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• problem with QPropertyAnimation in Qt

  - by belhaouary

  Hi , i have a problem with QPropertyAnimation in Qt my code: QString my_text = "Hello Animation"; ui->textBrowser->setText((quote_text)); ui->textBrowser->show(); QPropertyAnimation animation2(ui->textBrowser,"geometry"); animation2.setDuration(1000); animation2.setStartValue(QRect(10,220/4,1,1)); animation2.setEndValue(QRect(10,220,201,71)); animation2.setEasingCurve(QEasingCurve::OutBounce); animation2.start(); till now it seems very good , but the problem is that i can see this animation only when i show a message box after it . QMessageBox m; m.setGeometry(QRect(100,180,100,50)); m.setText("close quote"); m.show(); m.exec(); when i remove the code of this message box , i can't see the animation anymore. the functionality of the program doesn't require showing this MessageBox at all. Can anybody help?

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• how to Retrieve the parameters of document.write to detect the creation of dynamic tags

  - by user1335906

  In my Project i am supposed to identify the dynamically created tags which can be done in scripts through document.write("<script src='jquery.js'></script>") For this i used Regular expressions and my code is as follows function find_tag_docwrite(text) { var attrib=new Object; var pat_tag=/<((\S+)\s(.*))>/g; while(t=pat_tag.exec(text) { var tag=RegExp.$1; for(i=0;i<tags.length;i++) { var pat=/(\S+)=((['"]*)(\S+)(['"]*)\3)/g; while(p=pat.exec(f)) { attr=RegExp.$1;val=RegExp.$4; attrib[attr]=val; } } } } in the above function text is parameters of document.write function. Now through this code i am getting the tag names and all the attributes of the tags. But for the below example the above code is not working var gaJsHost = (("https:" == document.location.protocol) ? "https://ssl." : "http://www."); document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E")); In such cases Regular expressions does not work so after searching some time where i found hooks on dom methods. so by using this i thought of creating hook for document.write method but i am able to understand how it is done i included the following code in my program but it is not working. function someFunction(text) { console.log(text); } document.write = someFunction; where text is the parameters of document.write. Another problem is After monitoring all the document.write methods using hooks again i have to use regex for finding tag creations. Is there Any alternative

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• What's the best way to get a bunch of rows from MySQL if you have an array of integer primary keys?

  - by Evan P.

  I have a MySQL table with an auto-incremented integer primary key. I want to get a bunch of rows from the table based on an array of integers I have in memory in my program. The array ranges from a handful to about 1000 items. What's the most efficient query syntax to get the rows? I can think of a few: "SELECT * FROM thetable WHERE id IN (1, 2, 3, 4, 5)" (this is what I do now) "SELECT * FROM thetable where id = 1 OR id = 2 OR id = 3" Multiple queries of the form "SELECT * FROM thetable WHERE id = 1". Probably the most friendly to the query cache, but expensive due to having lots of query parsing. A union, like "SELECT * FROM thetable WHERE id = 1 UNION SELECT * FROM thetable WHERE id = 2 ..." I'm not sure if MySQL caches the results of each query; it's also the most verbose format. I think using the NoSQL interface in MySQL 5.6+ would be the most efficient way to do this, but I'm not yet up to MySQL 5.6.

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• Java sockets: multiple client threads on same port on same machine?

  - by espcorrupt

  I am new to Socket programming in Java and was trying to understand if the below code is not a wrong thing to do. My question is: Can I have multiple clients on each thread trying to connect to a server instance in the same program and expect the server to read and write data with isolation between clients" public class Client extends Thread { ... void run() { Socket socket = new Socket("localhost", 1234); doIO(socket); } } public class Server extends Thread { ... void run() { // serverSocket on "localhost", 1234 Socket clientSock = serverSocket.accept(); executor.execute(new ClientWorker(clientSock)); } } Now can I have multiple Client instances on different threads trying to connect on the same port of the current machine? For example, Server s = new Server("localhost", 1234); s.start(); Client[] c = new Client[10]; for (int i = 0; i < c.length; ++i) { c.start(); }

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• Use properties or methods to expose business rules in C#?

