Mac 下纯lua（三）

文件处理

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直接使用io调用

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io.close();文件流关闭

io.flush（）；如果文件流以bufferd缓存模式处理，输入不会立即存入文件，需要调用本函数

io.input(file)；输入

io.open(filename,mode);以相应的模式打开文件流.

io.output（file）输出文件

io.tmpfile（）打开一个临时文件流

io.type(obj) 类型

io.write(); 写入文件

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明确调用

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file:close();//关闭文件流

file = io.open("file.txt","w");

file:write("data data  data...");

file:close();

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file:read();//*n 数字 *a 全部 *l 按行 number

local filename = "data_test.txt";

local file = io.open(filename);

local contents = file:read("*a");

file:close();

print(""Contents: ",contens);

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file:seek(whence,offset);

//"set","cur","end"

文件设置或者得到当前文件字符指针位置

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file:setbuf(mode,size);

io.output():setbuf("no");//no 无buf full 全buf line 一行行

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file:write(); 写入

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保存变量

function writetofilesingle(value,filename)

　　local hfile = io.open("filename","w");

　　if hfile==nil then return end

　　hfile:write(value);

　　file:close();

end

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获得数据

function readfromfilesingle(filename)

　　local hfile = io.open("filename","r");

　　if hfile == nil then return end;

　　local value = hfile:read("*a")

　　hfile:close();

　　return value;

end

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文件流打开后，有固定的属性lines（）；可以遍历

local results = {}

local hfile = io.open(filename);

for line in hfile:lines() do

　　table.insert(results,line);

end

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全局变量

myvar =1

print (_G["myvar"]）;

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处理JSON

require（“json”）；

json.encode()

json.decode();