How To Use Javascript Async/await On Executing Shell Script

So I have a server listening to RabbitMQ requests: console.log(' [*] Waiting for messages in %s. To exit press CTRL+C', q); channel.consume(q, async function reply

Solution 1:

Since exec looks like it takes a callback, you can use that to wrap it into a promise. Then you can await that promise instead of awaiting the exec call directly. So, for your example, something like:

// Await a new promise:awaitnewPromise((resolve, reject) => {
    exec('./new_user_run_athena.sh ' + mongodbUserId, function(
        error,
        stdout,
        stderr
    ) {
        console.log('Running Athena...');
        console.log('stdout: ' + stdout);
        console.log('stderr: ' + stderr);
        if (error !== null) {
            console.log('exec error: ' + error);
            // Reject if there is an error:returnreject(error);
        }

        // Otherwise resolve the promise:resolve();
    });
});

Solution 2:

See the MDN documentation for await:

The await operator is used to wait for a Promise. It can only be used inside an async function.

The exec function does not return a Promise, so you cannot await for it.

You could write a function which wraps exec in a Promise and returns that Promise though.

Solution 3:

Wrap exec in a promise. Here a typescript example:

import { exec as childProcessExec } from'child_process'const exec = async (command: string): Promise<string> => {
  returnnewPromise((resolve, reject) => {
    childProcessExec(command, (error, stdout, stderr) => {
      if (error !== null) reject(error)
      if (stderr !== '') reject(stderr)
      elseresolve(stdout)
    })
  })
}

Usage:

const commandOutput = awaitexec('echo Hey there!')
console.log(commandOutput)