javascript - 使用 createWriteStream 为通过 FTP 下载的 txt 文件分配变量

Question

我正在尝试通过 FTP 下载一个 .txt 文件，然后将此文件分配给一个变量，以便稍后在代码中编辑文本。

当从 Node.js 中的 createWriteStream 创建时，不确定如何设置可以在 FTP 代码块之外使用的变量。

我如何将这个 ,txt 传递到变量 ftpItem 中，然后在 FTP 函数之外访问它？

AWS Lambda 返回的错误是 ftpItem is not defined - 总之，我正在尝试通过 FTP 下载 TXT 文件。将它放在 AWS Lambda 函数的/tmp/目录中，然后稍后在代码中打开并编辑该文本。

var fullPath = event.line_items[0].meta_data[2].value.tmp_name; 
const extension = path.extname(fullPath); 
const FileName = path.basename(fullPath, extension); 
const FileNameWithExtension = path.basename(fullPath); 

...

async function example() {
    const client = new ftp.Client()
    client.ftp.verbose = true
    try {
        await client.access({
            host: process.env.FTP_HOST,
            user: process.env.FTP_USERNAME,
            password: process.env.FTP_PASSWORD,
        })
        console.log(await client.list())
        await client.download(fs.createWriteStream('/tmp/' + FileNameWithExtension), FileNameWithExtension)
        var ftpItem = FileNameWithExtension.Body.toString('ascii');
        console.log(ftpItem);
    }
    catch(err) {
        console.log(err)
    }
    client.close()
}

...

// Use the variable ftpItem outside of the FTP call
// Also tried the following with the same error above
await client.download(fs.createWriteStream('/tmp/' + FileNameWithExtension), FileNameWithExtension)
        {
          var ftpItem = download.Body.toString('ascii');
        }  

Answer 1

在更高的范围内使用变量:

var fullPath = event.line_items[0].meta_data[2].value.tmp_name; 
const extension = path.extname(fullPath); 
const FileName = path.basename(fullPath, extension); 
const FileNameWithExtension = path.basename(fullPath); 
let ftpItem
...

async function example() {
    const client = new ftp.Client()
    client.ftp.verbose = true
    try {
        await client.access({
            host: process.env.FTP_HOST,
            user: process.env.FTP_USERNAME,
            password: process.env.FTP_PASSWORD,
        })
        console.log(await client.list())
        await client.download(fs.createWriteStream('/tmp/' + FileNameWithExtension), FileNameWithExtension)
        // asign the variable here
        ftpItem = FileNameWithExtension.Body.toString('ascii');
        console.log(ftpItem);
    }
    catch(err) {
        console.log(err)
    }
    client.close()
}

...

// Use the variable ftpItem outside of the FTP call
// Also tried the following with the same error above
await client.download(fs.createWriteStream('/tmp/' + FileNameWithExtension), FileNameWithExtension)
        {
          // Here you can use ftpItem
          console.log(ftpItem)
        }