A big one is that unquoted variable expansion does not split on whitespace. This avoids all sorts of spaces-in-filenames bugs. For a similar reason, command su

A big one is that unquoted variable expansion does not split on whitespace. This avoids all sorts of spaces-in-filenames bugs. For a similar reason, command substitution only splits on newlines. Unfortunately, some commands like pkg-config assume that the shell splits on regular spaces so you will need to use workarounds like (pkg-config | string split "")