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Articles indexed in December 2010

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Can I remove all-caps and shorten the disclaimer on my License?

- by stefano palazzo

I am using the MIT License for a particular piece of code. Now, this license has a big disclaimer in all-caps: THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF... ... I've seen a normally capitalised disclaimer on the zlib license (notice that it is above the license text), and even software with no disclaimer at all (which implies, i take it, that there is indeed a guarantee?), but i'd like some sourced advice by a trusted party. I just haven't found any. GNU's License notice for other files comes with this disclaimer: This file is offered as-is, without any warranty. Short and simple. My question therefore: Are there any trusted sources indicating that a short rather than long, and a normally spelled rather than capitalised disclaimer (or even one or the other) are safely usable in all of the jurisdictions I should be concerned with? If the answer turns out to be yes: Why not simply use the short license notice that the fsf proposes for readme-files and short help documents instead of the MIT License? Is there any evidence suggesting this short 'license' will not hold up? For the purposes of this question, the software is released in the European Union, should it make any difference.

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Is there any reason to use "plain old data" classes?

- by Michael

In legacy code I occasionally see classes that are nothing but wrappers for data. something like: class Bottle { int height; int diameter; Cap capType; getters/setters, maybe a constructor } My understanding of OO is that classes are structures for data and the methods of operating on that data. This seems to preclude objects of this type. To me they are nothing more than structs and kind of defeat the purpose of OO. I don't think it's necessarily evil, though it may be a code smell. Is there a case where such objects would be necessary? If this is used often, does it make the design suspect?

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Are there any actual examples of profitable programmer's "worker's cooperatives"?

- by Wannabe Tycoon

http://en.wikipedia.org/wiki/Worker_cooperative I'm curious whether there are, anywhere in the world, worker's cooperatives that center on a technology business that involves either programming, IT, or some sort of IT or programming related consulting or services. The wikipedia link above is an overview of the concept. The short form explanation is that a co-op is a worker-owned business. Also there is the notion that every worker owns shares in the business. I am interested in knowing whether an example of a "programmer's/IT co-op" even exists. Note: I am not talking about nor asking about a government-funded incubator nor any other socialized, state supported group. I also don't mean "co-working", which is renting an office with other self employed people doing their own thing. I mean a going, profitable IT business operating in a competitive environment that is worker-owned and run.

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Why can't I write just a try with no catch or finally?

- by Camilo Martin

Sometimes I do this and I've seen others doing it too: VB: Try DontWannaCatchIt() Catch End Try C#: try { DontWannaCatchIt(); } catch {} I know I should catch every important exception and do something about it, but sometimes it's not important to - or am I doing something wrong? Is this usage of the try block incorrect, and the requirement of at least one catch or finally block an indication of it?

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Determining two lines in MATLAB

- by Sanyi

Hi! I am making the game planarity in MATLAB, and i am stuck where the program have to determine that is there any lines that are in inscision with each other. Any ideas how could the program find the inscision points. Heres my source for the game: > clear; clc; a=1; b=10; x=floor(rand(5,1)*(b-a+1)+a); y=floor(rand(5,1)*(b-a+1)+a); fig1=figure; set(fig1,'Color','w','Position',[100 100 500 500]) plot(x,y,'o','MarkerSize',12,'MarkerFaceColor','r'); axis([0 11 0 11]); axis off grid on; hold on; FirstPlayerLines=[]; SecondPlayerLines=[]; for a1=1:+1:2 for a2=5:-1:2 plot([x(a1) x(a2)],[y(a1) y(a2)],'Color','black','LineWidth',3); end end waitforbuttonpress

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Html newbie! background-image question

- by Kevin Li

Hi! I'm learning HTML and I wanted to practice by recreating a invoice sent to me by Electronics Expo. However, I used the background-image property and repeated it by repeat-x and now, the background stretches across the page so much that it has a horizontal bar to drag. http://htmlpocketreference.110mb.com/index.html You can see what I did in my link above. Also, I would really appreciate some advice on simplifying my CSS coding. It seems really messy and I have to move every element once something changes. -.- Thanks!

