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  • htaccess mod_rewrite check file/directory existence, else rewrite?

    - by devians
    I have a very heavy htaccess mod_rewrite file that runs my application. As we sometimes take over legacy websites, I sometimes need to support old urls to old files, where my application processes everything post htaccess. My ultimate goal is to have a 'Demilitarized Zone' for old file structures, and use mod rewrite to check for existence there before pushing to the application. This is pretty easy to do with files, by using: RewriteCond %{IS_SUBREQ} true RewriteRule .* - [L] RewriteCond %{ENV:REDIRECT_STATUS} 200 RewriteRule .* - [L] RewriteCond Public/DMZ/$1 -F [OR] RewriteRule ^(.*)$ Public/DMZ/$1 [QSA,L] This allows pseudo support for relative urls by not hardcoding my base path (I cant assume I will ever be deployed in document root) anywhere and using subrequests to check for file existence. Works fine if you know the file name, ie http://domain.com/path/to/app/legacyfolder/index.html However, my legacy urls are typically http://domain.com/path/to/app/legacyfolder/ Mod_Rewrite will allow me to check for this by using -d, but it needs the complete path to the directory, ie RewriteCond Public/DMZ/$1 -F [OR] RewriteCond /var/www/path/to/app/Public/DMZ/$1 -d RewriteRule ^(.*)$ Public/DMZ/$1 [QSA,L] I want to avoid the hardcoded base path. I can see one possible solutions here, somehow determining my path and attaching it to a variable [E=name:var] and using it in the condition. Another option is using -U, but the tricky part is stopping it from hijacking every other request when they should flow through, since -U is really easy to satisfy. Any implementation that allows me to existence check a directory is more than welcome. I am not interested in using RewriteBase, as that requires my htaccess to have a hardcoded base path.

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  • How to customize the pop up menu in iPhone?

    - by Allen Dang
    The application I'm creating needs a function like user selects some text, a pop up menu shows, and user clicks "search" menu to perform a search directly. Problem is the current pop up menu provided by UIMenuController doesn't support to be extended. So my thought is to subscribe "UIMenuControllerDidShowMenuNotification", get the frame of pop up menu, and display the "search" button right aside. But during the implementation, I met a strange problem, the notification seems never be sent, means after the menu shown, I still cannot be notified, following are the key section of code. - (void)viewDidLoad { [super viewDidLoad]; [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(menuDidShow:) name:UIMenuControllerWillShowMenuNotification object:nil]; } - (void)viewDidUnload { // Release any retained subviews of the main view. // e.g. self.myOutlet = nil; [[NSNotificationCenter defaultCenter] removeObserver:self name:UIMenuControllerDidShowMenuNotification object:nil]; self.textView = nil; self.searchBar = nil; } - (void)menuDidShow:(NSNotification *)notification { NSLog(@"menu did show!"); } The code is too simple to make mistake, can someone help me to understand what's going on? Or what did I miss?

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  • Setting LD_LIBRARY_PATH in Apache PassEnv/SetEnv still cant find library

    - by DoMoreASAP
    I am trying to test the Cybersource 3d party implementation. I was able to get the test files running fine from the command line, which requires that on Linux I export the path to the payment libraries to LD_LIBRARY_PATH. to try to test this on my server I have created the apache config below <VirtualHost 127.0.0.1:12345> AddHandler cgi-script .cgi AddHandler fcgid-script .php .fcgi FCGIWrapper /my/path/to/php_fcgi/bin/php-cgi .php AddType text/html .shtml AddOutputFilter INCLUDES .shtml DocumentRoot /my/path/to/cybersource/simapi-php-5.0.1/ ProxyPreserveHost on <Directory /my/path/to/cybersource/simapi-php-5.0.1> SetEnv LD_LIBRARY_PATH /my/path/to/cybersource/LinkedLibraries/lib/ AllowOverride all Options +Indexes IndexOptions Charset=UTF-8 </Directory> </VirtualHost> I have set the env variable there with SetEnv command, which seems to be working when i run a page that prints <?php phpinfo(); ?> however the test script when called through the browser still wont work, apache says: tail /my/apache/error_log [Tue Mar 30 23:11:46 2010] [notice] mod_fcgid: call /my/path/to/cybersource/index.php with wrapper /my/path/to/cybersource/php_fcgi/bin/php-cgi PHP Warning: PHP Startup: Unable to load dynamic library '/my/path/to/cybersource/extensionsdir/php5_cybersource.so' - libspapache.so: cannot open shared object file: No such file or directory in Unknown on line 0 so it cant find the linked file libspapache.so even though it is in the LD_LIBRARY_PATH that is supposedly defined i really appreciate the help. thanks so much.