  - by Val

  I'm writing a class to encapsulate some business rules, each of which is represented by a boolean value. The class will be used in processing an InfoPath form, so the rules get the current program state by looking up values in a global XML data structure using XPath operations. What's the best (most idiomatic) way to expose these rules to callers -- properties or public methods? Call using properties Rules rules = new Rules(); if ( rules.ProjectRequiresApproval ) { // get approval } else { // skip approval } Call using methods Rules rules = new Rules(); if ( rules.ProjectRequiresApproval() ) { // get approval } else { // skip approval } Rules class exposing rules as properties public class Rules() { private int _amount; private int threshold = 100; public Rules() { _amount = someExpensiveXpathOperation; } // rule property public bool ProjectRequiresApproval { get { return _amount < threshold } } } Rules class exposing rules as methods public class Rules() { private int _amount; private int threshold = 100; public Rules() { _amount = someExpensiveXpathOperation; } // rule method public bool ProjectRequiresApproval() { return _amount < threshold; } } What are the pros and cons of one over the other?

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• ExecutorSerrvice memory leak on exception

  - by TofuBeer

  I am having a hard time tracking this down since the profiler keeps crashing (hotspot error). Before I go too deep into figuring it out I'd like to know if I really have a problem or not :-) I have a few thread pools created via: Executors.newFixedThreadPool(10); The threads connect to different web sites and, on occasion, I get connection refused and wind up throwing an exception. When I later on call Future.get() to get the result it will then catch the ExecutionException that wraps the exception that was thrown when the connection could not be made. The program uses a fairly constant amount of memory up until the point in time that the exceptions get thrown (they tend to happen in batches when a particular site is overloaded). After that point the memory again remains constant but at a higher level. So my question is along the lines of is the memory behaviour (reported by "top" on Unix) expected because the exceptions just triggered something or do I probably have an actual leak that I'll need to track down? Additionally when Future.get() throws an exception is there anything else I need to do besides catch the exception (such as call Future.cancel() on it)?

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• Java: Embedding Soundbank file in JAR

  - by Pyroclastic

  If I have a soundbank stored in a JAR, how would I load that soundbank into my application using resource loading...? I'm trying to consolidate as much of a MIDI program into the jar file as I can, and the last thing I have to add is the soundbank file I'm using, as users won't have the soundbanks installed. I'm trying to put it into my jar file, and then load it with getResource() in the Class class, but I'm getting an InvalidMidiDataException on a soundbank that I know is valid. Here's the code, it's in the constructor for my synthesizer object: try { synth = MidiSystem.getSynthesizer(); channels = synth.getChannels(); instrument = MidiSystem.getSoundbank(this.getClass().getResource("img/soundbank-mid.gm")).getInstruments(); currentInstrument = instrument[0]; synth.loadInstrument(currentInstrument); synth.open(); } catch (InvalidMidiDataException ex) { System.out.println("FAIL"); instrument = synth.getAvailableInstruments(); currentInstrument = instrument[0]; synth.loadInstrument(currentInstrument); try { synth.open(); } catch (MidiUnavailableException ex1) { Logger.getLogger(MIDISynth.class.getName()).log(Level.SEVERE, null, ex1); } } catch (IOException ex) { Logger.getLogger(MIDISynth.class.getName()).log(Level.SEVERE, null, ex); } catch (MidiUnavailableException ex) { Logger.getLogger(MIDISynth.class.getName()).log(Level.SEVERE, null, ex); }

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• wxPython: How to handle event binding and Show() properly.

