.vim/plugin/c.vim

c.vim

fu Select_c_style()
    set tabstop=8                   "A tab is 8 spaces
    set expandtab                   "Always uses spaces instead of tabs
    set softtabstop=8               "Insert 4 spaces when tab is pressed
    set shiftwidth=8                "An indent is 4 spaces
    set smarttab                    "Indent instead of tab at start of line
    set shiftround                  "Round spaces to nearest shiftwidth multiple
    set foldmethod=syntax
    " set nojoinspaces                "Don't convert spaces to tabs
endf

au BufRead,BufNewFile *.c call Select_c_style()
au BufRead,BufNewFile *.h call Select_c_style()