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  • Linux C debugging library to detect memory corruptions

    - by calandoa
    When working sometimes ago on an embedded system with a simple MMU, I used to program dynamically this MMU to detect memory corruptions. For instance, at some moment at runtime, the foo variable was overwritten with some unexpected data (probably by a dangling pointer or whatever). So I added the additional debugging code : at init, the memory used by foo was indicated as a forbidden region to the MMU; each time foo was accessed on purpose, access to the region was allowed just before then forbidden just after; a MMU irq handler was added to dump the master and the address responsible of the violation. This was actually some kind of watchpoint, but directly self-handled by the code itself. Now, I would like to reuse the same trick, but on a x86 platform. The problem is that I am very far from understanding how is working the MMU on this platform, and how it is used by Linux, but I wonder if any library/tool/system call already exist to deal with this problem. Note that I am aware that various tools exist like Valgrind or GDB to manage memory problems, but as far as I know, none of these tools car be dynamically reconfigured by the debugged code. I am mainly interested for user space under Linux, but any info on kernel mode or under Windows is also welcome!

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  • Is there a way to parse XML via SAX/DOM with line numbers available per node.

    - by Chris
    I already have written a DOM parser for a large XML document format that contains a number of items that can be used to automatically generate Java code. This is limited to small expressions that are then merged into a dynamically generated Java source file. So far - so good. Everything works. BUT - I wish to be able to embed the line number of the XML node where the Java code was included from (so that if the configuration contains uncompilable code, each method will have a pointer to the source XML document and the line number for ease of debugging). I don't require the line number at parse-time and I don't need to validate the XML Source Document and throw an error at a particular line number. I need to be able to access the line number for each node and attribute in my DOM or per SAX event. Any suggestions on how I might be able to achieve this? P.S. Also, I read the StAX has a method to obtain line number whilst parsing, but ideally I would like to achieve the same result with regular SAX/DOM processing in Java 4/5 rather than become a Java 6+ application or take on extra .jar files.

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  • invasive vs non-invasive ref-counted pointers in C++

    - by anon
    For the past few years, I've generally accepted that if I am going to use ref-counted smart pointers invasive smart pointers is the way to go -- However, I'm starting to like non-invasive smart pointers due to the following: I only use smart pointers (so no Foo* lying around, only Ptr) I'm starting to build custom allocators for each class. (So Foo would overload operator new). Now, if Foo has a list of all Ptr (as it easily can with non-invasive smart pointers). Then, I can avoid memory fragmentation issues since class Foo move the objects around (and just update the corresponding Ptr). The only reason why this Foo moving objects around in non-invasive smart pointers being easier than invasive smart pointers is: In non-invasive smart pointers, there is only one pointer that points to each Foo. In invasive smart pointers, I have no idea how many objects point to each Foo. Now, the only cost of non-invasive smart pointers ... is the double indirection. [Perhaps this screws up the caches]. Does anyone have a good study of expensive this extra layer of indirection is?

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  • HTML::TreeBuilder has mojibake problem, it shows wired chars in the output

    - by varun_vijay_r
    use strict; use WWW::Curl::Easy; use HTML::TreeBuilder; my $cookie_file ='/tmp/pcook'; my $curl = new WWW::Curl::Easy; my $response_body; my $charset = 'utf-8'; $DocOffline::charset = undef; $curl-setopt (CURLOPT_URL, 'http://www.breitbart.com/article.php?id=D9G7CR5O0&show_article=1'); $curl-setopt ( CURLOPT_USERAGENT, 'Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/533.9 (KHTML, like Gecko) Chrome/6.0.400.0 Safari/533.9'); $curl-setopt ( CURLOPT_HEADER, 0); $curl-setopt ( CURLOPT_FOLLOWLOCATION, 1); $curl-setopt ( CURLOPT_AUTOREFERER, 1); $curl-setopt ( CURLOPT_SSL_VERIFYPEER, 0); $curl-setopt ( CURLOPT_COOKIEFILE, $cookie_file); $curl-setopt ( CURLOPT_COOKIEJAR, $cookie_file); $curl-setopt ( CURLOPT_REFERER, 'http://www.iavian.com/docOff/'); $curl-setopt ( CURLOPT_HEADERFUNCTION, \&headerCallback ); open (my $fileb, "", \$response_body); $curl-setopt(CURLOPT_WRITEDATA,$fileb); my $retcode = $curl-perform; if ($retcode == 0) { my $dom_tree = HTML::TreeBuilder-new(); $dom_tree-ignore_elements(qw(script style)); $dom_tree-utf8_mode(1); $dom_tree-parse($response_body); $dom_tree-eof(); print $dom_tree-as_HTML('<&', ' ', {}); } else { print("An error happened: ".$curl-strerror($retcode)." ($retcode)\n"); } sub headerCallback { my($data, $pointer) = @_; $data =~ m/Content-Type:\s*.*;\s*charset=(.*)/; if ($1) { $charset = $1; $charset =~ s/[^a-zA-Z0-9_-]*//g; } return length($data); }