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Recursive Perl detail need help

- by Catarrunas

Hi everybody, i think this is a simple problem, but i'm stuck with it for some time now! I need a fresh pair of eyes on this. The thing is i have this code in perl: #!c:/Perl/bin/perl use CGI qw/param/; use URI::Escape; print "Content-type: text/html\n\n"; my $directory = param ('directory'); $directory = uri_unescape ($directory); my @contents; readDir($directory); foreach (@contents) { print "$_\n"; } #------------------------------------------------------------------------ sub readDir(){ my $dir = shift; opendir(DIR, $dir) or die $!; while (my $file = readdir(DIR)) { next if ($file =~ m/^\./); if(-d $dir.$file) { #print $dir.$file. " ----- DIR\n"; readDir($dir.$file); } push @contents, ($dir . $file); } closedir(DIR); } I've tried to make it recursive. I need to have all the files of all of the directories and subdirectories, with the full path, so that i can open the files in the future. But my output only returns the files in the current directory and the files in the first directory that it finds. If i have 3 folders inside the directory it only shows the first one. Ex. of cmd call: "perl readDir.pl directory=C:/PerlTest/" Thanks

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Print a HTML page in landscape mode?

- by yoz1k

Is it possible to print a simple page in landscape mode? (without the need for the user to go to printer settings?) <!DOCTYPE html> <html> <head> <title></title> <meta http-equiv="Content-Type" content="text/html;charset=utf-8" /> <style type="text/css" media="print"/> @page { size: landscape; margin: 2cm; } body { color: red; } </style> <style type="text/css" media="all" > body { font-size: 10pt; font-family: Arial; } table td { padding: 2em; } </style> </head> <body> <table> <tr> <td>a</td><td>b</td><td>c</td><td>d</td><td>e</td><td>f</td><td>g</td><td>h</td><td>i</td><td>j</td><td>k</td><td>l</td><td>m</td><td>n</td><td>o</td><td>p</td><td>q</td><td>r</td><td>s</td><td>t</td><td>u</td><td>v</td><td>w</td><td>x</td><td>y</td><td>z</td> </tr> <tr> <td>a</td><td>b</td><td>c</td><td>d</td><td>e</td><td>f</td><td>g</td><td>h</td><td>i</td><td>j</td><td>k</td><td>l</td><td>m</td><td>n</td><td>o</td><td>p</td><td>q</td><td>r</td><td>s</td><td>t</td><td>u</td><td>v</td><td>w</td><td>x</td><td>y</td><td>z</td> </tr> <tr> <td>a</td><td>b</td><td>c</td><td>d</td><td>e</td><td>f</td><td>g</td><td>h</td><td>i</td><td>j</td><td>k</td><td>l</td><td>m</td><td>n</td><td>o</td><td>p</td><td>q</td><td>r</td><td>s</td><td>t</td><td>u</td><td>v</td><td>w</td><td>x</td><td>y</td><td>z</td> </tr> <tr> <td>a</td><td>b</td><td>c</td><td>d</td><td>e</td><td>f</td><td>g</td><td>h</td><td>i</td><td>j</td><td>k</td><td>l</td><td>m</td><td>n</td><td>o</td><td>p</td><td>q</td><td>r</td><td>s</td><td>t</td><td>u</td><td>v</td><td>w</td><td>x</td><td>y</td><td>z</td> </tr> <tr> <td>a</td><td>b</td><td>c</td><td>d</td><td>e</td><td>f</td><td>g</td><td>h</td><td>i</td><td>j</td><td>k</td><td>l</td><td>m</td><td>n</td><td>o</td><td>p</td><td>q</td><td>r</td><td>s</td><td>t</td><td>u</td><td>v</td><td>w</td><td>x</td><td>y</td><td>z</td> </tr> <tr> <td>a</td><td>b</td><td>c</td><td>d</td><td>e</td><td>f</td><td>g</td><td>h</td><td>i</td><td>j</td><td>k</td><td>l</td><td>m</td><td>n</td><td>o</td><td>p</td><td>q</td><td>r</td><td>s</td><td>t</td><td>u</td><td>v</td><td>w</td><td>x</td><td>y</td><td>z</td> </tr> </table> </body> </html> the solution @page size: landscape didn't help. any ideas?