  - by Gopal

  Hi all, I'm just starting out with wxPython and this is what I would like to do: a) Show a Frame (with Panel inside it) and a button on that panel. b) When I press the button, a dialog box pops up (where I can select from a choice). c) When I press ok on dialog box, the dialog box should disappear (destroyed), but the original Frame+Panel+button are still there. d) If I press that button again, the dialog box will reappear. My code is given below. Unfortunately, I get the reverse effect. That is, a) The Selection-Dialog box shows up first (i.e., without clicking on any button since the TopLevelframe+button is never shown). b) When I click ok on dialog box, then the frame with button appears. c) Clicking on button again has no effect (i.e., dialog box does not show up again). What am I doing wrong ? It seems that as soon as the frame is initialized (even before the .Show() is called), the dialog box is initialized and shown automatically. I am doing this using Eclipse+Pydev on WindowsXP with Python 2.6 ============File:MainFile.py=============== import wx import MyDialog #This is implemented in another file: MyDialog.py class TopLevelFrame(wx.Frame): def __init__(self,parent,id): wx.Frame.__init__(self,parent,id,"Test",size=(300,200)) panel=wx.Panel(self) button=wx.Button(panel, label='Show Dialog', pos=(130,20), size=(60,20)) # Bind EVENTS --> HANDLERS. button.Bind(wx.EVT_BUTTON, MyDialog.start(self)) # Run the main loop to start program. if __name__=='__main__': app=wx.PySimpleApp() TopLevelFrame(parent=None, id=-1).Show() app.MainLoop() ============File:MyDialog.py=============== import wx def start(parent): inputbox = wx.SingleChoiceDialog(None,'Choose Fruit', 'Selection Title', ['apple','banana','orange','papaya']) if inputbox.ShowModal()==wx.ID_OK: answer = inputbox.GetStringSelection() inputbox.Destroy()

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• How do you use stl's functions like for_each?

  - by thomas-gies

  I started using stl containers because they came in very handy when I needed functionality of a list, set and map and had nothing else available in my programming environment. I did not care much about the ideas behind it. STL documentations were only interesting up to the point where it came to functions, etc. Then I skipped reading and just used the containers. But yesterday, still being relaxed from my holidays, I just gave it a try and wanted to go a bit more the stl way. So I used the transform function (can I have a little bit of applause for me, thank you). From an academic point of view it really looked interesting and it worked. But the thing that boroughs me is that if you intensify the use of those functions, you need 10ks of helper classes for mostly everything you want to do in your code. The hole logic of the program is sliced in tiny pieces. This slicing is not the result of god coding habits. It's just a technical need. Something, that makes my life probably harder not easier. And I learned the hard way, that you should always choose the simplest approach that solves the problem at hand. And I can't see what, for example, the for_each function is doing for me that justifies the use of a helper class over several simple lines of code that sit inside a normal loop so that everybody can see what is going on. I would like to know, what you are thinking about my concerns? Did you see it like I do when you started working this way and have changed your mind when you got used to it? Are there benefits that I overlooked? Or do you just ignore this stuff as I did (and will go an doing it, probably). Thanks. PS: I know that there is a real for_each loop in boost. But I ignore it here since it is just a convenient way for my usual loops with iterators I guess.

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• How to Create a Simple Dictation Pad in Delphi2009+Vista

  - by XBasic3000

  the code are not so complecated.. private { Private declarations } SpSharedRecoContext1 : TSpSharedRecoContext; fMyGrammar : ISpeechRecoGrammar; procedure SpSharedRecoContext1Recognition(ASender: TObject; StreamNumber: Integer; StreamPosition: OleVariant; RecognitionType: SpeechRecognitionType; const Result: ISpeechRecoResult); procedure SpSharedRecoContext1Hypothesis(ASender: TObject; StreamNumber: Integer; StreamPosition: OleVariant; const Result: ISpeechRecoResult); procedure TForm1.FormCreate(Sender: TObject); begin SpSharedRecoContext1 := TSpSharedRecoContext.Create(self); SpSharedRecoContext1.OnHypothesis := SpSharedRecoContext1Hypothesis; SpSharedRecoContext1.OnRecognition :=SpSharedRecoContext1Recognition; fMyGrammar := SpSharedRecoContext1.CreateGrammar(0); fMyGrammar.DictationSetState(SGDSActive); end; procedure TForm1.SpSharedRecoContext1Recognition(ASender: TObject; StreamNumber: Integer; StreamPosition: OleVariant; RecognitionType: SpeechRecognitionType; const Result: ISpeechRecoResult); begin Memo1.Text := Result.PhraseInfo.GetText(0,-1,true); end; procedure TForm1.SpSharedRecoContext1Hypothesis(ASender: TObject; StreamNumber: Integer; StreamPosition: OleVariant; const Result: ISpeechRecoResult); begin Memo1.Text := Result.PhraseInfo.GetText(0,-1,true); end; My Problem, was the vista-OS voice command will intercept on my program. if i say "START", instead of writing start on memo1 it press the start menu on my desktop. or what ever command like START CANCEL EDIT DELETE SELECT etc. please help..... sorry for my english

