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  • Windows XP self-installing virus [closed]

    - by Oliver
    Do you remember. Some years ago, there was a huge virus attacking Windows XP in its first version. Once you had installed Windows XP, and on your first internet access, the virus installed itself on your computer, closing your internet connection and making the computer reboot after some seconds. I wonder... How can a virus install itslef this way from nowhere ? Without any user action. You install Windows XP... the computer just connects itself to the internet (assuming Microsoft don't connect to bad sites on its first connection)... and you have a virus. There is something magic I don't understand here. Can someone explain me how that virus could attack Windows that way, without any user action on a fresh installed system...

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  • SAP vs Other Technologies

    - by Bunny Rabbit
    I am a fresher just out of collge .Till now i have worked on java,Python,javascript,groovy,django,JS, JQuery and web application develop has been my only intrest. I have been working for an IT company for past three months and it involves working with an erp package SAP and i am working on ABAP. Coming from a world of ORM and languages like python ,SAP and database tables doen't excite me much. With all the development being happening around HTML 5 and android etc i feel quite left out and bored in SAP . can you guys suggest me a proper way forward ?

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  • Real performance of node.js

    - by uther.lightbringer
    I've got a question concerning node.js performance. There is quite lot of "benchmarks" and a lot of fuss about great performance of node.js. But how does it stand in real world? Not just process empty request at high speed. If someone could try to compare this scenario: Java (or equivalent) server running an application with complex business logic between receiving request and sending response. How would node.js deal with it? If there was need for a lot of JavaScript processing on server side, is node.js really so fast that it can execute JavaScript, and stand a chance against more heavyveight competitors?

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  • One-week release cycle: how do I make this feasible?

    - by Arkaaito
    At my company (3-yr-old web industry startup), we have frequent problems with the product team saying "aaaah this is a crisis patch it now!" (doesn't everybody?) This has an impact on the productivity (and morale) of engineering staff, self included. Management has spent some time thinking about how to reduce the frequency of these same-day requests and has come up with the solution that we are going to have a release every week. (Previously we'd been doing one every two weeks, which usually slipped by a couple of days or so.) There are 13 developers and 6 local / 9 offshore testers; the theory is that only 4 developers (and all testers) will work on even-numbered releases, unless a piece of work comes up that really requires some specific expertise from one of the other devs. Each cycle will contain two days of dev work and two days of QA work (plus 1 day of scoping / triage / ...). My questions are: (a) Does anyone have experience with this length of release cycle? (b) Has anyone heard of this length of release cycle even being attempted? (c) If (a) or (b), how on Earth do you make it work? (Any pitfalls to avoid, etc., are also appreciated.) (d) How can we minimize the damage if this effort fails?

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  • Can I get a C++ Compiler to instantiate objects at compile time

    - by gam3
    I am writing some code that has a very large number of reasonably simple objects and I would like them the be created at compile time. I would think that a compiler would be able to do this, but I have not been able to figure out how. In C I could do the the following: #include <stdio.h> typedef struct data_s { int a; int b; char *c; } info; info list[] = { 1, 2, "a", 3, 4, "b", }; main() { int i; for (i = 0; i < sizeof(list)/sizeof(*list); i++) { printf("%d %s\n", i, list[i].c); } } Using #C++* each object has it constructor called rather than just being layed out in memory. #include <iostream> using std::cout; using std::endl; class Info { const int a; const int b; const char *c; public: Info(const int, const int, const char *); const int get_a() { return a; }; const int get_b() { return b; }; const char *get_c() const { return c; }; }; Info::Info(const int a, const int b, const char *c) : a(a), b(b), c(c) {}; Info list[] = { Info(1, 2, "a"), Info(3, 4, "b"), }; main() { for (int i = 0; i < sizeof(list)/sizeof(*list); i++) { cout << i << " " << list[i].get_c() << endl; } } I just don't see what information is not available for the compiler to completely instantiate these objects at compile time, so I assume I am missing something.

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  • Nested entities in Google App Engine. Do I do it right?

    - by Aleksandr Makov
    Trying to make most of the GAE Datastore entities concept, but some doubts drill my head. Say I have the model: class User(ndb.Model): email = ndb.StringProperty(indexed=True) password = ndb.StringProperty(indexed=False) first_name = ndb.StringProperty(indexed=False) last_name = ndb.StringProperty(indexed=False) created_at = ndb.DateTimeProperty(auto_now_add=True) @classmethod def key(cls, email): return ndb.Key(User, email) @classmethod def Add(cls, email, password, first_name, last_name): user = User(parent=cls.key(email), email=email, password=password, first_name=first_name, last_name=last_name) user.put() UserLogin.Record(email) class UserLogin(ndb.Model): time = ndb.DateTimeProperty(auto_now_add=True) @classmethod def Record(cls, user_email): login = UserLogin(parent=User.key(user_email)) login.put() And I need to keep track of times of successful login operations. Each time user logs in, an UserLogin.Record() method will be executed. Now the question — do I make it right? Thanks. EDIT 2 Ok, used the typed arguments, but then it raised this: Expected Key instance, got User(key=Key('User', 5418393301680128), created_at=datetime.datetime(2013, 6, 27, 10, 12, 25, 479928), email=u'[email protected]', first_name=u'First', last_name=u'Last', password=u'password'). It's clear to understand, but I don't get why the docs are misleading? They implicitly propose to use: # Set Employee as Address entity's parent directly... address = Address(parent=employee) But Model expects key. And what's worse the parent=user.key() swears that key() isn't callable. And I found out the user.key works. EDIT 1 After reading the example form the docs and trying to replicate it — I got type error: TypeError('Model constructor takes no positional arguments.'). This is the exacto code used: user = User('[email protected]', 'password', 'First', 'Last') user.put() stamp = UserLogin(parent=user) stamp.put() I understand that Model was given the wrong argument, BUT why it's in the docs?

