1 /* Tests for opening a file without destroying an old file with the same name.
2
3 Copyright (C) 2020-2023 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
21 test_fopen_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 FILE *fp =
34 fopen_supersede (filename, "wb",
35 supersede_if_exists, supersede_if_does_not_exist,
36 &action);
37 ASSERT (fp != NULL);
38 ASSERT (fwrite ("Hello world\n", 1, 12, fp) == 12 && fflush (fp) == 0);
39 if (supersede_if_does_not_exist)
40 ASSERT (stat (filename, &statbuf) < 0);
41 else
42 ASSERT (stat (filename, &statbuf) == 0);
43 ASSERT (fclose_supersede (fp, &action) == 0);
44
45 ASSERT (stat (filename, &statbuf) == 0);
46
47 size_t file_size;
48 char *file_contents = read_file (filename, RF_BINARY, &file_size);
49 ASSERT (file_size == 12);
50 ASSERT (memcmp (file_contents, "Hello world\n", 12) == 0);
51 }
52
53 /* Test the case that the file exists and is a regular file. */
54 {
55 ASSERT (stat (filename, &statbuf) == 0);
56 dev_t orig_dev = statbuf.st_dev;
57 ino_t orig_ino = statbuf.st_ino;
58
59 struct supersede_final_action action;
60 FILE *fp =
61 fopen_supersede (filename, "wb",
62 supersede_if_exists, supersede_if_does_not_exist,
63 &action);
64 ASSERT (fp != NULL);
65 ASSERT (fwrite ("Foobar\n", 1, 7, fp) == 7 && fflush (fp) == 0);
66 ASSERT (stat (filename, &statbuf) == 0);
67 {
68 size_t file_size;
69 char *file_contents = read_file (filename, RF_BINARY, &file_size);
70 if (supersede_if_exists)
71 {
72 ASSERT (file_size == 12);
73 ASSERT (memcmp (file_contents, "Hello world\n", 12) == 0);
74 }
75 else
76 {
77 ASSERT (file_size == 7);
78 ASSERT (memcmp (file_contents, "Foobar\n", 7) == 0);
79 }
80 }
81 ASSERT (fclose_supersede (fp, &action) == 0);
82
83 ASSERT (stat (filename, &statbuf) == 0);
84
85 size_t file_size;
86 char *file_contents = read_file (filename, RF_BINARY, &file_size);
87 ASSERT (file_size == 7);
88 ASSERT (memcmp (file_contents, "Foobar\n", 7) == 0);
89
90 if (supersede_if_exists)
91 {
92 /* Verify that the file now has a different inode number, on the same
93 device. */
94 #if !(defined _WIN32 && !defined __CYGWIN__)
95 /* Note: On Linux/mips, statbuf.st_dev is smaller than a dev_t! */
96 dev_t new_dev = statbuf.st_dev;
97 ASSERT (memcmp (&orig_dev, &new_dev, sizeof (dev_t)) == 0);
98 ASSERT (memcmp (&orig_ino, &statbuf.st_ino, sizeof (ino_t)) != 0);
99 #endif
100 }
101 }
102
103 /* Test the case that the file exists and is a character device. */
104 {
105 ASSERT (stat (DEV_NULL, &statbuf) == 0);
106
107 struct supersede_final_action action;
108 FILE *fp =
109 fopen_supersede (DEV_NULL, "wb",
110 supersede_if_exists, supersede_if_does_not_exist,
111 &action);
112 ASSERT (fp != NULL);
113 ASSERT (fwrite ("Foobar\n", 1, 7, fp) == 7 && fflush (fp) == 0);
114 ASSERT (stat (DEV_NULL, &statbuf) == 0);
115 ASSERT (fclose_supersede (fp, &action) == 0);
116
117 ASSERT (stat (DEV_NULL, &statbuf) == 0);
118 }
119
120 /* Test the case that the file is a symbolic link to an existing regular
121 file. */
122 {
123 const char *linkname = "link1";
124 unlink (linkname);
125 if (symlink (filename, linkname) >= 0)
126 {
127 ASSERT (stat (linkname, &statbuf) == 0);
128 dev_t orig_dev = statbuf.st_dev;
129 ino_t orig_ino = statbuf.st_ino;
130
131 struct supersede_final_action action;
132 FILE *fp =
133 fopen_supersede (linkname, "wb",
134 supersede_if_exists, supersede_if_does_not_exist,
135 &action);
136 ASSERT (fp != NULL);
137 ASSERT (fwrite ("New\n", 1, 4, fp) == 4 && fflush (fp) == 0);
138 ASSERT (stat (linkname, &statbuf) == 0);
139 {
140 size_t file_size;