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  • Fill 2D area bound by vertices in XNA

    - by oakskc
    I'm learning XNA by doing and, as the title states, I'm trying to see if there's a way to fill a 2D area that is defined by a collection of vertices on a plane. I want to fill with a color, not a file-based texture. For an example, take a rounded rectangle whose vertices are defined by four quarter-circle triangle fans. The vertices are defined by building a collection of triangles, but the triangles may not be adjacent. Additionally, I would like to fill it with more than a single color -- i.e. divide the bound area into four vertical bands and have each a different color. You don't have to provide me the code, pointing me towards resources will help a great deal. I can be handy with Google (which I did try first, but have failed miserably). This is as much an exploration into "what's appropriate for XNA" as it is the implementation of it. Being pretty new to XNA, I'm wanting to also learn what should and shouldn't be done on top of what can and can't be done.

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  • how to load multiple images in iCarousel using this code?

    - by Dany
    i'm loading bunch of images in coverflow using i carousel but i'm not getting it?..initially i got Signal sigabart issue..after i edited some of the code the view gets displayed...Am i missing something?... #import "CollectionViewController.h" @interface CollectionViewController () @property (nonatomic, retain) NSMutableArray *items; @end @implementation CollectionViewController @synthesize carousel; @synthesize items; - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil { self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]; if (self) { // Custom initialization } return self; } - (void)dealloc { carousel.delegate = nil; carousel.dataSource = nil; [items release]; [carousel release]; [super dealloc]; } - (void)viewDidLoad { [super viewDidLoad]; carousel.type = iCarouselTypeCoverFlow2; } - (void)viewDidUnload { [super viewDidUnload]; self.carousel = nil; } - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation { return (interfaceOrientation == UIInterfaceOrientationPortrait); } #pragma mark - #pragma mark iCarousel methods - (NSUInteger)numberOfItemsInCarousel:(iCarousel *)carousel { return [items count]; } - (NSUInteger)numberOfVisibleItemsInCarousel:(iCarousel *)carousel { return 29; } - (UIView *)carousel:(iCarousel *)carousel viewForItemAtIndex:(NSUInteger)index reusingView:(UIView *)view { //create new view if no view is available for recycling if (view == nil) { view = [NSArray arrayWithObjects:[UIImage imageNamed:@"gal1.jpg"], [UIImage imageNamed:@"gal2.jpg"], [UIImage imageNamed:@"gal3.jpg"], [UIImage imageNamed:@"gal5.jpg"], [UIImage imageNamed:@"gal6.jpg"], [UIImage imageNamed:@"gal7.jpg"], [UIImage imageNamed:@"gal8.jpg"], [UIImage imageNamed:@"gal9.jpg"], [UIImage imageNamed:@"gal10.jpg"], [UIImage imageNamed:@"gal11.jpg"], [UIImage imageNamed:@"gal12.jpg"], [UIImage imageNamed:@"gal13.jpg"], [UIImage imageNamed:@"gal14.jpg"], [UIImage imageNamed:@"gal15.jpg"], [UIImage imageNamed:@"gal16.jpg"], [UIImage imageNamed:@"gal17.jpg"], [UIImage imageNamed:@"gal18.jpg"], [UIImage imageNamed:@"gal19.jpg"], [UIImage imageNamed:@"gal20.jpg"], [UIImage imageNamed:@"gal21.jpg"], [UIImage imageNamed:@"gal22.jpg"], [UIImage imageNamed:@"gal23.jpg"], [UIImage imageNamed:@"gal24.jpg"], [UIImage imageNamed:@"gal25.jpg"], [UIImage imageNamed:@"gal26.jpg"], [UIImage imageNamed:@"gal27.jpg"], [UIImage imageNamed:@"gal28.jpg"], } else { } return view; } @end while running on simulator i just get the screen not images?...i got stuck here....

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  • How does 'lazy' work?

