Bash on Mac
Internal
bash Version on Mac
A specific bash executable is picked like any other executable, by scanning the PATH and using the first match. To force a specific bash version, ensure the directory it exists in comes first in PATH.
For example, a brew-installed bash (5.0.17) is picked from /usr/local/bin because /usr/local/bin precedes /bin in PATH.
The original Mac bash binary is available in /bin/bash, even if brew installs a newer version.
To force the native bash to be used, ensure /bin precedes /usr/local/bin in PATH.
bash Installation
brew install bash
Set up bash as Default Shell
System Preferences → Users & Groups → Unlock → Select Current User → Control + Right Click → Advanced Options → Login shell → /bin/bash (or /usr/local/bin/bash or /opt/homebrew/bin/bash if the latest Bash was installed with brew)
Ensure that ~/.bash_profile and ~/.bashrc exist.
Get Rid of Default Interactive Shell is Now zsh
In .bash_profile:
export BASH_SILENCE_DEPRECATION_WARNING=1