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  • Why should I adopt MVC?

    - by Andrew
    I decided to get my hands wet and got the YII framework for PHP. I created my first application, then created new controller, model and view. Connected to database, got my record passed from controller to the view and printed the hello world. I am confused now. If I have to do the same thing for each page, this seems like a nightmare to me. In each controller I have to do a lot of same operations - declare variables, and pass them to views. I also need to create models for each page and this is all confusing to me. In my idea the main goal of development is to avoid duplication, but what I see here is lots and lots of duplicated code. Please advise and clarify. Maybe you could suggest a good reading about MVC and coding patterns and best practices in MVC. Because so far, it takes much more time to create a small site using MVC than using my own programming schema.

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  • Should we choose Java over C# or we should consider using Mono?

    - by A. Karimi
    We are a small team of independent developers with an average experience of 7 years in C#/.NET platform. We almost work on small to average web application projects that allows us to choose our favorite platform. I believe that our current platform (C#/.NET) allows us to be more productive than if we were working in Java but what makes me think about choosing Java over C# is the costs and the community (of the open source). Our projects allow us even work with various frameworks as well as various platforms. For example we can even use Nancy. So we are able to decrease the costs by using Mono which can be deployed on Linux servers. But I'm looking for a complete ecosystem (IDE/Platform/Production Environment) that decreases our costs and makes us feel completely supported by the community. As an example of issues I've experienced with MonoDevelop, I can refer to the poor support of the Razor syntax on MonoDevelop. As another example, We are using "VS 2012 Express for Web" as our IDE to decrease the costs but as you know it doesn't support plugins and I have serious problems with XML comments (I missed GhostDoc). We strongly believe in strongly-typed programming languages so please don't offer the other languages and platforms such as Ruby, PHP, etc. Now I want to choose between: Keep going on C#, buy some products and be hopeful about openness of .NET ecosystem and its open source community. Changing the platform and start using the Java open source ecosystem

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  • Is Java much harder to "tweak" for performance compared with C/C++?

    - by user997112
    Does the "magic" of the JVM hinder the influence a programmer has over micro-optimisations in Java? I recently read in C++ sometimes the ordering of the data members can provide optimizations (granted, in the microsecond environment) and I presumed a programmer's hands are tied when it comes to squeezing performance from Java? I appreciate a decent algorithm provides greater speed-gains, but once you have the correct algorithm is Java harder to tweak due to the JVM control? If not, could people give examples of what tricks you can use in Java (besides simple compiler flags).

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  • Using an open source non-free license

    - by wagglepoons
    Are there any projects/products out there that use an open source license that basically says "free for small companies" and "cost money for larger companies" in addition to "make modifications available"? (And are there any standard licenses with such a wording?) If I were to release a project under such a license, would it be automatically shunned by every developer on the face of the earth, or, assuming it is actually a useful project, does it have a fair chance at getting contributions from Joe Programmer? The second part of this question can easily become subjective, but any well argued point of view will be highly appreciated. For example, do dual licensed projects made by commercial entities have success with the open source communities?

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  • What are the real life implications for an Apache 2 license?

    - by Duopixel
    I want to use SVG Edit for project. This software is distributed under the Apache 2 license. I've seen that: all copies, modified or unmodified, are accompanied by a copy of the licence all modifications are clearly marked as being the work of the modifier all notices of copyright, trademark and patent rights are reproduced accurately in distributed copies the licensee does not use any trademarks that belong to the licensor Do these pertain to the code or should I display the license somewhere in the GUI? The orignal software displays a "powered by SVG Edit", is it ok if I remove this? And most importantly: what is the correct etiquette for doing this? I don't want to be an asshole, but at the same time I want to simplify the UI as much as possible and removing the link will be part of it if it's not considered rude.

