I am new in developing native app using Salesforce SDK. I tried to create android project from command line using forcedroid tool but there is problem in setting environment
The above answer is correct. Works really well. There is also quick way to do this.
Type - echo export "ANDROID_HOME=/Users/yourName/Library/Android/sdk" >> ~/.bash_profile
Thats's it.
Close your terminal.
Open it again.
Type - echo $ANDROID_HOME to check if the home is set.