Batch File Rename Script

README.md

Batch File Rename

Use JavaScript for Automation to rename files in batch!

Motivation

While working on some client-side code at Oozou, I often have to rename a lot of image files. For example, Bourbon uses _2x.png for retina images, rather than @2x.png used by Retina.js.

I used to do this manually, until I am fed up and write this script.

Screenshot

rename.js

var app = Application.currentApplication()
app.includeStandardAdditions = true

var Finder = Application('Finder')
var selection = [].slice.call(Finder.selection())
var code = prompt('How to modify the name?', 'return name')
var fn = new Function('name', code)

try {

  var tasks = selection.map(function(item) {
    var name = item.name()
    try {
      var target = fn(name)
    } catch (e) {
      throw new Error('Cannot rename "' + name + '": ' + e)
    }
    if (!target) {
      throw new Error('Cannot rename "' + name + '": expression returned empty result')
    }
    return { item: item, from: name, to: target }
  }).filter(function(task) { return task.from != task.to })
  
  if (tasks.length == 0) throw new Error('No files to rename!')
  
  var message = 'These files will be renamed:\n\n' +
        tasks.map(function(task) { return '- ' + task.from + ' => ' + task.to }).join('\n')

  if (confirm(message)) {
    tasks.forEach(executeTask)
  }
  
} catch (e) {
  alert('Error!', String(e))
}

// Recipes from: https://github.com/dtinth/JXA-Cookbook/wiki/User-Interactions

function prompt(text, defaultAnswer) {
  var options = { defaultAnswer: defaultAnswer || '' }
  try {
    return app.displayDialog(text, options).textReturned
  } catch (e) {
    return null
  }
}

function alert(text, informationalText) {
  var options = { }
  if (informationalText) options.message = informationalText
  app.displayAlert(text, options)
}

function confirm(text) {
  try {
    app.displayDialog(text)
    return true
  } catch (e) {
    return false
  }
}

function executeTask(task) {
  task.item.name = task.to
}