> > (defun sort-file (filename)
> > (let ((lines
> > (with-open-file (s filename)
> > (loop for line = (read-line s nil nil)
> > while line collect line))))
> > (setq lines (sort lines #'string-<))
> > (mapc #'write-line lines)))
>
> It could also be done using the series functions:
>
> (defun sort-file (filename)
> (let ((lines (collect (scan-file filename #'read-line))))
> (mapc #'write-line (sort lines #'string-<))))
>
> The series functions aren't a part of CL, of course, but they
> can be found in the Lisp Repository.

Shorter (Racket):

(require threading)

(define (sort-file filename)
(~> filename
file->lines
(sort string<?)
(for-each displayln _)))