In Node.js, you can spawn child processes to execute external commands or scripts. Sometimes, you may need to pass arguments to the child process along with the command. This can be done using the spawn method from the child_process module.

Let’s see how you can pass arguments to a child process in Node.js.

Using spawn method to pass arguments

The spawn method is used to launch a new process and it returns a ChildProcess object which allows communication with the spawned process.

Here’s an example of how you can pass arguments to a child process using the spawn method:

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

const command = 'echo';
const args = ['Hello', 'World'];

// spawn the child process with the command and arguments
const childProcess = spawn(command, args);

// listen for the stdout event to capture the output
childProcess.stdout.on('data', (data) => {
  console.log(`Output: ${data}`);
});

// listen for the exit event to know when the process has finished
childProcess.on('exit', (code) => {
  console.log(`Exited with code ${code}`);
});

In this example, we are using the echo command and passing two arguments, “Hello” and “World”. The child process then echoes the arguments to the console.

To pass arguments, you need to provide an array of strings as the args parameter when calling the spawn method. Each element in the array represents an argument.

Conclusion

Passing arguments to a child process in Node.js is as simple as providing an array of strings as the arguments when calling the spawn method. You can then access these arguments within the child process and perform any necessary operations.

Remember to handle the output and exit events of the child process to process the results and ensure the process completes successfully.

#nodejs #childprocess