libio/tst-freopen.c

   1 /* Test freopen with mmap stdio.
   2    Copyright (C) 2002-2020 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Jakub Jelinek <jakub@redhat.com>, 2002.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <https://www.gnu.org/licenses/>.  */
  19
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <unistd.h>
  24
  25 #include <support/check.h>
  26 #include <support/temp_file.h>
  27
  28 static int fd;
  29 static char *name;
  30
  31 static void
  32 do_prepare (int argc, char *argv[])
  33 {
  34   fd = create_temp_file ("tst-freopen.", &name);
  35   TEST_VERIFY_EXIT (fd != -1);
  36 }
  37
  38 #define PREPARE do_prepare
  39
  40 /* Basic tests for freopen.  */
  41 static void
  42 do_test_basic (void)
  43 {
  44   const char * const test = "Let's test freopen.\n";
  45   char temp[strlen (test) + 1];
  46
  47   FILE *f = fdopen (fd, "w");
  48   if (f == NULL)
  49     FAIL_EXIT1 ("fdopen: %m");
  50
  51   fputs (test, f);
  52   fclose (f);
  53
  54   f = fopen (name, "r");
  55   if (f == NULL)
  56     FAIL_EXIT1 ("fopen: %m");
  57
  58   if (fread (temp, 1, strlen (test), f) != strlen (test))
  59     FAIL_EXIT1 ("fread: %m");
  60   temp [strlen (test)] = '\0';
  61
  62   if (strcmp (test, temp))
  63     FAIL_EXIT1 ("read different string than was written: (%s, %s)",
  64                 test, temp);
  65
  66   f = freopen (name, "r+", f);
  67   if (f == NULL)
  68     FAIL_EXIT1 ("freopen: %m");
  69
  70   if (fseek (f, 0, SEEK_SET) != 0)
  71     FAIL_EXIT1 ("fseek: %m");
  72
  73   if (fread (temp, 1, strlen (test), f) != strlen (test))
  74     FAIL_EXIT1 ("fread: %m");
  75   temp [strlen (test)] = '\0';
  76
  77   if (strcmp (test, temp))
  78     FAIL_EXIT1 ("read different string than was written: (%s, %s)",
  79                 test, temp);
  80
  81   fclose (f);
  82 }
  83
  84 /* Test for BZ#21398, where it tries to freopen stdio after the close
  85    of its file descriptor.  */
  86 static void
  87 do_test_bz21398 (void)
  88 {
  89   (void) close (STDIN_FILENO);
  90
  91   FILE *f = freopen (name, "r", stdin);
  92   if (f == NULL)
  93     FAIL_EXIT1 ("freopen: %m");
  94
  95   TEST_VERIFY_EXIT (ferror (f) == 0);
  96
  97   char buf[128];
  98   char *ret = fgets (buf, sizeof (buf), stdin);
  99   TEST_VERIFY_EXIT (ret != NULL);
 100   TEST_VERIFY_EXIT (ferror (f) == 0);
 101 }
 102
 103 static int
 104 do_test (void)
 105 {
 106   do_test_basic ();
 107   do_test_bz21398 ();
 108
 109   return 0;
 110 }
 111
 112 #include <support/test-driver.c>