How create a conditional function based on the current folder that I am accessing in vim?

Question

I am working on linux kernel code sometimes, and I almost every time I forget to set :set noexptab on vim when I am editing the kernel source code.

My default vimrc expands tabs into spaces, but I would like to have a function that could distinguish if I am currently editing kernel source code or not, and set the expandtab accordingly.

Basically, the kernel sources are in the linux-x.x.x directory, where is the root directory that I open the vim. I believe this is the start point.

Answer 1

There are a lot of Plugins and other methods to handle project specific settings. I would usually strongly support the plugin approach, since it does not cluster your vimrc. But in your case that would mean to copy the project setting file to every new kernel folder. So in this case I would use following autocommand:

autocmd BufNewFile,BufRead /path/to/folder/linux-*/* set noexpandtab