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  • Invoking a function (main()) from a binary file in C

    - by Dhara Darji
    I have simple c program like, my_bin.c: #include <stdio.h> int main() { printf("Success!\n"); return 0; } I compile it with gcc and got executable: my_bin. Now I want to invoke main (or run this my_bin) using another C program. That I did with mmap and function pointer like this: #include <stdio.h> #include <fcntl.h> #include <sys/mman.h> int main() { void (*fun)(); int fd; int *map; fd = open("./my_bin", O_RDONLY); map = mmap(0, 8378, PROT_READ, MAP_SHARED, fd, 0); fun = map; fun(); return 0; } PS: I went through some tutorial, for how to read binary file and execute. But this gives Seg fault, any help appreciated! Thanks!

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  • Interchange structured data between Haskell and C

    - by Eonil
    First, I'm a Haskell beginner. I'm planning integrating Haskell into C for realtime game. Haskell does logic, C does rendering. To do this, I have to pass huge complexly structured data (game state) from/to each other for each tick (at least 30 times per second). So the passing data should be lightweight. This state data may laid on sequential space on memory. Both of Haskell and C parts should access every area of the states freely. In best case, the cost of passing data can be copying a pointer to a memory. In worst case, copying whole data with conversion. I'm reading Haskell's FFI(http://www.haskell.org/haskellwiki/FFICookBook#Working_with_structs) The Haskell code look specifying memory layout explicitly. I have a few questions. Can Haskell specify memory layout explicitly? (to be matched exactly with C struct) Is this real memory layout? Or any kind of conversion required? (performance penalty) If Q#2 is true, Any performance penalty when the memory layout specified explicitly? What's the syntax #{alignment foo}? Where can I find the document about this? If I want to pass huge data with best performance, how should I do that? *PS Explicit memory layout feature which I said is just C#'s [StructLayout] attribute. Which is specifying in-memory position and size explicitly. http://www.developerfusion.com/article/84519/mastering-structs-in-c/ I'm not sure Haskell has matching linguistic construct matching with fields of C struct.

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  • Is there a fundamental difference between malloc and HeapAlloc (aside from the portability)?

    - by Lambert
    Hi, I'm having code that, for various reasons, I'm trying to port from the C runtime to one that uses the Windows Heap API. I've encountered a problem: If I redirect the malloc/calloc/realloc/free calls to HeapAlloc/HeapReAlloc/HeapFree (with GetProcessHeap for the handle), the memory seems to be allocated correctly (no bad pointer returned, and no exceptions thrown), but the library I'm porting says "failed to allocate memory" for some reason. I've tried this both with the Microsoft CRT (which uses the Heap API underneath) and with another company's run-time library (which uses the Global Memory API underneath); the malloc for both of those works well with the library, but for some reason, using the Heap API directly doesn't work. I've checked that the allocations aren't too big (= 0x7FFF8 bytes), and they're not. The only problem I can think of is memory alignment; is that the case? Or other than that, is there a fundamental difference between the Heap API and the CRT memory API that I'm not aware of? If so, what is it? And if not, then why does the static Microsoft CRT (included with Visual Studio) take some extra steps in malloc/calloc before calling HeapAlloc? I'm suspecting there's a difference but I can't think of what it might be. Thank you!

