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  • Replace System.Net.Mail.MailMessage with manually created message and send it

    - by DEH
    I am trying to send emails that will bounce to a known mailbox. I plan to use VERP. Unfortunately the System.Net.Mail.MailMessage object does not allow me to precisely set the From: and Sender: headers within my email - it forces the values so that the resulting email contains the phrase 'on behalf of', and does not allow me fine control over the relevant mime headers. I therefore plan to manually write mime email messages directly to the pickup directory so that I can independently control the From and Sender headers. My dev box is a Vista box and therefore does not have an SMTP server. I would like to configure the dev box so that I have an SMTP server running on it. I can then turn off the SMTP server, write messages to the pickup dir, then turn on the SMPT server and see how the individual emails that I have written will behave (some delivered, some bounced to a bounce handler on a different email domain, as dictated by the Sender). Two questions: 1. Can anyone recommend an SMTP server that will monitor a pickup directory? 2. If I set headers as follows; From:[email protected]; Sender:[email protected] then the recipient will see the email as having come from [email protected] ( and won't see any reference to [email protected]), but if the mail bounces then the NDR will be sent to [email protected]). It's a real pain to have to do this, but I can't see any way of using System.Net.Mail.MailMessage without it messing up my headers.

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  • Can i use the open source rich text editor in my site ? what does this GNU do with that ?

    - by Shyju
    I want to use one rich text editor to one of my ASP page.I searched in internet and found that there are lot of open source items available like TinyMCE,FCK Editror,nice edit etc.. Can i put the same samples in my website.There is a GNU license associated with it.Can somebody interpret it for me to answer these questions 1 . Can i use it in my website without getting a permission from anyone ? 2 . Do i need maintain the same files always ? Can i make some customization and use it ? Customization is only the CSS changes its going to be. 3 . Do i need to put all the files as it is of the package which downloaded.because my download has samples which supports all languages. Do i need to put all those folders too From GNU license " if you distribute copies of such a program, whether gratis or for a fee, you must pass on to the recipients the same freedoms that you received. You must make sure that they, too, receive or can get the source code. And you must show them these terms so they know their rights."

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  • How does this code break the Law of Demeter?

    - by Dave Jarvis
    The following code breaks the Law of Demeter: public class Student extends Person { private Grades grades; public Student() { } /** Must never return null; throw an appropriately named exception, instead. */ private synchronized Grades getGrades() throws GradesException { if( this.grades == null ) { this.grades = createGrades(); } return this.grades; } /** Create a new instance of grades for this student. */ protected Grades createGrades() throws GradesException { // Reads the grades from the database, if needed. // return new Grades(); } /** Answers if this student was graded by a teacher with the given name. */ public boolean isTeacher( int year, String name ) throws GradesException, TeacherException { // The method only knows about Teacher instances. // return getTeacher( year ).nameEquals( name ); } private Grades getGradesForYear( int year ) throws GradesException { // The method only knows about Grades instances. // return getGrades().getForYear( year ); } private Teacher getTeacher( int year ) throws GradesException, TeacherException { // This method knows about Grades and Teacher instances. A mistake? // return getGradesForYear( year ).getTeacher(); } } public class Teacher extends Person { public Teacher() { } /** * This method will take into consideration first name, * last name, middle initial, case sensitivity, and * eventually it could answer true to wild cards and * regular expressions. */ public boolean nameEquals( String name ) { return getName().equalsIgnoreCase( name ); } /** Never returns null. */ private synchronized String getName() { if( this.name == null ) { this.name == ""; } return this.name; } } Questions How is the LoD broken? Where is the code breaking the LoD? How should the code be written to uphold the LoD?

