windows下exec中文处理 gbk

gbk.js

String.prototype.each=function(i,fun){
  var index=0;
  var that=this;
  while(index<=that.length){
    (fun||function(){})(that.substr(index,i))
      index+=i;
  }
}
var exec=require('child_process').exec;
var iconv=require('./iconv-lite');
exec('ipconfig /all',{encoding:'hex'},function(e,r){
   var arr=[];
   r.each(2,function(data){
       arr.push(parseInt(data,16));
   });
   console.log(iconv.decode(new Buffer(arr), 'GBK'))
})；