同期的にシェルコマンドを実行して出力を返す elisp 関数

gistfile1.el

(defun exec-shell-command-sync (command &rest args)
  (let (ret
         (process
          (apply 'start-process-shell-command "exec" nil command args)))
    (set-process-filter
     process
     '(lambda (process output)
        (setq ret (cons output ret))
        ))
    (while (not (equalp (process-status process) 'exit))
      (sleep-for 0 10))
    (car ret)))