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  • Model View Control Issue: Null Pointer Initialization Question [closed]

    - by David Dimalanta
    Good morning again. This is David. Please, I need an urgent help regarding control model view where I making a code that uniquely separating into groups: An Activity Java Class to Display the Interface A View and Function Java Class for Drawing Cards and Display it on the Activity Class The problem is that the result returns a Null Pointer Exception. I have initialize for the ID for Text View and Image View. Under this class "draw_deck.java". Please help me. Here's my code for draw_deck.java: package com.bodapps.inbetween.model; import android.content.Context; import android.view.View; import android.widget.ImageView; import android.widget.TextView; import com.bodapps.inbetween.R; public class draw_deck extends View { public TextView count_label; public ImageView draw_card; private int count; public draw_deck(Context context) { super(context); // TODO Auto-generated constructor stub //I have initialized two widgets for ID. I still don't get it why I got forced closed by Null Pointer Exception thing. draw_card = (ImageView) findViewById(R.id.IV_Draw_Card); count_label = (TextView) findViewById(R.id.Text_View_Count_Card); } public void draw(int s, int c, String strSuit, String strValue, Pile pile, Context context) { //super(context); //Just printing the card drawn from pile int suit, value = 1; draw_card = (ImageView) findViewById(R.id.IV_Draw_Card); count_label = (TextView) findViewById(R.id.Text_View_Count_Card); Card card; if(!pile.isEmpty()) //Setting it to IF statement displays the card one by one. { card = pile.drawFromPile(); //Need to check first if card is null. if (card != null) { //draws an extra if (card != null) { //Get suit of card to print out. suit = card.getSuit(); switch (suit) { case CardInfo.DIAMOND: strSuit = "DIAMOND"; s=0; break; case CardInfo.HEART: strSuit = "HEART"; s=1; break; case CardInfo.SPADE: strSuit = "SPADE"; s=2; break; case CardInfo.CLUB: strSuit = "CLUB"; s=3; break; } //Get value of card to print out. value = card.getValue(); switch (value) { case CardInfo.ACE: strValue = "ACE"; c=0; break; case CardInfo.TWO: c=1; break; case CardInfo.THREE: strValue = "THREE"; c=2; break; case CardInfo.FOUR: strValue = "FOUR"; c=3; break; case CardInfo.FIVE: strValue = "FIVE"; c=4; break; case CardInfo.SIX: strValue = "SIX"; c=4; break; case CardInfo.SEVEN: strValue = "SEVEN"; c=4; break; case CardInfo.EIGHT: strValue = "EIGHT"; c=4; break; case CardInfo.NINE: strValue = "NINE"; c=4; break; case CardInfo.TEN: strValue = "TEN"; c=4; break; case CardInfo.JACK: strValue = "JACK"; c=4; break; case CardInfo.QUEEN: strValue = "QUEEN"; c=4; break; case CardInfo.KING: strValue = "KING"; c=4; break; } } } }// //Below two lines of code, this is where issued the Null Pointer Exception. draw_card.setImageResource(deck[s][c]); count_label.setText(new StringBuilder(strValue).append(" of ").append(strSuit).append(String.valueOf(" " + count++)).toString()); } //Choice of Suits in a Deck public Integer[][] deck = { //Array Group 1 is [0][0] (No. of Cards: 4 - DIAMOND) { R.drawable.card_dummy_1, R.drawable.card_dummy_2, R.drawable.card_dummy_4, R.drawable.card_dummy_5, R.drawable.card_dummy_3 }, //Array Group 2 is [1][0] (No. of Cards: 4 - HEART) { R.drawable.card_dummy_1, R.drawable.card_dummy_2, R.drawable.card_dummy_4, R.drawable.card_dummy_5, R.drawable.card_dummy_3 }, //Array Group 3 is [2][0] (No. of Cards: 4 - SPADE) { R.drawable.card_dummy_1, R.drawable.card_dummy_2, R.drawable.card_dummy_4, R.drawable.card_dummy_5, R.drawable.card_dummy_3 }, //Array Group 4 is [3][0] (No. of Cards: 4 - CLUB) { R.drawable.card_dummy_1, R.drawable.card_dummy_2, R.drawable.card_dummy_4, R.drawable.card_dummy_5, R.drawable.card_dummy_3 }, }; } And this one of the activity class, Player_Mode_2.java: package com.bodapps.inbetween; import java.util.Random; import android.app.Activity; import android.app.Dialog; import android.content.Context; import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.EditText; import android.widget.ImageView; import android.widget.TextView; import android.widget.Toast; import com.bodapps.inbetween.model.Card; import com.bodapps.inbetween.model.Pile; import com.bodapps.inbetween.model.draw_deck; /* * * Public class for Two-Player mode. * */ public class Player_Mode_2 extends Activity { //Image Views private ImageView draw_card; private ImageView player_1; private ImageView player_2; private ImageView icon; //Buttons private Button set_deck; //Edit Texts private EditText enter_no_of_decks; //text Views private TextView count_label; //Integer Data Types private int no_of_cards, count; private int card_multiplier; //Contexts final Context context = this; //Pile Model public Pile pile; //Card Model public Card card; //create View @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.play_2_player_mode); //-----[ Search for Views ]----- //Initialize for Image View draw_card = (ImageView) findViewById(R.id.IV_Draw_Card); player_1 = (ImageView) findViewById(R.id.IV_Player_1_Card); player_2 = (ImageView) findViewById(R.id.IV_Player_2_Card); //Initialize for Text view or Label count_label = (TextView) findViewById(R.id.Text_View_Count_Card); //-----[ Adding Values ]----- //Integer Values count = 0; no_of_cards = 0; //-----[ Adding Dialog ]----- //Initializing Dialog final Dialog deck_dialog = new Dialog(context); deck_dialog.setContentView(R.layout.dialog); deck_dialog.setTitle("Deck Dialog"); //-----[ Initializing Views for Dialog's Contents ]----- //Initialize for Edit Text enter_no_of_decks = (EditText) deck_dialog.findViewById(R.id.Edit_Text_Set_Number_of_Decks); //Initialize for Button set_deck = (Button) deck_dialog.findViewById(R.id.Button_Deck); //-----[ Setting onClickListener() ]----- //Set Event Listener for Image view draw_card.setOnClickListener(new Draw_Card_Model()); //Set Event Listener for Setting the Deck set_deck.setOnClickListener(new OnClickListener() { public void onClick(View v) { if(card_multiplier <= 8) { //Use "Integer.parseInt()" method to instantly convert from String to int value. card_multiplier = Integer.parseInt(enter_no_of_decks.getText().toString()); //Shuffling cards... pile = new Pile(card_multiplier); //Multiply no. of decks //Dismiss or close the dialog. deck_dialog.dismiss(); } else { Toast.makeText(getApplicationContext(), "Please choose a number from 1 to 8.", Toast.LENGTH_SHORT).show(); } } }); //Show dialog. deck_dialog.show(); } //Shuffling the Array public void Shuffle_Cards(Integer[][] Shuffle_Deck) { Random random = new Random(); for(int i = Shuffle_Deck[no_of_cards].length - 1; i >=0; i--) { int Index = random.nextInt(i + 1); //Simple Swapping Integer swap = Shuffle_Deck[card_multiplier-1][Index]; Shuffle_Deck[card_multiplier-1][Index] = Shuffle_Deck[card_multiplier-1][i]; Shuffle_Deck[card_multiplier-1][i] = swap; } } //Private Class for Random Card Draw private class Draw_Card_Model implements OnClickListener { public void onClick(View v) { //Just printing the card drawn from pile int suit = 0, value = 0; String strSuit = "", strValue = ""; draw_deck draw = new draw_deck(context); //This line is where issued the Null Pointer Exception. if (count == card_multiplier*52) { // A message shows up when all cards are draw out. Toast.makeText(getApplicationContext(), "All cards have been used up.", Toast.LENGTH_SHORT).show(); draw_card.setEnabled(false); } else { draw.draw(suit, value, strSuit, strValue, pile, context); count_label.setText(count); //This is where I got force closed error, although "int count" have initialized the number. This was supposed to accept in the setText() method. count++; } } } } Take note that the issues on Null Pointer Exception is the Image View and the Edit Text. I got to test it. Thanks. If you have any info about my question, let me know it frankly.

