old_contents: const process = require("child_process");
  
  // console.log(process);
  
  // process.exec("ls", (a, b) => {
  //     console.log(a);
  //     console.log(b);
  // })
  
  const exec = command => {
    return new Promise((resolve, reject) => {
      process.exec(command, (err, stdout, stderr) => {
        if(err) return reject(stderr);
        return resolve(stdout);
      });
    });
  }
  
  exec("ls")
  .then( result => console.log(result))
  .catch( err => console.error(err));
  
  exec("lsasdfad")
  .then( result => console.log(result))
  .catch( err => console.error(err));
new_contents: const childe_process = require("child_process");
  
  // console.log(process);
  
  // process.exec("ls", (a, b) => {
  //     console.log(a);
  //     console.log(b);
  // })
  
  const exec = command => {
    return new Promise((resolve, reject) => {
      childe_process.exec(command, (err, stdout, stderr) => {
        if(err) return reject(stderr);
        return resolve(stdout);
      });
    });
  }
  
  exec("ls")
  .then( result => console.log(result))
  .catch( err => console.error(err));
  
  exec("lsasdfad")
  .then( result => console.log(result))
  .catch( err => console.error(err));
subject: modify child_process