const fs = require("fs");
const path = "./"; // current folder

fs.readdir(path, function(err, items) {
  console.log('Old filenames:');
  console.log(items);

  for (var i = 0; i < items.length; i++) {

    const file = items[i];

    // only apply to jpg's in the folder
    if (file.substr(-3) === 'jpg'){
      // adjust this line to
      let newFilename = file.substring(file.indexOf('_', file.indexOf('_') + 1) + 1);

      console.log(`Renaming ${file} to ${newFilename}`);

      fs.rename(file,newFilename, (err) => {
        if (err) throw err;
      });

      console.log(newFilename);
    }
  }
  console.log('Finished');

});