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  • Area of testing

    - by ?????? ??????????
    I'm trying to understand which part of my code I should to test. I have some code. Below is example of this code, just to understand the idea. Depends of some parametrs I put one or another currency to "Event" and return his serialization in the controller. Which part of code I should to test? Just the final serialization, or only "Event" or every method: getJson, getRows, fillCurrency, setCurrency? class Controller { public function getJson() { $rows = $eventManager->getRows(); return new JsonResponse($rows); } } class EventManager { public function getRows() { //some code here if ($parameter == true) { $this->fillCurrency($event, $currency); } } public function fillCurrency($event, $currency) { //some code here if ($parameters == true) { $event->setCurrency($currency); } } } class Event { public function setCurrency($currency) { $this->updatedAt = new Datetime(); $this->currency = $currency; } }

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  • Converting 3 dimension byte array to a single byte array [on hold]

    - by Andrew Simpson
    I have a 3 dimensional byte array. The 3-d array represents a jpeg image. Each channel/array represents part of the RGB spectrum. I am not interested in retaining black pixels. A black pixel is represented by this atypical arrangement: myarray[0,0,0] =0; myarray[0,0,1] =0; myarray[0,0,2] =0; So, I have flattened this 3d array out to a 1d array by doing this byte[] AFlatArray = new byte[width x height x 3] and then assigning values respective to the coordinate. But like I said I do not want black pixels. So this array has to only contain color pixels with the x,y coordinate. The result I want is to re-represent the image from the i dimension byte array that only contains non-black pixels. How do I do that? It looks like I have to store black pixels as well because of the xy coordinate system. I have tried writing to a binary file but the size of that file is greater than the jpeg file as the jpeg file is compressed. I am using c#.

