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  • best REGEXP friendly Text Editors + most powerful REGEXP syntax?

    - by John
    I am fluent with Microsoft Visual 2005 regular expressions and they are a big time saver. I seem to learn them best by having a vaguely organized cheat sheet thrown at me, at which point I read just a little and play with them until I understand what's going on. That learning approach has worked well for me, for now. I would really like to take this to the next level though. Basically -- What is the REGEXP convention that is generally regarded as the most open-ended and powerful? VS2005 Regexps seem kind of gimped, so maybe I'm a kid playing in a sandbox. Are there text editors out there that can perform a highlight all matches, list lines containing string, or some kind of powerful function like that in conjunction with the very strongest REGEXP language? If not I can just use multiple programs and a weird technique but I'd like to avoid that. I wonder if a stronger REGEXP language or a "stronger" regEXP writer might be able to have his search match all results on all lines even by clicking a "find next" by adding some simple criteria to the search. Anyway, please provide advice!

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  • Help me understand WebDAV and Autoversioning

    - by Malfist
    I just read the WebDAV Appendex in the O'Reilly Subversion book. I don't quite understand it. It talked about users being able to "mount" WebDAV directories (trees) and manipulate the files like they would normally and on saves the server would automagically create a new revision. The way it explained it, it sounded like it would work for any program, but then at the end of the appendix, it listed a series of programs that worked with WebDAV servers, which leads me to think that maybe it doesn't work like it originally described it. My question is this: How exactly do you interact with a WebDAV repository? Can I do this for example: Copy a file locally via ftp, edit it with notepad++, and then upload it via ftp to the server and have the server do a commit and create a new revision with the file I just edited and uploaded. Also, if that is possible, what happens if two people edit the file locally (on their machines) and uploaded two reversions to the server? With webDAV will I be able to replace Dreamweaver's "Oops, someone edited this before you" with simple ftp uploads and subversion conflict resolutions?

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  • iPhone: Low memory crash...

    - by MacTouch
    Once again I'm hunting memory leaks and other crazy mistakes in my code. :) I have a cache with frequently used files (images, data records etc. with a TTL of about one week and a size limited cache (100MB)). There are sometimes more then 15000 files in a directory. On application exit the cache writes an control file with the current cache size along with other useful information. If the applications crashes for some reason (sh.. happens sometimes) I have in such case to calculate the size of all files on application start to make sure I know the cache size. My app crashes at this point because of low memory and I have no clue why. Memory leak detector does not show any leaks at all. I do not see any too. What's wrong with the code below? Is there any other fast way to calculate the total size of all files within a directory on iPhone? Maybe without to enumerate the whole contents of the directory? The code is executed on the main thread. NSUInteger result = 0; NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; NSDirectoryEnumerator *dirEnum = [[[NSFileManager defaultManager] enumeratorAtPath:path] retain]; int i = 0; while ([dirEnum nextObject]) { NSDictionary *attributes = [dirEnum fileAttributes]; NSNumber* fileSize = [attributes objectForKey:NSFileSize]; result += [fileSize unsignedIntValue]; if (++i % 500 == 0) { // I tried lower values too [pool drain]; } } [dirEnum release]; dirEnum = nil; [pool release]; pool = nil; Thanks, MacTouch

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  • Is there a Scala version of .irbrc or another way to define some default libraries for REPL use?

    - by Tom Morris
    I've written a little library that uses implicits to add functionality that one only needs when using the REPL in Scala. Ruby has libraries like this - for things like pretty printing, firing up text editors (like the interactive_editor gem which invokes Vim from irb - see this post), debuggers and the like. The library I am trying to write adds some methods to java.lang.Class and java.lang.reflect classes using the 'pimp my library' implicit conversion process to help you go and find documentation (initially, with Google, then later possibly with a JavaDoc/ScalaDoc viewer, and maybe the StackOverflow API eventually!). It's an itch-scratching library: I spend so much time copying and pasting classnames into Google that I figured I may as well automate the process. It is the sort of functionality that developers will want to add to their system for use only in the REPL - they shouldn't really be adding it to projects (partly because it may not be something that their fellow developers want, but also because if you are doing some exploratory development, it may be with just a Scala REPL that's not being invoked by an IDE or build tool). In my case, I want to include a few classes and set up some implicits - include a .jar on the CLASSPATH and import it, basically. In Ruby, this is the sort of thing that you'd add to your .irbrc file. Other REPLs have similar ways of setting options and importing libraries. Is there a similar file or way of doing this for the Scala REPL?

