How do I run adb on a mac terminal?

Question

adb shell run-as /data/data/com.mypackagename 

returns

adb command not found

though I see adb in the dir

Answer 1

If you are in that directory, you can run it with a leading dot-slash, i.e. ./adb shell run-as /data/data/com.mypackagename.

In general, you might want to add that directory to your PATH environment variable.