How to prevent this

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Maybe consider labeling the PCs, this way they won't loose the ids.

Metalhawk2012, on 30 May 2015 - 12:17 AM said:

… but when i add another computer running the same code the information gets "moved" down one row, i have to go into my minecraft folder and remove the lastId.txt to fix

is there anyway to sort this without deleting the lastid.txt?…

Do I understand correctly, that the original computer displays correctly, but the second computer displays one row lower? If so, what happens with a 3rd computer? Please post your code, I'm curious how you're formatting your output.

Dog, on 30 May 2015 - 12:37 AM said:

Metalhawk2012, on 30 May 2015 - 12:17 AM said:

… but when i add another computer running the same code the information gets "moved" down one row, i have to go into my minecraft folder and remove the lastId.txt to fix

is there anyway to sort this without deleting the lastid.txt?…

Do I understand correctly, that the original computer displays correctly, but the second computer displays one row lower? If so, what happens with a 3rd computer? Please post your code, I'm curious how you're formatting your output.

Yeah Sure Here's the code And the 3rd,4th 5th .ect will display 1 row lower then the previous computer on the same network

local drums = peripheral.getNames()
local monitor = peripheral.wrap("right")
monitor.setTextScale(0.5)
monitor.clear()

function scanDrum()
for i,d in pairs(drums) do
  if peripheral.getType(d) == "drum" then

  info = peripheral.call(d,"getTankInfo")

  t1 = info[1]


  capacity = t1.capacity
  amount = t1.contents.amount
  
  fill = math.floor(amount*100/capacity)

  if fill <=20 then color = colors.red end
  if fill <50 and fill>20 then color = colors.yellow end
  if fill <75 and fill>=50 then color = colors.orange end
  if fill >=75 then color = colors.green end

  monitor.setCursorPos(1,i-1)
  monitor.setTextColor(colors.green)
  monitor.write("Name: "..t1.contents.rawName)

  monitor.setCursorPos(30,i-1)
  monitor.setTextColor(colors.red)
  monitor.write("Amount: "..t1.contents.amount)

  monitor.setCursorPos(47,i-1)
  monitor.setTextColor(colors.blue)
  monitor.write("Capacity: "..t1.capacity)

  monitor.setCursorPos(66,i-1)
  monitor.setTextColor(color)
  monitor.write(fill.."% Full")

  end
end
end
while true do
sleep(0.1)
scanDrum()
end

Are the modems on the computers themselves turned on or off? They *should* be off. I have a feeling that the computers are being detected and one of your computers is seeing the drums as items 2-5 instead of items 1-4. That's my only guess, atm.

Dog, on 30 May 2015 - 12:54 AM said:

Are the modems on the computers themselves turned on or off? They *should* be off. I have a feeling that the computers are being detected and one of your computers is seeing the drums as items 2-5 instead of items 1-4. That's my only guess, atm.

i understand what you mean i havent had much experience with computercraft much i always thought that the modem had to be on for it to actually see whats in the network

Just tried it and no that didn't seem to work there's still a empty row. do you think this could be the monitor?

I don't have a way of testing atm but I guess it *could* be the monitor. However, only the bottom computer is touching both monitor arrays and it is displaying correctly, right? Do I understand correctly that the top computer is displaying incorrectly?

Oh, and just to cover all the obvious bases…you did restart the programs after turning off the computer modems, right?

Dog, on 30 May 2015 - 01:03 AM said:

I don't have a way of testing atm but I guess it *could* be the monitor. However, only the bottom computer is touching both monitor arrays and it is displaying correctly, right? Do I understand correctly that the top computer is displaying incorrectly?

Oh, and just to cover all the obvious bases…you did restart the programs after turning off the computer modems, right?

Yeah i did, ive now gone into a test world but it still seems to be a empty row on pos(1,1)
ive put the value of "i" next to the name which should correspond the drum number and the row number as you can see 2-6 are there but wheres 1?? it must be the monitor and the code is displaying it as a empty string

It could be the monitor. First - which monitor in your original setup is displaying incorrectly? Top or bottom? I'm guessing top. If that's the case, then the monitor doesn't make sense since only the bottom computer is touching both monitor arrays.

