[R] extract parts of a list before symbol

[Evan Cooch]

Suppose I have the following list:

test <- list(a=3,b=5,c=11)

I'm trying to figure out how to extract the characters to the left of 
the equal sign (i.e., I want to extract a list of the variable names, a, 
b and c.

I've tried the permutations I know of involving sub - things like 
sub("\\=.*", "", test), but no matter what I try, sub keeps returning 
(3, 5, 11). In other words, even though I'm trying to extract the 
'stuff' before the = sign, I seem to be successful only at grabbing the 
stuff after the equal sign.

Pointers to the obvious fix? Thanks...