fzf is a powerful tool to interactively select a line among data piped to stdin, a simple example is to pick a line in your shell history and it's my main fzf use.
fzf ships with bindings for bash, zsh or fish but doesn't provide anything for ksh, OpenBSD default shell. I found a way to run it with Ctrl+R but it comes with a limitation!
This setup will run fzf for looking a history line with Ctrl+R and will run it without allowing you to edit the line! /!\
In your interactive shell configuration file (should be the one set in $ENV), add the following function and binding, it will rebind Ctrl+R to fzf-histo function that will look into your shell history.
function fzf-histo {
RES=$(fzf --tac --no-sort -e < $HISTFILE)
test -n "$RES" || exit 0
eval "$RES"
}
bind -m ^R=fzf-histo^J
Reload your file or start a new shell, Ctrl+R should now run fzf for a more powerful history search. Don't forget to install fzf package.