Random Smile

function getNumber()
    local tCharacters = {'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'}
    local bShouldBeNumber = false;

    if math.random(0, 1) == 1 then
        bShouldBeNumber = true;
    end

    if bShouldBeNumber then
        return math.random(0, 9)
    else
        return tCharacters[math.random(1, 26)]
    end
end

function printEye_Left()
    printNumbers(2, 49/2 - 3, 2, 19/2 - 2)
end

function printEye_Right()
    printNumbers(49/2 + 4, 50, 2, 19/2 - 2)
end

function printMouth_LeftSide()
    printNumbers(2, 49/2 - 14, 19/2 + 2, 17)
end

function printMouth_RightSide()
    printNumbers(49/2 + 17, 50, 19/2 + 2, 17)
end

function printMouth_Middle()
    printNumbers(2, 49/2 + 17, 19/2 + 5, 17)
end

function printNose()
    printNumbers(49/2 - 2, 49/2 + 3, 19/2 - 1, 19/2 + 2)
end

function printNumbers(x_start, x_end, y_start, y_end)
    for xPos = x_start, x_end do
        for yPos = y_start, y_end do
            term.setCursorPos(xPos, yPos)
            term.write(getNumber())
        end
    end
end

while true do
    term.clear()
    term.setCursorPos(1, 1)

    printEye_Right()
    printEye_Left()

    printMouth_RightSide()
    printMouth_LeftSide()
    printMouth_Middle()

    printNose()
    sleep(0.1)
end