How can I generate a list of all the variables that have been assigned in an R language session?
For the sake of completeness of the answer, you can use
ls() to list all the assigned variables and data frames. This is similar to
whos in Matlab.
If you want to get the list data.frames only you can use something like this:
ls()[grepl('data.frame', sapply(ls(), function(x) class(get(x))))]
You should probably ask questions like this on R forums.