main.ss
#lang scheme/base
; This teachpack doesn't "provide" anything, but merely installs a stub file
; in the installed-teachpacks directory which invokes the real
; "picturing-programs".

 (require mzlib/etc)
 (require scheme/file)
  
  (define pp-module-spec '(planet sbloch/picturing-programs/picturing-programs))  
  (define destdir (build-path (find-system-path 'addon-dir)
                              (string->path (version))
                              (string->path "collects")
                              (string->path "installed-teachpacks")
                              ))
  
  (define (makefile filename module-spec)
    (let ((destfile (build-path destdir (string->path filename)))
          (require-stmt `(require ,module-spec))
          (provide-stmt `(provide (all-from-out ,module-spec))))
      (if (file-exists? destfile)
          (display "Teachpack file already exists.")
          (begin
            (unless (directory-exists? destdir)   
              (make-directory* destdir))
            (if (member 'write (file-or-directory-permissions destdir))
                (begin
                  (with-output-to-file destfile
                    (lambda ()
                      (begin (display "#lang scheme/base")
                             (newline)
                             (write require-stmt)
                             (newline)
                             (write provide-stmt)
			     (newline))))
                  (display (format "Wrote file ~s to installed-teachpacks directory~n" filename)))
                (display (format "Unable to write file ~s to installed-teachpacks directory~n" filename)))
            )
          )
      )
    )
  (makefile "picturing-programs.ss" pp-module-spec)