nodejs-stdin-byline

/**
 * Read input, line-by-line until get enough lines
 */
var input     = [];
var wantlines = 2;

process.stdin.setEncoding('utf8');
var readline = require('readline');
var rl       = readline.createInterface({ input: process.stdin });

rl.on('line', function (cmd) {
    if (input.length <= wantlines-1 && String(cmd).length > 0) {
        input.push(cmd.trim());
        if (input.length == wantlines) {
            /**
             * got needed input, do something
             */
            result = 'do something with input';
            process.stdout.write(result);
            process.exit();
        }
    }
});