To enable syntax highlighting for unique file names edit:
/home/USERNAME/.vimrc
au BufNewFile,BufRead FILE.NAME setf SYNTAX
Syntax files are in:
/usr/share/vim/vim74/syntax/
Find each occurrence of 'foo' (in all lines), and replace it with 'bar'.
:%s/foo/bar/gc
Change only whole words exactly matching 'foo' to 'bar'; ask for confirmation.
:%s/\<foo\>/bar/gc