Question about fish shell initialization settings...

[Carlo Tambuatco]

I installed the fish shell from mp a few days ago, and I’ve been loving it so far, but 
I’ve been wondering about where certain environment variables get set on startup…

On starting the shell, (within zsh at the moment, because fish isn’t yet my default 
shell, since I am only just now learning it), it already seems to know all of the 
environment variables eg: $PATH, $CPATH, $CLASSPATH, etc, that I set 
from within the zsh initialization files. Is it reading my zsh initialization files to 
get that information, or or getting that information from some other source? 

When I finally switch to fish as a default shell do I need to write those 
environment variables into a fish config file for fish to find it, or will it somehow 
find it on its own? I’ve read the fish documentation, and it isn’t totally clear 
on this point.