Did you read what I wrote? People have asked about that many, many times and the answer is always "just use your firewall". There's seemingly little interest in that functionality.
I was in the pool for a while but quit because ntpd is wholly incapable of protecting itself. I ended up with about 50 abusers that polled for time once a second. I tried using the built-in filtering but it doesn't work, so ntpd was gleefully replying to each and every one of those requests.
Keep in mind that it has the logic to detect abusers - it just won't do anything about it. Well, it can be made to send a KOD (Kiss Of Death) packed that should make clients blacklist the server, but those same broken clients ignore KODs. I kid you not, the standard recommendation is to firewall them off.
What? ntpd already knows its internal state, including a list of abusers. The code could be as simple as "def sendTimePacket(clientaddr): if clientaddr in blacklist then return; else sendpacket(clientaddr);", but they suppose that it's easier to write an external program to monitor that state, general firewall rules, connect to the firewall host, and insert them. No, really, that's not easier at all.
I like NTP and I liked the idea of helping serve it to the world, but until ISC decides to support at least basic anti-DOS functionality in ntpd, I won't be joining the pool again. And by "support", I mean at least lend moral support to people who would be willing to the work, instead of just telling them to alter their firewall.
In Perl, why do I have to load regular expression handling even if I'm not going to use it? What if I want a different type of pattern matching - I have to load both? Python lets you load just what you want.
or Strings in python?
There is almost nothing in "string" anymore except for some constant definitions, which brings us to:
or for that matter, just to get the command line args I have to import a freakin library?
Consistency. Why does Perl have so many special variables in the default namespace? In Python, you don't get what you don't ask for.
Do those people have a right to be upset that their "wedding" was so rudely interrupted?
Yes. What does the venue matter? A bunch of people spent time arranging something nice that they could all enjoy, and your asshat of a friend took glee in ruining it.
1. The over 67% P-grade members criterion to be amended as "Positive votes corresponding to over 67% of the total population represented". Populous natins like India, China, the UK, Brazil have all voted No. The present ISO rules allow this popular opinion to be sidelined.
I, for one, welcome our new standardized Mandarin overlords.
Konqueror is my favorite "slim" application. "What?", you say, "It requires half of KDE to run!" No. It re-uses half of KDE to run. All that functionality and almost all of it is pulled in from other components.
I am not a database programmer, but I always try to attack ongoing problems using newer tools and unique ways to look at things.
This is hard to phrase without sounding awful, but I mean it genuinely: does that also mean that you have not studied database design? Is your opinion because you know the research and that what you want isn't possible from an RDBMS on a theoretical level, or because in your experience you've never seen it be made to work?
I ask because I've heard similar ideas before, but generally from people who didn't know the theory behind what they were doing and had gotten frustrated by the problems that others had already solved, unbeknownst to them. If that's not the case for you, I apologize. If it is, though, you might want to get some good math-based books on the subject before you dismiss it.
For that, I warmly recommend the up-and-coming Python-based ORM called SQLAlchemy.
Exactly. If you're using Python, you're not allowed to complain about SQL because there are good alternatives. Besides Alchemy, Django has a very nice object mapper of its own. Both of those have progressed to the point that writing raw SQL is simple unnecessary for almost any application development.
Relational databases will be around as long as humans generate relational data. Take the classic example of an invoice that may have many entries, each entry referencing an inventory item. This sort of thing is likely to exist forever, and RDBMSes model that pretty well.
As far as whether the backend is row- or column-oriented - who cares? As long as I can use the one most appropriate to my access pattern, the implementation details just don't interest me enough to get worked into a furor. Don't get me wrong - I think that there are some neat developments in the works - it's just that I don't have a strong general preference on how my information is physically laid down on the platters.
A more interesting question for me is whether SQL is obsolete. For the most part, I'd say that it is in the sense that most people need never use it directly. We use SQLAlchemy instead of writing raw SQL, and the Java folks seem to be fond of Hibernate. I still look at the generated queries sometimes to convince myself that it's sane or for debugging or optimization purposes, but if they inserted a new middle layer between Alchemy and PostgreSQL that used something completely different, our code wouldn't notice the difference.
