stdio-common/test_rdwr.c

   1 /* Copyright (C) 1991-2018 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, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <errno.h>
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22
  23
  24 int
  25 main (int argc, char **argv)
  26 {
  27   static const char hello[] = "Hello, world.\n";
  28   static const char replace[] = "Hewwo, world.\n";
  29   static const size_t replace_from = 2, replace_to = 4;
  30   char filename[FILENAME_MAX];
  31   char *name = strrchr (*argv, '/');
  32   char buf[BUFSIZ];
  33   FILE *f;
  34   int lose = 0;
  35
  36   if (name != NULL)
  37     ++name;
  38   else
  39     name = *argv;
  40
  41   (void) sprintf (filename, "/tmp/%s.test", name);
  42
  43   f = fopen (filename, "w+");
  44   if (f == NULL)
  45     {
  46       perror (filename);
  47       exit (1);
  48     }
  49
  50   (void) fputs (hello, f);
  51   rewind (f);
  52   (void) fgets (buf, sizeof (buf), f);
  53   rewind (f);
  54   (void) fputs (buf, f);
  55   rewind (f);
  56   {
  57     size_t i;
  58     for (i = 0; i < replace_from; ++i)
  59       {
  60         int c = getc (f);
  61         if (c == EOF)
  62           {
  63             printf ("EOF at %Zu.\n", i);
  64             lose = 1;
  65             break;
  66           }
  67         else if (c != hello[i])
  68           {
  69             printf ("Got '%c' instead of '%c' at %Zu.\n",
  70                     (unsigned char) c, hello[i], i);
  71             lose = 1;
  72             break;
  73           }
  74       }
  75   }
  76
  77   {
  78     long int where = ftell (f);
  79     if (where == (long int) replace_from)
  80       {
  81         size_t i;
  82         for (i = replace_from; i < replace_to; ++i)
  83           if (putc(replace[i], f) == EOF)
  84             {
  85               printf ("putc('%c') got %s at %Zu.\n",
  86                       replace[i], strerror (errno), i);
  87               lose = 1;
  88               break;
  89             }
  90       }
  91     else if (where == -1L)
  92       {
  93         printf ("ftell got %s (should be at %Zu).\n",
  94                 strerror (errno), replace_from);
  95         lose = 1;
  96       }
  97     else
  98       {
  99         printf ("ftell returns %lu; should be %Zu.\n", where, replace_from);
 100         lose = 1;
 101       }
 102   }
 103
 104   if (!lose)
 105     {
 106       rewind (f);
 107       if (fgets (buf, sizeof (buf), f) == NULL)
 108         {
 109           printf ("fgets got %s.\n", strerror(errno));
 110           lose = 1;
 111         }
 112       else if (strcmp (buf, replace))
 113         {
 114           printf ("Read \"%s\" instead of \"%s\".\n", buf, replace);
 115           lose = 1;
 116         }
 117     }
 118
 119   if (lose)
 120     printf ("Test FAILED!  Losing file is \"%s\".\n", filename);
 121   else
 122     {
 123       (void) remove (filename);
 124       puts ("Test succeeded.");
 125     }
 126
 127   return lose ? EXIT_FAILURE : EXIT_SUCCESS;
 128 }