Node.js：如何使 spawn function 同步而不是使用 spawnSync？

Question

I'm currently using spawnSync and stdio:inherit to get the logs printed on my console. However I'm looking for custom logging to a separate file, in case if anything fails during the spawn.

I'm looking to create a wrapper around

spawn

so that it has following properties:

• Synchronous function where output is stored in a variable
• View output on the console
• Write stdout and stderr to a file

For instance:

const result = spawnSync('ls', [ '-l', '-a' ], { stdio: 'inherit'}); // will print as it's processing
console.log(result.stdout); // will print null

const result = spawnSync('ls', [ '-l', '-a' ], { encoding: 'utf-8' }); // won't print anything
console.log(result.stdout); // will print ls results only on completion

I need result such that it will print while it's processing and write to a file at the same time

Also I'm looking for some strategy or solution from node.js side apart from shell scripting

Answer 1

I guess we can't make all three possible because of the limitation of node.js

As per the documentation

If we are trying to use stdio:'inherit', we can either redirect output to parent stdout stream or file using

fs.openSync()

Because of the limitation, we can't use custom streams too.