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Java URL Connection Time Out

- by webren

Hello, I am attempting to connect to a website where I'd like to extract its HTML contents. My application will never connect to the site - only time out. Here is my code: URL url = new URL("www.website.com"); URLConnection connection = url.openConnection(); connection.setConnectTimeout(2000); connection.setReadTimeOut(2000); BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream()); String line; while ((line = reader.readLine()) != null) { // do stuff with line } reader.close(); Any ideas would be greatly appreciated. Thanks!

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How do I add a Marker to a jQuery UI Slider?

- by Bijan

I have a simple jQuery UI slider that has a numerical range from 25 to 35. It works fine and the default value is 28. I'm hoping to add a simple tick mark to the slider to indicate that 28 is where the default is. Is there a simple way to add an indicator? $('#cycle_length').slider({ range: "min", value: 28, min: 25, max: 35, step: 1, slide: function( event, ui ) { $( "#amount" ).val( ui.value ); } }); $( "#amount" ).val( $( "#cycle_length" ).slider( "value" ) );

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How can I use TDD to solve a puzzle with an unknown answer?

- by matthewsteele

Recently I wrote a Ruby program to determine solutions to a "Scramble Squares" tile puzzle: I used TDD to implement most of it, leading to tests that looked like this: it "has top, bottom, left, right" do c = Cards.new card = c.cards[0] card.top.should == :CT card.bottom.should == :WB card.left.should == :MT card.right.should == :BT end This worked well for the lower-level "helper" methods: identifying the "sides" of a tile, determining if a tile can be validly placed in the grid, etc. But I ran into a problem when coding the actual algorithm to solve the puzzle. Since I didn't know valid possible solutions to the problem, I didn't know how to write a test first. I ended up writing a pretty ugly, untested, algorithm to solve it: def play_game working_states = [] after_1 = step_1 i = 0 after_1.each do |state_1| step_2(state_1).each do |state_2| step_3(state_2).each do |state_3| step_4(state_3).each do |state_4| step_5(state_4).each do |state_5| step_6(state_5).each do |state_6| step_7(state_6).each do |state_7| step_8(state_7).each do |state_8| step_9(state_8).each do |state_9| working_states << state_9[0] end end end end end end end end end So my question is: how do you use TDD to write a method when you don't already know the valid outputs? If you're interested, the code's on GitHub: Tests: https://github.com/mattdsteele/scramblesquares-solver/blob/master/golf-creator-spec.rb Production code: https://github.com/mattdsteele/scramblesquares-solver/blob/master/game.rb

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disable dates using jquery inside gridview control

- by bladerunner

Hi there, I have a gridview which contains a textbox control. I need to show the calendar for the user to pick the date and certain dates are to be disabled using jquery. I found a post on stackoverflow that talked about how to disable certain dates. I am done with that part, except not sure how to pass the textbox control to this jquery function. Here is the code. <script type="text/javascript" language="javascript"> function pageLoad(sender, args) { var enabledDays = ['09/21/2011', '10/05/2011', '10/19/2011', '11/02/2011', '11/16/2011']; /* utility functions */ function editDays(date) { for (var i = 0; i < enabledDays.length; i++) { if (new Date(enabledDays[i]).toString() == date.toString()) { return [true]; } } return [false]; } /* create datepicker */ $(document).ready(function() { $('#<%= txtInHomeDate.ClientID %>').datepicker({ beforeShow: springDate, beforeShowDay: editDays, dateFormat: 'mm/dd/yy', buttonImage: 'images/cal.gif', buttonText: 'Choose date', firstDay: 1, buttonImageOnly: true, showOn: 'both', showAnim: 'fadeIn', onSelect: function() { $(this).trigger("onchange", null); } }); function springDate() { var defaultMin = new Date(); var defaultMax = new Date(); var Min = defaultMin; var Max = defaultMax; // make valid date from hiddenfied value format is MM/dd/yyyy dateMin = $('#<%= hfStDate.ClientID %>').val(); dateMin = new Date(dateMin); dateMax = $('#<%= hfEndDate.ClientID %>').val(); dateMax = new Date(dateMax); if (dateMin && dateMax) { Min = new Date(dateMin.getFullYear(), dateMin.getMonth(), dateMin.getDate()); Max = new Date(dateMax.getFullYear(), dateMax.getMonth(), dateMax.getDate()); } return { minDate: Min, maxDate: Max }; } }); } <.... <asp:TemplateField HeaderText="In-Home Date"> <ItemStyle HorizontalAlign="Center" /> <ItemTemplate> <asp:HiddenField ID="hfStDate" runat="server" Value="09/01/2011" /> <asp:HiddenField ID="hfEndDate" runat="server" Value="11/30/2011" /> <asp:TextBox ID="txtInHomeDate" runat="server" /> </ItemTemplate> </asp:TemplateField> Currently, it errors out since the jquery function won't find the txtInHomeDate. Could I get some help as I am pretty close to get this done? Thanks!!