Let's find out what the computer is seeing. Run this on each system and let's see what's different…

local perps = peripheral.getNames()
for k, v in pairs(perps) do
  print(k .. " / " .. v)
end

Computer 1 brings up
1 top
2 back
3 drum_0

4 drum_2

5 drum_1

6 drum_4

7 drum_3
8 right

Computer 2
1 back
2 drum_0

3 drum_2

4 drum_1

5 drum_4

6 drum_3
7 right

So now we know its the monitors how can we filter them out?

Well, there are a number of approaches you can use. Here are two off the top of my head:

1. Use a separate variable for y position instead of using i, increment as necessary

local yPos = 1
... code ...
monitor.setCursorPos(1, yPos)
monitor.write("Stuff")
yPos = yPos + 1

2. Filter the results before processing them

local drums = peripheral.getNames()
for i = #drums, 1, -1 do
  if peripheral.getType(drums[i]) ~= "drum" then
    table.remove(drums, i)
  end
end

Thank you!!! the 2nd code works perfectly thanks i can now be able to have multiple computers on that network as you can see with this picture, again thanks

You're very welcome. Glad I could help :)/>

local drums = peripheral.getNames()
local monitor = peripheral.wrap("right")
for i = #drums,1,-1 do
   if peripheral.getType(drums[i]) ~= "drum" then
   table.remove(drums,i)
   end
end
monitor.setTextScale(0.5)
monitor.clear()

function scanDrum()
for i,d in pairs(drums) do
  if peripheral.getType(d) == "drum" then

  info = peripheral.call(d,"getTankInfo")

  t1 = info[1]


  capacity = t1.capacity
  amount = t1.contents.amount
  
  fill = math.floor(amount*100/capacity)

  if fill <=20 then color = colors.red end
  if fill <50 and fill>20 then color = colors.yellow end
  if fill <75 and fill>=50 then color = colors.orange end
  if fill >=75 then color = colors.green end

  monitor.setCursorPos(1,i)
  monitor.setTextColor(colors.green)
  monitor.write("Name: "..t1.contents.rawName.." "..i)

  monitor.setCursorPos(30,i)
  monitor.setTextColor(colors.red)
  monitor.write("Amount: "..t1.contents.amount)

  monitor.setCursorPos(47,i)
  monitor.setTextColor(colors.blue)
  monitor.write("Capacity: "..t1.capacity)

  monitor.setCursorPos(66,i)
  monitor.setTextColor(color)
  monitor.write(fill.."% Full")

  end
end
end
while true do
sleep(0.1)
scanDrum()
end

That's what this "Ask a pro" forum is for ^^
oh and feel free to use the code if you need to it was a little project i wanted to do for my base on my sp world

Its Been a while since i last had this post up, but i require a little help when adding an empty barrel to the system, obviously when a new barrel is added it tries to output its contents(which is obviously doesnt have) so i get a nil value error, is there a way to run a code when a nil value is detected?

You have to start checking if things are nil before using them. For example;

  info = peripheral.call(d,"getTankInfo")
  t1 = info[1]
  capacity = t1.capacity


  --#here I use a two ternary operators to avoid indexing t1.contents if it is nil
  --#psudocode:  IF (t1.contents) THEN amount = t1.contents.amount ELSE amount = 0
  amount = (t1.contents and t1.contents.amount) or 0

  fill = math.floor(amount*100/capacity)

KingofGamesYami, on 13 February 2016 - 02:55 AM said:

You have to start checking if things are nil before using them. For example;

  info = peripheral.call(d,"getTankInfo")
  t1 = info[1]
  capacity = t1.capacity


  --#here I use a two ternary operators to avoid indexing t1.contents if it is nil
  --#psudocode:  IF (t1.contents) THEN amount = t1.contents.amount ELSE amount = 0
  amount = (t1.contents and t1.contents.amount) or 0

  fill = math.floor(amount*100/capacity)

That worked, cheers, i just had to do it with the capacity, name, and fill because i also kept getting nil values from them too

capacity = (t1.contents and t1.capacity) or "0	   "
  amount = (t1.contents and t1.contents.amount) or "0	   "
  rawName = (t1.contents and t1.contents.rawName) or "Empty Barrel"
 
  fill = (t1.contents and t1.capacity and math.floor(amount*100/capacity)) or 0