how to add answer to grepper
// how to find out which shell is running. ps -p $$ – Display your current shell name reliably echo "$SHELL" – Print the shell for the current user but not necessarily the shell that is running at the movement. echo $0 – Another reliable and simple method to get the current shell interpreter name on Linux or Unix-like systems. readlink /proc/$$/exe – Another option to get the current shell name reliably on Linux operating systems. cat /etc/shells – List pathnames of valid login shells currently installed grep "^$USER" /etc/passwd – Print the default shell name. The default shell runs when you open a terminal window. chsh -s /bin/ksh – Change the shell used from /bin/bash (default) to /bin/ksh for your account
