code: func (s *Action) CompletionBash(c *cli.Context) error {
  	out := `_gopass_bash_autocomplete() {
       local cur opts base
       COMPREPLY=()
       cur="${COMP_WORDS[COMP_CWORD]}"
       opts=$( ${COMP_WORDS[@]:0:$COMP_CWORD} --generate-bash-completion )
       local IFS=$'\n'
       COMPREPLY=( $(compgen -W "${opts}" -- ${cur}) )
       return 0
   }
  
  `
  	out += "complete -F _gopass_bash_autocomplete " + s.Name
  	if runtime.GOOS == "windows" {
  		out += "\ncomplete -F _gopass_bash_autocomplete " + s.Name + ".exe"
  	}
  	fmt.Fprintln(stdout, out)
  
  	return nil
  }
docs: // CompletionBash returns a bash script used for auto completion