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• How to upgrade the project build in visual studio 2005 to visual studio 2008?

  - by Shailesh Jaiswal

  I have one OPC ( OLE for Process control ) server project which is developed into visual studio 2005. I want to run it in visual studio 2008. The coding for the OPC server project is done in VC++. I want to connect my OPC client to this OPC server. When I was opened the OPC server project which was build into visual studio 2005 into visual studio 2008 first time it was asking for conversion wizard. I gone through that wizard & successfully finished that wizard. But when I build ( by right clicking on the project & choosing build solution ) it is giving lots of error near about 64 errors. Most of the errors are like - fetal error C1083:Can not open type library file:'msxml4.dll':No such file or directory, fetal error LINK1181:can not open input file 'rpcndr.lib' , error C2051:case expression not constant. only these 3 types of errors in am getting. All these 3 errors are repeated in Error list & becoming bunch of 64 errors. Please provide me the solution for the above issue. Can you provide me any suusgestion or link or any way through whcih I can resolve the above issue?

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• Regression Testing and Deployment Strategy

  - by user279516

  I'd like some advice on a deployment strategy. If a development team creates an extensive framework, and many (20-30) applications consume it, and the business would like application updates at least every 30 days, what is the best deployment strategy? The reason I ask is that there seems to be a lot of waste (and risk) in using an agile approach of deploying changes monthly, if 90% of the applications don't change. What I mean by this is that the framework can change during the month, and so can a few applications. Because the framework changed, all applications should be regression-tested. If, say, 10 of the applications don't change at all during the year, then those 10 applications are regression-tested EVERY MONTH, when they didn't have any feature changes or hot fixes. They had to be tested simply because the business is rolling updates every month. And the risk that is involved... if a mission-critical application is deployed, that takes a few weeks, and multiple departments, to test, is it realistic to expect to have to constantly regression-test this application? One option is to make any framework updates backward-compatible. While this would mean that applications don't need to change their code, they would still need to be tested because the underlying framework changed. And the risk involved is great; a constantly changing framework (and deploying this framework) means the mission-critical app can never just enjoy the same code base for a long time. These applications share the same database, hence the need for the constant testing. I'm aware of TDD and automated tests, but that doesn't exist at the moment. Any advice?

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• Worse is better. Is there an example?

  - by J.F. Sebastian

  Is there a widely-used algorithm that has time complexity worse than that of another known algorithm but it is a better choice in all practical situations (worse complexity but better otherwise)? An acceptable answer might be in a form: There are algorithms A and B that have O(N**2) and O(N) time complexity correspondingly, but B has such a big constant that it has no advantages over A for inputs less then a number of atoms in the Universe. Examples highlights from the answers: Simplex algorithm -- worst-case is exponential time -- vs. known polynomial-time algorithms for convex optimization problems. A naive median of medians algorithm -- worst-case O(N**2) vs. known O(N) algorithm. Backtracking regex engines -- worst-case exponential vs. O(N) Thompson NFA -based engines. All these examples exploit worst-case vs. average scenarios. Are there examples that do not rely on the difference between the worst case vs. average case scenario? Related: The Rise of ``Worse is Better''. (For the purpose of this question the "Worse is Better" phrase is used in a narrower (namely -- algorithmic time-complexity) sense than in the article) Python's Design Philosophy: The ABC group strived for perfection. For example, they used tree-based data structure algorithms that were proven to be optimal for asymptotically large collections (but were not so great for small collections). This example would be the answer if there were no computers capable of storing these large collections (in other words large is not large enough in this case). Coppersmith–Winograd algorithm for square matrix multiplication is a good example (it is the fastest (2008) but it is inferior to worse algorithms). Any others? From the wikipedia article: "It is not used in practice because it only provides an advantage for matrices so large that they cannot be processed by modern hardware (Robinson 2005)."

