SFTP file streams

sftp-stream.scm

#!/usr/bin/guile \
-e main -s
!#

;; Copyright (C) 2016 Artyom V. Poptsov <poptsov.artyom@gmail.com>
;;
;; This program is free software: you can redistribute it and/or
;; modify it under the terms of the GNU General Public License as
;; published by the Free Software Foundation, either version 3 of the
;; License, or (at your option) any later version.
;;
;; This program is distributed in the hope that it will be useful, but
;; WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
;; General Public License for more details.
;;
;; You should have received a copy of the GNU General Public License
;; along with this program.  If not, see <http://www.gnu.org/licenses/>.

(use-modules (srfi srfi-41)             ; streams
             (ssh session)
             (ssh sftp)
             (ssh auth))

(define (sftp-file->stream sftp-file)
  (stream-let loop ((c (read-char sftp-file)))
              (if (eof-object? c)
                  (begin
                    (close-input-port sftp-file)
                    stream-null)
                  (stream-cons c (loop (read-char sftp-file))))))

(define (main args)
  (let ((s (make-session #:host "localhost")))

    (connect! s)
    (userauth-agent! s)

    (let* ((sftp-session (make-sftp-session s))
           (remote-file  (sftp-open sftp-session "/etc/hosts" O_RDONLY))
           (rstream      (sftp-file->stream remote-file)))
      (stream-for-each display (stream-map char-upcase rstream)))))