+ma' "everything is byte" essay said:
About Zip Files
The most interesting detail about ZIP files is that they keep information
about their packed files in the LAST bytes of the zipped archive: this means
that you can add whatever you want or make slight changes at their beginning
and many programs, such as Winzip under Windoze or unzip under linux, will
open them without any problems. Note that FILE utility, instead, will not
recognize them anymore: the line
0 string PK\003\004 Zip archive data
inside magic means that it just checks for the first four bytes, which means
that if you change them with, for instance, "ZZ", FILE won't recognize the
zip anymore, while other programs will be able to open it anyway.
After all, this is not a great limit: FILE also gives you the chance to use
indirect offsets, which could help in tasks of this kind... and it's always
possible to change the sources, so that you can make it recognize offsets
starting from wherever you wish and not just from the beginning of the file.
This, of course, is left as an exercise to the reader...
----------------------------------------------------------------------------
About Image Formats
As you've seen, ZIP utils don't mind if you append anything at the beginning
of their files. On the other side, there are some image formats which don't
mind if you append something at their end: this is because, inside their
header, image width and height are specified, so all the exceeding bytes are
ignored. This works, for instance, for .gif and .jpg images... and joined
with ZIP's property this means that you can append a JPG and a ZIP together
(the image first, the archive last) and, under Windoze, open the first or
the second one just by changing the file extension!
ovid said:Hello fellow seekers,
we are about to leave the comfort of our homes.
We will search for hidden treasures unknown amongst
those zombies who killed their brain by watching too much TV.
But be aware, 3 doors will hide the gate to wisdom.
When you are ready to enter the first door please do not forget the
tools you found on your journey to level 4. Try to question every detail to find.
Bend it, negotiate it. When you see something,do not judge it by its appearance,
but try to see what is behind the mask it wears. And remember EVERYTHING is 0 and 1.
I'm sure you are all capable of seeing beauty where it is,
not as those who aren't capable of thinking.
Speaking of the TV zombies: have you ever reckognized that more and more
people forget about the ancient technique of reading ?
It's of course easier to let your brain be filled by some apparatus and
completely forget about the knowledge which is around us.
But being a seeker you are of course interested in many fields,
be it math, physics, linguistics or history (do you know about the Battle
of Issus ?).
I hope none of you will get lost on the dangerous path I prepared.
Work together and we will see us in the next level.
Kind regards,
ovid, September 2001
I don't sleep with a pillow. :grin:Cannon Fodder said:[highlight]Appendix A[/highlight]
3. Burn all of your pillows. Don't ask, just do it.
Yes. USWest.Ash Housewares said:anybody still playing? on what realm?
They've been wondering where you were.Ash Housewares said:perhaps I'll stop by wtf and see who is alive there
*lays out an array of whips, chains, cuffs, and leather regalia*doraemon said:hi
is this some kind of hidden elusive community?
do intruders like me get punished?
mmmmmmmmm
krischan said:There are a few secret community forum rules and violating them can have severe consequences. Your secret trial is already running and it doesn't look good, I heard.
BTW, asking the wrong questions will only make it worse. You can't change its outcome anyway.
* knocks over a shelf full of empty beer bottles * ... interesting im not on a computer but i can enter the forums. gg mobile forum posting!Dredd said:So quiet today ... :cloud9:
Ash Housewares said:everything on these forums is gibberish to me anyways
\rplusplus said:QFT
But it gets me through the long nights
Yarr++