Thanks for the response. I would like to use fzf with rg to search file contents with a previewer open. However when I first open fzf I don't wish to pass any argument to rg, until I start typing. Something like Telescope live_grep.

That's more a question for fzf than for ripgrep. ripgrep doesn't have any interactive mode. You give it arguments and it runs. That's it. ripgrep doesn't have any mode where it waits for user input (unless it's waiting for stdin).

Similar to other answers. With a nasty mix of vimscript generating shell commands for fzf to use, that's how I integrated rg and fd with "fzf.vim" in my neovim.

https://github.com/bombela/fzf.vim.rgfd

Nasty, but it works hey!

Certainly possible with fzf, everything you need is in the fzf docs. Here's something in vimscript (sorry) that does that: https://github.com/Emilv2/siefe.vim/blob/8432406581acbf450b5...