remove text after final period in string

Question

I have a grep puzzle that\'s eluding me: I\'d like to remove the text following the final period in a collection of strings (i am using R, so perl

Answer 1

And a non-regex answer for no reason whatsoever:

test <- c("abc.com.foo.bar","ABCD.txt")
sapply(strsplit(test,"\\."), function(x) paste0(head(x,-1),collapse=".") )
#[1] "abc.com.foo" "ABCD"