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• What is the best cross-platform language for desktop applications? (Java, Adobe Air, Flex, Silverlight??, Anything Else)

  - by Sootah

  My business partner needs a desktop application programmed, and it needs to be cross-platform as he wants Mac owners (OS X) to be able to run it as well. This, of course, is a bit of a problem for me as I program in PHP for my web projects and exclusively in C# (formerly used Visual Basic) for my desktop apps. I've been using (and love) NetBeans for my PHP stuff, and love Visual Studio just as much; they're both excellent IDEs. With this in mind, I'd like to find a language and IDE that's as similar to Visual Studio as possible (or at least something that makes development as easy as it does) for my cross-platform application development. In fact, if there is a language I can use with VS I'd be extremely happy. I realize that NetBeans has a Java Desktop App IDE, but have been having problems with it (my question in regards to that issue is here. I am also not sure that I really want to learn and use Java if there is a better, easier option out there. Obviously, the first language that came to mind that I can use cross-platform was Java, but I've also heard of people using Adobe Air, as well as Flex being used. I've never programmed in any of those languages, and as such have no frame of reference from which I can decide which would be best for me. I'm also not sure what other options there may be for me; perhaps there's another language I can use that'd be better than the three options I've already provided. (Can you make desktop apps with Silverlight? If so, did MS make an interpreter that will get them to work on OS X?) I like the syntax of C# quite a bit, and the Visual Studio IDE makes it extremely easy to make my apps with. As such, I'd like to find something that'll work as well for me with the cross-platform shatner as C# and its IDE does with my Windows apps. Thanks in advance for your help/opinions!

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• are C functions declared in <c____> headers gauranteed to be in the global namespace as well as std?

  - by Evan Teran

  So this is something that I've always wondered but was never quite sure about. So it is strictly a matter of curiosity, not a real problem. As far as I understand, what you do something like #include <cstdlib> everything (except macros of course) are declared in the std:: namespace. Every implementation that I've ever seen does this by doing something like the following: #include <stdlib.h> namespace std { using ::abort; // etc.... } Which of course has the effect of things being in both the global namespace and std. Is this behavior guaranteed? Or is it possible that an implementation could put these things in std but not in the global namespace? The only way I can think of to do that would be to have your libstdc++ implement every c function itself placing them in std directly instead of just including the existing libc headers (because there is no mechanism to remove something from a namespace). Which is of course a lot of effort with little to no benefit. The essence of my question is, is the following program strictly conforming and guaranteed to work? #include <cstdio> int main() { ::printf("hello world\n"); }

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• Preprocessor "macro function" vs. function pointer - best practice?

  - by Dustin

  I recently started a small personal project (RGB value to BGR value conversion program) in C, and I realised that a function that converts from RGB to BGR can not only perform the conversion but also the inversion. Obviously that means I don't really need two functions rgb2bgr and bgr2rgb. However, does it matter whether I use a function pointer instead of a macro? For example: int rgb2bgr (const int rgb); /* * Should I do this because it allows the compiler to issue * appropriate error messages using the proper function name, * not to mention possible debugging benefits? */ int (*bgr2rgb) (const int bgr) = rgb2bgr; /* * Or should I do this since it is merely a convenience * and they're really the same function anyway? */ #define bgr2rgb(bgr) (rgb2bgr (bgr)) I'm not necessarily looking for a change in execution efficiency as it's more of a subjective question out of curiosity. I am well aware of the fact that type safety is neither lost nor gained using either method. Would the function pointer merely be a convenience or are there more practical benefits to be gained of which I am unaware?