    - by Matt Fenwick
    What is the difference between these two functions? I see that lazy is intended to be lazy, but I don't understand how that is accomplished. -- | Identity function. id :: a -> a id x = x -- | The call '(lazy e)' means the same as 'e', but 'lazy' has a -- magical strictness property: it is lazy in its first argument, -- even though its semantics is strict. lazy :: a -> a lazy x = x -- Implementation note: its strictness and unfolding are over-ridden -- by the definition in MkId.lhs; in both cases to nothing at all. -- That way, 'lazy' does not get inlined, and the strictness analyser -- sees it as lazy. Then the worker/wrapper phase inlines it. -- Result: happiness Tracking down the note in MkId.lhs (hopefully this is the right note and version, sorry if it's not): Note [lazyId magic] ~~~~~~~~~~~~~~~~~~~ lazy :: forall a?. a? -> a? (i.e. works for unboxed types too) Used to lazify pseq: pseq a b = a `seq` lazy b Also, no strictness: by being a built-in Id, all the info about lazyId comes from here, not from GHC.Base.hi. This is important, because the strictness analyser will spot it as strict! Also no unfolding in lazyId: it gets "inlined" by a HACK in CorePrep. It's very important to do this inlining after unfoldings are exposed in the interface file. Otherwise, the unfolding for (say) pseq in the interface file will not mention 'lazy', so if we inline 'pseq' we'll totally miss the very thing that 'lazy' was there for in the first place. See Trac #3259 for a real world example. lazyId is defined in GHC.Base, so we don't have to inline it. If it appears un-applied, we'll end up just calling it. I don't understand that because it refers to lazyId instead of lazy. How does lazy work?

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  • Backend raising (INotify)PropertyChanged events to all connected clients?

    - by Jörg Battermann
    One of our 'frontend' developers keeps requesting from us backend developers that the backend notifies all connected clients (it's a client/server environment) of changes to objects. As in: whenever one user makes a change, all other connected clients must be notified immediately of the change. At the moment our architecture does not have a notification system of that kind and we don't have a sort of pub/sub model for explicitly chosen objects (e.g. the one the frontend is currently implementing).. which would make sense in such a usecase imho, but obviously requires extra implementation. However, I thought frontends typically check for locks for concurrently existing user changes on the same object and rather pull for changes / load on demand and in the background rather than the backend pushing all changes to all clients for all objects constantly.. which seems rather excessive to me. However, it's being argumented that e.g. the MS Entity Framework does in fact publish (INotify)PropertyChanged not only for local changes, but for all such changes including other client connections, but I have found no proof or details regarding this. Can anyone shed some light into this? Do other e.g. ORMs etc provide broadcasted (INotify)PropertyChanged events on entities?

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  • JSF 2.0: Validate equality of 2 InputSecret Fields (confirm password) without writing Code?

    - by yournamehere
    I'm developing a pure JavaEE6 application with JSF 2.0 and Glassfish. My JSF implementation is Primefaces (beside Mojarra provided by Glassfish). I want to verify if the values of 2 password fields in a JSF form are equal. With Seam, there is the neat component <s:validateEquality for="pw1"/>. I want do to the same without Seam, just using JSF (or maybe a component of a JSF library). Until now i only saw examples which validate the form with a custom validator. But i would like to compare the fields without writing Java code or Javascript code. Is that possible? This what it looks like with Seam: ... <h:inputSecret id="passwort" value="#{personHome.instance.password}" redisplay="true" required="true"> <f:validateLength minimum="8"/> <a:support event="onblur" reRender="passwortField" bypassUpdates="true" ajaxSingle="true" /> </h:inputSecret> ... <h:inputSecret id="passwort2" required="true" redisplay="true"> <!-- find the JSF2.0-equivalent to this tag: --> <s:validateEquality for="passwort"/> <a:support event="onblur" reRender="passwort2Field" bypassUpdates="true" ajaxSingle="true" /> </h:inputSecret> ... Any help is appreciated. Thanks!