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  • In PHP... best way to turn string representation of a folder structure into nested array

    - by Greg Frommer
    Hi everyone, I looked through the related questions for a similar question but I wasn't seeing quite what I need, pardon if this has already been answered already. In my database I have a list of records that I want represented to the user as files inside of a folder structure. So for each record I have a VARCHAR column called "FolderStructure" that I want to identify that records place in to the folder structure. The series of those flat FolderStructure string columns will create my tree structure with the folders being seperated by backslashes (naturally). I didn't want to add another table just to represent a folder structure... The 'file' name is stored in a separate column so that if the FolderStructure column is empty, the file is assumed to be at the root folder. What is the best way to turn a collection of these records into a series of HTML UL/LI tags... where each LI represents a file and each folder structure being an UL embedded inside it's parent?? So for example: file - folderStructure foo - bar - firstDir blue - firstDir/subdir would produce the following HTML: <ul> <li>foo</li> <ul> <li> bar </li> <ul> <li> blue </li> </ul> </ul> </ul> Thanks

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  • iPhone: objc_class_name_TTTabStrip symbol not found build error

    - by user187532
    Hello friends, I am trying to implement 'scrollview' effect in 'Tabbar' which has 'TabItems'. I found that the good example is from 'facebook' open source 'TTCatlog' project 'Tabs' section. So i included all the source from it to my project and trying to build it. I have followed the following links to go ahead on this: http://stackoverflow.com/questions/822792/how-to-create-a-horizontal-scrolling-view-on-iphone source: http://github.com/facebook/three20/tree/master/samples/ My calling code is like below: _tabBar1 = [[TTTabStrip alloc] initWithFrame:CGRectMake(10, 68, 300, 28)]; _tabBar1.tabItems = [NSArray arrayWithObjects: [[[TTTabItem alloc] initWithTitle:@"Item 1"] autorelease], [[[TTTabItem alloc] initWithTitle:@"Item 2"] autorelease], [[[TTTabItem alloc] initWithTitle:@"Item 3"] autorelease], [[[TTTabItem alloc] initWithTitle:@"Item 4"] autorelease], [[[TTTabItem alloc] initWithTitle:@"Item 5"] autorelease], [[[TTTabItem alloc] initWithTitle:@"Item 6"] autorelease], [[[TTTabItem alloc] initWithTitle:@"Item 7"] autorelease], [[[TTTabItem alloc] initWithTitle:@"Item 8"] autorelease], [[[TTTabItem alloc] initWithTitle:@"Item 9"] autorelease], [[[TTTabItem alloc] initWithTitle:@"Item 10"] autorelease], nil]; [self.navigationController.view addSubview:_tabBar1]; My project folder as like below: ..../iphone/MyProgram/MyProgram.xcodeproj ..../iphone/Three20/src/Three20.... In my project settings for header search path, I have ../Three20/src But when i try to build it, it throws the following error: "objc_class_name_TTTabStrip symbol not found" "objc_class_name_TTTabItem symbol not found" I see there, all these files (.h and .m) are availbale there. Could someone please help what's wrong there and how do i get rid of this issue and continue working with it?

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  • Which Table Should be Master and Child in Database Design

    - by Jason
    I am quickly learning the ins and outs of database design (something that, as of a week ago, was new to me), but I am running across some questions that don't seem immediately obvious, so I was hoping to get some clarification. The question I have right is about foreign keys. As part of my design, I have a Company table. Originally, I had included address information directly within the table, but, as I was hoping to achieve 3NF, I broke out the address information into its own table, Address. In order to maintain data integrity, I created a row in Company called "addressId" as an INT and the Address table has a corresponding addressId as its primary key. What I'm a little bit confused about (or what I want to make sure I'm doing correctly) is determining which table should be the master (referenced) table and which should be the child (referencing) table. When I originally set this up, I made the Address table the master and the Company the child. However, I now believe this is wrong due to the fact that there should be only one address per Company and, if a Company row is deleted, I would want the corresponding Address to be removed as well (CASCADE deletion). I may be approaching this completely wrong, so I would appreciate any good rules of thumb on how to best think about the relationship between tables when using foreign keys. Thanks!

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  • why unsigned int 0xFFFFFFFF is equal to int -1?