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• Scope of the c++ using directive

  - by ThomasMcLeod

  From section 7.3.4.2 of the c++11 standard: A using-directive specifies that the names in the nominated namespace can be used in the scope in which the using-directive appears after the using-directive. During unqualified name lookup (3.4.1), the names appear as if they were declared in the nearest enclosing namespace which contains both the using-directive and the nominated namespace. [ Note: In this context, “contains” means “contains directly or indirectly”. —end note ] What do the second and third sentences mean exactly? Please give example. Here is the code I am attempting to understand: namespace A { int i = 7; } namespace B { using namespace A; int i = i + 11; } int main(int argc, char * argv[]) { std::cout << A::i << " " << B::i << std::endl; return 0; } It print "7 7" and not "7 18" as I would expect. Sorry for the typo, the program actually prints "7 11".

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• I have problem using vesijama (Very Simple Java Mail)

  - by Huuhaacece

  Hi, i already read this tutorial from here and i have download all required libraries (Log4j, JavaMail API ,Activation framework) . But when i trying running this program i got this error log4j:WARN No appenders could be found for logger (org.codemonkey.vesijama.Mailer). org.codemonkey.vesijama.MailException: Generic error: Exception reading response log4j:WARN Please initialize the log4j system properly. this is the source code i use import javax.mail.Message.RecipientType; import org.codemonkey.vesijama.Email; import org.codemonkey.vesijama.MailException; import org.codemonkey.vesijama.Mailer; public class testSend { final Email email = new Email(); public testSend{ try{ email.setFromAddress("test", "[email protected]"); email.setSubject("hey"); email.addRecipient("hai", "[email protected]", RecipientType.TO); email.setText("We should meet up!"); email.setTextHTML("<b>We should meet up!</b>"); new Mailer("smtp.gmail.com", 465, "[email protected]", "XXXXXX").sendMail(email); } catch(MailException me) { System.out.println(me); } } } i have also trying using port 587. but i got same error .< btw , it say can add attachments what should i write if i want to attach .xls ( microsoft excel 2003) ? Thx B4.

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• How to visually reject user input in a table?

  - by FX

  In the programming of a table-based application module (i.e. the user mostly enters tabular data in an already laid-out table), how would you reject user input for a given cell? The scenario is: the user edits the cell, enters something (text, picture, ...) and you want them to notice when they finish editing (hitting enter, for example) that their entry is not valid for your given "format" (in the wider meaning: it can be that they entered a string instead of a number, that their entry is too long, too short, they include a picture while it's not acceptable, ...). I can see two different things happening: You can rather easily fit their entry into your format, and you do so, but you want them to notice it so they can change if your guess is not good enough (example: they entered "15.47" in a field that needs to be an integer, so your program makes it "15") You cannot guess what to do with their entry, and want to inform them that it's not valid. My question specifically is: what visual display can you offer to inform the user that his input is invalid? Is it preferable to refuse to leave the editing mode, or not? The two things I can imagine are: using colors (red background if invalid, yellow background for my case 1 above) when you reject an input, do something like Apple does for password entry of user accounts: you make the cell "shaking" (i.e. oscillating left and right) for one second, and keep the focus/editing in their so they don't loose what they've typed. Let's hear your suggestions. PS: This question is, at least in my thought process, somehow a continuation and a specialization of my previous question on getting users to read error messages. PPS: Made this community wiki, was that the right thing to do on this kind of question or not?

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• iPhone shooter game bullet physics!

  - by user298261

  Hello, Making a new shooter game here in the vein of "Galaga" (my fav shooter game growing up). Here's the code I have for bullet physics: -(IBAction)shootBullet:(id)sender{ imgBullet.hidden = NO; timer = [NSTimer scheduledTimerWithTimeInterval:0.05 target:self selector:@selector(fireBullet) userInfo:Nil repeats:YES]; } -(void)fireBullet{ imgBullet.center = CGPointMake(imgBullet.center.x + bulletVelocity.x , imgBullet.center.y + bulletVelocity.y); if(imgBullet.center.y <= 0){ imgBullet.hidden = YES; imgBullet.center = self.view.center; [timer invalidate]; } } Anyway, the obvious issue is that once the bullet leaves the screen, its center is being reset, so I'm reusing the same bullet for each press of the "fire" button. Ideally, I would like the user to be able to spam the "fire" button without causing the program to crash. How would I tinker this existing code so that a bullet object would spawn on the button press each time, and then despawn after it exits the screen, or collides with an enemy? Thank you for any assistance you can offer!

