index expected, got nil

I am trying to save an array to file using serialize, as part of this i am first checking to see if there is already an array saved to the file, if so, reading, unserializing and appending it, however I am currently trying to get the program to create an array where there isnt one already (creating the file rather than appending it). I get an error on line 54 (writing the cID into the array, I believe it is due to dataLength being a nil value despite being addressed earlier, can someone please provide a fix.

http://pastebin.com/f999Uzw8

regards

mistamadd001

you are ising dataLength out of the scope. Try adding the line
local dataLength = 1
between line 48 and 49; then you can even leave out your else block

http://pastebin.com/Eg88cFeL

new code with changes, still erroring same spot same error

Are you sure? I mean… Can you provide error message and new line number?

line 53: index expected, got nil

I currently unable to test myself, but it's almost like impossible to produce this exception in your current code. the only thing left to try out is commenting out line 51 for test purpuses

just tried that and no joy, this is getting weird

try it out by hardcoding the index. just replace dataLength by 1, just to test, whether the error is actually caused by this exact index

Ok, I tested the script and noticed that since i had no cids and the file was created blank, textutils.unserialize returned nil, so changing

if data ~= nil then
    dataLength = #data + 1
end

to

if data ~= nil then
    dataLength = #data + 1
else
    data={}
end

worked, also you need to add file.close() after you write the serialized table to file after line 55


Edit: ahhh, the formatting of

 is being finicky with the indents.
[b]Edit2: [/b]Fixed the indents, kinda.
I just gave up and used spaces.

Yeah, I was expecting more exceptions afterwards, but the "index expected, got nil" just didn't seem to go away. If data was nil, it would've said: Attempt to index (a nil value), or am I going completely crazy und stupid right now?

If the code works for Quin now, I would assume he wasn't testing the updated code correctly or I'm going insane :D/>

And by he I mean mistamadd001

I tested the updated code (and uncommented the dataLength = #data + 1) I also redid the cID, cName get to static strings just for testing sake

http://pastebin.com/QueZJQPz

Worked fine, or atleast it worked how i believe it should have. a file was written to clients/cids with 'test' in the serialized table

Oh, I just noticed something, you have the file clients/cids being written to and closed on lines 43 and 44, thus creating a blank file, then you read the file, so you will only ever have 1 client saved at a time.
ex:
Create client 'a'
file client/a is created
file client/cids is opened in write mode (thus clearing the file and rewriting the whole thing)
file client/cids is closed with nothing written to it
file client/cids is opened in read mode (always blank)
then the file is written to with the new table, only 1 entry

you should move that part of the code over to where you have to check if the 'clients' dir exists, and create cids at the same time

I have edited the pastebin link I gave with the fix to this problem

ah yea, i would have figured that out eventually, thanks, as for the rest, ill have a quick look at the code and see how it goes.

I have a feeling 1 thing that youre doing isnt quite what I want but ill play

thanks for the help so far.

I found a simpler way and less codey too

	local file = fs.open('clients/cids','r')
	local data = file.readAll()
	file.close()
	data = textutils.unserialize(data)
	if data == nil then
	  data = {}
	end
	table.insert(data,cID)
	local file = fs.open('clients/cids','w')
	file.write(textutils.serialize(data))
	print('Client Install Successful')
	rednet.send(cID, 'done')

so its not throwing errors now (YAY), but its still not actually saving the cID into an array then as a string in the cids file… any ideas??

I've updated my most recent pastebin for you to look at

mistamadd001, on 10 February 2015 - 10:07 PM said:

so its not throwing errors now (YAY), but its still not actually saving the cID into an array then as a string in the cids file… any ideas??

I've updated my most recent pastebin for you to look at

In the little snippet of code you posted right above your previous post you never close the file, and if you dont close the file it doesnt actually save. You need to do a file.close() after the file.write().

valithor, on 10 February 2015 - 10:11 PM said:

mistamadd001, on 10 February 2015 - 10:07 PM said:

so its not throwing errors now (YAY), but its still not actually saving the cID into an array then as a string in the cids file… any ideas??

I've updated my most recent pastebin for you to look at

In the little snippet of code you posted right above your previous post you never close the file, and if you dont close the file it doesnt actually save. You need to do a file.close() after the file.write().

thank you, that was the final thing, it works perfectly, now to use it in my other programs lol