set, env, source & "completely empty environment..." ?
LFS 6.0 chapter 4.4 Setting Up The Environment
After I create ~/.bash_profile and ~/.bashrc and then use the source command on ~/.bash_profile, according to the book, I should have a completely empty environment (except for the six variables created by the two ~/.bash* files). But by typing the env command, I see two extra variables (SHLVL=1 and PWD=/home/lfs). Additionally, and more troubling is when I then type in the set command, I see a ton of environment variables like COLUMNS=128 HISTSIZE=500 and stuff like that. The book clearly states that I should have a "completely empty environment", except of course for the six variables created by the new ~/.bash* files. What gives? Should I only be concerned with what the env command displays? Should I not be concerned about what the set command displays? And finally, is it possible or not to actually have a running Linux system where there are no environment variables set? Thanks a million! I've googled and searched LFS web site & couldn't find anything pertinant.
PS- I'm using Slackware 10.1 with kernel 2.6.9 as host.