How can I determine storage directory from ADB? Is there a way I can use ADB to determine the external storage directory (equivalent of the Android API call Environment.getExternalStorageDirectory())?
adb shell echo $EXTERNAL_STORAGE.  All credit goes to Flow for leading me to experiment and find this.

Naturally you can use cd $EXTERNAL_STORAGE or whatever else you might need during an adb shell session or from a terminal emulator.