Subj : Re: fstream arrays
To   : borland.public.cpp.borlandcpp
From : "D Kat" <disisdkat@hotmail.com>
Date : Wed Mar 10 2004 12:49 pm

Can you give me info on Memcheck?  9 times out of ten any of my problems
come down to buffer overwrites (one of the first things I thoroughly checked
on this issue...).  I really think C is a beautiful language EXCEPT for it
being perfectly happy to let you write beyond assigned space.... DKat


"Dwayne" <myfrienddr@yahoo.com> wrote in message
news:403d1775$1@newsgroups.borland.com...
>           Hello D Kat,
> /////////////////////CODE////////////////////////////////
> ofstream out_files[NSUB];//file to write data to
> get_subj_fp(int file)
> {
>   char name[20];
>
>   strcpy(name,"data/");
>   strcat(name, sub_name[file]);
>   strcat(name,".");
>   strcat(name,cdn);
>   out_files[file].open(name);
>   if (!out_files[file])
>   {
>   cerr << "\nerror on file " << sub_name[file] << "\n";
>   return(1);
>   }
>   return(0);
> }
>
>
>       A few other things.
>
> 1.  Clear the variable "Name".  Assign it to all blanks I realize that
> strcpy puts a NULL terminating character on the end of the copy, but it
may
> help in the debugging.
> 2.  make sure you use "Forward Slashes", not back slashes. in the "copy"
and
> "Cat" commands.  That way the compiler will not think it is a "special"
> character... like \0.   or \\.
> 3.  This may sound crazy, but it may solve your problem.... Build your
> string with a strins command.  Do not use the Strcat.  You may be building
> it backwards from what you are doing, but hey! the result is the same....
> 4.  Are you using  something like Memcheck? There is a very good chance
that
> you are overwriting your memory someplace. and you may not be seeing it
> until now.  Strcat is a dangerous command for overwriting memory if you
are
> not careful.
>
>   strcpy(name,"data/");
>   strcat(name, sub_name[file]);
>   strcat(name,".");
>   strcat(name,cdn);
>
>       changes to:
> strcpy(name,cdn);
> strins(".",name,0);
> strins("sub_name[file],name,0);
> strins("data/",name,0);
>
> Here is a source for a strins....
>
> int strins(char *r, char *s, int p)
>  {
>   int c,d;
>   d=0;
>   c=-1;
>   while(d<strlen(r))// don't use <=, it will inc. null
>   {
>   for(c=strlen(s);c>=p+d;c--)
>  {
>   *(s+c+1)=*(s+c);
>  }
>   *(s+p+d)=*(r+d);
>   d++;
>   c=0;
>   }
>   return(c);
>  };
>
>

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