stdio-common/test_rdwr.c

   1 /* Copyright (C) 1991-2023 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    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <errno.h>
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22
  23 #include <support/xstdio.h>
  24
  25 int
  26 main (int argc, char **argv)
  27 {
  28   static const char hello[] = "Hello, world.\n";
  29   static const char replace[] = "Hewwo, world.\n";
  30   static const size_t replace_from = 2, replace_to = 4;
  31   char filename[FILENAME_MAX];
  32   char *name = strrchr (*argv, '/');
  33   char buf[BUFSIZ];
  34   FILE *f;
  35   int lose = 0;
  36
  37   if (name != NULL)
  38     ++name;
  39   else
  40     name = *argv;
  41
  42   (void) sprintf (filename, OBJPFX "%s.test", name);
  43
  44   f = fopen (filename, "w+");
  45   if (f == NULL)
  46     {
  47       perror (filename);
  48       exit (1);
  49     }
  50
  51   (void) fputs (hello, f);
  52   rewind (f);
  53   xfgets (buf, sizeof (buf), f);
  54   rewind (f);
  55   (void) fputs (buf, f);
  56   rewind (f);
  57   {
  58     size_t i;
  59     for (i = 0; i < replace_from; ++i)
  60       {
  61         int c = getc (f);
  62         if (c == EOF)
  63           {
  64             printf ("EOF at %Zu.\n", i);
  65             lose = 1;
  66             break;
  67           }
  68         else if (c != hello[i])
  69           {
  70             printf ("Got '%c' instead of '%c' at %Zu.\n",
  71                     (unsigned char) c, hello[i], i);
  72             lose = 1;
  73             break;
  74           }
  75       }
  76   }
  77
  78   {
  79     long int where = ftell (f);
  80     if (where == (long int) replace_from)
  81       {
  82         size_t i;
  83         for (i = replace_from; i < replace_to; ++i)
  84           if (putc(replace[i], f) == EOF)
  85             {
  86               printf ("putc('%c') got %s at %Zu.\n",
  87                       replace[i], strerror (errno), i);
  88               lose = 1;
  89               break;
  90             }
  91       }
  92     else if (where == -1L)
  93       {
  94         printf ("ftell got %s (should be at %Zu).\n",
  95                 strerror (errno), replace_from);
  96         lose = 1;
  97       }
  98     else
  99       {
 100         printf ("ftell returns %lu; should be %Zu.\n", where, replace_from);
 101         lose = 1;
 102       }
 103   }
 104
 105   if (!lose)
 106     {
 107       rewind (f);
 108       xfgets (buf, sizeof (buf), f);
 109       if (strcmp (buf, replace))
 110         {
 111           printf ("Read \"%s\" instead of \"%s\".\n", buf, replace);
 112           lose = 1;
 113         }
 114     }
 115
 116   if (lose)
 117     printf ("Test FAILED!  Losing file is \"%s\".\n", filename);
 118   else
 119     {
 120       (void) remove (filename);
 121       puts ("Test succeeded.");
 122     }
 123
 124   return lose ? EXIT_FAILURE : EXIT_SUCCESS;
 125 }