curl -L https://get.rvm.io | bash -s stable
source ~/.rvm/scripts/rvm
rvm -v
rvm list known
rvm install 2.4.0 --- ruby
rvm list
gem source -l
sudo gem install cocoapods
pod setup
lscd desktop
ls
cd firstapp
ls
pod 'ShareSDK3'
pod search ShareSDK3
pod search MOBFoundation
pod installopen -e Podfile
vim Podfile
pod install