File System API Bug

z.write(x=x+1)

z.write("x=x+1")

theoriginalbit, on 07 December 2013 - 01:07 AM said:

You cannot do this

z.write(x=x+1)

did you mean for it to be a string like so?

z.write("x=x+1")

x=x+1

Lyqyd, on 07 December 2013 - 01:16 AM said:

All that will do is write the literal string to the file, so the contents of the file after you run this code will be:

x=x+1

If you want to change something that's already in the file, you'll have to open the file in read mode, read it into a variable (or a table of lines), change the specific spot you wish to increment the value of, then write the whole file contents to disk again.

Spoiler

Front:



Top:

local modem = peripheral.wrap("top")

while true do
	 local event = os.pullEvent("redstpne")
	 print("Input received!")		 --For debugging only, no other real purpose.
	 modem.transmit(1,1, "Up 1")
end

local modem = peripheral.wrap("left")
mode.open(1)

local message = os.pullEvent("modem_message")

print("Up 1 confirmed")	 -- Debugging purposes only


-- [[ Commented out because this is the issue where I don't know what to do.

z = fs.open("disk/startup", "r")
z.readAll()
z.close
os.shutdown()

]]--

x = 2

turtle.turnLeft()
turtle.select(1)
turtle.suck()
turtle.refuel()
turtle.turnLeft()
turtle.turnLeft()
turtle.up()

for i=1, x do
turtle.forward()
end

turtle.digDown()
rs.setOutput("left", true)
turtle.down()

print(peripheral.getType("front"))   --Purely debugging once again.
P = peripheral.wrap("front")
P.turnOn()

Bomb Bloke, on 07 December 2013 - 08:39 AM said:

-snip-

You'd be better off building a table in memory with details as to which movements are to be made and in what order, then writing the whole file in one go once you've got all the data you need to write out the full list of commands.

Bomb Bloke, on 07 December 2013 - 05:21 PM said:

Since ComputerCraft doesn't allow you to alter an existing part of a file (short of wiping the whole thing and re-writing it all), I would say your best bet here is to have two files on the disk - the "startup" script the turtle is to boot from, and an additional "data" file. Have Computer 2 read/write a number - or a table full of numbers - to the "data" file, and have the "startup" script on the disk read your number (… or table full of numbers) from that same "data" file.

Note that when I say "write a number", I mean that you'd just do something like "z.write(x)" (which'd put the contents of "x" in the file). If you wanted to retrieve that number back into your "x" variable, then you'd open the file in read mode and do "x = tonumber(z.readLine())".