using Backspace to delete last typed letter

Hi Again…


I am trying to make a input terminal(not really)
i want it to listen for 9 letters, which it would wrote down the terminal as they come…
But… i cant figure out how to use the Backspace to delete the last letter that was typed…

Spoiler

tP(25,7)
tB(colors.blue)
tT(colors.white)

print("		 ") -- password place...

tx,ty  = 25,7
   for i = 1, 9 do
	  local event, arg = os.pullEvent("char")
		 if event == "char" then
			   if arg == 14 or arg == keys.backspace then -- if i press backspace it SHOULD do the following, ( but it seems like it does not go into this if statement.. )
				  tP(tx-1,ty)
				  write(" ")
				  i = i - 1
			   else -- if not a backspace pressed, then input the letter...

				  tP(tx,ty)
				  write(arg)
				  table.insert(eTPassword, arg)
			  end
		 end
	  tx = tx + 1
   end

for j = 1, #eTPassword do -- this is to input the whole password ( when done ) to 1 variable.. ( please help me with this too ) ( it is inputting every letters that i've typed in, into a table ( eTPassword ) but i dont --	  

-- know how to insert all the letters from the table to 1 single variable.


end

Thanks in advance

You're pulling a char event, which you should not.

Do not pull an event in os.pullEvent() and then do this:

if event == "key" then
	if arg == keys.backspace then
		--
	elseif arg == keys.enter then
		table.insert(eTPassword, arg) -- Now insert it into the table after clicking enter

elseif event == "char" then
	write(arg)
	-- table.insert(eTPassword, arg)
	-- I'd suggest to only add the password into the table after the person clicks enter.
end

Also, why are you using a for loop?

EDIT: Heres a custom function I made to maximize the amount of characters allowed in the read.

function limitRead(nLimit, replaceChar)
    term.setCursorBlink(true)
    local cX, cY = term.getCursorPos()
    local rString = ""
    if replaceChar == "" then replaceChar = nil end
    repeat
        local event, p1 = os.pullEvent()
        if event == "char" then
            -- Character event
            if #rString + 1 <= nLimit then
                rString = rString .. p1
                write(replaceChar or p1)
            end
        elseif event == "key" and p1 == keys.backspace and #rString >= 1 then
            -- Backspace
            rString = string.sub(rString, 1, #rString-1)
            xPos, yPos = term.getCursorPos()
            term.setCursorPos(xPos-1, yPos)
            write(" ")
            term.setCursorPos(xPos-1, yPos)
        end
    until event == "key" and p1 == keys.enter
    term.setCursorBlink(false)
    print() -- Skip to the next line after clicking enter.
    return rString
end

-- And you call it like this
input = limitRead(10)

-- If you want to replace it with a char, like read("*") then
password = limitRead(10, "*")

but, Why are you using 2 term.getCursorPos() ??

For when it backspaces? Because when it does write(" ") it changes the cursor position back to it's original so it needs to go back again.

ahh… (i feel like im stupid) :(/>


thanks

remiX: you do not have to include the full #str-1 in string.sub

rString = string.sub(rString, 1, #rString-1)

can just be

rString = string.sub(rString, 1, -1)

But, KaoS.
it still works, with the

rString = string.sub(rString, 1, #rString-1)

and wasnt the most important thing, to get this code to work? yes.

Thanks to you guys, anyway :D/>

Oh, good to know. I haven't used string api much myself… but how does that work, Kaos?

If the number is negative does it start from the end of the string?

remiX, on 05 January 2013 - 01:57 AM said:

If the number is negative does it start from the end of the string?

exactly. it is quite a nice way of doing it I think. most languages work that way I think, I know VBS and JS do

Mikk809h, on 05 January 2013 - 01:56 AM said:

Thanks to you guys, anyway :D/>

hehe I did nothing. props to remiX

Yeah :D/>

but thanks :D/> (you did help remiX) :D/>