Date: 26 Mar 1993 17:17:51 -0800 (PST)
From: Gregory Eakin <XGEAKIN AT FULLERTON DOT EDU>
Subject: Re: Writting Binary files
To: djgpp AT sun DOT soe DOT clarkson DOT edu

On March 26, 1993, Lenny A. Krieg <LKRIEG AT dpc2 DOT hdos DOT hac DOT com> writes
 
> . . . The second
> program, PROGRAM 2, opens a BINARY file using OFSTREAM and attempts to
> write out 1600 unsigned ASCII 255 values.  The file produced is empty.
> The third program, PROGRAM 3, opens a BINARY file using OFSTREAM and
> attempts to write out 1600 unsigned ASCII 254 values.  It works fine.
>
> Am I doing something wrong or is there a problem with writing BINARY
> files that contain ASCII 255?  What is magical about ASCII 255?  Does
> anyone know a solution using OFSTREAM? . . .
 
No, the problem is OFSTREAM converts your (unsigned char) to a
(signed char), then a (signed int).  So when the the conversion
of 0xFF to 0xFFFFFFFF occures, it is treated as the EOF flag.  That's
why your file is empty.
 
I have two ideas:
    1) Tell OFSTREAM about unsigned chars, (ugh :={).
  or
    2) replace the code
           binfile << ( unsigned char ) data [ k ];
       with
           binfile._strbuf->sputc( ( unsigned char ) data [ k ]); // KLUDGE!
 
Greg Eakin, Student
California State Univeristy, Fullerton
xgeakin AT fullerton DOT edu