1  /* Copyright (C) 1991-2023 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"