tests/test-fseeko4.c

   1 /* Test of fseeko() function.
   2    Copyright (C) 2011-2020 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 3 of the License, or
   7    (at your option) any later version.
   8
   9    This program 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
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  16
  17 #include <config.h>
  18
  19 #include <stdio.h>
  20
  21 #include <errno.h>
  22 #include <unistd.h>
  23
  24 #include "macros.h"
  25
  26 int
  27 main (int argc, char **argv)
  28 {
  29   const char *filename = argv[1];
  30
  31   /* Test that fseeko() sets errno if someone else closes the stream
  32      fd behind the back of stdio.  */
  33   {
  34     FILE *fp = fopen (filename, "r");
  35     ASSERT (fp != NULL);
  36     setvbuf (fp, NULL, _IONBF, 0);
  37     ASSERT (ftell (fp) == 0);
  38     ASSERT (fseeko (fp, 0, SEEK_END) == 0);
  39     ASSERT (ftell (fp) > 0);
  40     ASSERT (close (fileno (fp)) == 0);
  41     errno = 0;
  42     ASSERT (fseeko (fp, 0, SEEK_SET) == -1);
  43     ASSERT (errno == EBADF);
  44     fclose (fp);
  45   }
  46
  47   /* Test that fseeko() sets errno if the stream was constructed with
  48      an invalid file descriptor.  */
  49   {
  50     FILE *fp = fdopen (-1, "w");
  51     if (fp != NULL)
  52       {
  53         errno = 0;
  54         ASSERT (fseeko (fp, 0, SEEK_END) == -1);
  55         ASSERT (errno == EBADF);
  56         fclose (fp);
  57       }
  58   }
  59   {
  60     FILE *fp;
  61     close (99);
  62     fp = fdopen (99, "w");
  63     if (fp != NULL)
  64       {
  65         errno = 0;
  66         ASSERT (fseeko (fp, 0, SEEK_END) == -1);
  67         ASSERT (errno == EBADF);
  68         fclose (fp);
  69       }
  70   }
  71
  72   return 0;
  73 }