One of the most annoying thing of Mac is that encoding, espeically you’re living in a non-Mac world.

Mac uses UTF-8 as the default encoding for text files. But Windows uses local encoding, so it changes according to your OS language. For Chinese users, Windows uses GB2312 as the default encoding.

So usually the movie subtitle files, the song lyrics files, the plain text novel files, the code contains Chinese, which you downloaded form web sites or recieved from others usually cannot be read because of the wrong encoding.

So I really wish to have an item in my finder’s context menu that I can adjust the encoding of selected files with 1-click.

Luckily, with the help of Ruby, Automator workflow and Mac OSX service, it isn’t that hard.

So basically, OSX loads all the workflow files saved in ~/Library/Services/, which is displayed as Context Menu in finder.

To build the service, work through the following steps:

1. To create a new service, just pick Service in Automator’s ‘create new document’ dialog.

2. Set service input as “files and folders from any application”.

3. Run Ruby Script to transcode the files

Add a “Run Shell Script” action to execute the following ruby code, which is used to transcode the files passed to service. (For more detail about how to embed Ruby in workflow, check out Using RVMed Ruby in Mac Automator Workflow )

Make sure the input is passed as arugments to the ruby script.

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old_files = []
ARGV.each do |name|
  next until File.file? name
  backup_name = name + '.old'
  File.rename name, backup_name
  source = File.open backup_name, 'r:GB2312:UTF-8'
  dest = File.open name, 'w'
  while line = source.gets
      dest.puts line
  end
  puts name
  old_files << backup_name
end
ENV['Transcode_Backup_Files'] = old_files.join('|')

4. Display a growl message when processing is done

5. Prompt user whether to keep the backup files

I use a Ask for confirmation action to ask whether user want to keep the backup files.
The workflow will abort if user clicks “No”, make sure you updated the text on the buttons, and texts are put on right button.

6. Add script to remove backup files

Add another “Run Shell Script” aciton to execute another piece of ruby code.

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if ENV['Transcode_Backup_Files']
    ENV['Transcode_Backup_Files'].split('|').each do |file|
        File.delete file
    end
    ENV.delete 'Transcode_Backup_Files'
end

7. Display notification to tell user that backup files has been deleted

TIP: The transcode ruby script requires Ruby 1.9+, but Mac OS X default provides Ruby 1.8.3, which doesn’t support encoding. To interprets workflow embedded code with ruby 1.9+, please refers to Using RVMed Ruby in Mac Automator Workflow

HINT This content is obsoleted on OSX 10.9 Mavericks

Embed Ruby into Automator Workflow

Automator workflow has the ability to execute ruby code, but it is not that obvious if you doesn’t know it.

To embed ruby code into workflow, you need to create a “Run Shell Script” action first, then choose “/usr/bin/ruby” as the shell. Then the script in the text box will be parsed and executed as ruby code.

So, from now on, you know how to embed ruby into automator workflow.

Use RVM ruby instead of System Ruby

By default, Automator will load system ruby at /usr/bin/ruby, which is ruby v1.8.7 without bundler support. For most ruby developers, they must have installed some kind of ruby version manager, such as RVM or rbenv. As to me, I uses RVM. So I wish I could use RVMed versions of Ruby rather than the system ruby, could be ruby 1.9.3 or even ruby 2.0 with bundler support.

To use the RVMed ruby, I tried several approaches by hacking different configurations or files. And at last, I made it doing this:

RVM provides a ruby executable file at ~/.rvm/bin/ruby. On the other hand, /usr/bin/ruby is actually a symbol link that pointed to ‘/System/Library/Frameworks/Ruby.framework/Versions/Current/usr/bin/ruby’.

So what we need to do is to replace the the symbol link with a new one pointed to ~/.rvm/bin/ruby.

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sudo mv /usr/bin/ruby /usr/bin/system_ruby
sudo ln -s /Users/timnew/.rvm/bin/ruby /usr/bin/ruby

(You might need to replace the /Users/timnew/.rvm/bin/ruby with the path to your ruby executable file)

After doing this, done, you have the RVMed ruby in your Automator Workflow.

You can try to excute the following code in Workflow to verify it:

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puts RUBY_VERSION

If you do it correct, then you should see ‘1.9.3’ or any other version of ruby you have configured.

The Arduino IDE 1.5.3 introduced some new features, such as support latest board Yun, or introduces new libraries and samples. But I found it is too buggy to use.

1. Compile code against Arduino Nano fails due to parameter mcu passed to avrdude is missing.

Reason:
The issue seems caused because the new IDE merged the menu items for Nano board. But for some reason, the configuration haven’t been updated accordingly.

Workaround:
Choose Arduino Duemilanove and Diecimila instead of Arduino Nano. Nano uses same chip as Duemilanove(ATmega328) and Diecimila(ATmega168), but uses a different PCB design. So the binary should be compatible.

2. Compile String(100, DEC) throws ambiguous matching error

Reason:
The issue is caused because the API signature updated to String(*, unsigned char), but constants are still declared as int.

Workaround:
Add force cast DEC, HEX, BIN to byte instead of int.