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  • Compiling GCC or Clang for thumb drive on OSX

    - by user105524
    I have a mac book that I don't have admin rights to which I would like to be able to use either GCC or clang. Since I lack admin right I can't install binutils or a compiler to /usr directory. My plan is to install both of these (using an old macbook that I do have admin rights for) to a flash drive and then run the compiler off of there. How would one go building gcc or clang so that it could run just off of a thumb drive? I've tried both but haven't had any success. I've tried doing it defining as many of the directories as possible through configure, but haven't been able to successfully build. My current configure script for gcc-4.8.1 is (where USB20D is the thumb drive): ../gcc-4.8.1/configure --prefix=/Volumes/USB20FD/usr \ --with-local-prefix=/Volumes/USB20FD/usr/local \ --with-native-system-header-dir=/Volumes/USB20FD/usr/include \ --with-as=/Volumes/USB20FD/usr/bin/as \ --enable-languages=c,c++,fortran\ --with-ld=/Volumes/USB20FD/usr/bin/ld \ --with-build-time-tools=/Volumes/USB20FD/usr/bin \ AR=/Volumes/USB20FD/usr/bin/ar \ AS=/Volumes/USB20FD/usr/bin/as \ RANLIB=/Volumes/USB20FD/usr/bin/ranlib \ LD=/Volumes/USB20FD/usr/bin/ld \ NM=/Volumes/USB20FD/usr/bin/nm \ LIPO=/Volumes/USB20FD/usr/bin/lipo \ AR_FOR_TARGET=/Volumes/USB20FD/usr/bin/ar \ AS_FOR_TARGET=/Volumes/USB20FD/usr/bin/as \ RANLIB_FOR_TARGET=/Volumes/USB20FD/usr/bin/ranlib \ LD_FOR_TARGET=/Volumes/USB20FD/usr/bin/ld \ NM_FOR_TARGET=/Volumes/USB20FD/usr/bin/nm \ LIPO_FOR_TARGET=/Volumes/USB20FD/usr/bin/lipo CFLAGS=" -nodefaultlibs -nostdlib -B/Volumes/USB20FD/bin -isystem/Volumes/USB20FD/usr/include -static-libgcc -v -L/Volumes/USB20FD/usr/lib " \ LDFLAGS=" -Z -lc -nodefaultlibs -nostdlib -L/Volumes/USB20FD/usr/lib -lgcc -syslibroot /Volumes/USB20FD/usr/lib/crt1.10.6.o " Any obvious ideas of which of these options need to be turned on to install the appropriate files on the thumb drive during installation? What other magic occurs during xcode installation which isn't occurring here? Thanks for any suggestions

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  • Splitting up revenue among development team members on Apple's app store

    - by itaiferber
    A friend and I have started developing an app to put on Apple's app store. Development is going fine, but thinking ahead, we're trying to come up with an easy way to share any revenue coming from our efforts. The app store allows you to deposit your revenue into a single bank account, but there's no easy way to split revenue among several people. How do (small) dev teams split up revenue on their products, on, and off the app store? As far as I can tell, banks don't offer an easy way to automatically split the balance on an account 50-50 (or any other percentage, for that matter), especially on a regular basis. So how do teams deal with this? We're not incorporated, and we don't have an official business set up. We're considering depositing all the money into one of our accounts and manually transferring half the money to the other person, but this isn't sustainable over long periods of time. Is there a low-cost, sustainable, automatic process for handling these finances?

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  • Teaching OO to VBA developers [closed]

    - by Eugene
    I work with several developers that come from less object oriented background like (VB6, VBA) and are mostly self-taught. As part of moving away from those technologies we recently we started having weekly workshops to go over the features of C#.NET and OO practices and design principles. After a couple of weeks of basic introduction I noticed that they had a lot of problems implementing even basic code. For instance it took probably 15 minutes to implement a Stack.push() and a full hour to implement a simple Stack fully. These developers were trying to do things like passing top index as a parameter to the method, not creating an private array, using variables out of scope. But most of all not going through the "design (dia/mono)log" (I need something to do X, so maybe I'll make an array, or put it here). I am a little confused because they are smart people and are able to produce functional code in their traditional environments. I'm curious if anybody else has encountered a similar thing and if there are any particular resources, exercises, books, ideas that would be helpful in this circumstance.

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  • What .NET objects should I use to create a cookie based session in MVC?

    - by makerofthings7
    I'm writing a custom password reset application that uses a validation technique that doesn't fit cleanly with ASP.NET Membership Provider's challenge questions. Namely I need to invoke a workflow and collect information from the end user (backup phone number, email address) after the user logs in using a custom form. The only way I know to create a cookie-based session (without too much "innovation" on my part) is to use WIF. What other standard objects can I use with ASP.NET MVC to create an authenticated session that works with non-windows user stores? Ideally I can store "role" or claim information in the session object such as "admin", "departmentXadmin", "normalUser", or "restrictedUser" The workflow would look like this: User logs in with username and password If the username and pw are correct a (stateless) cookie based session is created The user gets redirected to a HTML form that allows them to enter their backup phone number (for SMS dual factor), or validate it if already set. The user can then change their password using the form provided The "forgot password" would look like this User requests OTP code to be sent to the phone User logs in using username and OTP If the OTP is valid and not expired then create a cookie based session and redirect to a form that allows password reset Show password reset form, and process results.