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  • Using Traveling Salesman Solver to Decide Hamiltonian Path

    - by Firas Assaad
    This is for a project where I'm asked to implement a heuristic for the traveling salesman optimization problem and also the Hamiltonian path or cycle decision problem. I don't need help with the implementation itself, but have a question on the direction I'm going in. I already have a TSP heuristic based on a genetic algorithm: it assumes a complete graph, starts with a set of random solutions as a population, and works to improve the population for a number of generations. Can I also use it to solve the Hamiltonian path or cycle problems? Instead of optimizing to get the shortest path, I just want to check if there is a path. Now any complete graph will have a Hamiltonian path in it, so the TSP heuristic would have to be extended to any graph. This could be done by setting the edges to some infinity value if there is no path between two cities, and returning the first path that is a valid Hamiltonian path. Is that the right way to approach it? Or should I use a different heuristic for Hamiltonian path? My main concern is whether it's a viable approach since I can be somewhat sure that TSP optimization works (because you start with solutions and improve them) but not if a Hamiltonian path decider would find any path in a fixed number of generations. I assume the best approach would be to test it myself, but I'm constrained by time and thought I'd ask before going down this route... (I could find a different heuristic for Hamiltonian path instead)

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  • Why I cannot get correct class of a custom class through isKindOfClass?

    - by Anthony Chan
    Hi, I've created a custom class AnimalView which is a subclass of UIView containing a UILabel and a UIImageView. @interface AnimalView : UIView { UILabel *nameLabel; UIImageView *picture; } Then I added in several AnimalView onto the ViewController.view. In the touchesBegan:withEvent: method, I wanted to detect if the touched object is an AnimalView or not. Here is the code for the viewController: @implementation AppViewController - (void)viewDidLoad { UIScrollView *scrollView = [[UIScrollView alloc] initWithFrame:... [self.view addSubview scrollview]; for (int i = 0; i<10; i++) { AnimalView *newAnimal = [[AnimalView alloc] init]; // customization of newAnimal [scrollview addSubview:newAnimal; } } - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event { UITouch *touch = [touches anyObject]; UIView *hitView = touch.view; if ([hitView isKindOfClass:[AnimalView class]]) { AnimalView *animal = (AnimalView *)hitView; [animal doSomething]; } } However, nothing happened when I clicked on the animal. When I checked the class of hitView by NSLog(@"%@", [hitView class]), it always shows UIView instead of AnimalView. Is it true that the AnimalView changed to a UIView when it is added onto the ViewController? Is there any way I can get back the original class of a custom class?

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  • Why do properties require explicit typing during compilation?

    - by ctpenrose
    Compilation using property syntax requires the type of the receiver to be known at compile time. I may not understand something, but this seems like a broken or incomplete compiler implementation considering that Objective-C is a dynamic language. The property "comment" is defined with: @property (nonatomic, retain) NSString *comment; and synthesized with: @synthesize comment; "document" is an instance of one of several classes which conform to: @protocol DocumentComment <NSObject> @property (nonatomic, retain) NSString *comment; @end and is simply declared as: id document; When using the following property syntax: stringObject = document.comment; the following error is generated by gcc: error: request for member 'comment' in something not a structure or union However, the following equivalent receiver-method syntax, compiles without warning or error and works fine, as expected, at run-time: stringObject = [document comment]; I don't understand why properties require the type of the receiver to be known at compile time. Is there something I am missing? I simply use the latter syntax to avoid the error in situations where the receiving object has a dynamic type. Properties seem half-baked.

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  • Find unique vertices from a 'triangle-soup'

    - by sum1stolemyname
    I am building a CAD-file converter on top of two libraries (Opencascade and DWF Toolkit). However, my question is plattform agnostic: Given: I have generated a mesh as a list of triangular faces form a model constructed through my application. Each Triangle is defined through three vertexes, which consist of three floats (x, y & z coordinate). Since the triangles form a mesh, most of the vertices are shared by more then one triangle. Goal: I need to find the list of unique vertices, and to generate an array of faces consisting of tuples of three indices in this list. What i want to do is this: //step 1: build a list of unique vertices for each triangle for each vertex in triangle if not vertex in listOfVertices Add vertex to listOfVertices //step 2: build a list of faces for each triangle for each vertex in triangle Get Vertex Index From listOfvertices AddToMap(vertex Index, triangle) While I do have an implementation which does this, step1 (the generation of the list of unique vertices) is really slow in the order of O(n!), since each vertex is compared to all vertices already in the list. I thought "Hey, lets build a hashmap of my vertices' components using std::map, that ought to speed things up!", only to find that generating a unique key from three floating point values is not a trivial task. Here, the experts of stackoverflow come into play: I need some kind of hash-function which works on 3 floats, or any other function generating a unique value from a 3d-vertex position.

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  • How do you marshall a parameterized type with JAX-WS / JAXB?

