node.js同步合并.ts文件

writeFile('hls-360p','.ts');
function writeFile(file,ext){
var count = 0;
var fs = require('fs');
fs.writeFile(file+ext, '', function(err){
if(err)console.log("writeFile " + err);
else{
readFile(file,count,ext);
}
});
}
function readFile(file,count,ext){
var fs = require('fs');
fs.readFile(file+count+ext, function(err,data){
if(err)console.log("readFile " + err + " " + count);
else{
appendFile(file+ext,data);
count++;
if(count>43)return;
readFile(file,count,ext);
}
});
}
function appendFile(file,str){
var fs = require('fs');
fs.appendFile(file, str, function(err){
if(err)console.log("appendFile " + err);
});
}