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Stuck in implementing Pagination in Android

- by user443141

I am implementing pagination for ListView in Android . I am extending the BaseAdapater class for customising the ListView. Already I have the code working fine for the Customised ListView. Below is the new requirement. 1I am fetching 6 items from server & displaying them . Now when the user scrolls to the 6th item(end of list) , I need to call the server to fetch the next 6 items & update the Listview I have overriden the methods ipublic void onScroll(AbsListView view, int firstVisibleItem,int visibleItemCount, int totalItemCount) iipublic void onScrollStateChanged(AbsListView view, int scrollState) In the first response from the server, I get the total no of pages from the server & for each time I call the server , I get the current page value . Kindly provide me the steps/sample code on how to check the last item of the list & update the list . The code should be iterative since I may need to call multiple times & fetch from server. Warm Regards, CB

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IOS SDK : first advices for beginners

- by VdesmedT

I too often answer the same kind of questions regarding basic topics like memory management, UITableView, Interface Orientation, MVC, etc... I understand very well that everyone starting with that SDK is too exited about getting its hand on it but a few reading would save them hours of debugging and the frustration that come along with the feeling that "We miss something here". I'd like experience users to share the few small articles, white papers, docs, book chapters that helps other save their time and avoid frustration. My first vote would be for : IOS Memory Management Guide View Controller Programming Guide Table View Guide And as a General recommendation, read the Overview section that come along with every class documention in the reference library, they contains most of what you need to know to avoid big traps !

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parsing xml attribute value

- by vbNewbie

I have been parsing xml content using the xmlreader and cannot use the xml document but so far it works getting all elementcontent except for the attribute contents. I need to parse the link below found in the following entry; <title>XXXX UUUUUU posted a</title> <category term="NotePosted" label="Note Posted"/> <link rel="alternate" type="html" href="http://www.dfsddsfdsf.com/profile.php?id=sdfdfsfdsdfddfsfd&v=wall&story_dbid=dssdfasdfdasfdsafafafa"/> <source>......... <source> I need the href tag in the link attribute but it keeps coming back null. While ureader.Read If ureader.HasAttributes Then fId = ureader.GetAttribute("href") If fId.Contains("?v=wall&amp") Then fIdList.Add(fId) Exit While End If If String.IsNullOrEmpty(fId) Then fId = "NOTHING" End If End If End While

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Password hashing, salt and storage of hashed values