I don't have any good references to hand, but for the plain old wave equation (time inhomogeneous and homogeneous) you could try looking at discontinuous Galerkin methods. Depending on the inhomogeneity in your coefficients, you might be able to use a Godunov scheme.
You just made that all up, knowing that none of us would be smart enough to catch it, didn't you?
Ain't that the truth. I can't believe I just had to pay $45,000,000 for my 3-foot-thick diamond-plated Chevy Juggernaut with nano-airbags and built-in collision-predicting supercomputer that tracks all nearby objects and several near-Earth objects.
Oh, wait, you meant in reality? Yeah, I don't have any of than and my car cost less that $20,000.
An article on functional programming is the perfect time to introduce my new son, Nick, to Slashdot. Previous releases were in C, Perl, and Python. Since Nick's functional, this one is in Lisp.
Mod me up or my son will spit up on you.
Re:I know why it's been 10 years
on
Programming Erlang
·
· Score: 2, Informative
At this point, I don't even understand what situations this could be usefully applied to.
Well, functional programs have a lot of other restrictions, but it boils down to this: with very rare exceptions (such as file or socket handling), functions don't have side effects. That is, they don't modify a program's global state, and they don't depend on global state. You can call foo(args) 100 times in a row and each time the output will be identical. My C++ is rusty, but imagine something like:
int foo(int &bar, int &baz) { return bar++ * baz++; }
Any code that calls foo() will find its internal state changed - both bar and baz have been altered. In comparison, this is almost impossible to do accidentally in functional languages.
So, great, what does that buy you? Well, the map() function in you example knows that it's supposed to call compose2() on each item in source_list. Because it's impossible for compose2() to have strange global side effects and it doesn't depend on external state, map() is free to fork() 10 times and let each child process munch through independent subsets of source_list. In the case of Erlang, map() is also free to hand off chunks of source_list to other machines and coalesce the results from all of those hosts at the end. As long as compose2() gets called on each item at some point, the order (and indeed the physical location) of each call doesn't matter a lick.
Imagine that you have 20 quad-core systems in a cluster. Replacing the imperative example above with the functional example gives your code an 80x performance boost, minus a little network overhead. Does that sound more interesting now?
Looks more like one of the team leaders was afraid of the competition.
Either that, or your code sucks more than theirs. Even if that's not true, you might not want to run around telling the world that these jackasses didn't think you made the grade.
My grandmother was excommunicated from the Catholic church for marrying a protestant.
I think that says much more about that parish in particular than it does about Catholicism, let alone Christianity as a whole. Returning to my Southern Baptist example, the absolute harshest "punishment" that can be given to a church member is to tell them not to come back to that church (and I've never personally heard of that happening). Whether they join another church is between them and the new congregation. There's no equivalent to excommunication.
The reason I bring this up is that the Catholic church seems to have the highest media profile. If a TV show or movie requires a religious presence, it's typically a priest. Because of this, I think, a lot of people equate the Catholic church with Christianity. However, while they're certainly a part of the larger group, their actions have little bearing on how the rest of Christianity works.
All religions are basically cults with a large number of followers.
Oh really? If you want to learn what Baptists believe, go into a Baptist church and ask. They'll give you a Bible and as much denomination-specific literature as you care to leave with. You won't have to give your name, although they might ask for it. You won't have to join. You won't have to pay them anything. You won't have to sign a non-disclosure statement. And should you decide that you like it and wish to join that particular church, you're free to leave at any time. In fact, church membership isn't a requirement of their belief system at all (although it's recommended so that you can continue to learn about it and hang out with like-minded people). No one will tell you where to work or where to live or which doctor to go to or who you can be friends with.
And that, to me, is the difference between a religion and a cult. You may completely disagree with what Baptists believe, but they'll tell you the entire story in advance and let you decide for yourself. The same goes for pretty much every other mainstream religion. On the other hand, if a group requires a donation or commitment before they'll even tell you what you're joining, run screaming. There are enough Open Source religions around that there's not much point in joining a proprietary sect.
