1 /* Tests for opening a file without destroying an old file with the same name.
2
3 Copyright (C) 2020 Free Software Foundation, Inc.
4
5 This program is free software: you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 3 of the License, or
8 (at your option) any later version.
9
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
14
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <https://www.gnu.org/licenses/>. */
17
18 /* Written by Bruno Haible, 2020. */
19
20 static void
test_open_supersede(bool supersede_if_exists,bool supersede_if_does_not_exist)21 test_open_supersede (bool supersede_if_exists, bool supersede_if_does_not_exist)
22 {
23 char xtemplate[] = "gnulibtestXXXXXX";
24 char *dir = mkdtemp (xtemplate);
25 char *filename = file_name_concat (dir, "test.mo", NULL);
26 struct stat statbuf;
27
28 /* Test the case that the file does not yet exist. */
29 {
30 ASSERT (stat (filename, &statbuf) < 0);
31
32 struct supersede_final_action action;
33 int fd = open_supersede (filename, O_RDWR | O_TRUNC, 0666,
34 supersede_if_exists, supersede_if_does_not_exist,
35 &action);
36 ASSERT (fd >= 0);
37 ASSERT (write (fd, "Hello world\n", 12) == 12);
38 if (supersede_if_does_not_exist)
39 ASSERT (stat (filename, &statbuf) < 0);
40 else
41 ASSERT (stat (filename, &statbuf) == 0);
42 ASSERT (close_supersede (fd, &action) == 0);
43
44 ASSERT (stat (filename, &statbuf) == 0);
45
46 size_t file_size;
47 char *file_contents = read_file (filename, RF_BINARY, &file_size);
48 ASSERT (file_size == 12);
49 ASSERT (memcmp (file_contents, "Hello world\n", 12) == 0);
50 }
51
52 /* Test the case that the file exists and is a regular file. */
53 {
54 ASSERT (stat (filename, &statbuf) == 0);
55 dev_t orig_dev = statbuf.st_dev;
56 ino_t orig_ino = statbuf.st_ino;
57
58 struct supersede_final_action action;
59 int fd = open_supersede (filename, O_RDWR | O_TRUNC, 0666,
60 supersede_if_exists, supersede_if_does_not_exist,
61 &action);
62 ASSERT (fd >= 0);
63 ASSERT (write (fd, "Foobar\n", 7) == 7);
64 ASSERT (stat (filename, &statbuf) == 0);
65 {
66 size_t file_size;
67 char *file_contents = read_file (filename, RF_BINARY, &file_size);
68 if (supersede_if_exists)
69 {
70 ASSERT (file_size == 12);
71 ASSERT (memcmp (file_contents, "Hello world\n", 12) == 0);
72 }
73 else
74 {
75 ASSERT (file_size == 7);
76 ASSERT (memcmp (file_contents, "Foobar\n", 7) == 0);
77 }
78 }
79 ASSERT (close_supersede (fd, &action) == 0);
80
81 ASSERT (stat (filename, &statbuf) == 0);
82
83 size_t file_size;
84 char *file_contents = read_file (filename, RF_BINARY, &file_size);
85 ASSERT (file_size == 7);
86 ASSERT (memcmp (file_contents, "Foobar\n", 7) == 0);
87
88 if (supersede_if_exists)
89 {
90 /* Verify that the file now has a different inode number, on the same
91 device. */
92 #if !(defined _WIN32 && !defined __CYGWIN__)
93 ASSERT (memcmp (&orig_dev, &statbuf.st_dev, sizeof (dev_t)) == 0);
94 ASSERT (memcmp (&orig_ino, &statbuf.st_ino, sizeof (ino_t)) != 0);
95 #endif
96 }
97 }
98
99 /* Test the case that the file exists and is a character device. */
100 {
101 ASSERT (stat (DEV_NULL, &statbuf) == 0);
102
103 struct supersede_final_action action;
104 int fd = open_supersede (DEV_NULL, O_RDWR | O_TRUNC, 0666,
105 supersede_if_exists, supersede_if_does_not_exist,
106 &action);
107 ASSERT (fd >= 0);
108 ASSERT (write (fd, "Foobar\n", 7) == 7);
109 ASSERT (stat (DEV_NULL, &statbuf) == 0);
110 ASSERT (close_supersede (fd, &action) == 0);
111
112 ASSERT (stat (DEV_NULL, &statbuf) == 0);
113 }
114
115 /* Test the case that the file is a symbolic link to an existing regular
116 file. */
117 {
118 const char *linkname = "link1";
119 unlink (linkname);
120 if (symlink (filename, linkname) >= 0)
121 {
122 ASSERT (stat (linkname, &statbuf) == 0);
123 dev_t orig_dev = statbuf.st_dev;
