🚀 go-pugleaf

Elias Berelian wrote:
> ...
> My first question is why I don't get the "too many files open" as is DOS/C?

Because you get a different message: fopen() will fail if too many files are 
open already.
Example:

void __fastcall TForm1::fopenButtonClick(TObject *Sender)
{
   Memo1->Clear();

   int filenr = 0;

   while ( ++ filenr <= maxwanted )
      {
       char path [MAXPATH+2];

       sprintf ( path, "fopen.%d.txt", filenr );

       if ( ! fopen ( path, "wb" ) )
         break;

       Memo1->Lines->Add ( path );
      }
}

> What is the best way to increase the allowable number? (Besides editing
> _nfiles.h and resetting _NFILE_.)

Use CreateFile(), WriteFile() and CloseHandle().
Then the amount is unlimited.
Example:

void __fastcall TForm1::CreateFileButtonClick(TObject *Sender)
{
   Memo1->Clear();

   int filenr = 0;

   while ( ++ filenr <= maxwanted ) /* private int maxwanted == 400 */
      {
       char path [MAXPATH+2];

       sprintf ( path, "CreateFile.%d.txt", filenr );

       // CreateFile
       HANDLE handle = CreateFile(
         path,                   // LPCTSTR lpFileName,	
         GENERIC_WRITE,          // DWORD dwDesiredAccess,	
         FILE_SHARE_WRITE,       // DWORD dwShareMode,	
         NULL,                   // LPSECURITY_ATTRIBUTES lpSecurityAttributes, 
         	CREATE_ALWAYS,          // DWORD dwCreationDistribution,	
         FILE_ATTRIBUTE_NORMAL,  // DWORD dwFlagsAndAttributes,	
         NULL                    // HANDLE hTemplateFile
         );

       if ( ! handle ) break;

       handles [filenr] = handle;
	/* private int array to keep the
	handles, for writing and closing later */

       Memo1->Lines->Add ( path );

       strcat ( path, "\r\n" );

       DWORD nwritten = 0;

       /* write path in the file */

       int done = WriteFile(
         handle,           //HANDLE hFile,	
         path,             //LPCVOID lpBuffer,	
         strlen ( path ),  //DWORD nNumberOfBytesToWrite,	
         &nwritten,        //LPDWORD lpNumberOfBytesWritten,	
         NULL              //LPOVERLAPPED lpOverlapped 	
         );

       if ( ! done )
         {
         Memo1->Lines->Add ( "Could not write to " + AnsiString ( path ) );

         break;
         }
      }
}
> Is there a way to figure out how many files are open?

Keep track of that yourself (need only one -global- counter or see above.

> What contributes to this number? (e.g. Does opening a socket count as an
> open file? How about a COM port?)

Don't know, but you can -now- easily try for yourself.

Hans.