vim modeline magic
http://vim.wikia.com/wiki/Modeline_magic
For example in python executables that does not ends with .py. I know, do never ever do this. Rollout packages using entry_point console_script. But however.
# vim: set filetype=python tabstop=4 softtabstop=4 shiftwidth=4 textwidth=120 smarttab expandtab:
Do not forget to use "set modeline" in your ~/.vimrc.
But only if you are aware of https://bugs.gentoo.org/show_bug.cgi?id=14088 and https://bugs.gentoo.org/show_bug.cgi?id=73715