Node.js synchronous prompt

Question

I'm using the prompt library for Node.js and I have this code:

var fs = require('fs'),
    prompt = require('prompt'),
    toCreate = toCreate.toLowerCase(),
    stats = fs.lstatSync('./' + toCreate);

if(stats.isDirectory()){
    prompt.start();
    var property = {
        name: 'yesno',
        message: 'Directory esistente vuoi continuare lo stesso? (y/n)',
        validator: /y[es]*|n[o]?/,
        warning: 'Must respond yes or no',
        default: 'no'
    };
    prompt.get(property, function(err, result) {                
        if(result === 'no'){
            console.log('Annullato!');
            process.exit(0);
        }
    });
}
console.log("creating ", toCreate);
console.log('\nAll done, exiting'.green.inverse);

If the prompt is show it seems that it doesn't block code execution but the execution continues and the last two messages by the console are shown while I still have to answer the question.

Is there a way to make it blocking?

Answer 1

This is dependency free, synchronous and works on Windows, Linux and OSX:

// Synchronously prompt for input
function prompt(message)
{
    // Write message
    process.stdout.write(message);

    // Work out shell command to prompt for a string and echo it to stdout
    let cmd;
    let args;
    if (os.platform() == "win32")
    {
        cmd = 'cmd';
        args = [ '/V:ON', '/C', 'set /p response= && echo !response!' ];
    }
    else
    {
        cmd = 'bash';
        args = [ '-c', 'read response; echo "$response"' ];
    }

    // Pipe stdout back to self so we can read the echoed value
    let opts = { 
        stdio: [ 'inherit', 'pipe', 'inherit' ],
        shell: false,
    };

    // Run it
    return child_process.spawnSync(cmd, args, opts).stdout.toString().trim();
}