    - by conejoroy
    perhaps it's a very stupid question but I'm having a hard time figuring this out =) in C or C++ it is said that the maximum number a size_t (an unsigned int data type) can hold is the same as casting -1 to that data type. for example see http://stackoverflow.com/questions/1420982/invalid-value-for-sizet Why?? I'm confused.. I mean, (talking about 32 bit ints) AFAIK the most significant bit holds the sign in a signed data type (that is, bit 0x80000000 to form a negative number). then, 1 is 0x00000001.. 0x7FFFFFFFF is the greatest positive number a int data type can hold. then, AFAIK the binary representation of -1 int should be 0x80000001 (perhaps I'm wrong). why/how this binary value is converted to anything completely different (0xFFFFFFFF) when casting ints to unsigned?? or.. how is it possible to form a binary -1 out of 0xFFFFFFFF? I have no doubt that in C: ((unsigned int)-1) == 0xFFFFFFFF or ((int)0xFFFFFFFF) == -1 is equally true than 1 + 1 == 2, I'm just wondering why. thanks!

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  • Castle Windsor, Fluent Nhibernate, and Automapping Isession closed problem

    - by SImon
    I'm new to the whole castle Windsor, Nhibernate, Fluent and Automapping stack so excuse my ignorance here. I didn't want to post another question on this as it seems there are already a huge number of questions that try to get a solution the Windsor nhib Isession management problem, but none of them have solved my problem so far. I am still getting a ISession is closed exception when I'm trying to call to the Db from my Repositories,Here is my container setup code. container.AddFacility<FactorySupportFacility>() .Register( Component.For<ISessionFactory>() .LifeStyle.Singleton .UsingFactoryMethod(() => Fluently.Configure() .Database( MsSqlConfiguration.MsSql2005. ConnectionString( c => c.Database("DbSchema").Server("Server").Username("UserName").Password("password"))) .Mappings ( m => m.AutoMappings.Add ( AutoMap.AssemblyOf<Message>(cfg) .Override<Client>(map => { map.HasManyToMany(x => x.SICCodes).Table("SICRefDataToClient"); }) .IgnoreBase<BaseEntity>() .Conventions.Add(DefaultCascade.SaveUpdate()) .Conventions.Add(new StringColumnLengthConvention(),new EnumConvention()) .Conventions.Add(new EnumConvention()) .Conventions.Add(DefaultLazy.Never()) ) ) .ExposeConfiguration(ConfigureValidator) .ExposeConfiguration(BuildDatabase) .BuildSessionFactory() as SessionFactoryImpl), Component.For<ISession>().LifeStyle.PerWebRequest.UsingFactoryMethod(kernel => kernel.Resolve<ISessionFactory>().OpenSession() )); In my repositories i inject private readonly ISession session; and use it as followes public User GetUser(int id) { User u; u = session.Get<User>(id); if (u != null && u.Id > 0) { NHibernateUtil.Initialize(u.UserDocuments); } return u; in my web.config inside <httpModules>. i have also added this line <add name="PerRequestLifestyle" type="Castle.MicroKernel.Lifestyle.PerWebRequestLifestyleModule, Castle.Windsor"/> I'm i still missing part of the puzzle here, i can't believe that this is such a complex thing to configure for a basic need of any web application development with nHibernate and castle Windsor. I have been trying to follow the code here windsor-nhibernate-isession-mvc and i posted my question there as they seemed to have the exact same issue but mine is not resolved.

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  • I'm trying to grasp the concept of creating a program that uses a MS SQL database, but I'm used to r

    - by Sergio Tapia
    How can I make a program use a MS SQL server, and have that program work on whatever computer it's installed on. If you've been following my string of questions today, you'd know that I'm making an open source and free Help Desk suite for small and medium businesses. The client application. The client application is a Windows Forms app. On installation and first launch on every client machine, it'll ask for the address of the main Help Desk server. The server. Here I plan to handle all incoming help requests, show them to the IT guys, and provide WCF services for the Client application to consume. My dilemma lies in that, I know how to make the program run on my local machine; but I'm really stumped on how to make this work for everyone who wants to download and install the server bit on their Windows Server. Would I have to make an SQL Script and have it run on the MS SQL server when a user wants to install the 'server' application? Many thanks to all for your valuable time and effort to teach me. It's really really appreciated. :)

