function copy(url){
var copyer = new Promise((reslove,reject)=>{
fs.readFile(url,(err,org)=>{
if (err) {
reject(err)
return
}
copyer={copyer,org}
reslove(copyer)
})
}).then((copyer)=>{
var org = copyer.org
baseImg = org.toString('base64')
var decodeImg = new Buffer(baseImg,'base64')
fs.writeFile('sucpend3.txt',baseImg,(err)=>{console.log('write succeed!')})
return decodeImg
}).then((decodeImg)=>{
fs.writeFile('final.gif',decodeImg,(err)=>{
console.log('copied!')
})
}).catch((err)=>{
console.log(err+'所读取的文件不存在！')
})
}
copy('baidu.gif')