- by Jonathan Leffler

Suppose you were at liberty to decide how hashed passwords were to be stored in a DBMS. Are there obvious weaknesses in a scheme like this one? To create the hash value stored in the DBMS, take: A value that is unique to the DBMS server instance as part of the salt, And the username as a second part of the salt, And create the concatenation of the salt with the actual password, And hash the whole string using the SHA-256 algorithm, And store the result in the DBMS. This would mean that anyone wanting to come up with a collision should have to do the work separately for each user name and each DBMS server instance separately. I'd plan to keep the actual hash mechanism somewhat flexible to allow for the use of the new NIST standard hash algorithm (SHA-3) that is still being worked on. The 'value that is unique to the DBMS server instance' need not be secret - though it wouldn't be divulged casually. The intention is to ensure that if someone uses the same password in different DBMS server instances, the recorded hashes would be different. Likewise, the user name would not be secret - just the password proper. Would there be any advantage to having the password first and the user name and 'unique value' second, or any other permutation of the three sources of data? Or what about interleaving the strings? Do I need to add (and record) a random salt value (per password) as well as the information above? (Advantage: the user can re-use a password and still, probably, get a different hash recorded in the database. Disadvantage: the salt has to be recorded. I suspect the advantage considerably outweighs the disadvantage.) There are quite a lot of related SO questions - this list is unlikely to be comprehensive: Encrypting/Hashing plain text passwords in database Secure hash and salt for PHP passwords The necessity of hiding the salt for a hash Clients-side MD5 hash with time salt Simple password encryption Salt generation and Open Source software I think that the answers to these questions support my algorithm (though if you simply use a random salt, then the 'unique value per server' and username components are less important).

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Building MobileVLCKit from git.videolan.org repository on macOsX with XCode

- by ztepsic

I would like to make an application for iOS(iPhone and iPad) that can play streaming videos through RTSP protocol (that includes mms). I imagined to achive a specified application using VLC player or libVLC library. On the official vlc git repository (http://git.videolan.org/?p=vlc.git;a=tree) in projects/macosx/framework/ folder there is xcode project MobileVLCKit.xcodeproj for which I assume that is a somewhat usable VLC framework for iOS. Now the problem is that I can't/don't know how to build this project. When I try to build MobileVLCKit.xcodeproj I get an error that says it can't find files inside extras/contrib/hosts/i686-apple-darwin10/ios/ folder. I have looked within that folder (extras/contrib) and managed to create folder (with files) extras/contrib/hosts/i686-apple-darwin10/ with make, but there is no ios folder. So, does anybody knows how to successfully build MobileVLCKit?

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Spring MVC: How to get the remaining path after the controller path?

- by Willis Blackburn

I've spent over an hour trying to find the answer to this question, which seems like it should reflect a common use case, but I can't figure it out! Basically I am writing a file-serving controller using Spring MVC. The URLs are of the format http://www.bighost.com/serve/the/path/to/the/file.jpg, in which the part after "/serve" is the path to the requested file, which may have an arbitrary number of path segments. I have a controller like this: @Controller class ServerController { @RequestMapping(value = "/serve/???") public void serve(???) { } } What I am trying to figure out is: What do I use in place of "???" to make this work? I have two theories about how this should work. The first theory is that I could replace the first "???" in the RequestMapping with a path variable placeholder that has some special syntax meaning "capture to the end of the path." If a regular placeholder looks like "{path}" then maybe I could use "{path:**}" or "{path:/}" or something like that. Then I could use a @PathVariable annotation to refer to the path variable in the second "???". The other theory is that I could replace the first "???" with "**" (match anything) and that Spring would give me an API to obtain the remainder of the path (the part matching the "**"). But I can't find such an API. Thanks for any help you can provide!

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Question SpeechSynthesizer.SetOutputToAudioStream audio format problem

