foreach (sort keys %files) { 
# the previous line iterates over the unique file names in the hash %files. Each name is stored  
# in the $_ special variable 
my @files_latest = glob("$_*"); 
# the previous line looks in the directory for files having each of the unique file names  
#and stores the result in the @files_latest array  
print "$files_latest[$#files_latest]\n";  
# this prints the last element of the @files_latest array, i.e. the most recent backup