tests/test-supersede-fopen.h

   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
  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         ASSERT (memcmp (&orig_dev, &statbuf.st_dev, sizeof (dev_t)) == 0);
  96         ASSERT (memcmp (&orig_ino, &statbuf.st_ino, sizeof (ino_t)) != 0);
  97 #endif
  98       }
  99   }
 100
 101   /* Test the case that the file exists and is a character device.  */
 102   {
 103     ASSERT (stat (DEV_NULL, &statbuf) == 0);
 104
 105     struct supersede_final_action action;
 106     FILE *fp =
 107       fopen_supersede (DEV_NULL, "wb",
 108                        supersede_if_exists, supersede_if_does_not_exist,
 109                        &action);
 110     ASSERT (fp != NULL);
 111     ASSERT (fwrite ("Foobar\n", 1, 7, fp) == 7 && fflush (fp) == 0);
 112     ASSERT (stat (DEV_NULL, &statbuf) == 0);
 113     ASSERT (fclose_supersede (fp, &action) == 0);
 114
 115     ASSERT (stat (DEV_NULL, &statbuf) == 0);
 116   }
 117
 118   /* Test the case that the file is a symbolic link to an existing regular
 119      file.  */
 120   {
 121     const char *linkname = "link1";
 122     unlink (linkname);
 123     if (symlink (filename, linkname) >= 0)
 124       {
 125         ASSERT (stat (linkname, &statbuf) == 0);
 126         dev_t orig_dev = statbuf.st_dev;
 127         ino_t orig_ino = statbuf.st_ino;
 128
 129         struct supersede_final_action action;
 130         FILE *fp =
 131           fopen_supersede (linkname, "wb",
 132                            supersede_if_exists, supersede_if_does_not_exist,
 133                            &action);
 134         ASSERT (fp != NULL);
 135         ASSERT (fwrite ("New\n", 1, 4, fp) == 4 && fflush (fp) == 0);
 136         ASSERT (stat (linkname, &statbuf) == 0);
 137         {
 138           size_t file_size;
 139           char *file_contents = read_file (linkname, RF_BINARY, &file_size);
 140           if (supersede_if_exists)
 141             {
 142               ASSERT (file_size == 7);
 143               ASSERT (memcmp (file_contents, "Foobar\n", 7) == 0);
 144             }
 145           else
 146             {
 147               ASSERT (file_size == 4);
 148               ASSERT (memcmp (file_contents, "New\n", 4) == 0);
 149             }
 150         }
 151         ASSERT (fclose_supersede (fp, &action) == 0);
 152
 153         ASSERT (stat (linkname, &statbuf) == 0);
 154
 155         size_t file_size;
 156         char *file_contents = read_file (linkname, RF_BINARY, &file_size);
 157         ASSERT (file_size == 4);
 158         ASSERT (memcmp (file_contents, "New\n", 4) == 0);
 159
 160         if (supersede_if_exists)
 161           {
 162             /* Verify that the file now has a different inode number, on the
 163                same device.  */
 164 #if !(defined _WIN32 && !defined __CYGWIN__)
 165             ASSERT (memcmp (&orig_dev, &statbuf.st_dev, sizeof (dev_t)) == 0);
 166             ASSERT (memcmp (&orig_ino, &statbuf.st_ino, sizeof (ino_t)) != 0);
 167 #endif
 168           }
 169
 170         /* Clean up.  */
 171         unlink (linkname);
 172       }
 173   }
 174
 175   /* Test the case that the file is a symbolic link to an existing character
 176      device.  */
 177   {
 178     const char *linkname = "link2";
 179     unlink (linkname);
 180     if (symlink (DEV_NULL, linkname) >= 0)
 181       {
 182         ASSERT (stat (linkname, &statbuf) == 0);
 183
 184         struct supersede_final_action action;
 185         FILE *fp =
 186           fopen_supersede (linkname, "wb",
 187                            supersede_if_exists, supersede_if_does_not_exist,
 188                            &action);
 189         ASSERT (fp != NULL);
 190         ASSERT (fwrite ("New\n", 1, 4, fp) == 4 && fflush (fp) == 0);
 191         ASSERT (stat (linkname, &statbuf) == 0);
 192         ASSERT (fclose_supersede (fp, &action) == 0);
 193
 194         ASSERT (stat (linkname, &statbuf) == 0);
 195
 196         /* Clean up.  */
 197         unlink (linkname);
 198       }
 199   }
 200
 201   /* Clean up.  */
 202   unlink (filename);
 203
 204   /* Test the case that the file is a symbolic link to a nonexistent file in an
 205      existing directory.  */
 206   {
 207     const char *linkname = "link3";
 208     unlink (linkname);
 209     if (symlink (filename, linkname) >= 0)
 210       {
 211         ASSERT (stat (linkname, &statbuf) < 0);
 212
 213         struct supersede_final_action action;
 214         FILE *fp =
 215           fopen_supersede (linkname, "wb",
 216                            supersede_if_exists, supersede_if_does_not_exist,
 217                            &action);
 218         ASSERT (fp != NULL);
 219         ASSERT (fwrite ("Hello world\n", 1, 12, fp) == 12 && fflush (fp) == 0);
 220         if (supersede_if_does_not_exist)
 221           ASSERT (stat (linkname, &statbuf) < 0);
 222         else
 223           ASSERT (stat (linkname, &statbuf) == 0);
 224         ASSERT (fclose_supersede (fp, &action) == 0);
 225
 226         ASSERT (stat (linkname, &statbuf) == 0);
 227
 228         size_t file_size;
 229         char *file_contents = read_file (linkname, RF_BINARY, &file_size);
 230         ASSERT (file_size == 12);
 231         ASSERT (memcmp (file_contents, "Hello world\n", 12) == 0);
 232
 233         /* Clean up.  */
 234         unlink (linkname);
 235       }
 236   }
 237
 238   /* Test the case that the file is a symbolic link to a nonexistent file in a
 239      nonexistent directory.  */
 240   {
 241     const char *linkname = "link4";
 242     unlink (linkname);
 243     if (symlink ("/nonexistent/gnulibtest8237/24715863701440", linkname) >= 0)
 244       {
 245         ASSERT (stat (linkname, &statbuf) < 0);
 246
 247         struct supersede_final_action action;
 248         FILE *fp =
 249           fopen_supersede (linkname, "wb",
 250                            supersede_if_exists, supersede_if_does_not_exist,
 251                            &action);
 252         ASSERT (fp == NULL);
 253         ASSERT (errno == ENOENT);
 254
 255         ASSERT (stat (linkname, &statbuf) < 0);
 256
 257         /* Clean up.  */
 258         unlink (linkname);
 259       }
 260   }
 261
 262   /* Clean up.  */
 263   unlink (filename);
 264   rmdir (dir);
 265 }