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• Problem running RoR app in production environment

  - by normalocity

  Have an app that has "listings" - think classified ads - and each listing has a list of tags. The following code fails when I run the app in production mode, but works fine under development mode uninitialized constant ActiveRecord::Acts::Taggable::InstanceMethods::TagList Extracted source (around line #45): 42: 43: <span class="listingIndexTags"> 44: Location: [location] | Tags: 45: <% tag_list = listing.tag_list %> 46: <% if tag_list != nil %> 47: <% for tag in tag_list %> 48: <%= link_to tag.to_s, { :action => "filter_on", The command line I'm using to start my mongrel instance in this test case: ruby script/server mongrel -e development Defaults to port 3000. I can access other views in the app that DON'T call "listing.tag_list". ".tag_list" is provided by "acts_as_taggable_on_steroids", which I'm using in this app. It is installed as a gem. Maybe my environment files are wonky? Here's my development.rb file config.cache_classes = false config.whiny_nils = true config.action_controller.consider_all_requests_local = true config.action_view.debug_rjs = true config.action_controller.perform_caching = false config.action_mailer.raise_delivery_errors = true config.action_mailer.delivery_method = :smtp config.action_mailer.smtp_settings = { ...took these settings out for this post... } And my production.rb file... config.cache_classes = true config.threadsafe! config.action_controller.consider_all_requests_local = false config.action_controller.perform_caching = true config.cache_store = :mem_cache_store config.action_mailer.raise_delivery_errors = false config.action_mailer.delivery_method = :smtp config.action_mailer.smtp_settings = { ...took these settings out for this post... }

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• How to know about MySQL 'refused connections'

  - by celalo

  Hello, I am using MONyog to montitor my two mysql servers. I get alert emails from MONyog when something goes wrong. There is an error I could not find out why. It says: Connection History: Percentage of refused connections) - 66.67% the percentage is not important, this is just about having refused connections. I get this email every half an hour. So this is like a constant situation. This must be my mistake, because I just set up those servers and there is no chance somebody else could be interfering the servers. MONyog advices me: Try to isolate users/applications that are using an incorrect password or trying to connect from unauthorized hosts. A client will be disallowed to connect if it takes more than connect_timeout seconds to connect. Set the value of log_warnings system variable to 2. This will force the MySQL server to log further information about the error. I added log_warnings=2 to my.cnf and I enabled logging like this: [mysqld_safe] . . log_warnings=2 log-error = /var/log/mysql/error.log . . . . [mysqld_safe] . log-error=/var/log/mysqld.log . . I cannot see any warnings at /var/log/mysql/error.log I can see some warnings at /var/log/mysqld.log but they are about something else. In sum, my question is how can I detect refused connections? Please let me know if any more info is required. Thanks in advance.

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• Bitwise Interval Arithmetic

  - by KennyTM

  I've recently read an interesting thread on the D newsgroup, which basically asks, Given two signed integers a ∈ [amin, amax], b ∈ [bmin, bmax], what is the tightest interval of a | b? I'm think if interval arithmetics can be applied on general bitwise operators (assuming infinite bits). The bitwise-NOT and shifts are trivial since they just corresponds to -1 − x and 2n x. But bitwise-AND/OR are a lot trickier, due to the mix of bitwise and arithmetic properties. Is there a polynomial-time algorithm to compute the intervals of bitwise-AND/OR? Note: Assume all bitwise operations run in linear time (of number of bits), and test/set a bit is constant time. The brute-force algorithm runs in exponential time. Because ~(a | b) = ~a & ~b and a ^ b = (a | b) & ~(a & b), solving the bitwise-AND and -NOT problem implies bitwise-OR and -XOR are done. Although the content of that thread suggests min{a | b} = max(amin, bmin), it is not the tightest bound. Just consider [2, 3] | [8, 9] = [10, 11].)

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• What is the difference between AF_INET and PF_INET constants?

  - by Denilson Sá

  Looking at examples about socket programming, we can see that some people use AF_INET while others use PF_INET. In addition, sometimes both of them are used at the same example. The question is: Is there any difference between them? Which one should we use? If you can answer that, another question would be... Why there are these two similar (but equal) constants? What I've discovered, so far: The socket manpage In (Unix) socket programming, we have the socket() function that receives the following parameters: int socket(int domain, int type, int protocol); The manpage says: The domain argument specifies a communication domain; this selects the protocol family which will be used for communication. These families are defined in <sys/socket.h>. And the manpage cites AF_INET as well as some other AF_ constants for the domain parameter. Also, at the NOTES section of the same manpage, we can read: The manifest constants used under 4.x BSD for protocol families are PF_UNIX, PF_INET, etc., while AF_UNIX etc. are used for address families. However, already the BSD man page promises: "The protocol family generally is the same as the address family", and subsequent standards use AF_* everywhere. The C headers The sys/socket.h does not actually define those constants, but instead includes bits/socket.h. This file defines around 38 AF_ constants and 38 PF_ constants like this: #define PF_INET 2 /* IP protocol family. */ #define AF_INET PF_INET Python The Python socket module is very similar to the C API. However, there are many AF_ constants but only one PF_ constant (PF_PACKET). Thus, in Python we have no choice but use AF_INET. I think this decision to include only the AF_ constants follows one of the guiding principles: "There should be one-- and preferably only one --obvious way to do it." (The Zen of Python)