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  • Access values of a group of select boxes in php from post

    - by 2Real
    Hi, I'm new to PHP, and I can't figure this out. I'm trying to figure out how to access the data of a group of select boxes I have defined in my HTML code. I tried grouping them as a class, but that doesn't seem to work... maybe I was doing it wrong. This is the following HTML code. <form action="" method="post"> <select class="foo"> <option> 1.....100</option> </select> <select class="foo"> <option> 1.... 500></option> </select> <input type="submit" value="Submit" name="submit"/> </form> I essentially want to group all my select boxes and access all the values in my PHP code. Thanks

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  • Qt/C++ Error handling

    - by ShiGon
    I've been doing a lot of research about handling errors with Qt/C++ and I'm still as lost as when I started. Maybe I'm looking for an easy way out (like other languages provide). One, in particular, provides for an unhandled exception which I use religiously. When the program encounters a problem, it throws the unhandled exception so that I can create my own error report. That report gets sent from my customers machine to a server online which I then read later. The problem that I'm having with C++ is that any error handling that's done has to be thought of BEFORE hand (think try/catch or massive conditionals). In my experience, problems in code are not thought of before hand else there wouldn't be a problem to begin with. Writing a cross-platform application without a cross-platform error handling/reporting/trace mechanism is a little scary to me. My question is: Is there any kind of Qt or C++ Specific "catch-all" error trapping mechanism that I can use in my application so that, if something does go wrong I can, at least, write a report before it crashes?

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  • CSS/JQUERY make div scrollable without showing scrollbar

    - by Ispuk
    is there any way to make a div scrollable with overflow-y:hidden; and overflow-x:hidden? i'm trying without success, maybe i need some js or jquery script? i mean, i would like to make div scroll on y axes without showing scrollbar on right side( as it is now). itryed: .get-list{ position:absolute; z-index:444; text-align: center; display: none; bottom:0; clear:both !important; left:0; right:0; top:11%; margin:0 auto; background:#fff; max-height:800px; overflow-y:no-display; overflow-x:hidden; display: block; } thanks EDIT log-widget-list{ position:absolute; z-index:444; text-align: center; display: none; width:99%; margin:0 auto; background:#fff; height:800px; overflow: hidden; } .log-widget-list .scroller{ overflow: scroll; height:800px; width:100%; } it shows right scrollbar anyway

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  • protect form hijacking hack

    - by Karem
    Yes hello today I discovered a hack for my site. When you write a msg on a users wall (in my communitysite) it runs a ajax call, to insert the msg to the db and will then on success slide down and show it. Works fine with no problem. So I was rethinking alittle, I am using POST methods for this and if it was GET method you could easily do ?msg=haxmsg&usr=12345679. But what could you do to come around the POST method? I made a new html document, made a form and on action i set "site.com/insertwall.php" (the file that normally are being used in ajax), i made some input fields with names exactly like i am doing with the ajaxcall (msg, uID (userid), BuID (by userid) ) and made a submit button. I know I have a page_protect() function on which requires you to login and if you arent you will be header to index.php. So i logged in (started session on my site.com) and then I pressed on this submit button. And then wops I saw on my site that it has made a new message. I was like wow, was it so easy to hijack POST method i thought maybe it was little more secure or something. I would like to know what could I do to prevent this hijacking? As i wouldnt even want to know what real hackers could do with this "hole". The page_protect secures that the sessions are from the same http user agent and so, and this works fine (tried to run the form without logging in, and it just headers me to startpage) but yea wouldnt take long time to figure out to log in first and then run it. Any advices are appreciated alot. I would like to keep my ajax calls most secure as possible and all of them are running on the POST method. What could I do to the insertwall.php, to check that it comes from the server or something.. Thank you