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  • Book about tcp, http, named pipe, shared memory, wcf and other inter-process communication protocol

    - by Samuel
    Recently, I had to create a program to send messages between two winforms executable. I used a tool with simple built-in functionalities to prevent having to figure out all the ins and outs of this vast quantity of protocols that exist. But now, I'm ready to learn more about the internals difference between each of theses protocols. I googled a couple of them but it would be greatly appreciate to have a good reference book that gives me a clean idea of how each protocol works and what are the pros and cons in a couple of context. Here is a list of nice protocols that I found: Shared memory TCP List item Named Pipe File Mapping Mailslots MSMQ (Microsoft Queue Solution) WCF I know that all of these protocols are not specific to a language, it would be nice if example could be in .net. Thank you very much.

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  • How to keep background requests in sequence

    - by Jason Lewis
    I'm faced with implementing interfaces for some rather archaic systems, for handling online deposits to stored value accounts (think campus card accounts for students). Here's my dilemma: stage 1 of the process involves passing the user off to a thrid-party site for the credit card transaction, like old-school PayPal. Step two involves using a proprietary protocol for communicating with a legacy system for conducting the actual deposit. Step two requires that each transaction have a unique sequence number, and that the requests' seqnums are in order. Since we're logging each transaction in Postgres, my first thought was to take a number from a sequence in the DB, guaranteeing uniqueness. But since we're dealing with web requests that might come in near-simultaneously, and since latency with the return from the off-ste payment processor is beyond our control, there's always the chance for a race condition in the order of requests passed back to the proprietary system, and if the seqnums are out of order, the request fails silently (brilliant, right?). I thought about enqueuing the requests in Redis and using Resque workers to process them (single worker, single process, so they are processed in order), but we need to be able to give the user feedback as to whether the transaction was processed successfully, so this seems less feasible to me. I've tried to make this application handle concurrency well (as much as possible for a Ruby on Rails app), but now we're in a situation where we have to interact with a system that is designed to be single process, single threaded, and sequential. If it at least gave an "out of order" error, I could just increment (or take the next value off the sequence), but it's designed to fail silently in the event of ANY error. We are handling timeouts in a way that blocks on I/O, but since the application uses multiple workers (Unicorn), that's no guarantee. Any ideas/suggestions would be appreciated.

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  • Masters for Artificial Intelligence

    - by Frenchie
    I am very interested in going to graduate school to study Artificial Intelligence. I am currently an undergrad student majoring in Computer Science, I will be finished in a year and a half so I figured now is a good time to start looking. I do not have a competitive GPA(3.3) so I am not looking for the top 25 graduate schools in AI such as listed in this ranking. So far I am taking into consideration the University of Georgia, they have a masters in AI, separate from a masters in CS. If you know of any other schools that has a decent masters in CS with an emphasis on AI or a masters in AI by itself please let me know. Thank you. USA/Canada schools only.

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  • lowering the use of the memory controller in OpenCL based applications

    - by user827992
    With my first experiments I noticed that OpenCL is a good technology but often hampered by the X86 architecture and finding a mid-range VGA driven by a low-end chipset is not that unusual in the real world scenarios, sometimes this can happen with some high-end VGA too. Are there some caching techniques? Something that can bypass this inconvenience in some ways. The amount of dedicated memory on today's VGA is usually high, it's possible to use this memory to create some kind of buffer with instructions.

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  • How do I start my career on a 3-year-old degree [on hold]

    - by Gabriel Burns
    I received my bachelor's degree in Com S (second major in math) in December 2011. I didn't have the best GPA (I was excellent at programming projects and had a deep understanding of CS concepts, but school is generally not the best format for displaying my strengths), and my only internship was with a now-defunct startup. After graduation I applied for several jobs, had a fair number of interviews, but never got hired. After a while, I got somewhat discouraged, and though I still said I was looking, and occasionally applied for something, my pace slowed down considerably. I remain convinced that software development is the right path for me, and that I could make a real contribution to someones work force, but I'm at a loss as to how I can convince anyone of this. My major problems are as follows. Lack of professional experience-- a problem for every entry-level programmer, I suppose, but everyone seems to want someone with a couple of years under their belt. Rustiness-- I've not really done any programming in about a year, and since school all I've really done is various programming competitions and puzzles. (codechef, hackerrank, etc.) I need a way to sharpen my skills. Long term unemployment-- while I had a basic fast-food job after I graduated, I've been truly unemployed for about a year now. Furthermore, no one has ever hired me as a programmer, and any potential employer is liable to wonder why. Old References-- my references are all college professors and one supervisor from my internship, none of whom I've had any contact with since I graduated. Confidence-- I have no doubt that I could be a good professional programmer, and make just about any employer glad that they hired me, but I'm aware of my red flags as a candidate, and have a hard time heading confidently into an interview. How can I overcome these problems and keep my career from being over before it starts?