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• MySQL Connector for .NET - Is it REALLY mature?

  - by effkay

  After spending a miserable month with MySQL/.NET/EntityFramework, my findings: Support for Entity Framework is VERY primitive, please use it for student-subjects type of database. Kindly do not consider it using for serious development as they ARE STILL unable to sort out VERY BASIC things like: it DOES NOT support unsigned stuff it DOES NOT support unsigned columns as FK; if you try, it gives you a beautiful exception; "The specified value is not an instance of a valid constant type\r\nParameter name: value" [http://bugs.mysql.com/bug.php?id=44801] blob cannot store more then few KB; cannot compare null object with a column with a LEGAL null value [http://bugs.mysql.com/bug.php?id=49936] they are unable to write VERY PRIMITIVE check to return date as null if value in column is 0000-00-00 00:00:00 if you use Visual Studio; sorry; mysql/sun guys hate Microsoft, they will NOT LET you import more then two or three tables (for Micky Mouse type of tables, they allow five; but thats it) - if you try, it will throw TIME OUT error on your face ... unless you are smart enough to change the connection time in connection string Anyone who would like to add in above list? WISH I would have seen a list like this before I selected MySQL :(

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• Secure hash and salt for PHP passwords

  - by luiscubal

  It is currently said that MD5 is partially unsafe. Taking this into consideration, I'd like to know which mechanism to use for password protection. Is “double hashing” a password less secure than just hashing it once? Suggests that hashing multiple times may be a good idea. How to implement password protection for individual files? Suggests using salt. I'm using PHP. I want a safe and fast password encryption system. Hashing a password a million times may be safer, but also slower. How to achieve a good balance between speed and safety? Also, I'd prefer the result to have a constant number of characters. The hashing mechanism must be available in PHP It must be safe It can use salt (in this case, are all salts equally good? Is there any way to generate good salts?) Also, should I store two fields in the database(one using MD5 and another one using SHA, for example)? Would it make it safer or unsafer? In case I wasn't clear enough, I want to know which hashing function(s) to use and how to pick a good salt in order to have a safe and fast password protection mechanism. EDIT: The website shouldn't contain anything too sensitive, but still I want it to be secure. EDIT2: Thank you all for your replies, I'm using hash("sha256",$salt.":".$password.":".$id) Questions that didn't help: What's the difference between SHA and MD5 in PHP Simple Password Encryption Secure methods of storing keys, passwords for asp.net How would you implement salted passwords in Tomcat 5.5

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• shortest digest of a string

  - by meta

  [Description] Given a string of char type, find a shortest digest, which is defined as: a shortest sub-string which contains all the characters in the original string. [Example] A = "aaabedacd" B = "bedac" is the answer. [My solution] Define an integer table with 256 elements, which is used to record the occurring times for each kind of character in the current sub-string. Scan the whole string, statistic the total kinds of character in the given string by using the above table. Use two pointers, start, end, which are initially pointing to the start and (start + 1) of the given string. The current kinds of character is 1. Expand sub-string[start, end) at the end until it contains all kinds of character. Update the shortest digest if possible. Contract sub-string[start, end] at the start by one character each time, try to restore its digest property if necessary by step 4. The time cost is O(n), and the extra space cost is constant. Any better solution without extra space?