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  • Weird margin in a list

    - by kevin
    I'm trying to style a menu, but I keep running into this weird margin that's appearing in both FF4 and IE. This is the only affecting css: #header ul { display: inline; } #header ul li { list-style-type: none; background: #000; display: inline; margin: 0; padding: 0; } #header ul li a { color: #fff; text-decoration: none; display: inline-block; width: 100px; text-align: center; } And this is the HTML: <div id="header"> <ul id="toplinks"> <li><a href="#">Hello</a></li> <li><a href="#">Herp</a></li> <li><a href="#">Derp</a></li> </ul> </div> As you can see, there's a margin appearing on both sides, and I'd like it so it would have no margin (or maybe 1px would be okay)...

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  • Best practice- How to team-split a django project while still allowing code reusal

    - by Infinity
    I know this sounds kind of vague, but please let me explain- I'm starting work on a brand new project, it will have two main components: "ACME PRODUCT" (think Gmail, Meebo, etc), and "THE SITE" (help, information, marketing stuff, promotional landing pages, etc lots of marketing-induced cruft). So basically the url /acme/* will load stuff in the uber cool ajaxy application, and every other URI will load stuff in the other site. Problem: "THE SITE" component is out of my hands, and will be handled by a consultants team that will work closely with marketing, And I and my team will work solely on the ACME PRODUCT. Question: How to set up the django project in such a way that we can have: Seperate releases. (They can push new marketing pages and functionality without having to worry about the state of our code. Maybe even separate Subversion "projects") Minimize impact (on our product) of whatever flying-unicorns-hocus-pocus the other team codes into the site. Still allow some code reusal. My main concern is that the ACME product needs to be rock solid, and therefore needs to be somewhat isolated of whatever mistakes/code bloopers the consultants make in their marketing side of the site. How have you handled this? Any ideas? Thanks!

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  • Entity Framework POCO objects

    - by Dan
    I'm struggling with understanding Entity Framework and POCO objects. Here's what I'm trying to achieve. 1) Separate the DAL from the Business Layer by having my business layer use an interface to my DAL. Maybe use Unity to create my context. 2) Use Entity Framework inside my DAL. I have a Domain model with objects that reside in my business layer. I also have a database full of tables that doesn't really represent my domain model. I setup Entity Framework and generated POCO objects by using the ADO.NET POCO Generator extension. This gave me an object for each table in my database. Now I want to be able to say context.GetAll<User>(); and have it return a list of my User objects. The User object is in my business layer. Is that possible? Does that make sense or am I totally off and should start over? I'm guessing I need to use the repository pattern to achieve this, but I'm not sure. Can anyone help?

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  • cocoa/c++ relative path to load resources

    - by moka
    Hi, I am currently working directly with cocoa for the first time, to built a screen saver. Now I came across a problem when trying to load resources from within the .saver bundle. I basically have a small c++ wrapper class to load .exr files using freeImage. That works as long as I use absoulte paths, but thats not very useful, is it? So basically I tried everything, putting the .exr file on the level of the .saver bundle itself, inside the bundles Resources folder and so on. Then I simply tried to load the .exr like this without success particleTex = [self loadExrTexture: "ball.exr"]; I also tried making it go to the .saver bundles location like this: particleTex = [self loadExrTexture: "../../../ball.exr"]; to maybe load the .exr from that location but without success. I then came across this: NSString * path = [[NSBundle mainBundle] pathForResource:@"ball" ofType:@"exr"]; const char * pChar = [path UTF8String]; which seems to be a common way to find resources in cocoa, but for some reason its emty in my case. any ideas about that? I really tried out anything that came to my mind without success so I would be glad about some input!

