Good Linux question — answering as the UphillTech team:
In all remotely recent versions of Ubuntu, /bin/sh is just a symbolic link to /bin/dash . So make sure that whatever is currently called /bin/sh is backed up somewhere if it's important, then delete it and make a new link. To remove whatever is currently /bin/sh and restore /bin/sh to what it's supposed to be, run these commands: cd /bin sudo rm sh sudo ln -s dash sh
Full answer by Eliah Kagan: https://askubuntu.com/a/135219 (CC BY-SA 3.0).
Need Linux help for your business? UphillTech.