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• Stack and Hash joint

  - by Alexandru

  I'm trying to write a data structure which is a combination of Stack and HashSet with fast push/pop/membership (I'm looking for constant time operations). Think of Python's OrderedDict. I tried a few things and I came up with the following code: HashInt and SetInt. I need to add some documentation to the source, but basically I use a hash with linear probing to store indices in a vector of the keys. Since linear probing always puts the last element at the end of a continuous range of already filled cells, pop() can be implemented very easy without a sophisticated remove operation. I have the following problems: the data structure consumes a lot of memory (some improvement is obvious: stackKeys is larger than needed). some operations are slower than if I have used fastutil (eg: pop(), even push() in some scenarios). I tried rewriting the classes using fastutil and trove4j, but the overall speed of my application halved. What performance improvements would you suggest for my code? What open-source library/code do you know that I can try?

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• Two strange efficiency problems in Mathematica

  - by Jess Riedel

  FIRST PROBLEM I have timed how long it takes to compute the following statements (where V[x] is a time-intensive function call): Alice = Table[V[i],{i,1,300},{1000}]; Bob = Table[Table[V[i],{i,1,300}],{1000}]^tr; Chris_pre = Table[V[i],{i,1,300}]; Chris = Table[Chris_pre,{1000}]^tr; Alice, Bob, and Chris are identical matricies computed 3 slightly different ways. I find that Chris is computed 1000 times faster than Alice and Bob. It is not surprising that Alice is computed 1000 times slower because, naively, the function V must be called 1000 more times than when Chris is computed. But it is very surprising that Bob is so slow, since he is computed identically to Chris except that Chris stores the intermediate step Chris_pre. Why does Bob evaluate so slowly? SECOND PROBLEM Suppose I want to compile a function in Mathematica of the form f(x)=x+y where "y" is a constant fixed at compile time (but which I prefer not to directly replace in the code with its numerical because I want to be able to easily change it). If y's actual value is y=7.3, and I define f1=Compile[{x},x+y] f2=Compile[{x},x+7.3] then f1 runs 50% slower than f2. How do I make Mathematica replace "y" with "7.3" when f1 is compiled, so that f1 runs as fast as f2? Many thanks!

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• Collision detection of huge number of circles

  - by Tomek Tarczynski

  What is the best way to check collision of huge number of circles? It's very easy to detect collision between two circles, but if we check every combination then it is O(n^2) which definitely not an optimal solution. We can assume that circle object has following properties: -Coordinates -Radius -Velocity -Direction Velocity is constant, but direction can change. I've come up with two solutions, but maybe there are some better solutions. Solution 1 Divide whole space into overlapping squares and check for collision only with circles that are in the same square. Squares needs to overlap so there won't be a problem when circle moves from one square to another. Solution 2 At the beginning distances between every pair of circles need to be calculated. If the distance is small then these pair is stored in some list, and we need to check for collision in every update. If the distance is big then we store after which update there can be a collision (it can be calculated because we know the distance and velocitites). It needs to be stored in some kind of priority queue. After previously calculated number of updates distance needs to be checked again and then we do the same procedure - put it on the list or again in the priority queue.

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• Why is WMDC/ActiveSync so flaky?

  - by Ira Rainey

  I'm developing a Windows Mobile app using the .NET Compact Framework 3.5 and VS2008, and for debugging using the Device Emulator V3, on Win7, and seem to have constant problems with Windows Mobile Device Centre (6.1) connecting. Using the Emulator Manager (9.0.21022.8) I cradle the device using DMA in WMDC. The problem is it's so flaky at actually connecting that it's becoming a pain. I find that when I turn my computer on, before I can get it to connect I have to open up WMDC, disable Connect over DMA, close WMDC down, reopen it again, and then it might cradle. Often I have to do this twice before it will cradle. Once it's cradled it's generally fine, but nothing seems consistent in getting it to connect. Connecting with physical devices is often better, although not always. If I plug a PDA into a USB socket other than the one it was originally plugged into then it won't connect at all. Often the best/most reliable connection method seems to be over Bluetooth, but that's quite slow. Anybody got any tips or advice?

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• Bubble Breaker Game Solver better than greedy?

