const hash256Sync = createFileHash256Sync(filePath)
                const hash256Syncafter = createFileHash256Sync(filePath2)
                if (hash256Sync == hash256Syncafter) {
                    fs.unlink(filePath2,(err,data)=>{
                        if (err) {
                            console.log(err);
                        } else{
                            console.log('删除文件成功');
                        }
                    })
                }      

export function createFileHash256(file) {
    //从文件创建一个可读流
    return new Promise((resolve, reject) => {
        const stream = fs.createReadStream(file);
        const fsHash = crypto.createHash('sha256');

        stream.on('data', function (d) {
            fsHash.update(d);
        });

        stream.on('end', function () {
            const md5 = fsHash.digest('hex');
            resolve(md5);
        });
    })
}

export function createFileHash256Sync(file) {
    const crypto = require('crypto');
    const fs = require('fs');
    //读取一个Buffer
    const buffer = fs.readFileSync(file);
    const fsHash = crypto.createHash('sha256');
    fsHash.update(buffer);
    const md5 = fsHash.digest('hex');
    return md5
}