- by Chris Kugler

Hi, I'm currently working on an application which requires transmission of speech encoded to a specific audio format. System.Speech.AudioFormat.SpeechAudioFormatInfo synthFormat = new System.Speech.AudioFormat.SpeechAudioFormatInfo(System.Speech.AudioFormat.EncodingFormat.Pcm, 8000, 16, 1, 16000, 2, null); This states that the audio is in PCM format, 8000 samples per second, 16 bits per sample, mono, 16000 average bytes per second, block alignment of 2. When I attempt to execute the following code there is nothing written to my MemoryStream instance; however when I change from 8000 samples per second up to 11025 the audio data is written successfully. SpeechSynthesizer synthesizer = new SpeechSynthesizer(); waveStream = new MemoryStream(); PromptBuilder pbuilder = new PromptBuilder(); PromptStyle pStyle = new PromptStyle(); pStyle.Emphasis = PromptEmphasis.None; pStyle.Rate = PromptRate.Fast; pStyle.Volume = PromptVolume.ExtraLoud; pbuilder.StartStyle(pStyle); pbuilder.StartParagraph(); pbuilder.StartVoice(VoiceGender.Male, VoiceAge.Teen, 2); pbuilder.StartSentence(); pbuilder.AppendText("This is some text."); pbuilder.EndSentence(); pbuilder.EndVoice(); pbuilder.EndParagraph(); pbuilder.EndStyle(); synthesizer.SetOutputToAudioStream(waveStream, synthFormat); synthesizer.Speak(pbuilder); synthesizer.SetOutputToNull(); There are no exceptions or errors recorded when using a sample rate of 8000 and I couldn't find anything useful in the documentation regarding SetOutputToAudioStream and why it succeeds at 11025 samples per second and not 8000. I have a workaround involving a wav file that I generated and converted to the correct sample rate using some sound editing tools, but I would like to generate the audio from within the application if I can. One particular point of interest was that the SpeechRecognitionEngine accepts that audio format and successfully recognized the speech in my synthesized wave file... Update: Recently discovered that this audio format succeeds for certain installed voices, but fails for others. It fails specifically for LH Michael and LH Michelle, and failure varies for certain voice settings defined in the PromptBuilder.

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Is SharePoint a good solution for me?

- by Pam Bullock

My company has many branches that use the same software suite that we've written for them. We're looking at SharePoint as a way to open a dialog with them about the software - reviews, change requests (not official ones, just for us to get an idea and for them to discuss amongst themselves what would be helpful). We would also like to utilize the document repository feature and possibly the blog. SharePoint is already available to us if we'd like to use it so that's why we're looking into it. I've done a lot of research and watched a lot of starter tutorials. It seems like it has what we're looking for. For those of you that know it well: Do you think it would be a good solution for us? Do you think it would be overkill? If so, Do you have an alternative suggestion? Are there other aspects of SharePoint that I haven't discovered yet that seems like it would be helpful for what we're doing? I will continue to research online but it's always great to hear the opinion of someone experienced with the product. Thanks so much! Pam

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How to implement escape Sequence in SDL

- by Sa'me Smd

Im trying to use the STL library inside the SDL. but it gives me the error "undeclared identifier" Is there any way i can use "\n"or even cout<<endl; Can the function SDL_WarpMousewhich places the mouse cursor on a desired location on screen help me with this. Because i want to put a tile on the next line sequence. I hope you get the Question. Its very vague and messed up question though (sorry for that). EDIT: void putMap(SDL_Surface* tile, SDL_Surface* screen) { for(int y = 0; y < 21; y++) { for(int x = 0; x < 60; x++) { if(maze[x][y] != '#') { apply_surface( x*10 , y*10 , tile, screen); } } cout<<endl; } } c:\documents and settings\administrator\my documents\visual studio 2008\projects\craptest\craptest\main.cpp(605) : error C2065: 'cout' : undeclared identifier c:\documents and settings\administrator\my documents\visual studio 2008\projects\craptest\craptest\main.cpp(605) : error C2065: 'endl' : undeclared identifier This is my apply_surface funtion. void apply_surface( int x, int y, SDL_Surface* source, SDL_Surface* destination ) { //Make a temporary rectangle to hold the offsets SDL_Rect offset; //Give the offsets to the rectangle offset.x = x; offset.y = y; //Blit the surface SDL_BlitSurface( source, NULL, destination, &offset ); }

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Export enviroment variable Mac

- by mujer esponja

Hello, I am starting with spring-roo, so I downloaded it and now I'm trying to export the variable. To get it, I tryed: PATH=$PATH:/Users/myUsr/spring-roo/bin export PATH PATH variable my-Name-3:~ myUsr$ echo $PATH /sw/bin:/sw/sbin:/usr/local/mysql/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/usr/X11/bin:/usr/X11R6/bin:/Users/myUsr/spring-roo/bin In this path (/Users/myUsr/spring-roo/bin), there is roo.sh But then, I can not run the command roo as it is suposed to be. Any idea?? Thanks in advance

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It's called College.

