[R] "Copy-pastable" output of 1000 plus variables

[Bruce Ratner PhD]

R-helpers:
I'm reading "Advanced R" (Wickham), which provides his way, quoted below, of keeping variables. This cherry-picking approach clearly is not practical with a large dataset. 

"If you know the columns you don’t want, use set operations to work out which colums to keep: df[setdiff(names(df), "z")]"

I'm looking for a way of producing an output of 1000 plus variables, such that I can get a clean listing of variables, not like from st(), that are easily copy-pastable for selecting the variables I want to keep. 

Any suggestion is appreciated.
Thanks. 
Bruce