1. For that, you would need to make your own read() function. This is an edit of the vanilla read() that centers text, but also clears the entire current line (because it has to.)
Spoiler
function centerRead( _sReplaceChar, _tHistory )
term.setCursorBlink( true )
local sLine = ""
local nHistoryPos = nil
local nPos = 0
if _sReplaceChar then
_sReplaceChar = string.sub( _sReplaceChar, 1, 1 )
end
local w, h = term.getSize()
local sx, sy = term.getCursorPos()
local function redraw( _sCustomReplaceChar )
--[[
local nScroll = 0
if sx + nPos >= w then
nScroll = (sx + nPos) - w
end
term.setCursorPos( sx, sy )
local sReplace = _sCustomReplaceChar or _sReplaceChar
if sReplace then
term.write( string.rep(sReplace, string.len(sLine) - nScroll) )
else
term.write( string.sub( sLine, nScroll + 1 ) )
end
term.setCursorPos( sx + nPos - nScroll, sy )
]]
local sReplace = _sCustomReplaceChar or _sReplaceChar
term.clearLine()
term.setCursorPos(w/2 - #sLine/2, sy)
term.write(sReplace and string.rep(sReplace, #sLine) or sLine)
end
while true do
local sEvent, param = os.pullEvent()
if sEvent == "char" then
sLine = string.sub( sLine, 1, nPos ) .. param .. string.sub( sLine, nPos + 1 )
nPos = nPos + 1
redraw()
elseif sEvent == "key" then
if param == keys.enter then
-- Enter
break
elseif param == keys.left then
-- Left
if nPos > 0 then
nPos = nPos - 1
redraw()
end
elseif param == keys.right then
-- Right
if nPos < string.len(sLine) then
nPos = nPos + 1
redraw()
end
elseif param == keys.up or param == keys.down then
-- Up or down
if _tHistory then
redraw(" ");
if param == keys.up then
-- Up
if nHistoryPos == nil then
if #_tHistory > 0 then
nHistoryPos = #_tHistory
end
elseif nHistoryPos > 1 then
nHistoryPos = nHistoryPos - 1
end
else
-- Down
if nHistoryPos == #_tHistory then
nHistoryPos = nil
elseif nHistoryPos ~= nil then
nHistoryPos = nHistoryPos + 1
end
end
if nHistoryPos then
sLine = _tHistory[nHistoryPos]
nPos = string.len( sLine )
else
sLine = ""
nPos = 0
end
redraw()
end
elseif param == keys.backspace then
-- Backspace
if nPos > 0 then
redraw(" ");
sLine = string.sub( sLine, 1, nPos - 1 ) .. string.sub( sLine, nPos + 1 )
nPos = nPos - 1
redraw()
end
elseif param == keys.home then
-- Home
nPos = 0
redraw()
elseif param == keys.delete then
if nPos < string.len(sLine) then
redraw(" ");
sLine = string.sub( sLine, 1, nPos ) .. string.sub( sLine, nPos + 2 )
redraw()
end
elseif param == keys["end"] then
-- End
nPos = string.len(sLine)
redraw()
end
end
end
term.setCursorBlink( false )
term.setCursorPos( w + 1, sy )
print()
return sLine
end
2. It would probably help to know that \n represents the newline character, and therefore, doing write('\n\n\n') would make three new lines, and move the cursor down three times.
Note that this only works with print and write and not term.write, and when using this with print, it will print one more newline than you have provided, since print automatically makes a newline.
There's also the method of simply using term.setCursorPos() to print where you want your text.
