javascript - stdio 流 : WriteStream 的值不正确

Question

const barStream = fs.createWriteStream('bar');
const foo = spawn('foo', [], { stdio: ['ignore', barStream, 'inherit'] });

抛出一个错误:

Incorrect value for stdio stream: WriteStream

像 foo.stdout.pipe(barStream) 这样反向执行此操作在某些情况下可能会成功。

但是为什么 WriteStream 不能作为标准输出流提供呢？有没有办法让 barStream 适合 stdout？

Answer 1

来自documentation for the stdio option ，强调我的:

<Stream> object - Share a readable or writable stream that refers to a tty, file, socket, or a pipe with the child process. The stream's underlying file descriptor is duplicated in the child process to the fd that corresponds to the index in the stdio array. Note that the stream must have an underlying descriptor (file streams do not until the 'open' event has occurred).

所以:

const barStream = fs.createWriteStream('bar');

barStream.on('open', () => {
    const foo = spawn('foo', [], { stdio: ['ignore', barStream, 'inherit'] });
    ⋮
});

我承认错误消息肯定会更有帮助。