[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20040408151842.35783.qmail@web20212.mail.yahoo.com>
From: visitbipin at yahoo.com (bipin gautam)
Subject: Re: [EXPLAIN!] FAT32 input > output = null?
well... a simple explaination could be...
if you,
del.exe >del.exe
mark the single ">" it means to output the data " to
the file" by over
writing the whole file.
but if you do,
del.exe >>del.exe
mark the double ">>" it means to output the data but
just "APPEND"
at the end of the file.........
lets guess then,
if you execute a normal program, named "del.exe"
normally...
c:\> del.exe
it gets executed...........
but if you add a strange junk command after an
execudable............
as...
c:\> del.exe >del.exe
well... cmd.exe marks it as "INVALID" and closes the
open handle for
del.exe without any operation [hence null output]
but......
the second half of the command is ">del.exe" right?
as the open handles/threads of del.exe is closed with
"null" output
windows procedes the second half of the command by
writing "null" to
the file.......
if you do, [append] ie: '>>'
c:\> del.exe >>del.exe
cmd simply quits by appending "null" [nothing] at the
end of the
file!!!
HAY, AFTERALL WRITING AND READING THE SAME FILE AT
ONCE [at the same
time] ISN'T possible......... so there is a conflict
so it closes the
open handle's of del.exe " marking it as invalid
process" hence output
is null! which is written ............... as it is the
2'nd half of the
command requested!
what do you say?
MY 2 CENTS
./hUNT3R
http://www.geocities.com/visitbipin/
--- morning_wood <se_cur_ity@...mail.com> wrote:
> > You can also delete files by using the "del"
> command. I tested this with the
> > 5.1 ntos kernel (Slackware XP):
> >
> > C:\>del testfile.exe
> >
> if you were trying to be sarcastic in saying this is
> "normal, any dummy knows that" then you failed
> horrendously, sir.
> where did the delete command came from ????
> this has nothing to do with any system command
> it was simply an odd behavior where by ">" piping
> output of a file into itself, causes a 0 byte or
> corrupted file
> C:>del.exe >del.exe
> in particular, executeable files.
>
>
> m.wood
>
>
> _______________________________________________
> Full-Disclosure - We believe in it.
> Charter:
http://lists.netsys.com/full-disclosure-charter.html
__________________________________
Do you Yahoo!?
Protect your identity with Yahoo! Mail AddressGuard
http://antispam.yahoo.com/whatsnewfree
Powered by blists - more mailing lists