file_rename.js

#!/usr/bin/env node

var args = process.argv
var dictFile = args[2] || 'image_names.csv'
var filesDir = args[3] || ''

var fs = require('fs')

var dictStr = fs.readFileSync(dictFile, {
  encoding: 'utf8'
})

var dict = dictStr.split('\n').slice(1).filter(function(row) {
  return row.length
}).map(function(row) {
  return row.split(',')
}).map(function(row) {
  return {
    old: row[0],
    new: row[1]
  }
})

console.log(dict);

function findAndRename(img) {
  fs.rename(filesDir + img.old, filesDir + img.new, function(err) {
    if (err) {
      console.error('Could not rename file "' + filesDir + img.old + '"; Cause: ', err)
      fail++
    } else {
      success++
    }
    if (success + fail == fileCount) {
      console.info('Successfully renamed ' + success + ' files;\n' + fail + ' failures;')
    }
  })
}

var fileCount = dict.length
var success = 0
var fail = 0

dict.forEach(findAndRename)