lavanyashastri's blog

http://developer.android.com/guide/tutorials/hello-world.html#avd

The instructions read:
To create an AVD, use the "android" tool provided in the Android SDK. Open a command prompt or terminal, navigate to the tools/ directory in the SDK package and execute:

That means you need to type
./android create avd --target 2 --name my_av

in the command line (on Linux) since android is an executable file.