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Did you read what I wrote? People have asked about that many, many times and the answer is always "just use your firewall". There's seemingly little interest in that functionality.
Flamebait subject, but I kind of mean it.
I was in the pool for a while but quit because ntpd is wholly incapable of protecting itself. I ended up with about 50 abusers that polled for time once a second. I tried using the built-in filtering but it doesn't work, so ntpd was gleefully replying to each and every one of those requests.
Keep in mind that it has the logic to detect abusers - it just won't do anything about it. Well, it can be made to send a KOD (Kiss Of Death) packed that should make clients blacklist the server, but those same broken clients ignore KODs. I kid you not, the standard recommendation is to firewall them off.
What? ntpd already knows its internal state, including a list of abusers. The code could be as simple as "def sendTimePacket(clientaddr): if clientaddr in blacklist then return; else sendpacket(clientaddr);", but they suppose that it's easier to write an external program to monitor that state, general firewall rules, connect to the firewall host, and insert them. No, really, that's not easier at all.
I like NTP and I liked the idea of helping serve it to the world, but until ISC decides to support at least basic anti-DOS functionality in ntpd, I won't be joining the pool again. And by "support", I mean at least lend moral support to people who would be willing to the work, instead of just telling them to alter their firewall.
Nope. "touch" doesn't truncate the file if it already exists. You want ": > x".
">"!
">"!
So simple and yet powerful, your friend and mine: ">"!
I think I need to take a shower, and not for smelly Unix hacker reasons.
Zsh, actually. I'm not sure if that's a specific feature or if it's emulating something else.
Turning that around:
Why do I have to import Regular expressionIn Perl, why do I have to load regular expression handling even if I'm not going to use it? What if I want a different type of pattern matching - I have to load both? Python lets you load just what you want.
or Strings in python?There is almost nothing in "string" anymore except for some constant definitions, which brings us to:
or for that matter, just to get the command line args I have to import a freakin library?Consistency. Why does Perl have so many special variables in the default namespace? In Python, you don't get what you don't ask for.
Is loading a 18KB slab of bloated code on top of that going to make it take less memory somehow? Repeat after me! ">"! Not cat, >!
Yes. What does the venue matter? A bunch of people spent time arranging something nice that they could all enjoy, and your asshat of a friend took glee in ruining it.
Freakin' wastrel! That's why they made ">". Not vim. Not ed. Not cat. ">".
"cat". Hrmph.
I, for one, welcome our new standardized Mandarin overlords.
Yeah, turning the legal department loose on Java will certainly improve the situation.
Konqueror is my favorite "slim" application. "What?", you say, "It requires half of KDE to run!" No. It re-uses half of KDE to run. All that functionality and almost all of it is pulled in from other components.
This is hard to phrase without sounding awful, but I mean it genuinely: does that also mean that you have not studied database design? Is your opinion because you know the research and that what you want isn't possible from an RDBMS on a theoretical level, or because in your experience you've never seen it be made to work?
I ask because I've heard similar ideas before, but generally from people who didn't know the theory behind what they were doing and had gotten frustrated by the problems that others had already solved, unbeknownst to them. If that's not the case for you, I apologize. If it is, though, you might want to get some good math-based books on the subject before you dismiss it.
Exactly. If you're using Python, you're not allowed to complain about SQL because there are good alternatives. Besides Alchemy, Django has a very nice object mapper of its own. Both of those have progressed to the point that writing raw SQL is simple unnecessary for almost any application development.
Relational databases will be around as long as humans generate relational data. Take the classic example of an invoice that may have many entries, each entry referencing an inventory item. This sort of thing is likely to exist forever, and RDBMSes model that pretty well.
As far as whether the backend is row- or column-oriented - who cares? As long as I can use the one most appropriate to my access pattern, the implementation details just don't interest me enough to get worked into a furor. Don't get me wrong - I think that there are some neat developments in the works - it's just that I don't have a strong general preference on how my information is physically laid down on the platters.