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  • Creating PHP Forms with show/hide functionality [migrated]

    - by ronquiq
    I want to create two reports and submit the report data to database by using two functions defined in a class: Here I have two buttons: "Create ES" and "Create RP". Rightnow, my forms are working fine, I can insert data successfully, but the problem was when I click on submit after filling the form data, the content is hiding and displays the fist div content "cs_content" and again I need to onclick to submit again. Could anyone give a solution for this. Requirement : When I click on "Create CS", I should be able to fill the form and submit data successfully with a message within "cs_content" and any form input errors, the errors should display within "cs_content". When I click on "Create RP", I should be able to fill the form and submit data successfully with a message within "rp_content" and any form input errors, the errors should display within "rp_content". home.php <?php require 'classes/class.report.php'; $report = new Report($db); ?> <html> <head> <script src="js/jqueryv1.10.2.js"></script> <script> $ (document).ready(function () { //$("#cs_content").show(); $('#cs').click(function () { $('#cs_content').fadeIn('slow'); $('#rp_content').hide(); }); $('#rp').click(function () { $('#rp_content').fadeIn('slow'); $('#cs_content').hide(); }); }); </script> </head> <body> <div class="container2"> <div style="margin:0px 0px;padding:3px 217px;overflow:hidden;"> <div id="cs" style="float:left;margin:0px 0px;padding:7px;"><input type="button" value="CREATE CS"></div> <div id="rp" style="float:left;margin:0px 0px;padding:7px;"><input type="button" value="CREATE RP"></div><br> </div> <div id="cs_content"> <?php $report->create_cs_report(); ?> </div> <div id="rp_content" style="display:none;"> <?php $report->create_rp_report(); ?> </div> </div> </body> </html> class.report.php <?php class Report { private $db; public function __construct($database){ $this->db = $database; } public function create_cs_report() { if (isset($_POST['create_es_report'])) { $report_name = htmlentities($_POST['report_name']); $from_address = htmlentities($_POST['from_address']); $subject = htmlentities($_POST['subject']); $reply_to = htmlentities($_POST['reply_to']); if (empty($_POST['report_name']) || empty($_POST['from_address']) || empty($_POST['subject']) || empty($_POST['reply_to'])) { $errors[] = '<span class="error">All fields are required.</span>'; } else { if (isset($_POST['report_name']) && empty($_POST['report_name'])) { $errors[] = '<span class="error">Report Name is required</span>'; } else if (!ctype_alnum($_POST['report_name'])) { $errors[] = '<span class="error">Report Name: Whitespace is not allowed, only alphabets and numbers are required</span>'; } if (isset($_POST['from_address']) && empty($_POST['from_address'])) { $errors[] = '<span class="error">From address is required</span>'; } else if (filter_var($_POST['from_address'], FILTER_VALIDATE_EMAIL) === false) { $errors[] = '<span class="error">Please enter a valid From address</span>'; } if (isset($_POST['subject']) && empty($_POST['subject'])) { $errors[] = '<span class="error">Subject is required</span>'; } else if (!ctype_alnum($_POST['subject'])) { $errors[] = '<span class="error">Subject: Whitespace is not allowed, only alphabets and numbers are required</span>'; } if (isset($_POST['reply_to']) && empty($_POST['reply_to'])) { $errors[] = '<span class="error">Reply To is required</span>'; } else if (filter_var($_POST['reply_to'], FILTER_VALIDATE_EMAIL) === false) { $errors[] = '<span class="error">Please enter a valid Reply-To address</span>'; } } if (empty($errors) === true) { $query = $this->db->prepare("INSERT INTO report(report_name, from_address, subject, reply_to) VALUES (?, ?, ?, ?) "); $query->bindValue(1, $report_name); $query->bindValue(2, $from_address); $query->bindValue(3, $subject); $query->bindValue(4, $reply_to); try { $query->execute(); } catch(PDOException $e) { die($e->getMessage()); } header('Location:home.php?success'); exit(); } } if (isset($_GET['success']) && empty($_GET['success'])) { header('Location:home.php'); echo '<span class="error">Report is succesfully created</span>'; } ?> <form action="" method="POST" accept-charset="UTF-8"> <div style="font-weight:bold;padding:17px 80px;text-decoration:underline;">Section A</div> <table class="create_report"> <tr><td><label>Report Name</label><span style="color:#A60000">*</span></td> <td><input type="text" name="report_name" required placeholder="Name of the report" value="<?php if(isset($_POST["report_name"])) echo $report_name; ?>" size="30" maxlength="30"> </td></tr> <tr><td><label>From</label><span style="color:#A60000">*</span></td> <td><input type="text" name="from_address" required placeholder="From address" value="<?php if(isset($_POST["from_address"])) echo $from_address; ?>" size="30"> </td></tr> <tr><td><label>Subject</label><span style="color:#A60000">*</span></td> <td><input type="text" name="subject" required placeholder="Subject" value="<?php if(isset($_POST["subject"])) echo $subject; ?