)
term.write("Press a number to select the menu option...")

local selected = false --This will be our selected menu item, but since nothing has been selected yet we''ll just set it to false
while true do
  local e = {os.pullEvent()} --This will take events and put them into an event table
  if e[1] == "char" then --If the returned event is a character then
    if menu_options[tonumber(e[2])] then --Check if the pressed key is inside of the menu_options table
	  selected = tonumber(e[2]) --If so, set selected to the index and break out of our loop
	  break
    end
  end
end

print("You've selected: ".. menu_options[selected])

In case you're confused by anything in this tutorial, here's a small list of the important stuff:

• Tables - signified by brackets { }, this contains a number of items that correlate to the given index.
• tonumber(e[2]) - This simply converts the event returned by os.pullEvent() into a number, if it is one. If it is not a number, it will return a nil value (essentially nothing)
• term.setCursorPos(termX/2-#text/2, y) - This divides the length of the terminal in half, and then subtracts the length of the text/2 from that so we can center the text nicely

And that's about it. If you've got any more questions, feel free to ask.

EDIT: Haha damn ninja's :ph34r:/>

Something like this would do the trick.

local function openDoor()
  rs.setOutput('back', true)
  sleep(4)
  rs.setOutput('back', false)
end

local options = {
  {"shut down" = os.shutdown},
  {"reboot" = os.reboot},
  {"open door" = openDoor},
}
print("What would you like to do?")
for i = 1, #options do
  print('['..i..'] '..options[i][1])
end

while true do
  local input = read()
  if not tonumber(input) then
	print('Not a number between 1 and '..#options)
  elseif options[tonumber(input)] then
	options[tonumber(input)]()
  else
	print('Not a valid number between 1 and '..#options)
  end
end

Bubba, on 02 May 2013 - 10:07 PM said:

Huh. Actually now that I've looked around in the tutorials section, I'm not seeing anything that's very simple to follow while at the same time making use of good coding habits. I myself have made a tutorial on menus, but it's more for intermediate-advanced Lua programmers than for those new to programming.

Anyway, here's how I would go about it:

local termX, termY = term.getSize()
local function centerPrint(text, y)
  term.setCursorPos(termX/2-#text/2, y)
  term.write(text)
end

local menu_options = {
[1] = "menu option 1";
[2] = "menu option 2";
[3] = "menu option 3";
}

local startY = termY/2-#menu_options/2
for i=1, #menu_options do
  centerPrint("["..i.."] "..menu_options[i], startY)
  startY = startY + 1
end

local selected = false
while true do
  local e = {os.pullEvent()
  if e[1] == "char" then
	if menu_options(tonumber(e[2])) then
	  selected = tonumber(e[2])
	  break
	end
  end
end

print("You've selected: ".. menu_options[selected])

would that allow me to just press the corespding number? Cause that's what I'm trying to do. Sorry about all the questions, Im new to programming.

ironwiccan, on 02 May 2013 - 10:12 PM said:

would that allow me to just press the corespding number? Cause that's what I'm trying to do. Sorry about all the questions, Im new to programming.

Indeed it would. Sorry, I tend to type out a quick reply and then edit my post to add more detail (hence the ninja :lol:/>). I've added comments now, so hopefully that'll help you out some.