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  • Debugging fortran code in Eclipse with Photran and GDB debugger: missing symbols

    - by tvandenbrande
    I have a program, written in fortran90, previously successfully compiled on a compaq compiler and working, that I'm now trying to compile with gfortran. I can compile the code to an .exe and run it. It works fine until a certain point in the routine and then an error is thrown. My current configuration: Windows 7 Eclipse Juno with CDT Photran Cygwin installation with gfortran compiler and GDB debugger (gdb.exe) Configurations for the debugger: GDB command set: Standard (Windows) Protocol: mi Shared libraries: don't load shared library symbols automatically (when activating this, no changes are noted). When running the debug command I get the following output: .gdbinit: No such file or directory. Reading symbols from /cygdrive/c/Users/thys/Documents/doctoraat/12_in progress/Hamfem/Debug/Hamfem.exe...done. auto-solib-add on Undefined command: "auto-solib-add". Try "help". Warning: C:/Users/thys/Documents/doctoraat/12_in progress/Hamfem/Hamfem/in: No such file or directory. [New Thread 5816.0x1914] [New Thread 5816.0x654] Basicly that leaves me with 2 questions: Where can I find the .gdbinit file in the cygwin installation? Are there any other possible errors in my setup, or points to think about?

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  • remove specific values from multi value dictionary

    - by Anthony
    I've seen posts here on how to make a dictionary that has multiple values per key, like one of the solutions presented in this link: Multi Value Dictionary it seems that I have to use a List< as the value for the keys, so that a key can store multiple values. the solution in the link is fine if you want to add values. But my problem now is how to remove specific values from a single key. I have this code for adding values to a dictionary: private Dictionary<TKey, List<TValue>> mEventDict; // this is for initializing the dictionary public void Subscribe(eVtEvtId inEvent, VtEvtDelegate inCallbackMethod) { if (mEventDict.ContainsKey(inEvent)) { mEventDict[inEvent].Add(inCallbackMethod); } else { mEventDict.Add(inEvent, new List<TValue>() { v }); } } // this is for adding values to the dictionary. // if the "key" (inEvent) is not yet present in the dictionary, // the key will be added first before the value my problem now is removing a specific value from a key. I have this code: public void Unsubscribe(eVtEvtId inEvent, VtEvtDelegate inCallbackMethod) { try { mEventDict[inEvent].Remove(inCallbackMethod); } catch (ArgumentNullException) { MessageBox.Show("The event is not yet present in the dictionary"); } } basically, what I did is just replace the Add() with Remove() . Will this work? Also, if you have any problems or questions with the code (initialization, etc.), feel free to ask. Thanks for the advice.

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  • Problem installing mysql gem on Snow Leopard: uninitialized constant MysqlCompat::MysqlRes

    - by emson
    Hi All I've got a problem trying to install the Ruby mysql gem driver. I recently upgraded to Snow Leopard and did the Hivelogic manual install of MySQL. This all seems to work fine as I can access mysql from the command line and make changes to the database. My problem is that if I now use rake db:migrate I get: rake aborted! uninitialized constant MysqlCompat::MysqlRes (See full trace by running task with --trace) Now it appears that my mysql gem isn't working correctly as I can access MySQL fine from Python using the Python driver (which I compiled to). I therefore tried to rebuild the gem using the following command from this site: http://techliberty.blogspot.com/, (incidentally I am using a recent Intel MacBook Pro): sudo env ARCHFLAGS="-arch x86_64" gem install mysql -- --with-mysql-config=/usr/local/mysql/bin/mysql_config This compiles although I get No definition for the documentation: Building native extensions. This could take a while... Successfully installed mysql-2.8.1 1 gem installed Installing ri documentation for mysql-2.8.1... No definition for next_result No definition for field_name ... I'm a little stumped as my mysql_config is located in the correct place: /usr/local/mysql/bin/mysql_config And I have removed all other instances of the mysql gem, from my system. Any suggestions would be greatly appreciated. Many thanks. PS I saw this previous post http://stackoverflow.com/questions/1332207/uninitialized-constant-mysqlcompatmysqlres-using-mms2r-gem but it doesn't seem applicable for my version.