124 ino_t orig_ino = statbuf.st_ino;
125
126 struct supersede_final_action action;
127 int fd =
128 open_supersede (linkname, O_RDWR | O_TRUNC, 0666,
129 supersede_if_exists, supersede_if_does_not_exist,
130 &action);
131 ASSERT (fd >= 0);
132 ASSERT (write (fd, "New\n", 4) == 4);
133 ASSERT (stat (linkname, &statbuf) == 0);
134 {
135 size_t file_size;
136 char *file_contents = read_file (linkname, RF_BINARY, &file_size);
137 if (supersede_if_exists)
138 {
139 ASSERT (file_size == 7);
140 ASSERT (memcmp (file_contents, "Foobar\n", 7) == 0);
141 }
142 else
143 {
144 ASSERT (file_size == 4);
145 ASSERT (memcmp (file_contents, "New\n", 4) == 0);
146 }
147 }
148 ASSERT (close_supersede (fd, &action) == 0);
149
150 ASSERT (stat (linkname, &statbuf) == 0);
151
152 size_t file_size;
153 char *file_contents = read_file (linkname, RF_BINARY, &file_size);
154 ASSERT (file_size == 4);
155 ASSERT (memcmp (file_contents, "New\n", 4) == 0);
156
157 if (supersede_if_exists)
158 {
159 /* Verify that the file now has a different inode number, on the
160 same device. */
161 #if !(defined _WIN32 && !defined __CYGWIN__)
162 ASSERT (memcmp (&orig_dev, &statbuf.st_dev, sizeof (dev_t)) == 0);
163 ASSERT (memcmp (&orig_ino, &statbuf.st_ino, sizeof (ino_t)) != 0);
164 #endif
165 }
166
167 /* Clean up. */
168 unlink (linkname);
169 }
170 }
171
172 /* Test the case that the file is a symbolic link to an existing character
173 device. */
174 {
175 const char *linkname = "link2";
176 unlink (linkname);
177 if (symlink (DEV_NULL, linkname) >= 0)
178 {
179 ASSERT (stat (linkname, &statbuf) == 0);
180
181 struct supersede_final_action action;
182 int fd =
183 open_supersede (linkname, O_RDWR | O_TRUNC, 0666,
184 supersede_if_exists, supersede_if_does_not_exist,
185 &action);
186 ASSERT (fd >= 0);
187 ASSERT (write (fd, "New\n", 4) == 4);
188 ASSERT (stat (linkname, &statbuf) == 0);
189 ASSERT (close_supersede (fd, &action) == 0);
190
191 ASSERT (stat (linkname, &statbuf) == 0);
192
193 /* Clean up. */
194 unlink (linkname);
195 }
196 }
197
198 /* Clean up. */
199 unlink (filename);
200
201 /* Test the case that the file is a symbolic link to a nonexistent file in an
202 existing directory. */
203 {
204 const char *linkname = "link3";
205 unlink (linkname);
206 if (symlink (filename, linkname) >= 0)
207 {
208 ASSERT (stat (linkname, &statbuf) < 0);
209
210 struct supersede_final_action action;
211 int fd =
212 open_supersede (linkname, O_RDWR | O_TRUNC, 0666,
213 supersede_if_exists, supersede_if_does_not_exist,
214 &action);
215 ASSERT (fd >= 0);
216 ASSERT (write (fd, "Hello world\n", 12) == 12);
217 if (supersede_if_does_not_exist)
218 ASSERT (stat (linkname, &statbuf) < 0);
219 else
220 ASSERT (stat (linkname, &statbuf) == 0);
221 ASSERT (close_supersede (fd, &action) == 0);
222
223 ASSERT (stat (linkname, &statbuf) == 0);
224
225 size_t file_size;
226 char *file_contents = read_file (linkname, RF_BINARY, &file_size);
227 ASSERT (file_size == 12);
228 ASSERT (memcmp (file_contents, "Hello world\n", 12) == 0);
229
230 /* Clean up. */
231 unlink (linkname);
232 }
233 }
234
235 /* Test the case that the file is a symbolic link to a nonexistent file in a
236 nonexistent directory. */
237 {
238 const char *linkname = "link4";
239 unlink (linkname);
240 if (symlink ("/nonexistent/gnulibtest8237/24715863701440", linkname) >= 0)
241 {
242 ASSERT (stat (linkname, &statbuf) < 0);
243
244 struct supersede_final_action action;
245 int fd =
246 open_supersede (linkname, O_RDWR | O_TRUNC, 0666,
247 supersede_if_exists, supersede_if_does_not_exist,
248 &action);
249 ASSERT (fd < 0);
250 ASSERT (errno == ENOENT);
251
252 ASSERT (stat (linkname, &statbuf) < 0);
253
254 /* Clean up. */
255 unlink (linkname);
256 }
257 }
258
259 /* Clean up. */
260 unlink (filename);
261 rmdir (dir);
262 }
263