thanks for your solution, but I wanna use those functions in any place not only at start of line.

e.g.

rm grep {/.pl$/} ls ¹

If you wanna implement (start of line) aliases, you should simply us "!!"

  DB<112> =du !!du
 
  DB<113> du /tmp
8    /tmp/pulse-lanx
4    /tmp/virtual-lanx.AqXwcf
...
  DB<114>  $DB::alias{du} 
 => "s\adu\a!!du\a"
[download]

!! cmd      Run cmd in a subprocess (reads from DB::IN, writes to DB::
+OUT)
        See 'O shellBang' too.
[download]

¹) Yes I could use the file-glob <*> instead, but this is only an example for chaining commands