  - by Gregory

  For a mental exercise I decided to try and solve the bubble breaker game found on many cell phones as well as an example here:Bubble Break Game The random (N,M,C) board consists N rows x M columns with C colors The goal is to get the highest score by picking the sequence of bubble groups that ultimately leads to the highest score A bubble group is 2 or more bubbles of the same color that are adjacent to each other in either x or y direction. Diagonals do not count When a group is picked, the bubbles disappear, any holes are filled with bubbles from above first, ie shift down, then any holes are filled by shifting right A bubble group score = n * (n - 1) where n is the number of bubbles in the bubble group The first algorithm is a simple exhaustive recursive algorithm which explores going through the board row by row and column by column picking bubble groups. Once the bubble group is picked, we create a new board and try to solve that board, recursively descending down Some of the ideas I am using include normalized memoization. Once a board is solved we store the board and the best score in a memoization table. I create a prototype in python which shows a (2,15,5) board takes 8859 boards to solve in about 3 seconds. A (3,15,5) board takes 12,384,726 boards in 50 minutes on a server. The solver rate is ~3k-4k boards/sec and gradually decreases as the memoization search takes longer. Memoization table grows to 5,692,482 boards, and hits 6,713,566 times. What other approaches could yield high scores besides the exhaustive search? I don't seen any obvious way to divide and conquer. But trending towards larger and larger bubbles groups seems to be one approach Thanks to David Locke for posting the paper link which talks above a window solver which uses a constant-depth lookahead heuristic.

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• testing devise with shoulda and machinist

  - by mattherick

  hello! I´d like to test my app with shoulda and machinist. I use the devise authentification gem. I get following error: $ ruby unit/page_test.rb c:/Ruby/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/rails/gem_dependency.rb:119:Warning: Gem::Dependency#version_requirements is deprecated and will be rem oved on or after August 2010. Use #requirement c:/Ruby/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/active_support/dependencies.rb:443:in load_missing_constant': uninitialized constant Admins (N ameError) from c:/Ruby/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/active_support/dependencies.rb:80:inconst_missing' from c:/Ruby/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/active_support/dependencies.rb:92:in const_missing' from c:/Users/Mattherick/Desktop/heimspiel/heimspiel_app/app/controllers/admins_controller.rb:1 from c:/Ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:ingem_original_require' from c:/Ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in require' from c:/Ruby/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/active_support/dependencies.rb:158:inrequire' from c:/Ruby/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/active_support/dependencies.rb:265:in require_or_load' from c:/Ruby/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/active_support/dependencies.rb:224:independ_on' ... 12 levels... from ./unit/../test_helper.rb:2 from c:/Ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in gem_original_require' from c:/Ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:inrequire' from unit/page_test.rb:1 Somebody an idea what´s wrong? If I don´t use devise my tests are okay. And my second question: Does somebdoy has a good tutorial for increasing different roles in the devise gem? If I generate my own views and add a few attributes to my devise-model, they won´t be save in the database. I read the docu at github, but don´t really checked it. mattherick

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• Encoding / Error Correction Challenge

  - by emi1faber

  Is it mathematically feasible to encode and initial 4 byte message into 8 bytes and if one of the 8 bytes is completely dropped and another is wrong to reconstruct the initial 4 byte message? There would be no way to retransmit nor would the location of the dropped byte be known. If one uses Reed Solomon error correction with 4 "parity" bytes tacked on to the end of the 4 "data" bytes, such as DDDDPPPP, and you end up with DDDEPPP (where E is an error) and a parity byte has been dropped, I don't believe there's a way to reconstruct the initial message (although correct me if I am wrong)... What about multiplying (or performing another mathematical operation) the initial 4 byte message by a constant, then utilizing properties of an inverse mathematical operation to determine what byte was dropped. Or, impose some constraints on the structure of the message so every other byte needs to be odd and the others need to be even. Alternatively, instead of bytes, it could also be 4 decimal digits encoded in some fashion into 8 decimal digits where errors could be detected & corrected under the same circumstances mentioned above - no retransmission and the location of the dropped byte is not known. I'm looking for any crazy ideas anyone might have... Any ideas out there?