    - by LES2
    Consider the following classes (please assume public getter and setter methods for the private fields). // contains a bunch of properties public abstract class Person { private String name; } // adds some properties specific to teachers public class Teacher extends Person { private int salary; } // adds some properties specific to students public class Student extends Person { private String course; } // adds some properties that apply to an entire group of people public class Result<T extends Person> { private List<T> group; private String city; // ... } We might have the following web service implementation annotated as follows: @WebService public class PersonService { @WebMethod public Result<Teacher> getTeachers() { ... } @WebMethod public Result<Student> getStudents() { ... } } The problem is that JAXB appears to marshall the Result object as a Result<Person> instead of the concrete type. So the Result returned by getTeachers() is serialized as containing a List<Person> instead of List<Teacher>, and the same for getStudents(), mutatis mutandis. Is this the expected behavior? Do I need to use @XmlSeeAlso on Person? Thanks! LES

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  • Correct use of WSDL-generated sources

    - by John K
    How can I easily convert between manually written classes and WSDL-generated equivalents? I have a Java SE 6 thick client that calls a web service to get and store data. The client has a DAO that works with my entity classes, calls <Entity.toDto() to convert them to DTOs, and sends/receives that data with the web service. My issue stems from the fact that the entity classes live on both sides of the service interface: client and server. Each entity has a constructor from the DTO and a toDto function: public class EntityClass { public EntityClass(EntityClassDto dto); public EntityClassDto toDto(); ... } This means I have a handwritten DTO class that the client and server both use. However, the service interface expects the WSDL-generated classes. I have tried writing conversion code between the hand-written DTO and the WSDL-generated DTO and it is tedious and error-prone. What is a reasonable alternative to this? Some back-story: The thick client should be able to have a configurable backend: either direct to the DB or through this web service. The aforementioned DAO is the web service based implementation and another imlpementation that is JPA-based exists.

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  • How to estimate the contribution of an individual to a software project?

    - by Amit Kumar
    I work on a software project and would like to estimate the percentage out of the total contribution that I have put in the development of the software. Is there some tool doing this? Such a tool can be useful for appraisals or negotiations, for example. After all, we work for money (yes, not only money, put the point remains). I think there is enough hand-waving for the most important things. The estimation is very subjective (at least to me now) but I do not know of any tool that provides even a subjective estimate. I know of Sloccount that spells out the total effort using the lines of code but not on per-developer basis. My idea of an ideal tool for this purpose would: measure the complexity of the code (more complex is more effort, but more effort is not necessarily more contribution) measure the decomposibility/flexibility of the software (more decomposable is better) how much library code is used -- using library code speeds up the development process, increases the associated risk and requires the developer to know from before or learn about the library. be intelligent enough to differentiate between "who wrote the code", "who copied the code" and "who indented the code". It is difficult to differentiate between the complexity in the implementation and the intrinsic complexity of the problem. Perhaps a comparison can be made with an equivalent open source counterpart if there is, or for each submodule separately. If there is no such tool, is there no merit in having such a tool? Or do you believe in "I do work, I do not measure"? It takes time after all. Perhaps the project manager should do this estimation continuously, say, weekly. Are there any standards? Yes, standardization is difficult because every project has a different goal, but difficult does not mean it is not useful.

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  • Writing PHP extension - Unable to load dynamic library

