1  /* Common f{truncate} tests definitions.
       2     Copyright (C) 2016-2023 Free Software Foundation, Inc.
       3     This file is part of the GNU C Library.
       4  
       5     The GNU C Library is free software; you can redistribute it and/or
       6     modify it under the terms of the GNU Lesser General Public
       7     License as published by the Free Software Foundation; either
       8     version 2.1 of the License, or (at your option) any later version.
       9  
      10     The GNU C Library 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 GNU
      13     Lesser General Public License for more details.
      14  
      15     You should have received a copy of the GNU Lesser General Public
      16     License along with the GNU C Library; if not, see
      17     <https://www.gnu.org/licenses/>.  */
      18  
      19  #include <unistd.h>
      20  #include <sys/types.h>
      21  #include <sys/stat.h>
      22  #include <unistd.h>
      23  
      24  static void do_prepare (void);
      25  #define PREPARE(argc, argv)     do_prepare ()
      26  static int do_test (void);
      27  #define TEST_FUNCTION           do_test ()
      28  
      29  #include <test-skeleton.c>
      30  
      31  static char *temp_filename;
      32  static int temp_fd;
      33  
      34  static void
      35  do_prepare (void)
      36  {
      37    temp_fd = create_temp_file ("tst-trucate.", &temp_filename);
      38    if (temp_fd == -1)
      39      {
      40        printf ("cannot create temporary file: %m\n");
      41        exit (1);
      42      }
      43  }
      44  
      45  #define FAIL(str) \
      46    do { printf ("error: %s (line %d)\n", str, __LINE__); return 1; } while (0)
      47  
      48  static int
      49  do_test_with_offset (off_t offset)
      50  {
      51    struct stat st;
      52    char buf[1000];
      53  
      54    memset (buf, 0xcf, sizeof (buf));
      55  
      56    if (pwrite (temp_fd, buf, sizeof (buf), offset) != sizeof (buf))
      57      FAIL ("write failed");
      58    if (fstat (temp_fd, &st) < 0 || st.st_size != (offset + sizeof (buf)))
      59      FAIL ("initial size wrong");
      60  
      61    if (ftruncate (temp_fd, offset + 800) < 0)
      62      FAIL ("size reduction with ftruncate failed");
      63    if (fstat (temp_fd, &st) < 0 || st.st_size != (offset + 800))
      64      FAIL ("size after reduction with ftruncate is incorrect");
      65  
      66    /* The following test covers more than POSIX.  POSIX does not require
      67       that ftruncate() can increase the file size.  But we are testing
      68       Unix systems.  */
      69    if (ftruncate (temp_fd, offset + 1200) < 0)
      70      FAIL ("size increate with ftruncate failed");
      71    if (fstat (temp_fd, &st) < 0 || st.st_size != (offset + 1200))
      72      FAIL ("size after increase is incorrect");
      73  
      74    if (truncate (temp_filename, offset + 800) < 0)
      75      FAIL ("size reduction with truncate failed");
      76    if (fstat (temp_fd, &st) < 0 || st.st_size != (offset + 800))
      77      FAIL ("size after reduction with truncate incorrect");
      78  
      79    /* The following test covers more than POSIX.  POSIX does not require
      80       that truncate() can increase the file size.  But we are testing
      81       Unix systems.  */
      82    if (truncate (temp_filename, (offset + 1200)) < 0)
      83      FAIL ("size increase with truncate failed");
      84    if (fstat (temp_fd, &st) < 0 || st.st_size != (offset + 1200))
      85      FAIL ("size increase with truncate is incorrect");
      86  
      87    return 0;
      88  }