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• Perf4j Not Logging to Separate File

  - by Jehud

  I setup some stop watch calls in my code to measure some code blocks and all the messages are going into my primary log and not into the timing log. The perfStats.log file gets created just fine but all the messages go to the root log which I didn't think was supposed to happen according to the docs I've read. Is there something obvious I'm missing here? Example log4j.xml <!-- This file appender is used to output aggregated performance statistics --> <appender name="fileAppender" class="org.apache.log4j.FileAppender"> <param name="File" value="perfStats.log"/> <layout class="org.apache.log4j.PatternLayout"> <param name="ConversionPattern" value="%m%n"/> </layout> </appender> <!-- Loggers --> <!-- The Perf4J logger. Note that org.perf4j.TimingLogger is the value of the org.perf4j.StopWatch.DEFAULT_LOGGER_NAME constant. Also, note that additivity is set to false, which is usually what is desired - this means that timing statements will only be sent to this logger and NOT to upstream loggers. --> <logger name="org.perf4j.TimingLogger" additivity="false"> <level value="INFO"/> <appender-ref ref="CoalescingStatistics"/> </logger> <root> <priority value="info"/> <appender-ref ref="STDOUT-DEBUG"/> </root>

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• Use Math class to calculate

  - by LC

  Write a JAVA program that calculates the surface area of a cylinder, C= 2( p r2) + 2 p r h, where r is the radius and h is the height of the cylinder. Allow the user to enter in a radius and a height. Format the output to three decimal places. Use the constant PI and the method pow() from the Math class. This is what I've done so far but it can not run. Can anyone help me ? import Java.util Scanner; public class Ex5 { public static void main (String[] args) { Scanner input.new Scanner(System.in); double radius,height,area; System.out.print("Please enter the radius of the Cylinder"); radius = input.nextDouble(); System.out.print("Please enter the height of the Cylinder"); height = input.nextDouble(); area = (4*Math.PI*radius)+2*Math.PIMath.POW(radius,2); System.out.println("The surface of the cylinder" + area); } }

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• Free solution for automatic updates with a .NET/C# app?

  - by a2h

  Yes, from searching I can see this has been asked time and time again. Here's a backstory. I'm an individual hobbyist developer with zero budget. A program I've been developing has been in need of constant bugfixes, and me and users are getting tired of having to manually update. Me, because my current solution of Manually FTP to my website Update a file "newest.txt" with the newest version Update index.html with a link to the newest version Hope for people to see the "there's an update" message Have them manually download the update sucks, and whenever I screw up an update, I get pitchforks. Users, because, well, "Are you ever going to implement auto-update?" "Will there ever be an auto-update feature?" Over the past I have looked into: WinSparkle - No in-app updates, and the DLL is 500 KB. My current solution is a few KBs in the executable and has no in-app updates. http://windowsclient.net/articles/appupdater.aspx - I can't comprehend the documentation http://www.codeproject.com/KB/vb/Auto_Update_Revisited.aspx - Doesn't appear to support anything other than working with files that aren't in use wyUpdate - wyBuild isn't free, and the file specification is simply too complex. Maybe if I was under a company paying me I could spend the time, but then I may as well pay for wyBuild. http://www.kineticjump.com/update/default.aspx - Ditto the last sentence. ClickOnce - Workarounds for implementing launching on startup are massive, horrendous and not worth it for such a simple feature. Publishing is a pain; manual FTP and replace of all files is required for servers without FrontPage Extensions. I'm pretty much ready to throw in the towel right now and strangle myself. And then I think about Sparkle... EDIT: I came across SparkleDotNET just then. Looks good, though the DLL is 200 KB. Don't know if that's really that big of an issue, though.

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• How to detect hidden field tampering?

  - by Myron

  On a form of my web app, I've got a hidden field that I need to protect from tampering for security reasons. I'm trying to come up with a solution whereby I can detect if the value of the hidden field has been changed, and react appropriately (i.e. with a generic "Something went wrong, please try again" error message). The solution should be secure enough that brute force attacks are infeasible. I've got a basic solution that I think will work, but I'm not security expert and I may be totally missing something here. My idea is to render two hidden inputs: one named "important_value", containing the value I need to protect, and one named "important_value_hash" containing the SHA hash of the important value concatenated with a constant long random string (i.e. the same string will be used every time). When the form is submitted, the server will re-compute the SHA hash, and compare against the submitted value of important_value_hash. If they are not the same, the important_value has been tampered with. I could also concatenate additional values with the SHA's input string (maybe the user's IP address?), but I don't know if that really gains me anything. Will this be secure? Anyone have any insight into how it might be broken, and what could/should be done to improve it? Thanks!

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• Where's the Win32 resource for the mouse cursor for dragging splitters?

