My `.vimrc` uses pathogen by doing

```
execute pathogen#infect()

```

However if I set up a new computer and haven't installed pathogen with

```
mkdir -p ~/.vim/autoload ~/.vim/bundle && \
curl -LSso ~/.vim/autoload/pathogen.vim https://tpo.pe/pathogen.vim

```

Then every time I go to edit a file I get a message about pathogen not working (and then I can edit the file).

I'd like my .vimrc call to `execute pathogen#infect` be dependent on `~/.vim/autoload` actually existing.

In shell scripting I would do something like

```
if test -f ~/.vim/autoload
  execute pathogen#infect()
fi

```

but of course that gives undefined method test. `.vimrc` uses a different syntax like having `"` instead of `#` for comments and for a conditional I don't know what the right format is.

What format I would use for a `.vimrc` file?