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Here's some resources on parsing CSV files in Lua.

Parser in Lua

A simple parser for comma-separated-value (.csv) files:

function ParseCSVLine (line,sep) 
	local res = {}
	local pos = 1
	sep = sep or ','
	while true do 
		local c = string.sub(line,pos,pos)
		if (c == "") then break end
		if (c == '"') then
			-- quoted value (ignore separator within)
			local txt = ""
			repeat
				local startp,endp = string.find(line,'^%b""',pos)
				txt = txt..string.sub(line,startp+1,endp-1)
				pos = endp + 1
				c = string.sub(line,pos,pos) 
				if (c == '"') then txt = txt..'"' end 
				-- check first char AFTER quoted string, if it is another
				-- quoted string without separator, then append it
				-- this is the way to "escape" the quote char in a quote. example:
				--   value1,"blub""blip""boing",value3  will result in blub"blip"boing  for the middle
			until (c ~= '"')
			table.insert(res,txt)
			assert(c == sep or c == "")
			pos = pos + 1
		else	
			-- no quotes used, just look for the first separator
			local startp,endp = string.find(line,sep,pos)
			if (startp) then 
				table.insert(res,string.sub(line,pos,startp-1))
				pos = endp + 1
			else
				-- no separator found -> use rest of string and terminate
				table.insert(res,string.sub(line,pos))
				break
			end 
		end
	end
	return res
end


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Last edited April 24, 2012 5:17 pm GMT (diff)