How to add cscopes multiple times in vim

I want to add the cscope files only if the type of the editing file is of *.cpp. I have done like this.

au FileType cpp cs add mycscope.out.

The 开发者_开发百科problem is if i open some other cpp file it tries to add again, how to avoid it.

You could simply ignore the error:

au FileType cpp silent! cs add mycscope.out