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• C: Global ,Static variables understanding

  - by pavun_cool

  Hi All, In following program . I have one doubt. I have declared one global variable . I am printing the address of the global variable in the function . It is giving me same address when I am not changing the value of global . If I did any changes in the global variables It is giving me different address why...........? Like that it is happening for static also. #include<stdio.h> int global=10 ; // Global variables void function(); main() { global=20; printf ( " %p \n" , global ) ; printf ( " Val: %d\n", global ) ; function(); new(); } void function() { global=30; printf ( " %p \n" , global ) ; printf ( " Val: %d\n", global ) ; } Thanks.

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• Windows 7 taskbar icon grouping with multiple similar windows

  - by user1266104

  When I have a number of similar windows opens, for example, multiple explorer windows, they are all grouped into the same icon on the taskbar. When I hover over this I get a thumbnail of the window, and a piece of truncated text which is supposed to help me work out what that window is. However I also like to have the full path shown in explorer windows, so the truncated text is usually C:\CommonPathToEveryWind... I have noticed that if I have over 14 explorer windows open, then Windows gives up trying to display these useless thumbnails, and instead gives me a nicely formatted list of paths. My question is how can I customise this behaviour, to either disable thumbnails all together for a subset of applications where a thumbnail is inappropriate (explorer, 'Everything'); or to lower the max number of thumbnails per grouped taskbar icon to 2; or just to disable thumbnails all together, (without loosing the entire windows theme) Edit: Just to make it clear what I currently get, and what I actually want. I do still want to keep the grouping behaviour, so that multiple instances of the same program, Explorer for example, only take one slot on the taskbar. What I want is to alter what is displayed when I hover over the grouped icon: What I actually see - useless thumbnails:- http://i.stack.imgur.com/8bTxX.png The style I want for any number of instances:- http://i.stack.imgur.com/zv6Si.png

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• Why does the output look like this?

  - by cjk

  I have a c program below, I would like to send out a 32 bit message in a particular order Eg.0x00000001. #include <unistd.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <sys/types.h> #include <stdint.h> struct test { uint16_t a; uint16_t b; }; int main(int argc, char const *argv[]) { char buf[4]; struct test* ptr=(struct test*)buf; ptr->a=0x0000; ptr->b=0x0001; printf("%x %x\n",buf[0],buf[1]); //output is 0 0 printf("%x %x\n",buf[2],buf[3]); //output is 1 0 return 0; } Then I test it by print out the values in char array. I got output in the above comments. Shouldn't the output be 0 0 and 0 1? since but[3] is the last byte? Is there anything I missed? Thanks!

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• Managing libraries and imports in a programming language

  - by sub

  I've created an interpreter for a stupid programming language in C++ and the whole core structure is finished (Tokenizer, Parser, Interpreter including Symbol tables, core functions, etc.). Now I have a problem with creating and managing the function libraries for this interpreter (I'll explain what I mean with that later) So currently my core function handler is horrible: // Simplified version myLangResult SystemFunction( name, argc, argv ) { if ( name == "print" ) { if( argc < 1 ) { Error('blah'); } cout << argv[ 0 ]; } else if ( name == "input" ) { if( argc < 1 ) { Error('blah'); } string res; getline( cin, res ); SetVariable( argv[ 0 ], res ); } else if ( name == "exit ) { exit( 0 ); } And now think of each else if being 10 times more complicated and there being 25 more system functions. Unmaintainable, feels horrible, is horrible. So I thought: How to create some sort of libraries that contain all the functions and if they are imported initialize themselves and add their functions to the symbol table of the running interpreter. However this is the point where I don't really know how to go on. What I wanted to achieve is that there is e.g.: an (extern?) string library for my language, e.g.: string, and it is imported from within a program in that language, example: import string myString = "abcde" print string.at( myString, 2 ) # output: c My problems: How to separate the function libs from the core interpreter and load them? How to get all their functions into a list and add it to the symbol table when needed? What I was thinking to do: At the start of the interpreter, as all libraries are compiled with it, every single function calls something like RegisterFunction( string namespace, myLangResult (*functionPtr) ); which adds itself to a list. When import X is then called from within the language, the list built with RegisterFunction is then added to the symbol table. Disadvantages that spring to mind: All libraries are directly in the interpreter core, size grows and it will definitely slow it down.

