The only solution I\'ve encountered is to use regular expressions and recursively replace the first directory until you get a word with no slashes.
gsub(\"/\
Your example code doesn't work for me, but you're probably looking for either basename or dirname:
basename
dirname
> getwd() [1] "C:/cvswork/data" > basename(getwd()) [1] "data" > dirname(getwd()) [1] "C:/cvswork"