[Lua][Question] 2 things about saving to and loading files.

print("Running eMail server")
n=0
a=0
local table1={}
local hHandle = fs.open("table1.txt", "r")
repeat
if hHandle:readLine(a) == nil then
print("Database Empty")
else
local line = tostring(hHandle:readLine(a))
print(line)
table.insert(table1, line)
print("Added name to database")
a = a+1
line2 = hHandle:readLine(a)
table1[line]=line2
print(line2)
print("Tied ID to name in database")
a = a+1
n = n+1
end
until line == nil
hHandle.close()

if message == "register" then
id, regname = rednet.receive()
rednet.broadcast("reged")
table.insert(table1,regname)
table1[regname]=id
print("Computer " .. table1[regname])
print(" registered as name " .. table1[n+1])
print(table.maxn(table1))
local file = fs.open("table1.txt", "w") -- open the file
if file then -- check if it's open
local s = tostring(table1[n+1]) -- serialize the table, so we have a string to save to the file
file.writeLine(s) -- write it to the file
local s = tostring(table1[regname]) -- serialize the table, so we have a string to save to the file
print("Printing S" .. s)
file.writeLine(s) -- write it to the file
file.close() -- always close the file handles
end

"a" to open for writing but keep existing data and append any writes to the end of the file, plus optionally the second character

print("Running eMail server")
n=0
a=0
local table1={}
local hHandle = fs.open("table1.txt", "r")
repeat
local line = hHandle.readLine()
print("Name: " .. line)
table.insert(table1, line)
print("Added name to database")
a = a+1
line2 = hHandle.readLine()
table1[line]=line2
print(line2)
print("Tied ID to name in database")
a = a+1
n = n+1
line = line2
until line ~= nil
hHandle.close()

local file = fs.open("filePath", "r");
local sFileContents = file.readAll();
file.close();
-- The following n is a common escape sequence within strings that represent a new line, or line break
sFileContents = sFileContents.."n"..sFileAddtion; -- This will be the string holding whatever you wanted to add
file = fs.open("filePath", "w");
file.write(sFileContents);
file.close();

PaymentOption, on 09 July 2012 - 04:59 AM said:

In all honesty, I did not read your code as best I could have, however I think I may be able to offer some insight. Try and read the file into a string variable for temporary holding, then concatenate both the string holding the whole file with whatever you want to add and then write it back to the file.

Here is an example:

local file = fs.open("filePath", "r");
local sFileContents = file.readAll();
file.close();
-- The following n is a common escape sequence within strings that represent a new line, or line break
sFileContents = sFileContents.."n"..sFileAddtion; -- This will be the string holding whatever you wanted to add
file = fs.open("filePath", "w");
file.write(sFileContents);
file.close();

Please forgive my use of unnecessary semicolons for I have been doing a lot of Java programming as of late, and thus the OCD demon inside me refuses to let little errors like that slip :)/>/>

I hope this helps!

Cloudy, on 09 July 2012 - 12:17 PM said:

Post the error? "crashing the java" isn't specific enough to see what's wrong.