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  • Valueurl Binding On Large Arrays Causes Sluggish User Interface

    - by Hooligancat
    I have a large data set (some 3500 objects) that returns from a remote server via HTTP. Currently the data is being presented in an NSCollectionView. One aspect of the data is a path pack to the server for a small image that represents the data (think thumbnail for simplicity). Bindings works fantastically for the data that is already returned, and binding the image via a valueurl binding is easy to do. However, the user interface is very sluggish when scrolling through the data set - which makes me think that the NSCollectionView is retrieving all the image data instead of just the image data used to display the currently viewable images. I was under the impression that Cocoa controls were smart enough to only retrieve data for the information that is actually being output to the user interface through lazy loading. This certainly seems to be the case with NSTableView - but I could be misguided on this thought. Should valueurl binding act lazily and, moreover, should it act lazily in an NSCollectionView? I could create a caching mechanism (in fact I already have such a thing in place for another application - see my post here if you are interested http://stackoverflow.com/questions/1740209/populating-nsimage-with-data-from-an-asynchronous-nsurlconnection) but I really don't want to go this route if I don't have to for this specific implementation as the user could potentially change data sets often and may only want small sub-sets of the data. Any suggested approaches? Thanks!

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  • Perl, regex, extract data from a line

    - by perlnoob
    Im trying to extract part of a line with perl use strict; use warnings; # Set path for my.txt and extract datadir my @myfile = "C:\backups\MySQL\my.txt"; my @datadir = ""; open READMYFILE, @myfile or die "Error, my.txt not found.\n"; while (<READMYFILE>) { # Read file and extract DataDir path if (/C:\backups/gi) { push @datadir, $_; } } # ensure the path was found print @datadir . " \n"; Basically at first im trying to set the location of the my.txt file. Next im trying to read it and pull part of the line with regex. The error Im getting is: Unrecognized escape \m passed through at 1130.pl line 17. I took a look at http://stackoverflow.com/questions/1040657/how-can-i-grab-multiple-lines-after-a-matching-line-in-perl to get an idea of how to read a file and match a line within it, however im not 100% sure I'm doing this right or in the best way. I also seem to produce the error: Error, my.txt not found. But the file does exist in the folder C:\backups\MySQL\

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  • Dojo dialog, the iPad and the virtual keyboard issue

    - by Chris Butler
    Recently, I have been working on a project where the interface should work for desktop and tablets (in particular the iPad). One issue I am coming across is with a Dojo dialog on the iPad when text entry is taking place. Basically here is what happens: Load Dojo interface with buttons on iPad - OK Press button (touch) to show dialog (90% height and width) - OK Click on text box (touch) like DateTextBox or TimeTextBox - OK, the virtual keyboard is opened Click the date or time I want in the UI (touch) - OK, but I can't see all of the options since it is longer than the screen size... Try to scroll down (swipe up with two fingers or click 'next' in the keyboard) - not OK and the dialog repositions itself to have it's top at the top of the viewport area. Basically, the issue is that the dialog keeps trying to reposition itself. Am I able to stop dialog resizing and positioning if I catch the window onResize events? Does anyone else have this issue with the iPad and Dojo dialogs? Also, I found this StackOverflow topic on detecting the virtual keyboard, but it wasn't much help in this case... http://stackoverflow.com/questions/2593139/ipad-web-app-detect-virtual-keyboard-using-javascript-in-safari Thanks!

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  • Is there a way to get an ASMX Web Service created in VS 2005 to receive and return JSON?

