Read & Write a File

These are general functions that can be used to read or write any type of string data to or from a permanent text file. These make use of Lua's Io Library functions, which can be hard to understand without a template.

ReadFile

function ReadFile(FilePath)
	-- HANDLE RELATIVE PATH OPTIONS.
	FilePath = SKIN:MakePathAbsolute(FilePath)

	-- OPEN FILE.
	local File = io.open(FilePath)

	-- HANDLE ERROR OPENING FILE.
	if not File then
		print('ReadFile: unable to open file at ' .. FilePath)
		return
	end

	-- READ FILE CONTENTS AND CLOSE.
	local Contents = File:read('*all')
	File:close()

	return Contents
end

ReadFileLines

Alternatively, instead of getting the entire file as a single string, you may instead want to break it down into its individual lines.

function ReadFileLines(FilePath)
	-- HANDLE RELATIVE PATH OPTIONS.
	FilePath = SKIN:MakePathAbsolute(FilePath)

	-- OPEN FILE.
	local File = io.open(FilePath)

	-- HANDLE ERROR OPENING FILE.
	if not File then
		print('ReadFile: unable to open file at ' .. FilePath)
		return
	end

	-- READ FILE CONTENTS AND CLOSE.
	local Contents = {}
	for Line in File:lines() do
		table.insert(Contents, Line)
	end

	File:close()

	return Contents
end

WriteFile

function WriteFile(FilePath, Contents)
	-- HANDLE RELATIVE PATH OPTIONS.
	FilePath = SKIN:MakePathAbsolute(FilePath)

	-- OPEN FILE.
	local File = io.open(FilePath, 'w')

	-- HANDLE ERROR OPENING FILE.
	if not File then
		print('WriteFile: unable to open file at ' .. FilePath)
		return
	end

	-- WRITE CONTENTS AND CLOSE FILE
	File:write(Contents)
	File:close()

	return true
end

To merge a table of "lines" into a single string with each value on a separate line, use String = table.concat(Table, '\n')