carrierwave

https://github.com/carrierwaveuploader/carrierwave

Ruby

Classier solution for file uploads for Rails, Sinatra and other Ruby web frameworks

Mail::Message#[]

Allows you to read an arbitrary header

Example:

 mail['foo'] = '1234'
 mail['foo'].to_s #=> '1234'

Source | Google | Stack overflow

Edit

git clone [email protected]:carrierwaveuploader/carrierwave.git
cd carrierwave
open

Contribute

# Make a new branch
git checkout -b -your-name--update-docs-Mail--Message----for-pr

# Commit to git
git add git commit -m "better docs for Mail::Message#[]"

# Open pull request
gem install hub # on a mac you can `brew install hub`
hub fork
git push <your name> -your-name--update-docs-Mail--Message----for-pr
hub pull-request

# Celebrate!