nicot

(defvar helm-fzf-source
  (helm-build-async-source "fzf"
    :candidates-process 'helm-fzf--do-candidate-process
    :nohighlight t
    :requires-pattern 2
    :candidate-number-limit 9999))

(defun helm-fzf--do-candidate-process ()
  (let* ((cmd-args `("fzf" "-x" "-f" ,helm-pattern))
         (proc (apply #'start-file-process "helm-fzf" nil cmd-args)))