How to save and load files with an array in it?

Hello there,

I am having a program which saves and loads an array in a file.

My questions are now:
I save an one dimensional array with e.g. 10 variables set on '0'. Then i want to expand this array by 40 more variables. How do i do this without losing the old variables.

How are all the commands for the direction the file will be safed, so that a computer and turtle can access it.

Thank you for your help :D/>
UN0BTANIUM

Use the append mode

f = fs.open("file", "a")

to write to a file keepin the old stuff. Using "w" will overwrite eveything.

If I understood you correctly?

Yeah, thats kinda what i want.
And how do i expand existing arrays, so they can hold more variables than before.
and how to load and save from different folder directions?

So you want to insert variables into an existing table?

table.insert(tableName, "stuff")

To save into a different folder directory, use the full path.

f = fs.open("myOS/tables/myFile", "a")

Take not: You can't write to rom

table.insert() appends more variables?

And the starting folder ist rom?


edit:
What if i create a table at the beginning of the program and then load an array out of a file into this one. I dont want to append the table from the file. I just want want the variables from the file in the existing array.

UNOBTANIUM, on 04 February 2013 - 05:55 AM said:

table.insert() appends more variables?

And the starting folder ist rom?


edit:
What if i create a table at the beginning of the program and then load an array out of a file into this one. I dont want to append the table from the file. I just want want the variables from the file in the existing array.

Then make sure your table is empty by doing

tableName = {}

first. Then you can insert the elements from the file into it.

But i dont want to have a empty array. The size of the array in the program and the array in the file are maybe different :/

Just you can follow for what i need this (just a simple version):
I make a logistic storage with chests. Below the turtle is a chest which contains items as indicator for thge number of all chests the storage has. The player can add chests manually and then has to change the amount of items in this chest. By starting the turtle, it sucks these items in its inventory and creates an array based on the item count. All variables are set on default, means that every chest in the storage is empty. Then it loads the array out of the file. This array might be smaller. And thats were i dont know how to get it to work :/

You're leaving out the relevant part. What are you going to do with the eventually smaller array? Do you mean that part of the counted items could already be stored into the file and only some will have to be added to it?

The eventually smaller array should be implemented into the created array.

Maybe i have an idea how to do it but i want a solution from you.

Spoiler

I have an array like this allready saved in the file from a session before:

chest[1]=true
chest[2]=true
chest[3]=false
chest[4]=true

That means there are four items in the chest below the turtle, called the indicator items.
The setup includes 4 chests. The player added 2 more chests and placed 2 more indicator items in the chest below the turtle. The player restarts the program and the turtle creates with the indicator items an array.

chest[1]=false
chest[2]=false
chest[3]=false
chest[4]=false
chest[5]=false
chest[6]=false

Now the turtle loads the array from the file, which includes just four variables. The final array should look like this:

chest[1]=true
chest[2]=true
chest[3]=false
chest[4]=true
chest[5]=false
chest[6]=false

I hope this was clear enough what i want. Maybe there is an easier version of this and i am thinking too complicated :/

Try this?

chest = {}

chest[1]=true
chest[2]=true
chest[3]=false
chest[4]=true
f = fs.open("file", "w")
for i = 1, #chest do
    f.writeLine(chest[i]) -- write to file
end
f.close()

chest = {}

chest[1]=false
chest[2]=false
chest[3]=false
chest[4]=false
chest[5]=false
chest[6]=false



f = fs.open("file", "r")
line = f.readLine()
i = 1
while line do
    chest[i] = (line == "true") -- will make it true if the read line is true, else false.
    i = i + 1
    line = f.readLine()
end
f.close()

for i = 1, #chest do
print(chest[i])
end

Yeah. Thats what i need. And if i want to use numbers and strings instead of boolean?

Ok then change the while line do loop to

while line do
    chest[i] = (line == "true" or line == "false") and line == "true" or line -- checks to see if line is true or false, according to that it turns it into a boolean, else it just makes it line
    i = i + 1
    line = f.readLine()
end

Thank you very much <3

One last question!
If i want to open the same file from a turtle and a computer, do i just have to use something like "myOS/tables/myFile" and both have access to the same file?

No - computers and turtles have their own unique ID and own unique folder. One can not access either.

For this, rednet will be required.

remiX, on 05 February 2013 - 11:04 PM said:

For this, rednet will be required.

Or the file on a disk in a drive that is directly in between the both.
Or in "/rom/".

TheOriginalBIT, on 05 February 2013 - 11:13 PM said:

remiX, on 05 February 2013 - 11:04 PM said:

For this, rednet will be required.

Or the file on a disk in a drive that is directly in between the both.
Or in "/rom/".

Well… If he's using a turtle, I doubt it's going to sit in one spot.Also, he's saving his own variables in the file, so he can't write it to rom.

remiX, on 05 February 2013 - 11:20 PM said:

Also, he's saving his own variables in the file, so he can't write it to rom.

Core files to rom and a separate 'variables' file in the local system.

I will use rednet ;D