51–60 of 70 posts
Some years ago, doing high performance dense matrix code in C, I replaced a bunch of modulo calls with a bunch of bit operations. You had to work with matrices that were a power of 2 in rows and columns, but you could pad it out and stuff worked. A year later I looked at the code and couldn't figure out how it ever worked in the first place . . .
Isn't that the norm ?
Anyway, BMB gets this information and signs on to the account. Usually by this time the employee has figured out that you stole his information and is in the process of reporting it, so you don't have much time. BMB immediately attempts to go to the AOL Keyword Manager, which lets certain employees manage where specific AOL keywords take you. As it so happens, this employee had that access (it was very rare).
BMB redirected keyword "Welcome", which normally takes you to the AOL welcome screen, to our site, AOL-Files.com. Every person that signs on AOL, you see, gets automatically sent to keyword "Welcome" when they sign on.
For 20 minutes, every person that signed on AOL got sent to our site. We got 75,000 hits before AOL finally fixed it.
For anyone interested, I've got an archive of AOL-Files up on my site, which has a security breaches section that lists a lot of exploits like this one, including one where we stole every three character AIM name: http://www.mattmazur.com/archive/aol-files/index.html
I no longer support stealing people's stuff, but I still think the keyword Welcome exploit was badass.
I am writing PHP in Common Lisp, and my codebase is litered with the following: (defun make-record (&rest args) ; insert &allow-other-keys ;-) (let ((*db-auto-sync* t)) (object (make-instance 'record args))) (when object (update-records-from-instance object)))) Both the LET binding of db-auto-sync and the update-records call do the EXACT same thing. However, due to weirdness I don't grok quite yet, the calls to the d…
I hope no one was misled by the above false alarm; It seems like I have perfected a problem-solving technique known as "debugging through public embarassment". I just seem to catch agonizing problems the moment I write about them online or tell someone about them.
CLSQL:UPDATE-RECORDS-FROM-INSTANCE should NOT be fucked with; I am not sure how it's supposed to operate, but under MySQL, it will update all the records in a table and set them to the same slot-values as the instance. I.e. all identical records!
The feature I needed is cleanly implemented using WITH-TRANSACTIONS. Again, embarassed and sorry for the confusion.
Some years ago, doing high performance dense matrix code in C, I replaced a bunch of modulo calls with a bunch of bit operations. You had to work with matrices that were a power of 2 in rows and columns, but you could pad it out and stuff worked. A year later I looked at the code and couldn't figure out how it ever worked in the first place . . .
> A year later I looked at the code and couldn't figure out how it ever worked in the first place . . . Isn't that the norm ?
I'll schedule a code review with peers. If I can explain/justify an ugly hack maybe it's not so bad. But sometimes the fundamental "wrongness" of some piece of code just drives me to try and find a better fix. One of those classic trade-offs, elegance vs expediency.
Earlier quoted context omitted.
> A year later I looked at the code and couldn't figure out how it ever worked in the first place . . . Isn't that the norm ?
Probably. It actually had the opposite effect on me. I try to keep my code cleaner and more understandable now. I'll stick in better, more expansive comments in difficult spots. I'll schedule a code review with peers. If I can explain/justify an ugly hack maybe it's not so bad. But sometimes the fundamental "wrongness" of some piece of code just drives me to try and find a better fix. One of those classic trade-offs,…
My 'new' code looks so simple and direct in comparision. No more trickery with setjmp and longjmp and no more abuse of side effects.
Then I realize that the simplicity is actually better, not the hacks of old.
What is surprising though is that it seems almost as if every generation of programmers has to learn these lessons all over again.
I am writing PHP in Common Lisp, and my codebase is litered with the following: (defun make-record (&rest args) ; insert &allow-other-keys ;-) (let ((*db-auto-sync* t)) (object (make-instance 'record args))) (when object (update-records-from-instance object)))) Both the LET binding of db-auto-sync and the update-records call do the EXACT same thing. However, due to weirdness I don't grok quite yet, the calls to the d…
I've always wanted to do sort of the opposite... That is to say, I've always wanted to compile Scheme to PHP. I make the claim that PHP is the web's assembly language. Or, at least it's portable assembly language.
Well, I had seen what my mother-in-law did to kids: set them on her lap and pumped them so dry they squeaked for a week. I figured daughter == mother...
So, little Jeremy and I went shopping. All the way to the store I told Jeremy to not tell Mom what we bought (the hook ;-). At the store, I picked up a CD/alarm clock for Mom's present. Of course, Jeremy couldn't read, so he really didn't know what it was. I asked him if he thought Mom would like a thingamajig, and he thought it was a fine idea (baiting the hook ;-).
All the way home, I emphasized to little Jeremy that he was not to tell Mom that we bought her a thingamajig (setting the hook ;-).
When we got home, I disappeared into another room, but stayed within earshot. Sure enough, Mom got little Jeremy on her lap and started pumping him. He resisted valiantly, but he was only four and cracked after a couple of minutes. "It was a thingamajig!" he said.
CAUGHT! :-D
I don’t know if I should be ashamed or proud.