share/txr/stdlib/path-test.tl


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
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153

;; Copyright 2015-2016
;; Kaz Kylheku <kaz@kylheku.com>
;; Vancouver, Canada
;; All rights reserved.
;;
;; Redistribution of this software in source and binary forms, with or without
;; modification, is permitted provided that the following two conditions are met.
;;
;; Use of this software in any manner constitutes agreement with the disclaimer
;; which follows the two conditions.
;;
;; 1. Redistributions of source code must retain the above copyright
;;    notice, this list of conditions and the following disclaimer.
;; 2. Redistributions in binary form must reproduce the above copyright
;;    notice, this list of conditions and the following disclaimer in
;;    the documentation and/or other materials provided with the
;;    distribution.
;;
;; THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
;; WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
;; MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  IN NO EVENT SHALL THE
;; COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DAMAGES, HOWEVER CAUSED,
;; AND UNDER ANY THEORY OF LIABILITY, ARISING IN ANY WAY OUT OF THE USE OF THIS
;; SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

(defun sys:do-path-test (statfun path testfun)
  [testfun (if (stringp path) (ignerr [statfun path]) path)])

(defmacro sys:path-test ((var statfun path) . body)
  ^[sys:do-path-test ,statfun ,path
     (lambda (,var) (when ,var ,*body))])

(defun sys:path-test-mode (statfun path mask)
  (sys:path-test (s statfun path)
    (plusp (logand s.mode mask))))

(defun path-exists-p (path)
  (sys:path-test (s stat path) t))

(defun path-file-p (path)
  [sys:path-test-mode stat path s-ifreg])

(defun path-dir-p (path)
  [sys:path-test-mode stat path s-ifdir])

(defun path-symlink-p (path)
  [sys:path-test-mode lstat path s-iflnk])

(defun path-blkdev-p (path)
  [sys:path-test-mode stat path s-ifblk])

(defun path-chrdev-p (path)
  [sys:path-test-mode stat path s-ifchr])

(defun path-sock-p (path)
  [sys:path-test-mode stat path s-ifsock])

(defun path-pipe-p (path)
  [sys:path-test-mode stat path s-ififo])

(defun path-setgid-p (path)
  [sys:path-test-mode stat path s-isgid])

(defun path-setuid-p (path)
  [sys:path-test-mode stat path s-isuid])

(defun path-sticky-p (path)
  [sys:path-test-mode stat path s-isvtx])

(defun path-mine-p (path)
  (sys:path-test (s stat path)
    (= s.uid (geteuid))))

(defun path-my-group-p (path)
  (sys:path-test (s stat path)
    (let ((g s.gid))
      (or (= g (getegid))
          (find g (getgroups))))))

;; umask, gmask and omask must test identical permissions
;; multiple permissions may be tested, but not a combination
;; of x with any other permission.
(defun sys:path-access (path umask gmask omask)
  (sys:path-test (s stat path)
    (let ((m s.mode)
          (euid (geteuid)))
      (cond
        ((zerop euid) (or (zerop (logand umask s-ixusr))
                          (plusp (logand m (logior umask gmask omask)))))
        ((= euid s.uid) (= umask (logand m umask)))
        ((let ((g s.gid))
           (or (= g (getegid))
               (find g (getgroups))))
         (= gmask (logand m gmask)))
        (t (= omask (logand m omask)))))))

(defun path-executable-to-me-p (path)
  (sys:path-access path s-ixusr s-ixgrp s-ixoth))

(defun path-writable-to-me-p (path)
  (sys:path-access path s-iwusr s-iwgrp s-iwoth))

(defun path-readable-to-me-p (path)
  (sys:path-access path s-irusr s-irgrp s-iroth))

(defun path-read-writable-to-me-p (path)
  (sys:path-access path
                   (logior s-irusr s-iwusr)
                   (logior s-irgrp s-iwgrp)
                   (logior s-iroth s-iwoth)))

(defun path-private-to-me-p (path)
  (sys:path-test (s stat path)
    (let ((m s.mode)
          (euid (geteuid)))
      (mlet ((g (getgrgid s.gid)))
        (and (eql euid s.uid)
             (zerop (logand m s-iwoth))
             (or (zerop (logand m s-iwgrp))
                 (null g.mem)
                 (and (not (rest g.mem))
                      (equal (getpwuid euid).name (first g.mem)))))))))

(defun path-strictly-private-to-me-p (path)
  (sys:path-test (s stat path)
    (let ((m s.mode)
          (euid (geteuid)))
      (mlet ((g (getgrgid s.gid)))
        (and (eql euid s.uid)
             (zerop (logand m (logior s-iroth s-iwoth)))
             (or (zerop (logand m (logior s-iroth s-iwgrp)))
                 (null g.mem)
                 (and (not (rest g.mem))
                      (equal (getpwuid euid).name (first g.mem)))))))))

(defmacro sys:path-examine ((var statfun path) . body)
  ^[sys:do-path-test ,statfun ,path
     (lambda (,var) ,*body)])

(defun path-newer (path-0 path-1)
  (sys:path-examine (s0 stat path-0)
    (sys:path-examine (s1 stat path-1)
      (and s0 (or (not s1) (> s0.mtime s1.mtime))))))

(defun path-older (path-0 path-1)
  (path-newer path-1 path-0))

(defun path-same-object (path-0 path-1)
  (sys:path-examine (s0 stat path-0)
    (sys:path-examine (s1 stat path-1)
      (and s0 s1
           (eql s0.dev s1.dev)
           (eql s0.ino s1.ino)))))