Courtesy of StackExchange, here are some methods of obtaining a list of shell variables.
Print exported environment variables:
printenvor
env
To show a list of environment variables plus shell variables (unexported environment variables):
( set -o posix ; set ) | less
In KDE, to see environment variables exported/inherited to the graphic environment:
press Alt-F2 run: xterm -e bash --noprofile --norc run: env