    - by Luke
    I'm writing a PHP extension similar to V8JS. The goal, like V8JS, is to embed the V8 engine into PHP so I can execute sandboxed JavaScript code in PHP. (The implementation is different.) The extension compiles fine, but when I attempt to run it I get: PHP Warning: PHP Startup: Unable to load dynamic library '/phpdev/lib/php/extensions/debug-zts-20090626/v8php.so' - dlopen(/phpdev/lib/php/extensions/debug-zts-20090626/v8php.so, 9): Symbol not found: __ZN2v88internal8Snapshot13context_size_E Referenced from: /phpdev/lib/php/extensions/debug-zts-20090626/v8php.so Expected in: flat namespace PHP is compiled with the prefix /phpdev (with debug and maintainer flags). v8 is compiled in /v8/ with gyp with the commands make dependencies and make x64 which produced /v8/out/x64.release and /v8/out/x64.debug. I soft-linked the header files from /v8/include to /phpdev/include and libv8_base.a from /v8/out/x64.release/libv8_base.a to /phpdev/lib/libv8.a. This is my config.m4 file: PHP_ARG_ENABLE(v8php, [V8PHP], [--enable-v8php Include V8 JavaScript Engine]) if test $PHP_V8PHP != "no"; then SEARCH_PATH="$prefix /usr/local /usr" SEARCH_FOR="/include/v8.h" if test -r $PHP_V8PHP/$SEARCH_FOR; then V8_DIR=$PHP_V8PHP else AC_MSG_CHECKING([for V8 files in default path]) for i in $SEARCH_PATH ; do if test -r $i/$SEARCH_FOR; then V8_DIR=$i AC_MSG_RESULT(found in $i) fi done fi if test -z "$V8_DIR"; then AC_MSG_RESULT([not found]) AC_MSG_ERROR([Unable to locate V8]) fi PHP_ADD_INCLUDE($V8_DIR/include) PHP_SUBST(V8PHP_SHARED_LIBADD) PHP_ADD_LIBRARY_WITH_PATH(v8, $V8_DIR/$PHP_LIBDIR, V8PHP_SHARED_LIBADD) PHP_REQUIRE_CXX() PHP_NEW_EXTENSION(v8php, v8php.cc v8_class.cc, $ext_shared) fi What am I doing wrong?

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  • Having Uploadify e-mail a link to download the file

    - by kwek-kwek
    Uploadify is a jQuery plugin that allows the easy integration of a multiple (or single) file uploads on your website. It requires Flash and any backend development language. An array of options allow for full customization for advanced users, but basic implementation is so easy that even coding novices can do it. I wanted to ask if It is possible to sends out a link of a file that has just been uploaded wioth the e-mail notification of Uploadify. Here is the code for uploadify.php : <?php if (!empty($_FILES)) { $tempFile = $_FILES['Filedata']['tmp_name']; $targetPath = $_SERVER['DOCUMENT_ROOT'] . $_REQUEST['folder'] . '/'; $targetFile = str_replace('//','/',$targetPath) . $_FILES['Filedata']['name']; // $fileTypes = str_replace('*.','',$_REQUEST['fileext']); // $fileTypes = str_replace(';','|',$fileTypes); // $typesArray = split('\|',$fileTypes); // $fileParts = pathinfo($_FILES['Filedata']['name']); // if (in_array($fileParts['extension'],$typesArray)) { // Uncomment the following line if you want to make the directory if it doesn't exist // mkdir(str_replace('//','/',$targetPath), 0755, true); move_uploaded_file($tempFile,$targetFile); echo "1"; // } else { // echo 'Invalid file type.'; // } } //define the receiver of the email $to = '[email protected]'; //define the subject of the email $subject = 'Test email'; //define the message to be sent. Each line should be separated with \n $message = "Hello World!\n\nThis is my first mail."; //define the headers we want passed. Note that they are separated with \r\n $headers = "From: [email protected]\r\nReply-To: [email protected]"; //send the email $mail_sent = @mail( $to, $subject, $message, $headers ); //if the message is sent successfully print "Mail sent". Otherwise print "Mail failed" echo $mail_sent ? "Mail sent" : "Mail failed"; ?>

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  • Parsing Lisp S-Expressions with known schema in C#

    - by Drew Noakes
    I'm working with a service that provides data as a Lisp-like S-Expression string. This data is arriving thick and fast, and I want to churn through it as quickly as possible, ideally directly on the byte stream (it's only single-byte characters) without any backtracking. These strings can be quite lengthy and I don't want the GC churn of allocating a string for the whole message. My current implementation uses CoCo/R with a grammar, but it has a few problems. Due to the backtracking, it assigns the whole stream to a string. It's also a bit fiddly for users of my code to change if they have to. I'd rather have a pure C# solution. CoCo/R also does not allow for the reuse of parser/scanner objects, so I have to recreate them for each message. Conceptually the data stream can be thought of as a sequence of S-Expressions: (item 1 apple)(item 2 banana)(item 3 chainsaw) Parsing this sequence would create three objects. The type of each object can be determined by the first value in the list, in the above case "item". The schema/grammar of the incoming stream is well known. Before I start coding I'd like to know if there are libraries out there that do this already. I'm sure I'm not the first person to have this problem.

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  • Are PyArg_ParseTuple() "s" format specifiers useful in Python 3.x C API?

