How to execute program that using threads in node.js?

Question

#!/usr/bin/node

const { spawn } = require("child_process");

const ls = spawn("./vanitygen", ["-p bc1qu"]);

ls.stdout.on("data", data => {
    console.log(`stdout: ${data}`);
});

ls.stderr.on("data", data => {
    console.log(`stderr: ${data}`);
});

ls.on('error', (error) => {
    console.log(`error: ${error.message}`);
});

ls.on("close", code => {
    console.log(`child process exited with code ${code}`);
});

When I am running it using spawn or exec it finishes immediately and I can't read program output.

child process exited with code 1

Is there any other method to run command and get what it output?

Then detect when its all threads are closed?

Answer 1

If you want to see the program output when it crashes you'll need to let the child process inherit the parent's stdio right from the start, e.g.

const ls = spawn("./vanitygen", ["-p bc1qu"], {
    stdio: 'inherit',
  });

Btw, not sure if you meant this too -- if you want your program to pause until the child process complete, use "execSync" instead of "spawn".