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  • application trying to connect to mirrored sql db

    - by hp
    Hello, We have 4 web servers that host our asp.net (3.5) application. Randomly, we get error messages like : 1) "Login failed for user 'userid'" 2) "A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)" we are running sql2005 and have a principle and a mirror db (sync). When these exceptions are thrown, I look at the SQL error logs on the mirrored db and noticed the failed login messages in there. The principle db is running fine and the other web apps are working great. this will happen for maybe 10 min, then the app pool recycles and it starts hitting the principle db again. Is there a configuration I have incorrect? my theory is that our principle db is forwarding the request to the mirror, but that should never happen. any help??

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  • How to intercept touch events globally?

    - by mystify
    I have an view which is sometimes covered by some other views. However, if the user slides the finger across the screen, I want to slide that underlying view across the screen, too. I could start making custom views for all those covering subviews and forward all kinds of touch events, but that's somewhat cumbersome. Maybe there's some kind of notification or another way that a UIView or UIControl subclass can be aware of touch events happening right now, no matter where they are. In short: I need an UIView subclass or UIControl subclass which knows about any touch events happening on the entire screen. Or at least if tht's not possible, knowing about any touch events happening above itself in the same underlying superview. Another description: There are 20 views, all reside inside the same superview. The first view is covered by 19 others. But if the user slides across the screen, that first view must slide too, so it must be aware of touch events. Is there any better solution that making all 19 views forward touch events? (yes, all 19 views respond to touch events in this example)

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  • C++: defining maximum/minimum limits for a class

    - by Luis
    Basically what the title says... I have created a class that models time slots in a variable-granularity daily schedule (where for example the first time slot is 30 minutes, but the second time slot can be 40 minutes); the first available slot starts at (a value comparable to) 1. What I want to do now is to define somehow the maximum and minimum allowable values that this class takes and I have two practical questions in order to do so: 1.- does it make sense to define absolute minimum and maximum in such a way for a custom class? Or better, does it suffice that a value always compares as lower-than any other possible value of the type, given the class's defined relational operators, to be defined the min? (and analogusly for the max) 2.- assuming the previous question has an answer modeled after "yes" (or "yes but ..."), how do I define such max/min? I know that there is std::numeric_limits<> but from what I read it is intended for "numeric types". Do I interpret that as meaning "represented as a number" or can I make a broader assumption like "represented with numbers" or "having a correspondence to integers"? After all, it would make sense to define the minimum and maximum for a date class, and maybe for a dictionary class, but numeric_limits may not be intended for those uses (I don't have much experience with it). Plus, numeric_limits has a lot of extra members and information that I don't know what to make with. If I don't use numeric_limits, what other well-known / widely-used mechanism does C++ offer to indicate the available range of values for a class?

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  • How to catch an incomming text message

    - by Espen
    Hi! I want to be able to control incoming text messages. My application is still on a "proof of concept" version and I'm trying to learn Android programming as I go. First my application need to catch incomming text messages. And if the message is from a known number then deal with it. If not, then send the message as nothing has happened to the default text message application. I have no doubt it can be done, but I still have some concern and I see some pitfalls at how things are done on Android. So getting the incomming text message could be fairly easy - except when there are other messaging applications installed and maybe the user wants to have normal text messages to pop up on one of them - and it will, after my application has had a look at it first. How to be sure my application get first pick of incomming text messages? And after that I need to send most text messages through to any other text message application the user has chosen so the user can actually read the message my application didn't need. Since Android uses intents that are relative at best, I don't see how I can enforce my application to get a peek at all incomming text messages, and then stop it or send it through to the default text messaging application...