    - by Craig McQueen
    I'm trying to write a Python C extension that processes byte strings, and I have something basically working for Python 2.x and Python 3.x. For the Python 2.x code, near the start of my function, I currently have a line: if (!PyArg_ParseTuple(args, "s#:in_bytes", &src_ptr, &src_len)) ... I notice that the s# format specifier accepts both Unicode strings and byte strings. I really just want it to accept byte strings and reject Unicode. For Python 2.x, this might be "good enough"--the standard hashlib seems to do the same, accepting Unicode as well as byte strings. However, Python 3.x is meant to clean up the Unicode/byte string mess and not let the two be interchangeable. So, I'm surprised to find that in Python 3.x, the s format specifiers for PyArg_ParseTuple() still seem to accept Unicode and provide a "default encoded string version" of the Unicode. This seems to go against the principles of Python 3.x, making the s format specifiers unusable in practice. Is my analysis correct, or am I missing something? Looking at the implementation for hashlib for Python 3.x (e.g. see md5module.c, function MD5_update() and its use of GET_BUFFER_VIEW_OR_ERROUT() macro) I see that it avoids the s format specifiers, and just takes a generic object (O specifier) and then does various explicit type checks using the GET_BUFFER_VIEW_OR_ERROUT() macro. Is this what we have to do?

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  • C++: Check istream has non-space, non-tab, non-newline characters left without extracting chars

    - by KRao
    I am reading a std::istream and I need to verify without extracting characters that: 1) The stream is not "empty", i.e. that trying to read a char will not result in an fail state (solved by using peek() member function and checking fail state, then setting back to original state) 2) That among the characters left there is at least one which is not a space, a tab or a newline char. The reason for this is, is that I am reading text files containing say one int per line, and sometimes there may be extra spaces / new-lines at the end of the file and this causes issues when I try get back the data from the file to a vector of int. A peek(int n) would probably do what I need but I am stuck with its implementation. I know I could just read istream like: while (myInt << myIstream) {...} //Will fail when I am at the end but the same check would fail for a number of different conditions (say I have something which is not an int on some line) and being able to differentiate between the two reading errors (unexpected thing, nothing left) would help me to write more robust code, as I could write: while (something_left(myIstream)) { myInt << myIstream; if (myStream.fail()) {...} //Horrible things happened } Thank you!

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  • Versioning friendly, extendible binary file format

    - by Bas Bossink
    In the project I'm currently working on there is a need to save a sizable data structure to disk (edit: think dozens of MB's). Being an optimist, I thought that there must be a standard solution for such a problem; however, up to now I haven't found a solution that satisfies the following requirements: .NET 2.0 support, preferably with a FOSS implementation Version friendly (this should be interpreted as: reading an old version of the format should be relatively simple if the changes in the underlying data structure are simple, say adding/dropping fields) Ability to do some form of random access where part of the data can be extended after initial creation (think of this as extending intermediate results) Space and time efficient (XML has been excluded as option given this requirement) Options considered so far: Protocol Buffers: was turned down by verdict of the documentation about Large Data Sets - since this comment suggested adding another layer on top, this would call for additional complexity which I wish to have handled by the file format itself. HDF5,EXI: do not seem to have .net implementations SQLite/SQL Server Compact edition: the data structure at hand would result in a pretty complex table structure that seems too heavyweight for the intended use BSON: does not appear to support requirement 3. Fast Infoset: only seems to have paid .NET implementations. Any recommendations or pointers are greatly appreciated. Furthermore if you believe any of the information above is not true, please provide pointers/examples to prove me wrong.

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  • Implementing arrays using a stack

    - by Zack
    My programming language has no arrays, no lists, no pointers, no eval and no variable variables. All it has: Ordinary variables like you know them from most programming languages: They all have an exact name and a value. One stack. Functions provided are: push (add element to top), pop (remove element from top, get value) and empty (check if stack is empty) My language is turing-complete. (Basic arithmetics, conditional jumps, etc implemented) That means, it must be possible to implement some sort of list or array, right? But I have no idea how... What I want to achieve: Create a function which can retrieve and/or change an element x of the stack. I could easily add this function in the implementation of my language, in the interpreter, but I want to do it in my programming language. "Solution" one (Accessing an element x, counting from the stack top) Create a loop. Pop off the element from the stack top x times. The last element popped of is element number x. I end up with a destroyed stack. Solution two: Do the same as above, but store all popped off values in a second stack. Then you could move all elements back after you are done. But you know what? I don't have a second stack!