- by jeffreyabecker

Today I saw yet another 'GUID vs int as your primary key' article. Like most of the ones I've read this was filled with technical misrepresentations and out-right fallices. Chef's famous line that "There's a time and a place for everything children" applies here. GUIDs have distinct advantages and disadvantages which should be considered when choosing a data type for the primary key. Fallacy 1: "Its easier" An integer data type(tinyint, smallint, int, bigint) is a better artifical key than a GUID because its easier to remember. I'm a firm believer that your artifical primary keys should be opaque gibberish. PK's are an implementation detail which should never be exposed to the user or relied on for business logic. If you want things to come back in an order, add and ORDER BY clause and SortOrder fields. If you want a human-usable look-up add a business key with a unique constraint. If you want to know what order things were inserted into a table add a timestamp. Fallacy 2: "Size Matters" For many applications, the size of the artifical primary key is going to be irrelevant. The particular article which kicked this post off stated repeatedly that joining against an int has better performance than joining against a GUID. In computer science the performance of your algorithm is always a function of the number of data points. This still holds true for databases. Unless your table is very large, the performance difference between an int and a guid probably isnt going to be mesurable let alone noticeable. My personal experience is that the performance becomes an issue when you start having billions of rows in the table. At this point, you should probably start looking to move from int to bigint so the effective space/performance gain isnt as much as you'd think. GUID Advantages: Insert-ability / Mergeability: You can reliably insert guids into tables without key collisions. Database Independence: Saving entities to the database often requires knowing ids. With identity based ids the id must be selected back after every insert. GUIDs can be generated application-side allowing much faster inserts. GUID Disadvantages: Generatability: You can calculate the next id for an integer pk pretty easily in your head but will need a program to generate GUIDs. Solution: "Select top 100 newid() from sysobjects" Fragmentation: most GUID generation algorithms generate pseudo random GUIDs. This can cause inserts into the middle of your clustered index. Solutions: add a default of newsequentialid() or use GuidComb in NHibernate.

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OEM to Virtual Machine for Diaster Recovery / Business Continuity.

- by James

Hello, We are trying to deploy a Business Continuity Appliance (Zenith BDR) for a customer and one of the features is the ability to bring up the failed server in a virtual machine on the appliance. Great feature. However, the customer has OEM version of Server 2003 on that server and it comes up requiring immediate re-activation since it is now on different hardware. We would be happy with a 2-3 day grace period which is what we expected, but this isn't happening. What are the solutions without having to purchase another VLK copy of Server 2008 and re-installing the server with that license just so we can set this thing up.

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Mounting Solaris UFS partition on Debian(with FreeBSD kernel)

- by hayalci

I have some disks that were being used on a Solaris system. The disks are formatted as UFS. I attached them to a Debian system (with FreeBSD kernel. Debian/kFreeBSD), but I cannot mount them. $ mount -t ufs /dev/da2s1 /mnt/diska mount: /dev/da2s1 : Invalid argument Also the tunefs.ufs does not work; $ tunefs.ufs -p /dev/da2s1 tunefs.ufs: /dev/da2s1: could not read superblock to fill out disk Is there an incompatibility between FreeBSD UFS and Solaris UFS? Is it possible to mount one, under the other OS ? Note: tunefs.ufs works on the root partition $ tunefs.ufs -p /dev/da7s2 tunefs.ufs: ACLs: (-a) disabled tunefs.ufs: MAC multilabel: (-l) disabled tunefs.ufs: soft updates: (-n) disabled tunefs.ufs: gjournal: (-J) disabled tunefs.ufs: maximum blocks per file in a cylinder group: (-e) 2048 tunefs.ufs: average file size: (-f) 16384 tunefs.ufs: average number of files in a directory: (-s) 64 tunefs.ufs: minimum percentage of free space: (-m) 8% tunefs.ufs: optimization preference: (-o) time tunefs.ufs: volume label: (-L)

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