This is just a wrapper for ls, ls.str and lsf.str with the appropriate arguments (as I always forgot how to do the trick).
LsObj lists all objects, LsFct just the functions and LsData the data in an package (strictly speaking the lists).
References
Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.