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  }