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  • Android Signal 11 (SIGSEGV)

    - by Naturjoghurt
    I read many posts here and on other sites, but can not find the problem creating my Error: I use an AsyncTask because I want to easily manipulate the UI Thread before and after Execution. In doInBackground I create a ThreadPoolExecutor and execute Runnables. If I only execute 1 Runnable with the Executor, there is no Problem, but if I execute another Runnable I get following Error: 06-26 18:00:42.288: A/libc(25073): Fatal signal 11 (SIGSEGV) at 0x7f486162 (code=1), thread 25106 (pool-1-thread-2) 06-26 18:00:42.304: D/dalvikvm(25073): GC_CONCURRENT freed 119K, 2% free 8908K/9056K, paused 4ms+4ms, total 45ms 06-26 18:00:42.327: I/System.out(25073): In Check All with Prefix: a and Length: 4 06-26 18:00:42.390: I/DEBUG(126): *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** 06-26 18:00:42.390: I/DEBUG(126): Build fingerprint: 'google/yakju/maguro:4.2.2/JDQ39/573038:user/release-keys' 06-26 18:00:42.390: I/DEBUG(126): Revision: '9' 06-26 18:00:42.390: I/DEBUG(126): pid: 25073, tid: 25106, name: pool-1-thread-2 >>> de.uni_duesseldorf.cn.distributed_computing2 <<< 06-26 18:00:42.390: I/DEBUG(126): signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr 7f486162 ... 06-26 18:00:42.538: I/DEBUG(126): memory map around fault addr 7f486162: 06-26 18:00:42.538: I/DEBUG(126): 60292000-60391000 06-26 18:00:42.538: I/DEBUG(126): (no map for address) 06-26 18:00:42.538: I/DEBUG(126): bed14000-bed35000 [stack] I set up the ThreadPoolExecutor like this: // numberOfPackages: Number of Runnables to be executed public void initializeThreadPoolExecutor (int numberOfPackages) { int corePoolSize = Runtime.getRuntime().availableProcessors(); int maxPoolSize = numberOfPackages; long keepAliveTime = 60; final BlockingQueue workingQueue = new LinkedBlockingQueue(); executor = new ThreadPoolExecutor(corePoolSize, maxPoolSize, keepAliveTime, TimeUnit.SECONDS, workingQueue); } I have no clue, why it fails when starting the second Thread. Maybe Memory Leaks? Any Help appreciated. Thanks in Advance

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  • PHP: How do I rename a directory where the parent directory is variable?

    - by gsquare567
    i would like to move the files inside uploads/pension/#SOME_VARIABLE_NUMBER#/#SOME_CONSTANT_NUMBER#/ here is my code: // move pension statements // located at uploads/pension/%COMPANY_ID%/%USER_ID%/%HASH% // so just move the %USER_ID% folder to the new company $oldPensionDir = "uploads/pension/" . $demo_user[Users::companyID] . "/" . $demo_user[Users::userID] . "/"; $newPensionDir = "uploads/pension/" . $newCompanyID . "/" . $demo_user[Users::userID] . "/"; // see if the user had any files, and if so, move them if(file_exists($oldPensionDir)) { // if it doesnt exist, make it if(!file_exists($newPensionDir)) mkdir($newPensionDir); // move the folder rename($oldPensionDir, $newPensionDir); } however... when i need to make the directory with the "mkdir" function, i get: mkdir() [<a href='function.mkdir'>function.mkdir</a>]: No such file or directory ok, maybe the mkdir won't work, but what about the rename? perhaps that will make the directory if it's not there... nope! rename(uploads/pension/1001/783/,uploads/pension/1000/783/) [<a href='function.rename'>function.rename</a>]: The system cannot find the path specified. (code: 3) so, there are two errors. i'm pretty sure if the renaming works, i won't even need the mkdir, but who knows... can anyone tell me why these are errors and how to fix them? thanks!

