How to rehash executables in $PATH with bash

hash -r is what needs to be done. In zsh it is rehash and rehash doesn't exist (by default) in bash.

I use both shells and rehash has been reinforced in my hind-brain for decades, it comes out of my fingers without asking. To accommodate those reflexes I have added alias rehash='hash -r' to my .aliases_bash file, which I test for and source from .bashrc.

To summarize, in .bashrc I use the line:

[[ -f ~/.aliases_bash ]] && . ~/.aliases_bash 

and in /.aliases_bash I use the line

alias rehash='hash -r'