    - by Ben McCormack
    I'm using .NET 2.0 and Visual Studio 2005 to try to create a web service that can be consumed both as SOAP/XML and JSON. I read Dave Ward's Answer to the question How to return JSON from a 2.0 asmx web service (in addition to reading other articles at Encosia.com), but I can't figure out how I need to set up the code of my asmx file in order to work with JSON using jQuery. Two Questions: How do I enable JSON in my .NET 2.0 ASMX file? What's a simple jQuery call that could consume the service using JSON? Also, I notice that since I'm using .NET 2.0, I i'm not able to implement using System.Web.Script.Services.ScriptService. Here's my C# code for the demo ASMX service: using System; using System.Web; using System.Collections; using System.Web.Services; using System.Web.Services.Protocols; /// <summary> /// Summary description for StockQuote /// </summary> [WebService(Namespace = "http://tempuri.org/")] [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)] public class StockQuote : System.Web.Services.WebService { public StockQuote () { //Uncomment the following line if using designed components //InitializeComponent(); } [WebMethod] public decimal GetStockQuote(string ticker) { //perform database lookup here return 8; } [WebMethod] public string HelloWorld() { return "Hello World"; } } Here's a snippet of jQuery I found on the internet and tried to modify: $(document).ready(function(){ $("#btnSubmit").click(function(event){ $.ajax({ type: "POST", contentType: "application/json; charset=utf-8", url: "http://bmccorm-xp/WebServices/HelloWorld.asmx", data: "", dataType: "json" }) event.preventDefault(); }); });

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  • DQL delete from multiple tables (doctrine)

    - by singer
    Need to perform DQL delete from multple related tables. In SQL it is something like this: DELETE r1,r2 FROM ComRealty_objects r1, com_realty_objects_phones r2 WHERE r1.id IN (10,20) AND r2.id_object IN (10,20) I need to perform this statement using DQL, but I'm stuck on this :( <?php $dql = Doctrine_Query::create() ->delete('phones, comrealtyobjects') ->from('ComRealtyObjects comrealtyobjects') ->from('ComRealtyObjectsPhones phones') ->whereIn("comrealtyobjects.id", $ids) ->whereIn("phones.id_object", $ids); echo($dql->getSqlQuery()); ?> But DQL parser gives me this result: DELETE FROM `com_realty_objects_phones`, `ComRealty_objects` WHERE (`id` IN (?) AND `id_object` IN (?)) Searching google and stack overflow I found this(useful) topic: http://stackoverflow.com/questions/2247905/what-is-the-syntax-for-a-multi-table-delete-on-a-mysql-database-using-doctrine But this is not exactly my case - there was delete from single table. If there is a way to override dql parser behaviour? Or maybe some other way to delete records from multiple tables using doctrine. Note: If you are using doctrine behaviours(Doctrine_Record_Generator) you need first to initialize those tables using Doctrine_Core::initializeModels() to perform DQL operations on them.

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  • Obtaining touch location for a uiscrollview touch

    - by LOSnively
    I have a uiscrollview as an element of a uiscrollviewcontroller, along with other view objects. The image scrolls and zooms as expected, when the scrollView is the top subview. However, I also need to get the screen location of the touch, in particular when there is no scroll action. (I understand the location may change during a scroll, but that's not important.) I haven't found a way to do that. In the scrollviewcontroller implementation I have customized all of the standard methods that should do this: "touchesShouldBegin...", "touchesBegan:...", "touchesEnded:...", and so on. As far as I can tell, none of these are being called during a touch event when the scrollView is the top subview. I've tried setting the delayContentTouches property to both YES and NO, and that doesn't seem to make a difference. As an alternative, I've tried putting a UIView as the top subview and then tried passing the touches to the now underlying scrollView. In this configuration, the standard methods are called and I can get the touch location, but I haven't found a mechanism for the touches to be passed to the scrollView so scrolling occurs. Doing something like sending the touch messages to the specific scrollView, or to "super" or just sending them to nextResponder doesn't do it. It seems I can make the scroll work or find the location of the touch but not both, depending on what the "top" subview is. I suspect this is trivial, but after two weeks of struggling, it's time to eat my embarrassment for not being able to do this seemingly simplest of things. I've read all of the related questions here on stackoverflow, tried most if not all of the suggestions, and so far, nothing has worked. I've looked through the various links and references suggested by the answers, including Apple's documentation, but none have pointed out the gap in my understanding. Any ideas would be appreciated.

