lua加载csv文件

文章转自http://www.cnblogs.com/newlist/p/3595739.html
--
-- Author: My Name
-- Date: 2013-12-16 18:52:11
-- csv解析
--

-- 去掉字符串左空白
local function trim_left(s)
return string.gsub(s, "^%s+", "");
end

-- 去掉字符串右空白
local function trim_right(s)
return string.gsub(s, "%s+$", "");
end

-- 解析一行
local function parseline(line)
local ret = {};

local s = line .. ",";  -- 添加逗号,保证能得到最后一个字段

while (s ~= "") do
--print(0,s);
local v = "";
local tl = true;
local tr = true;

while(s ~= "" and string.find(s, "^,") == nil) do
--print(1,s);
if(string.find(s, "^\"")) then
local _,_,vx,vz = string.find(s, "^\"(.-)\"(.*)");
--print(2,vx,vz);
if(vx == nil) then
return nil;  -- 不完整的一行
end

-- 引号开头的不去空白
if(v == "") then
tl = false;
end

v = v..vx;
s = vz;

--print(3,v,s);

while(string.find(s, "^\"")) do
local _,_,vx,vz = string.find(s, "^\"(.-)\"(.*)");
--print(4,vx,vz);
if(vx == nil) then
return nil;
end

v = v.."\""..vx;
s = vz;
--print(5,v,s);
end

tr = true;
else
local _,_,vx,vz = string.find(s, "^(.-)([,\"].*)");
--print(6,vx,vz);
if(vx~=nil) then
v = v..vx;
s = vz;
else
v = v..s;
s = "";
end
--print(7,v,s);

tr = false;
end
end

if(tl) then v = trim_left(v); end
if(tr) then v = trim_right(v); end

ret[table.getn(ret)+1] = v;
--print(8,"ret["..table.getn(ret).."]=".."\""..v.."\"");

if(string.find(s, "^,")) then
s = string.gsub(s,"^,", "");
end

end

return ret;
end

--解析csv文件的每一行
local function getRowContent(file)
local content;

local check = false
local count = 0
while true do
local t = file:read()
if not t then  if count==0 then check = true end  break end

if not content then
content = t
else
content = content..t
end

local i = 1
while true do
local index = string.find(t, "\"", i)
if not index then break end
i = index + 1
count = count + 1
end

if count % 2 == 0 then check = true break end
end

if not check then  assert(1~=1) end
return content
end

--解析csv文件
function LoadCsv(fileName)
local ret = {};

local file = io.open(fileName, "r")
assert(file)
local content = {}
while true do
local line = getRowContent(file)
if not line then break end
table.insert(content, line)
end

for k,v in pairs(content) do
ret[table.getn(ret)+1] = parseline(v);
end

file:close()

return ret
end

function Csv2Lua(fileName, filePath, desFilePath )
local t = LoadCsv(filePath);
if t then
t = luautil.serialize(fileName,t);
end
if t then
luautil.writefile(t, desFilePath)
end
end

--test
--local t= LoadCsv("csvtesttxt.csv")
--for k,v in pairs(t) do
--  local tt = v
--  local s = ""
--  for i,j in pairs(tt) do
--      s = string.format("%s,%s",s,j)
--  end
--  print ("",s)
--end