  - by Luther Baker

  I am building a custom win32 control/widget and would like to change the cursor to a horizontal "splitter" symbol when hovering over a particular vertical line in the control. IE: I want to drag this vertical line (splitter bar) left and right (WEST and EAST). Of the the system cursors (OCR_*), the only cursor that makes sense is the OCR_SIZEWE. Unfortunately, that is the big, awkward cursor the system uses when resizing a window. Instead, I am looking for the cursor that is about 20 pixels tall and around 3 or 4 pixel wide with two small arrows pointing left and right. I can easily draw this and include it as a resource in my application but the cursor itself is so prevalent that I wanted to be sure it wasn't missing something. For example: when you use the COM drag and drop mechanism (CLSID_DragDropHelper, IDropTarget, etc) you implicitly have access to the "drag" icon (little box under the pointer). I didn't see an explicit OCR_* constant for this guy ... so likewise, if I can't find this splitter cursor outright, I am wondering if it is part of a COM object or something else in the win32 lib.

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• How to write PIL image filter for plain pgm format?

  - by Juha

  How can I write a filter for python imaging library for pgm plain ascii format (P2). Problem here is that basic PIL filter assumes constant number of bytes per pixel. My goal is to open feep.pgm with Image.open(). See http://netpbm.sourceforge.net/doc/pgm.html or below. Alternative solution is that I find other well documented ascii grayscale format that is supported by PIL and all major graphics programs. Any suggestions? br, Juha feep.pgm: P2 # feep.pgm 24 7 15 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 3 3 3 3 0 0 7 7 7 7 0 0 11 11 11 11 0 0 15 15 15 15 0 0 3 0 0 0 0 0 7 0 0 0 0 0 11 0 0 0 0 0 15 0 0 15 0 0 3 3 3 0 0 0 7 7 7 0 0 0 11 11 11 0 0 0 15 15 15 15 0 0 3 0 0 0 0 0 7 0 0 0 0 0 11 0 0 0 0 0 15 0 0 0 0 0 3 0 0 0 0 0 7 7 7 7 0 0 11 11 11 11 0 0 15 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 edit: Thanks for the answer, I works... but I need a solution that uses Image.open(). Most of python programs out there use PIL for graphics manipulation (google: python image open). Thus, I need to be able to register a filter to PIL. Then, I can use any software that uses PIL. I now think mostly scipy, pylab, etc. dependent programs.

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• Database migration pattern for Java?

  - by Eno

  Im working on some database migration code in Java. Im also using a factory pattern so I can use different kinds of databases. And each kind of database im using implements a common interface. What I would like to do is have a migration check that is internal to the class and runs some database schema update code automatically. The actual update is pretty straight forward (I check schema version in a table and compare against a constant in my app to decide whether to migrate or not and between which versions of schema). To make this automatic I was thinking the test should live inside (or be called from) the constructor. OK, fair enough, that's simple enough. My problem is that I dont want the test to run every single time I instantiate a database object (it runs a query so having it run on every construction is not efficient). So maybe this should be a class static method? I guess my question is, what is a good design pattern for this type of problem? There ought to be a clean way to ensure the migration test runs only once OR is super-efficient.

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• PLKs and Web Service Software Factory

  - by Nix

  We found a bug in Web Service Software Factory a description can be found here. There has been no updates on it so we decided to download the code and fix it ourself. Very simple bug and we patched it with maybe 3 lines of code. However* we have now tried to repackage it and use it and are finding that this is seemingly an impossible process. Can someone please explain to me the process of PLKs? I have read all about them but still don't understand what is really required to distribute a VS package. I was able to get it to load and run using a PLK obtained from here, but i am assuming that you have to be a partner to get a functional PLK that will be recognized on other peoples systems? Every time i try and install this on a different computer I get a "Package Load Failure". Is the reason I am getting errors because I am not using a partner key? Is there any other way around this? For instance is there any way we can have an "internal" VS package that we can distribute? Edit Files I had to change to get it to work. First run devenv PostInstall.proj Generate your plks and replace ##Package PLK## (.resx files) --Just note that package version is not the class name but is "Web Service Software Factory: Modeling Edition" -- And you need to remove the new lines from the key ProductDefinitionRegistryFragment.wxi line 1252(update version to whatever version you used in plk) Uncomment all // [VSShell::ProvideLoadKey("Standard", Constant in .tt files.

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