1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
|
; listhome.scm
; Sample usage of TinyScheme Extension
; This simple program lists the directory entries on the
; user's home directory.
; It uses the following TinyScheme Extension functions:
; getenv
; Used to get HOME environment variable.
; open-dir-stream
; Used to open directory stream.
; read-dir-entry
; Used to read directory entries.
; close-dir-entry
; Used at the end, to close directory stream when done.
; check that extensions are enabled
(if (not (defined? 'load-extension))
(begin
(display "TinyScheme has extensions disabled. Enable them!!")
(newline)
(quit)))
; load TinyScheme extension
(load-extension "tsx-1.1/tsx")
; check that the necessary functions are available (the user
; might have removed some functionality...)
(if (or
(not (defined? 'getenv))
(not (defined? 'dir-open-stream))
(not (defined? 'dir-read-entry))
(not (defined? 'dir-close-stream)))
(begin
(display "Some necessary functions are not available. Exiting!")
(newline)
(quit)))
; get user's home dir from HOME environment var
(define homedir (getenv "HOME"))
(display "Listing contents of ") (display homedir) (newline)
; create directory stream to read dir entries
(define dirstream (dir-open-stream homedir))
(if (not dirstream)
(begin
(display "Unable to open home directory!! Check value of HOME environment var.")
(quit)))
(let listentry ((entry (dir-read-entry dirstream)))
(if (eof-object? entry)
#t
(begin
(display entry)
(newline)
(listentry (dir-read-entry dirstream)))))
(dir-close-stream dirstream)
|
