$ pwd
/

$ ruby -e 'p File.expand_path(*ARGV)' a/.. b
\000\000 ....
....
... so on so on.. \000
...
\000\000

$ ruby -e 'p File.expand_path(*ARGV).size' a/.. b
3680

$ ruby -v
ruby 1.8.0 (2003-04-11) [i386-freebsd4]