stdio-common/test-fseek.c

   1 /* Copyright (C) 1991-2024 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <stdio.h>
  19
  20 #define TESTFILE OBJPFX "test.dat"
  21
  22 static int
  23 do_test (void)
  24 {
  25   FILE *fp;
  26   int i, j;
  27
  28   puts ("\nFile seek test");
  29   fp = fopen (TESTFILE, "w");
  30   if (fp == NULL)
  31     {
  32       perror (TESTFILE);
  33       return 1;
  34     }
  35
  36   for (i = 0; i < 256; i++)
  37     putc (i, fp);
  38   if (freopen (TESTFILE, "r", fp) != fp)
  39     {
  40       perror ("Cannot open file for reading");
  41       return 1;
  42     }
  43
  44   for (i = 1; i <= 255; i++)
  45     {
  46       printf ("%3d\n", i);
  47       fseek (fp, (long) -i, SEEK_END);
  48       if ((j = getc (fp)) != 256 - i)
  49         {
  50           printf ("SEEK_END failed %d\n", j);
  51           break;
  52         }
  53       if (fseek (fp, (long) i, SEEK_SET))
  54         {
  55           puts ("Cannot SEEK_SET");
  56           break;
  57         }
  58       if ((j = getc (fp)) != i)
  59         {
  60           printf ("SEEK_SET failed %d\n", j);
  61           break;
  62         }
  63       if (fseek (fp, (long) i, SEEK_SET))
  64         {
  65           puts ("Cannot SEEK_SET");
  66           break;
  67         }
  68       if (fseek (fp, (long) (i >= 128 ? -128 : 128), SEEK_CUR))
  69         {
  70           puts ("Cannot SEEK_CUR");
  71           break;
  72         }
  73       if ((j = getc (fp)) != (i >= 128 ? i - 128 : i + 128))
  74         {
  75           printf ("SEEK_CUR failed %d\n", j);
  76           break;
  77         }
  78     }
  79   fclose (fp);
  80   remove (TESTFILE);
  81
  82   puts ((i > 255) ? "Test succeeded." : "Test FAILED!");
  83   return (i > 255) ? 0 : 1;
  84 }
  85
  86 #define TEST_FUNCTION do_test ()
  87 #include "../test-skeleton.c"