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  • Objective-C Protocols within Protocols

    - by LucasTizma
    I recently began trying my hand at using protocols in my Objective-C development as an (obvious) means of delegating tasks more appropriately among my classes. I completely understand the basic notion of protocols and how they work. However, I came across a roadblock when trying to create a custom protocol that in turn implements another protocol. I since discovered the solution, but I am curious why the following DOES NOT work: @protocol STPickerViewDelegate < UIPickerViewDelegate > - ( void )customCallback; @end @interface STPickerView : UIPickerView { id < STPickerViewDelegate > delegate; } @property ( nonatomic, assign ) id < STPickerViewDelegate > delegate; @end Then in a view controller, which conforms to STPickerViewDelegate: STPickerView * pickerView = [ [ STPickerView alloc ] init ]; pickerView.delegate = self; - ( void )customCallback { ... } - ( NSString * )pickerView:( UIPickerView * )pickerView titleForRow:( NSInteger )row forComponent:( NSInteger )component { ... } The problem was that pickerView:titleForRow:forComponent: was never being called. On the other hand, customCallback was being called just fine, which isn't too surprising. I don't understand why STPickerViewDelegate, which itself conforms to UIPickerViewDelegate, does not notify my view controller when events from UIPickerViewDelegate are supposed to occur. Per my understanding of Apple's documentation, if a protocol (A) itself conforms to another protocol (B), then a class (C) that conforms to the first protocol (A) must also conform to the second protocol (B), which is exactly the behavior I want and expected. What I ended up doing was removing the id< STPickerViewDelegate > delegate property from STViewPicker and instead doing something like the following in my STViewPicker implementation where I want to evoke customCallback: if ( [ self.delegate respondsToSelector:@selector( customCallback ) ] ) { [ self.delegate performSelector:@selector( customCallback ) ]; } This works just fine, but I really am puzzled as to why my original approach did not work.

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  • Difference in performance between Stax and DOM parsing

    - by Fazal
    I have been using DOM for a long time and as such DOM parsing performance wise has been pretty good. Even when dealing with XML of about 4-7 MB the parsing has been fast. The issue we face with DOM is the memory footprint which become huge as soon as we start dealing with large XMLs. Lately I tried moving to Stax (Streaming parsers for XML) which are supposed top be second generation parsers (reading about Stax it said its the fastest parser now). When I tried stax parser for large XML for about 4MB memory footprint definitely reduced drastically but time take to parse entire XML and create java object out of it increased almost by 5 times over DOM. I used sjsxp.jar implementation of Stax. I can deuce to some extent logically that performance may not be extremely good due to streaming nature of the parser but a reduction of 5 time (e.g. DOM takes about 8 seconds to build object for this XML, whereas Stax parsing took about 40 seconds on average) is definitely not going to be acceptable. Am I missing some point here completely as I am not able to come to terms with these performance numbers

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  • Best way to close nested streams in Java?

    - by dirtyvagabond
    What is considered the best, most comprehensive way to close nested streams in Java? For example, consider the setup: FileOutputStream fos = new FileOutputStream(...) BufferedOS bos = new BufferedOS(fos); ObjectOutputStream oos = new ObjectOutputStream(bos); I understand the close operation needs to be insured (probably by using a finally clause). What I wonder about is, is it necessary to explicitly make sure the nested streams are closed, or is it enough to just make sure to close the outer stream (oos)? One thing I notice, at least dealing with this specific example, is that the inner streams only seem to throw FileNotFoundExceptions. Which would seem to imply that there's not technically a need to worry about closing them if they fail. Here's what a colleague wrote: Technically, if it were implemented right, closing the outermost stream (oos) should be enough. But the implementation seems flawed. Example: BufferedOutputStream inherits close() from FilterOutputStream, which defines it as: 155 public void close() throws IOException { 156 try { 157 flush(); 158 } catch (IOException ignored) { 159 } 160 out.close(); 161 } However, if flush() throws a runtime exception for some reason, then out.close() will never be called. So it seems "safest" (but ugly) to mostly worry about closing FOS, which is keeping the file open. What is considered to be the hands-down best, when-you-absolutely-need-to-be-sure, approach to closing nested streams? And are there any official Java/Sun docs that deal with this in fine detail?

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