> Because if you are not 100% compatible with bourne shell you shouldn't automatically execute script made for bourne shell. The same can be said about bash.

> Because if you are not 100% compatible with bourne shell you shouldn't automatically execute script made for bourne shell. The same can be said about bash. > It is fine with bash because it is bourne shell compatible. I was running an HPC cluster when we upgraded Debian during the bash->dash change, and there were all sorts of problems: IIRC most folks simply changed their scripts from /bin/sh to /bin/bash.