>" size="30"> </td></tr> <tr><td><label>Reply To</label><span style="color:#A60000">*</span></td> <td><input type="text" name="reply_to" required placeholder="Reply address" value="<?php if(isset($_POST["reply_to"])) echo $reply_to; ?>" size="30"> </td></tr> <tr><td><input type="submit" value="create report" style="background:#8AC007;color:#080808;padding:6px;" name="create_es_report"></td></tr> </table> </form> <?php //IF THERE ARE ERRORS, THEY WOULD BE DISPLAY HERE if (empty($errors) === false) { echo '<div>' . implode('</p><p>', $errors) . '</div>'; } } public function create_rp_report() { if (isset($_POST['create_rp_report'])) { $report_name = htmlentities($_POST['report_name']); $to_address = htmlentities($_POST['to_address']); $subject = htmlentities($_POST['subject']); $reply_to = htmlentities($_POST['reply_to']); if (empty($_POST['report_name']) || empty($_POST['to_address']) || empty($_POST['subject']) || empty($_POST['reply_to'])) { $errors[] = '<span class="error">All fields are required.</span>'; } else { if (isset($_POST['report_name']) && empty($_POST['report_name'])) { $errors[] = '<span class="error">Report Name is required</span>'; } else if (!ctype_alnum($_POST['report_name'])) { $errors[] = '<span class="error">Report Name: Whitespace is not allowed, only alphabets and numbers are required</span>'; } if (isset($_POST['to_address']) && empty($_POST['to_address'])) { $errors[] = '<span class="error">to address is required</span>'; } else if (filter_var($_POST['to_address'], FILTER_VALIDATE_EMAIL) === false) { $errors[] = '<span class="error">Please enter a valid to address</span>'; } if (isset($_POST['subject']) && empty($_POST['subject'])) { $errors[] = '<span class="error">Subject is required</span>'; } else if (!ctype_alnum($_POST['subject'])) { $errors[] = '<span class="error">Subject: Whitespace is not allowed, only alphabets and numbers are required</span>'; } if (isset($_POST['reply_to']) && empty($_POST['reply_to'])) { $errors[] = '<span class="error">Reply To is required</span>'; } else if (filter_var($_POST['reply_to'], FILTER_VALIDATE_EMAIL) === false) { $errors[] = '<span class="error">Please enter a valid Reply-To address</span>'; } } if (empty($errors) === true) { $query = $this->db->prepare("INSERT INTO report(report_name, to_address, subject, reply_to) VALUES (?, ?, ?, ?) "); $query->bindValue(1, $report_name); $query->bindValue(2, $to_address); $query->bindValue(3, $subject); $query->bindValue(4, $reply_to); try { $query->execute(); } catch(PDOException $e) { die($e->getMessage()); } header('Location:home.php?success'); exit(); } } if (isset($_GET['success']) && empty($_GET['success'])) { header('Location:home.php'); echo '<span class="error">Report is succesfully created</span>'; } ?> <form action="" method="POST" accept-charset="UTF-8"> <div style="font-weight:bold;padding:17px 80px;text-decoration:underline;">Section A</div> <table class="create_report"> <tr><td><label>Report Name</label><span style="color:#A60000">*</span></td> <td><input type="text" name="report_name" required placeholder="Name of the report" value="<?php if(isset($_POST["report_name"])) echo $report_name; ?>" size="30" maxlength="30"> </td></tr> <tr><td><label>to</label><span style="color:#A60000">*</span></td> <td><input type="text" name="to_address" required placeholder="to address" value="<?php if(isset($_POST["to_address"])) echo $to_address; ?>" size="30"> </td></tr> <tr><td><label>Subject</label><span style="color:#A60000">*</span></td> <td><input type="text" name="subject" required placeholder="Subject" value="<?php if(isset($_POST["subject"])) echo $subject; ?>" size="30"> </td></tr> <tr><td><label>Reply To</label><span style="color:#A60000">*</span></td> <td><input type="text" name="reply_to" required placeholder="Reply address" value="<?php if(isset($_POST["reply_to"])) echo $reply_to; ?>" size="30"> </td></tr> <tr><td><input type="submit" value="create report" style="background:#8AC007;color:#080808;padding:6px;" name="create_rp_report"></td></tr> </table> </form> <?php //IF THERE ARE ERRORS, THEY WOULD BE DISPLAY HERE if (empty($errors) === false) { echo '<div>' . implode('</p><p>', $errors) . '</div>'; } } }//Report CLASS ENDS

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  • Why using the word "mechanism" in CS?

    - by Nick Rosencrantz
    I'm not sure about the usage of the word "mechanism" when in fact most of the time what is meant is an algorithm. For instance there's talk about Java's "thread-scheduling mechanism" - why not call it an algorithm and why borrow a term from mechanics where relations sometimes are the opposites than of computer science? I'm aware that an algorithm is considered a "mechanical solution" but is this really the case in fact when a lot of algorithm don't have mechanical representations for instance a file-sharing network that gets quicker and faster as the usage grows, that would be the reverse of a mechanical structure that would go slower when usage grows.

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