Install adb on mac os

1. Delete your old installation (optional) 
   

   rm -rf ~/.android-sdk-macosx/

2. Download adb 
3. Go folder download 
   cd Download
4. Unzip file
   

   unzip platform-tools-latest*.zip

5. Create and move adb
   

   mkdir ~/.android-sdk-macosx
   mv platform-tools/ ~/.android-sdk-macosx/platform-tools

6. Add platform your path
   

   echo 'export PATH=$PATH:~/.android-sdk-macosx/platform-tools/' >> ~/.bash_profile

7. Refresh your bash profile (restart terminal)
   

   source ~/.bash_profile

8. Start adb devices
   

   adb devices