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  • UITableView reloaddata doesn't reload immediately

    - by D33
    Hi everyone. I'm trying to work with online data in my iPhone app. But I'm getting mad because of this: I have object for downloading data with NSURLConnection. Method starting the work with connection (and other stuff) in separate thread - [ NSThread detachNewThreadSelector:@selector( doConnectionInNewThread ) toTarget: self withObject: nil ]; When data are loaded (connectionDidFinishLoading) I give them to my viewController. This all stuff works fine. When I use breakpoints or NSLog I have the data ready to show in UITableView. When I call reloadData, nothing happens immediately. It reloads data after maybe 2 seconds (- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath is called after this delay). BUT when I slide the tableView, it reloads data immediately. So the connection and so on works fine but it just doesn't reload the data. Why? I thought it could be due to blocked mainThread by URLConnection. But now I use it in separate thread and it is still the same...

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  • Advantage of WPF app vs Winform for business apps?

    - by Abdu
    I know asp.net and winform development. I am not the type of developer who jumps into a new technology just because it's new. It needs to give me extra benefits like higher productivity. What are the advantages of WPF over Winforms for pure business apps? I am not interested in the extra eye candy, animation, gradients, image display effects and so on which WPF provides. The business apps are for data entry, data reporting and maybe some charts and static display of photos. How will WPF help in these apps? Better richer data binding? WinForm is a mature proven technology and I like the fact I can do everything in Visual Studio vs multiple IDE's for WPF (VS & Blend family). Plus I think WPF doesn't have as rich data binding controls like their Winform counterparts (DataGridView..etc). AFAIK, Microsoft will still support Winforms for many years. Try to convince someone like me to switch.

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  • Slightly different execution times between python2 and python3

    - by user557634
    Hi. Lastly I wrote a simple generator of permutations in python (implementation of "plain changes" algorithm described by Knuth in "The Art... 4"). I was curious about the differences in execution time of it between python2 and python3. Here is my function: def perms(s): s = tuple(s) N = len(s) if N <= 1: yield s[:] raise StopIteration() for x in perms(s[1:]): for i in range(0,N): yield x[:i] + (s[0],) + x[i:] I tested both using timeit module. My tests: $ echo "python2.6:" && ./testing.py && echo "python3:" && ./testing3.py python2.6: args time[ms] 1 0.003811 2 0.008268 3 0.015907 4 0.042646 5 0.166755 6 0.908796 7 6.117996 8 48.346996 9 433.928967 10 4379.904032 python3: args time[ms] 1 0.00246778964996 2 0.00656183719635 3 0.01419159912 4 0.0406293644678 5 0.165960511097 6 0.923101452814 7 6.24257639835 8 53.0099868774 9 454.540967941 10 4585.83498001 As you can see, for number of arguments less than 6, python 3 is faster, but then roles are reversed and python2.6 does better. As I am a novice in python programming, I wonder why is that so? Or maybe my script is more optimized for python2? Thank you in advance for kind answer :)

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  • How to Set up Virtual Static Subdomain

    - by Chip D
    Given current rewrite rules at http://www.example.com/: Options +FollowSymlinks +Includes RewriteEngine on RewriteBase / RewriteCond %{HTTP_HOST} !^www\.example\.com [NC] RewriteCond %{HTTP_HOST} !^$ RewriteRule ^/?(.*) http://www.example.com/$1 [L,R,NE] # Remove all "index.html"s. RewriteCond %{THE_REQUEST} \ /(.+/)?index\.html(\?.*)?\ [NC] RewriteRule ^(.+/)?index\.html$ /%1 [R=301,L] # Remove all "index.php"s. RewriteCond %{THE_REQUEST} \ /(.+/)?index\.php(\?.*)?\ [NC] RewriteRule ^(.+/)?index\.php$ /%1 [R=301,L] I'm attempting to serve some site assets (.png|.ico|.jpg|.gif|.css|.js) from a static subdomain like http://static.example.com which my Apache 1.3 shared host (GoDaddy) has mapped to a subdirectory for file management (http://www.example.com/static/). Currently these assets live in same-site subdirectories such as images/, js/, css/, etc. (1) Something...maybe the "+www" rewrite rule?...is not letting me access the subdomain. Is this likely caused by my rewrite rules above, or do I need to set up DNS changes with the host to enable access to the subdirectory, in addition to changing the rewrite rules? (2) Do I have to move those assets to that subdirectory and change all references sitewide? Would that perform the fastest? (3) Or can .htaccess make this much easier? (4) Should my first rewrite rule above include L,R=301,NE instead of [L,R,NE]?

