libio/tst-freopen.c

   1 /* Test freopen with mmap stdio.
   2    Copyright (C) 2002 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, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <unistd.h>
  25
  26 int
  27 main (void)
  28 {
  29   char name[] = "/tmp/tst-freopen.XXXXXX";
  30   const char * const test = "Let's test freopen.\n";
  31   char temp[strlen (test) + 1];
  32   int fd = mkstemp (name);
  33   FILE *f;
  34
  35   if (fd == -1)
  36     {
  37       printf ("%u: cannot open temporary file: %m\n", __LINE__);
  38       exit (1);
  39     }
  40
  41   f = fdopen (fd, "w");
  42   if (f == NULL)
  43     {
  44       printf ("%u: cannot fdopen temporary file: %m\n", __LINE__);
  45       exit (1);
  46     }
  47
  48   fputs (test, f);
  49   fclose (f);
  50
  51   f = fopen (name, "r");
  52   if (f == NULL)
  53     {
  54       printf ("%u: cannot fopen temporary file: %m\n", __LINE__);
  55       exit (1);
  56     }
  57
  58   if (fread (temp, 1, strlen (test), f) != strlen (test))
  59     {
  60       printf ("%u: couldn't read the file back: %m\n", __LINE__);
  61       exit (1);
  62     }
  63   temp [strlen (test)] = '\0';
  64
  65   if (strcmp (test, temp))
  66     {
  67       printf ("%u: read different string than was written:\n%s%s",
  68               __LINE__, test, temp);
  69       exit (1);
  70     }
  71
  72   f = freopen (name, "r+", f);
  73   if (f == NULL)
  74     {
  75       printf ("%u: cannot freopen temporary file: %m\n", __LINE__);
  76       exit (1);
  77     }
  78
  79   if (fseek (f, 0, SEEK_SET) != 0)
  80     {
  81       printf ("%u: couldn't fseek to start: %m\n", __LINE__);
  82       exit (1);
  83     }
  84
  85   if (fread (temp, 1, strlen (test), f) != strlen (test))
  86     {
  87       printf ("%u: couldn't read the file back: %m\n", __LINE__);
  88       exit (1);
  89     }
  90   temp [strlen (test)] = '\0';
  91
  92   if (strcmp (test, temp))
  93     {
  94       printf ("%u: read different string than was written:\n%s%s",
  95               __LINE__, test, temp);
  96       exit (1);
  97     }
  98
  99   fclose (f);
 100
 101   unlink (name);
 102   exit (0);
 103 }