libio/tst-fwrite-error.c

   1 /* Test of fwrite() function, adapted from gnulib-tests in grep.
   2    Copyright (C) 2011-2024 Free Software Foundation, Inc.
   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 <errno.h>
  19 #include <fcntl.h>
  20 #include <unistd.h>
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23
  24 static int
  25 do_test (void)
  26 {
  27   char tmpl[] = "/tmp/tst-fwrite-error.XXXXXX";
  28   int fd = mkstemp (tmpl);
  29   if (fd == -1)
  30     {
  31       printf ("mkstemp failed with errno %d\n", errno);
  32       return 1;
  33     }
  34   FILE *fp = fdopen (fd, "w");
  35   if (fp == NULL)
  36     {
  37       printf ("fdopen failed with errno %d\n", errno);
  38       return 1;
  39     }
  40
  41   char buf[] = "world";
  42   setvbuf (fp, NULL, _IONBF, 0);
  43   close (fd);
  44   unlink (tmpl);
  45   errno = 0;
  46
  47   int ret = fwrite (buf, 1, sizeof (buf), fp);
  48   if (ret != 0)
  49     {
  50       printf ("fwrite returned %d\n", ret);
  51       return 1;
  52     }
  53   if (errno != EBADF)
  54     {
  55       printf ("Errno is not EBADF: %d\n", errno);
  56       return 1;
  57     }
  58   if (ferror (fp) == 0)
  59     {
  60       printf ("ferror not set\n");
  61       return 1;
  62     }
  63
  64   return 0;
  65 }
  66
  67 #define TEST_FUNCTION do_test ()
  68 #include "../test-skeleton.c"