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  • performance of large number calculations in python (python 2.7.3 and .net 4.0)

    - by g36
    There is a lot of general questions about python performance in comparison to other languages. I've got more specific example: There are two simple functions wrote in python an c#, both checking if int number is prime. python: import time def is_prime(n): num =n/2 while num >1: if n % num ==0: return 0 num-=1 return 1 start = time.clock() probably_prime = is_prime(2147483629) elapsed = (time.clock() - start) print 'time : '+str(elapsed) and C#: using System.Diagnostics; public static bool IsPrime(int n) { int num = n/2; while(num >1) { if(n%num ==0) { return false; } num-=1; } return true; } Stopwatch sw = new Stopwatch(); sw.Start(); bool result = Functions.IsPrime(2147483629); sw.Stop(); Console.WriteLine("time: {0}", sw.Elapsed); And times ( which are surprise for me as a begginer in python:)): Python: 121s; c#: 6s Could You explain where does this big diffrence come from ?

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  • Detecting a Dispose() from an exception inside using block

    - by Augusto Radtke
    I have the following code in my application: using (var database = new Database()) { var poll = // Some database query code. foreach (Question question in poll.Questions) { foreach (Answer answer in question.Answers) { database.Remove(answer); } // This is a sample line that simulate an error. throw new Exception("deu pau"); database.Remove(question); } database.Remove(poll); } This code triggers the Database class Dispose() method as usual, and this method automatically commits the transaction to the database, but this leaves my database in an inconsistent state as the answers are erased but the question and the poll are not. There is any way that I can detect in the Dispose() method that it being called because of an exception instead of regular end of the closing block, so I can automate the rollback? I don´t want to manually add a try ... catch block, my objective is to use the using block as a logical safe transaction manager, so it commits to the database if the execution was clean or rollbacks if any exception occured. Do you have some thoughts on that?

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  • Help needed in grokking password hashes and salts

    - by javafueled
    I've read a number of SO questions on this topic, but grokking the applied practice of storing a salted hash of a password eludes me. Let's start with some ground rules: a password, "foobar12" (we are not discussing the strength of the password). a language, Java 1.6 for this discussion a database, postgreSQL, MySQL, SQL Server, Oracle Several options are available to storing the password, but I want to think about one (1): Store the password hashed with random salt in the DB, one column Found on SO and elsewhere is the automatic fail of plaintext, MD5/SHA1, and dual-columns. The latter have pros and cons MD5/SHA1 is simple. MessageDigest in Java provides MD5, SHA1 (through SHA512 in modern implementations, certainly 1.6). Additionally, most RDBMSs listed provide methods for MD5 encryption functions on inserts, updates, etc. The problems become evident once one groks "rainbow tables" and MD5 collisions (and I've grokked these concepts). Dual-column solutions rest on the idea that the salt does not need to be secret (grok it). However, a second column introduces a complexity that might not be a luxury if you have a legacy system with one (1) column for the password and the cost of updating the table and the code could be too high. But it is storing the password hashed with a random salt in single DB column that I need to understand better, with practical application. I like this solution for a couple of reasons: a salt is expected and considers legacy boundaries. Here's where I get lost: if the salt is random and hashed with the password, how can the system ever match the password? I have theory on this, and as I type I might be grokking the concept: Given a random salt of 128 bytes and a password of 8 bytes ('foobar12'), it could be programmatically possible to remove the part of the hash that was the salt, by hashing a random 128 byte salt and getting the substring of the original hash that is the hashed password. Then re hashing to match using the hash algorithm...??? So... any takers on helping. :) Am I close?