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• Is boost shared_ptr <XXX> thread safe?

  - by sxingfeng

  I have a question about boost :: shared_ptr. There are lots of thread. class CResource { xxxxxx } class CResourceBase { public: void SetResource(shared_ptr<CResource> res) { m_Res = res; } shared_ptr<CResource> GetResource() { return m_Res; } private: shared_ptr<CResource> m_Res; } CResourceBase base; //---------------------------------------------- Thread A: while (true) { ...... shared_ptr<CResource> nowResource = base.GetResource(); nowResource.doSomeThing(); ... } Thread B: shared_ptr<CResource> nowResource; base.SetResource(nowResource); ... //----------------------------------------------------------- If thread A do not care the nowResource is the newest . Will this part of code have problem? I mean when ThreadB do not SetResource completely, Thread A get a wrong smart point by GetResource? Another question : what does thread-safe mean? If I do not care about whether the resource is newest, will the shared_ptr nowResource crash the program when the nowResource is released or will the problem destroy the shared_point?

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• Specifying character

  - by danutenshu

  So below I have a code in C++ that is supposed to invert the arguments in a vector, but not the sequence. I have listed my problems as sidenotes in the code below. The invert function is supposed to invert each argument, and then the main function just outputs the inverted words in same order For instance, program("one two three four")=ruof eerth owt eno #include <iostream> #include <string> using namespace std; int invert(string normal) { string inverted; for (int num=normal.size()-1; num>=0; num--) { inverted.append(normal[num]); //I don't know how to get each character //I need another command for append } return **inverted**; <---- } int main(int argc, char* argv[]) { string text; for (int a=1; a<argc; a++) { text.append(invert(argv[a])); //Can't run the invert function text.append(" "); } cout << text << endl; return 0; }

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• Process a set of files from a source directory to a destination directory in Python

  - by Spoike

  Being completely new in python I'm trying to run a command over a set of files in python. The command requires both source and destination file (I'm actually using imagemagick convert as in the example below). I can supply both source and destination directories, however I can't figure out how to easily retain the directory structure from the source to the destination directory. E.g. say the srcdir contains the following: srcdir/ file1 file3 dir1/ file1 file2 Then I want the program to create the following destination files on destdir: destdir/file1, destdir/file3, destdir/dir1/file1 and destdir/dir1/file2 So far this is what I came up with: import os from subprocess import call srcdir = os.curdir # just use the current directory destdir = 'path/to/destination' for root, dirs, files in os.walk(srcdir): for filename in files: sourceFile = os.path.join(root, filename) destFile = '???' cmd = "convert %s -resize 50%% %s" % (sourceFile, destFile) call(cmd, shell=True) The walk method doesn't directly provide what directory the file is under srcdir other than concatenating the root directory string with the file name. Is there some easy way to get the destination file, or do I have to do some string manipulation in order to do this?

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• Uniquely identify files/folders in NTFS, even after move/rename

  - by Felix Dombek

  I haven't found a backup (synchronization) program which does what I want so I'm thinking about writing my own. What I have now does the following: It goes through the data in the source and for every file which has its archive bit set OR does not exist in the destination, copies it to the destination, overwriting a possibly existing file. When done, it checks for all files in the destination if it exists in the source, and if it doesn't, deletes it. The problem is that if I move or rename a large folder, it first gets copied to the destination even though it is in principle already there, just has a different path. Then the folder which was already there is deleted afterwards. Apart from the unnecessary copying, I frequently run into space problems because my backup drive isn't large enough to hold the original data twice. Is there a way to programmatically identify such moved/renamed files or folders, i.e. by NTFS ID or physical location on media or something else? Are there solutions to this problem? I do not care about the programming language, but hints for doing this with Python, C++, C#, Java or Prolog are appreciated.

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