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  • Ideal HTTP cache control headers for different types of resources

    - by chris_l
    I want to find a minimal set of headers, that work with "all" caches and browsers (also when using HTTPS!) On my (GWT-based) web site, I'll have three kinds of resources: 1. Forever cacheable (public / equal for all users) These files don't ever change, and they get a filename based on the MD5 of their contents (this is GWT's approach). They should get cached as much as possible, even when using HTTPS (so I assume, I should set Cache-Control: public, especially for Firefox?) 2. Changing for every new version of the site (public / equal for all users) These files can be cached, but probably need to be revalidated every time. 3. Individual for each request (private / user specific) These resources (e. g. JSON responses) should never be cached unencrypted to disk under no circumstances. (Maybe I'll have a few specific requests that could be cached.) I have a general idea on which headers I would probably use for each type, but there's always something I could be missing.

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  • Handling close-to-impossible collisions on should-be-unique values

    - by balpha
    There are many systems that depend on the uniqueness of some particular value. Anything that uses GUIDs comes to mind (eg. the Windows registry or other databases), but also things that create a hash from an object to identify it and thus need this hash to be unique. A hash table usually doesn't mind if two objects have the same hash because the hashing is just used to break down the objects into categories, so that on lookup, not all objects in the table, but only those objects in the same category (bucket) have to be compared for identity to the searched object. Other implementations however (seem to) depend on the uniqueness. My example (that's what lead me to asking this) is Mercurial's revision IDs. An entry on the Mercurial mailing list correctly states The odds of the changeset hash colliding by accident in your first billion commits is basically zero. But we will notice if it happens. And you'll get to be famous as the guy who broke SHA1 by accident. But even the tiniest probability doesn't mean impossible. Now, I don't want an explanation of why it's totally okay to rely on the uniqueness (this has been discussed here for example). This is very clear to me. Rather, I'd like to know (maybe by means of examples from your own work): Are there any best practices as to covering these improbable cases anyway? Should they be ignored, because it's more likely that particularly strong solar winds lead to faulty hard disk reads? Should they at least be tested for, if only to fail with a "I give up, you have done the impossible" message to the user? Or should even these cases get handled gracefully? For me, especially the following are interesting, although they are somewhat touchy-feely: If you don't handle these cases, what do you do against gut feelings that don't listen to probabilities? If you do handle them, how do you justify this work (to yourself and others), considering there are more probable cases you don't handle, like a supernonva?

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  • Resource placement (optimal strategy)

    - by blackened
    I know that this is not exactly the right place to ask this question, but maybe a wise guy comes across and has the solution. I'm trying to write a computer game and I need an algorithm to solve this question: The game is played between 2 players. Each side has 1.000 dollars. There are three "boxes" and each player writes down the amount of money he is going to place into those boxes. Then these amounts are compared. Whoever placed more money in a box scores 1 point (if draw half point each). Whoever scores more points wins his opponents 1.000 dollars. Example game: Player A: [500, 500, 0] Player B: [333, 333, 334] Player A wins because he won Box A and Box B (but lost Box C). Question: What is the optimal strategy to place the money? I have more questions to ask (algorithm related, not math related) but I need to know the answer to this one first. Update (1): After some more research I've learned that these type of problems/games are called Colonel Blotto Games. I did my best and found few (highly technical) documents on the subject. Cutting it short, the problem I have (as described above) is called simple Blotto Game (only three battlefields with symmetric resources). The difficult ones are the ones with, say, 10+ battle fields with non-symmetric resources. All the documents I've read say that the simple Blotto game is easy to solve. The thing is, none of them actually say what that "easy" solution is.

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