TIP: Click on subject to list as thread! ANSI
echo: quik_bas
to: DAVID WILLIAMS
from: CHRIS GUNN
date: 1998-04-02 00:43:00
subject: Re: Multiple eofs

 DW> In any (reasonable) DOS, EOF is *not* just an ASCII character. The
 DW> stuff that is recorded on a disk is a whole lot more complex than it
 DW> appears "through" the DOS. There are extra bits that are used for
 DW> error detection and correction.
Howdy David,
Mostly right!  Most of the file heading entries you are referring to happen 
for *.COM and *.EXE files.  The parity codes are a function of the disk drive 
and the DOS kernel and are not accessable unless you directly read sectors 
from the disk.  I used to do that stuff way back {grin}.
The End-Of-File character CHR$(26) is a left over from CP/M and early DOS
programs.  QuickBasic tries to stay compatible by observing it for text based 
files.  Some programs still put an EOF character at the end of text files. 
Most newer programs do not.  They go by the length stored in the directory 
entry for the file.
The EOF character is ignored when opening a file for BINARY or RANDOM.  If 
CHR$(26) and some other lower 32 control codes appear inside a file, it's not 
intended for sequential text access by opening the file for INPUT.
Chris
--- FMail 0.96â
---------------
* Origin: BIZynet - Worldwide Business via the E-Ways (1:15/55.1)

SOURCE: echomail via exec-pc

Email questions or comments to sysop@ipingthereforeiam.com
All parts of this website painstakingly hand-crafted in the U.S.A.!
IPTIA BBS/MUD/Terminal/Game Server List, © 2025 IPTIA Consulting™.