Xref: utzoo comp.os.msdos.programmer:2032 comp.windows.ms.programmer:173 alt.msdos.programmer:2219
Path: utzoo!utgpu!cs.utexas.edu!yale!cmcl2!polyof!karl
From: karl@polyof.poly.edu (Karl H. Muhlbach, Staff)
Newsgroups: comp.os.msdos.programmer,comp.windows.ms.programmer,alt.msdos.programmer
Subject: DOS dir command - How does it work?
Message-ID: <1990Nov19.212134.6012@polyof.poly.edu>
Date: 19 Nov 90 21:21:34 GMT
Organization: Polytechnic University
Lines: 36


Dear Fellow Netters:

	I am writing a little utility but I need to get some
insight on something.  I was wondering how DOS accomplishes the dir command.
Is it done via the DOS system calls or is it bios related?  The reason I
ask is that part of my utility is to read a diskette and reference every
file on the diskette to see its file attributes (ie. size, date,
permissions, etc.). Unlike DOS I need to traverse the tree structure to
recursively reference every file.  DOS will only indicate that a
particular file is a subdirectory and not change dir to reference the files
in it.  I was considering using the ftw (file tree walk) system call but
was concerned about the max. open file limitation of 20.  Could anyone shed
some light on this for me.  This aspect and its speed performance are the
only things holding back the efficient completion of the utility.  I have
it working with referencing the disk using the ftw call but there must be a
more efficient and quicker method.

	I would greatly appreciate any help that might be sent my way.
Please EMail me any responses so that I may have a quicker turn around time
on an answer since I do not get much time to read news.  Also, if your
response is to RTFM then fine, point me in the direction of a decent book
on DOS internals and I will RTFM! The books I have seen do not go into
stuff like this.

					Thanks to all
					in advance!

						Karl M.


-- 
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  Karl H. Muhlbach   	Email: karl@polyof.poly.edu
			Voice: (516) 794-0142
			  FAX: (516) 794-0142