Setting Vim options depending on file name
===

[Pentadactyl] allows you to use an external text editor for `<textarea>` and `<input type="text">` elements on websites. I use GVim for this. This functionality is very useful but drives me to a question. I frequently want to wrap the text after editing, so my workflow is as follows:

  1. <kbd>CTRL+I</kbd> to launch GVim
  2. Use `:set tw=72`
  3. Perform my text manipulation
  4. Use `gq` to re-wrap areas that require it
  5. `:wq`

I would like to skip step #2 without affecting other editing in [G]Vim (i.e. I don't want to outright set `tw=72` in `.[g]vimrc` for all files). What is the best way to `:set tw=72` in this specific circumstance on Linux for example, where Pentadactyl always launches `$EDITOR` on `/tmp/pentadactyl.txt`?

[Pentadactyl]: <http://5digits.org/pentadactyl/>