[Tekkit Classic/v1.33][SSP/SMP]Error - nil: vm error: java.lang.NullPointerException

Hi. When i run this code:

local pass = "pass"
local doorSide = "bottom"
local delay = 3

while true do
	event, driveSide = os.pullEventRaw
	if event == "disk" and driveSide then
		if disk.getMountPath(driveSide) then
			path = path.."/password"
			file = fs.exists(path) and io.open(path, "r") or nil
		end
		if file and file:read() == pass then
			rs.setOutput(doorSide, true)
			sleep(delay)
			rs.setOutput(doorSide, false)
		end
		disk.eject(driveSide)
		if file then
			file:close()
			file = nil
		end
	end
end

after several seconds error appears and computer's going off. I remember on another modpack this code worked well. I don't know what is wrong with it…

FireHead996, on 07 July 2014 - 12:23 PM said:

Hi. When i run this code:

local pass = "pass"
local doorSide = "bottom"
local delay = 3

while true do
	event, driveSide = os.pullEventRaw
	if event == "disk" and driveSide then
		if disk.getMountPath(driveSide) then
			path = path.."/password"
			file = fs.exists(path) and io.open(path, "r") or nil
		end
		if file and file:read() == pass then
			rs.setOutput(doorSide, true)
			sleep(delay)
			rs.setOutput(doorSide, false)
		end
		disk.eject(driveSide)
		if file then
			file:close()
			file = nil
		end
	end
end

after several seconds error appears and computer's going off. I remember on another modpack this code worked well. I don't know what is wrong with it…

os.pullEventRaw /= os.pullEventRaw()

Geforce Fan, on 07 July 2014 - 08:09 PM said:

FireHead996, on 07 July 2014 - 12:23 PM said:

Hi. When i run this code:

local pass = "pass"
local doorSide = "bottom"
local delay = 3

while true do
	event, driveSide = os.pullEventRaw
	if event == "disk" and driveSide then
		if disk.getMountPath(driveSide) then
			path = path.."/password"
			file = fs.exists(path) and io.open(path, "r") or nil
		end
		if file and file:read() == pass then
			rs.setOutput(doorSide, true)
			sleep(delay)
			rs.setOutput(doorSide, false)
		end
		disk.eject(driveSide)
		if file then
			file:close()
			file = nil
		end
	end
end

after several seconds error appears and computer's going off. I remember on another modpack this code worked well. I don't know what is wrong with it…

os.pullEventRaw /= os.pullEventRaw()

In other words you forgot the parenthesis.

Not a bug, moved to Ask A Pro.

Agoldfish, on 07 July 2014 - 08:18 PM said:

Geforce Fan, on 07 July 2014 - 08:09 PM said:

FireHead996, on 07 July 2014 - 12:23 PM said:

Hi. When i run this code:

local pass = "pass"
local doorSide = "bottom"
local delay = 3

while true do
	event, driveSide = os.pullEventRaw
	if event == "disk" and driveSide then
		if disk.getMountPath(driveSide) then
			path = path.."/password"
			file = fs.exists(path) and io.open(path, "r") or nil
		end
		if file and file:read() == pass then
			rs.setOutput(doorSide, true)
			sleep(delay)
			rs.setOutput(doorSide, false)
		end
		disk.eject(driveSide)
		if file then
			file:close()
			file = nil
		end
	end
end

after several seconds error appears and computer's going off. I remember on another modpack this code worked well. I don't know what is wrong with it…

os.pullEventRaw /= os.pullEventRaw()

In other words you forgot the parenthesis.

OK. This error is not showing, but now is another one:
startup:6: attempt to concatenate nil and string
I don't understand this. Both of vars (event and driveSide) are selfprinting good (as strings), but when i insert disc, error appears.

You say the error points to line 6, but the only line on which you're concatenating is line 9. In any case, you're attempting to concatenate "path" with the string "/password"; but since "path" isn't already a string, it errors.

Seems you want to use disk.getMountPath(driveSide) there instead.

Bomb Bloke, on 08 July 2014 - 12:21 AM said:

You say the error points to line 6, but the only line on which you're concatenating is line 9. In any case, you're attempting to concatenate "path" with the string "/password"; but since "path" isn't already a string, it errors.

Seems you want to use disk.getMountPath(driveSide) there instead.

Ooo… That was my fault. I didn't used after first condition this:

path = disk.getMountPath(diskSide)
if(path) then

Now it works. :)/> Thanks for help.