A more interesting question for me is whether SQL is obsolete. For the most part, I'd say that it is in the sense that most people need never use it directly. We use SQLAlchemy instead of writing raw SQL, and the Java folks seem to be fond of Hibernate. I still look at the generated queries sometimes to convince myself that it's sane or for debugging or optimization purposes, but if they inserted a new middle layer between Alchemy and PostgreSQL that used something completely different, our code wouldn't notice the difference.
You just made that all up, knowing that none of us would be smart enough to catch it, didn't you?
Ain't that the truth. I can't believe I just had to pay $45,000,000 for my 3-foot-thick diamond-plated Chevy Juggernaut with nano-airbags and built-in collision-predicting supercomputer that tracks all nearby objects and several near-Earth objects.
Oh, wait, you meant in reality? Yeah, I don't have any of than and my car cost less that $20,000.
An article on functional programming is the perfect time to introduce my new son, Nick, to Slashdot. Previous releases were in C, Perl, and Python. Since Nick's functional, this one is in Lisp.
Mod me up or my son will spit up on you.
Well, functional programs have a lot of other restrictions, but it boils down to this: with very rare exceptions (such as file or socket handling), functions don't have side effects. That is, they don't modify a program's global state, and they don't depend on global state. You can call foo(args) 100 times in a row and each time the output will be identical. My C++ is rusty, but imagine something like:
Any code that calls foo() will find its internal state changed - both bar and baz have been altered. In comparison, this is almost impossible to do accidentally in functional languages.
So, great, what does that buy you? Well, the map() function in you example knows that it's supposed to call compose2() on each item in source_list. Because it's impossible for compose2() to have strange global side effects and it doesn't depend on external state, map() is free to fork() 10 times and let each child process munch through independent subsets of source_list. In the case of Erlang, map() is also free to hand off chunks of source_list to other machines and coalesce the results from all of those hosts at the end. As long as compose2() gets called on each item at some point, the order (and indeed the physical location) of each call doesn't matter a lick.
Imagine that you have 20 quad-core systems in a cluster. Replacing the imperative example above with the functional example gives your code an 80x performance boost, minus a little network overhead. Does that sound more interesting now?
"You were using an up-to-date version of Word then, too. That just cost you $3,000."
Yes, it's much easier just to assign an arbitrarily label to something than to try to understand the nuances. Ignorant, but easier.
Darn stodgy ol' antidisestablishmentarianists.
Either that, or your code sucks more than theirs. Even if that's not true, you might not want to run around telling the world that these jackasses didn't think you made the grade.
I think that says much more about that parish in particular than it does about Catholicism, let alone Christianity as a whole. Returning to my Southern Baptist example, the absolute harshest "punishment" that can be given to a church member is to tell them not to come back to that church (and I've never personally heard of that happening). Whether they join another church is between them and the new congregation. There's no equivalent to excommunication.
The reason I bring this up is that the Catholic church seems to have the highest media profile. If a TV show or movie requires a religious presence, it's typically a priest. Because of this, I think, a lot of people equate the Catholic church with Christianity. However, while they're certainly a part of the larger group, their actions have little bearing on how the rest of Christianity works.
Oh really? If you want to learn what Baptists believe, go into a Baptist church and ask. They'll give you a Bible and as much denomination-specific literature as you care to leave with. You won't have to give your name, although they might ask for it. You won't have to join. You won't have to pay them anything. You won't have to sign a non-disclosure statement. And should you decide that you like it and wish to join that particular church, you're free to leave at any time. In fact, church membership isn't a requirement of their belief system at all (although it's recommended so that you can continue to learn about it and hang out with like-minded people). No one will tell you where to work or where to live or which doctor to go to or who you can be friends with.
And that, to me, is the difference between a religion and a cult. You may completely disagree with what Baptists believe, but they'll tell you the entire story in advance and let you decide for yourself. The same goes for pretty much every other mainstream religion. On the other hand, if a group requires a donation or commitment before they'll even tell you what you're joining, run screaming. There are enough Open Source religions around that there's not much point in joining a proprietary sect.