stdio-common/test-fseek.c

   1 /* Copyright (C) 1991, 1992, 1996, 1997 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, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <stdio.h>
  20
  21 #define TESTFILE "/tmp/test.dat"
  22
  23 int
  24 main (void)
  25 {
  26   FILE *fp;
  27   int i, j;
  28
  29   puts ("\nFile seek test");
  30   fp = fopen (TESTFILE, "w");
  31   if (fp == NULL)
  32     {
  33       perror (TESTFILE);
  34       return 1;
  35     }
  36
  37   for (i = 0; i < 256; i++)
  38     putc (i, fp);
  39   if (freopen (TESTFILE, "r", fp) != fp)
  40     {
  41       perror ("Cannot open file for reading");
  42       return 1;
  43     }
  44
  45   for (i = 1; i <= 255; i++)
  46     {
  47       printf ("%3d\n", i);
  48       fseek (fp, (long) -i, SEEK_END);
  49       if ((j = getc (fp)) != 256 - i)
  50         {
  51           printf ("SEEK_END failed %d\n", j);
  52           break;
  53         }
  54       if (fseek (fp, (long) i, SEEK_SET))
  55         {
  56           puts ("Cannot SEEK_SET");
  57           break;
  58         }
  59       if ((j = getc (fp)) != i)
  60         {
  61           printf ("SEEK_SET failed %d\n", j);
  62           break;
  63         }
  64       if (fseek (fp, (long) i, SEEK_SET))
  65         {
  66           puts ("Cannot SEEK_SET");
  67           break;
  68         }
  69       if (fseek (fp, (long) (i >= 128 ? -128 : 128), SEEK_CUR))
  70         {
  71           puts ("Cannot SEEK_CUR");
  72           break;
  73         }
  74       if ((j = getc (fp)) != (i >= 128 ? i - 128 : i + 128))
  75         {
  76           printf ("SEEK_CUR failed %d\n", j);
  77           break;
  78         }
  79     }
  80   fclose (fp);
  81   remove (TESTFILE);
  82
  83   puts ((i > 255) ? "Test succeeded." : "Test FAILED!");
  84   return (i > 255) ? 0 : 1;
  85 }