141 char *file_contents = read_file (linkname, RF_BINARY, &file_size);
142 if (supersede_if_exists)
143 {
144 ASSERT (file_size == 7);
145 ASSERT (memcmp (file_contents, "Foobar\n", 7) == 0);
146 }
147 else
148 {
149 ASSERT (file_size == 4);
150 ASSERT (memcmp (file_contents, "New\n", 4) == 0);
151 }
152 }
153 ASSERT (fclose_supersede (fp, &action) == 0);
154
155 ASSERT (stat (linkname, &statbuf) == 0);
156
157 size_t file_size;
158 char *file_contents = read_file (linkname, RF_BINARY, &file_size);
159 ASSERT (file_size == 4);
160 ASSERT (memcmp (file_contents, "New\n", 4) == 0);
161
162 if (supersede_if_exists)
163 {
164 /* Verify that the file now has a different inode number, on the
165 same device. */
166 #if !(defined _WIN32 && !defined __CYGWIN__)
167 /* Note: On Linux/mips, statbuf.st_dev is smaller than a dev_t! */
168 dev_t new_dev = statbuf.st_dev;
169 ASSERT (memcmp (&orig_dev, &new_dev, sizeof (dev_t)) == 0);
170 ASSERT (memcmp (&orig_ino, &statbuf.st_ino, sizeof (ino_t)) != 0);
171 #endif
172 }
173
174 /* Clean up. */
175 unlink (linkname);
176 }
177 }
178
179 /* Test the case that the file is a symbolic link to an existing character
180 device. */
181 {
182 const char *linkname = "link2";
183 unlink (linkname);
184 if (symlink (DEV_NULL, linkname) >= 0)
185 {
186 ASSERT (stat (linkname, &statbuf) == 0);
187
188 struct supersede_final_action action;
189 FILE *fp =
190 fopen_supersede (linkname, "wb",
191 supersede_if_exists, supersede_if_does_not_exist,
192 &action);
193 ASSERT (fp != NULL);
194 ASSERT (fwrite ("New\n", 1, 4, fp) == 4 && fflush (fp) == 0);
195 ASSERT (stat (linkname, &statbuf) == 0);
196 ASSERT (fclose_supersede (fp, &action) == 0);
197
198 ASSERT (stat (linkname, &statbuf) == 0);
199
200 /* Clean up. */
201 unlink (linkname);
202 }
203 }
204
205 /* Clean up. */
206 unlink (filename);
207
208 /* Test the case that the file is a symbolic link to a nonexistent file in an
209 existing directory. */
210 {
211 const char *linkname = "link3";
212 unlink (linkname);
213 if (symlink (filename, linkname) >= 0)
214 {
215 ASSERT (stat (linkname, &statbuf) < 0);
216
217 struct supersede_final_action action;
218 FILE *fp =
219 fopen_supersede (linkname, "wb",
220 supersede_if_exists, supersede_if_does_not_exist,
221 &action);
222 ASSERT (fp != NULL);
223 ASSERT (fwrite ("Hello world\n", 1, 12, fp) == 12 && fflush (fp) == 0);
224 if (supersede_if_does_not_exist)
225 ASSERT (stat (linkname, &statbuf) < 0);
226 else
227 ASSERT (stat (linkname, &statbuf) == 0);
228 ASSERT (fclose_supersede (fp, &action) == 0);
229
230 ASSERT (stat (linkname, &statbuf) == 0);
231
232 size_t file_size;
233 char *file_contents = read_file (linkname, RF_BINARY, &file_size);
234 ASSERT (file_size == 12);
235 ASSERT (memcmp (file_contents, "Hello world\n", 12) == 0);
236
237 /* Clean up. */
238 unlink (linkname);
239 }
240 }
241
242 /* Test the case that the file is a symbolic link to a nonexistent file in a
243 nonexistent directory. */
244 {
245 const char *linkname = "link4";
246 unlink (linkname);
247 if (symlink ("/nonexistent/gnulibtest8237/24715863701440", linkname) >= 0)
248 {
249 ASSERT (stat (linkname, &statbuf) < 0);
250
251 struct supersede_final_action action;
252 FILE *fp =
253 fopen_supersede (linkname, "wb",
254 supersede_if_exists, supersede_if_does_not_exist,
255 &action);
256 ASSERT (fp == NULL);
257 ASSERT (errno == ENOENT);
258
259 ASSERT (stat (linkname, &statbuf) < 0);
260
261 /* Clean up. */
262 unlink (linkname);
263 }
264 }
265
266 /* Clean up. */
267 unlink (filename);
268 rmdir (dir);
269 }