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  • Applets failing to load

    - by Roy Tang
    While testing our setup for user acceptance testing, we got some reports that java applets in our web application would occasionally fail to load. The envt where it was reported was WinXP/IE6, and there were no errors found in the java console. Obviously we'd like to avoid it. What sort of things should we be checking for here? On our local servers, everything seems fine. There's some turnaround time when sending questions to the on-site guy, so I'd look to cover as many possible causes as possible. Some more info: We have multiple applets, in the instance that they fail loading, all of them fail loading. The applet jar files vary in size from 2MB to 8MB. I'm told it seems more likely to happen if the applet isn't cached yet, i.e. if they've been able to load the applets once on a given machine, further runs on that machine go smoothly. I'm wondering if there's some sort of network transfer error when downloading the applets, but I don't know how to verify that. Any advise is welcome!

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  • Windows Batch file to echo a specific line number

    - by Lee
    So for the second part of my current dilemma, I have a list of folders in c:\file_list.txt. I need to be able to extract them (well, echo them with some mods) based on the line number because this batch script is being called by an iterative macro process. I'm passing the line number as a parameter. @echo off setlocal enabledelayedexpansion set /a counter=0 set /a %%a = "" for /f "usebackq delims=" %%a in (c:\file_list.txt) do ( if "!counter!"=="%1" goto :printme & set /a counter+=1 ) :printme echo %%a which gives me an output of %a. Doh! So, I've tried echoing !a! (result: ECHO is off.); I've tried echoing %a (result: a) I figured the easy thing to do would be to modify the head.bat code found here: http://stackoverflow.com/questions/130116/dos-batch-commands-to-read-first-line-from-text-file except rather than echoing every line - I'd just echo the last line found. Not as simple as one might think. I've noticed that my counter is staying at zero for some reason; I'm wondering if the set /a counter+=1 is doing what I think it's doing.

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  • How to perform spatial partitioning in n-dimensions?

    - by kevin42
    I'm trying to design an implementation of Vector Quantization as a c++ template class that can handle different types and dimensions of vectors (e.g. 16 dimension vectors of bytes, or 4d vectors of doubles, etc). I've been reading up on the algorithms, and I understand most of it: here and here I want to implement the Linde-Buzo-Gray (LBG) Algorithm, but I'm having difficulty figuring out the general algorithm for partitioning the clusters. I think I need to define a plane (hyperplane?) that splits the vectors in a cluster so there is an equal number on each side of the plane. [edit to add more info] This is an iterative process, but I think I start by finding the centroid of all the vectors, then use that centroid to define the splitting plane, get the centroid of each of the sides of the plane, continuing until I have the number of clusters needed for the VQ algorithm (iterating to optimize for less distortion along the way). The animation in the first link above shows it nicely. My questions are: What is an algorithm to find the plane once I have the centroid? How can I test a vector to see if it is on either side of that plane?

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  • Can protobuf-net serialize this combination of interface and generic collection?

    - by tsupe
    I am trying to serialize a ItemTransaction and protobuf-net (r282) is having a problem. ItemTransaction : IEnumerable<KeyValuePair<Type, IItemCollection>></code> and ItemCollection is like this: FooCollection : ItemCollection<Foo> ItemCollection<T> : BindingList<T>, IItemCollection IItemCollection : IList<Item> where T is a derived type of Item. ItemCollection also has a property of type IItemCollection. I am serializing like this: IItemCollection itemCol = someService.Blah(...); ... SerializeWithLengthPrefix<IItemCollection>(stream, itemCol, PrefixStyle.Base128); My eventual goal is to serialize ItemTransaction, but am snagged with IItemCollection. Item and it's derived types can be [de]serialized with no issues, see [1], but deserializing an IItemCollection fails (serializing works). ItemCollection has a ItemExpression property and when deserializing protobuf can't create an abstract class. This makes sense to me, but I'm not sure how to get through it. ItemExpression<T> : ItemExpression, IItemExpression ItemExpression : Expression ItemExpression is abstract as is Expression How do I get this to work properly? Also, I am concerned that ItemTransaction will fail since the IItemCollections are going to be differing and unknown at compile time (an ItemTransaction will have FooCollection, BarCollection, FlimCollection, FlamCollection, etc). What am I missing (Marc) ? [1] http://stackoverflow.com/questions/2276104/protobuf-net-deserializing-across-assembly-boundaries

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