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  • css Checkbox Label Selector

    - by HW90
    I'm developing a MVC3 application and need to select the checkboxes label. In ASP MVC3 you have helper methods which creat a part of the code. So the code for a checkbox looks like this: <input id="Jumping_successleicht" type="checkbox" value="true" name="Jumping_successleicht"> <input type="hidden" value="false" name="Jumping_successleicht"> <label for="Jumping_successleicht"> <span>leicht (4)</span> </label> Now I've thought I can use following code to select the label: input[type=checkbox] + label { background: url("../../Images/Controls/Checkbox.png") no-repeat scroll left center transparent; clear: none; cursor: pointer; margin: 0; padding: 5px 0 4px 24px; } But it does not work. It looks like label and input have to be next to each other. Does any ony have a solution how to solve this problem?

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  • Implementing list position locator in C++?

    - by jfrazier
    I am writing a basic Graph API in C++ (I know libraries already exist, but I am doing it for the practice/experience). The structure is basically that of an adjacency list representation. So there are Vertex objects and Edge objects, and the Graph class contains: list<Vertex *> vertexList list<Edge *> edgeList Each Edge object has two Vertex* members representing its endpoints, and each Vertex object has a list of Edge* members representing the edges incident to the Vertex. All this is quite standard, but here is my problem. I want to be able to implement deletion of Edges and Vertices in constant time, so for example each Vertex object should have a Locator member that points to the position of its Vertex* in the vertexList. The way I first implemented this was by saving a list::iterator, as follows: vertexList.push_back(v); v->locator = --vertexList.end(); Then if I need to delete this vertex later, then rather than searching the whole vertexList for its pointer, I can call: vertexList.erase(v->locator); This works fine at first, but it seems that if enough changes (deletions) are made to the list, the iterators will become out-of-date and I get all sorts of iterator errors at runtime. This seems strange for a linked list, because it doesn't seem like you should ever need to re-allocate the remaining members of the list after deletions, but maybe the STL does this to optimize by keeping memory somewhat contiguous? In any case, I would appreciate it if anyone has any insight as to why this happens. Is there a standard way in C++ to implement a locator that will keep track of an element's position in a list without becoming obsolete? Much thanks, Jeff

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  • Problems using (building?) native gem extensions on OS X

    - by goodmike
    I am having trouble with some of my rubygems, in particular those that use native extensions. I am on a MacBookPro, with Snow Leopard. I have XCode 3.2.1 installed, with gcc 4.2.1. Ruby 1.8.6, because I'm lazy and a scaredy cat and don't want to upgrade yet. Ruby is running in 32-bit mode. I built this ruby from scratch when my MBP ran OSX 10.4. When I require one of the affected gems in irb, I get a Load Error for the gem extension's bundle file. For example, here's nokogigi dissing me: > require 'rubygems' = true > require 'nokogiri' LoadError: Failed to load /usr/local/lib/ruby/gems/1.8/gems/nokogiri-1.4.1/lib/nokogiri/nokogiri.bundle This is also happening with the Postgres pg and MongoDB mongo gems. My first thought was that the extensions must not be building right. But gem install wasn't throwing any errors. So I reinstalled with the verbose flag, hoping to see some helpful warnings. I've put the output in a Pastie, and the only warning I see is a consistent one about "passing argument n of ‘foo’ with different width due to prototype." I suspect that this might be an issue from upgrading to Snow Leopard, but I'm a little surprised to experience it now, since I've updated my XCode. Could it stem from running Ruby in 1.8.6? I'm embarrassed that I don't know quite enough about my Mac and OSX to know where to look next, so any guidance, even just a pointer to some document I couldn't find via Google, would be most welcome. Michael

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  • Drawing an image is completely out

    - by ct2k7
    Hi I'm using this code below to let a user "draw" their signature on a UIView component on my app: UIGraphicsBeginImageContext(signature.frame.size); [drawImage.image drawInRect:CGRectMake(0, 0, signature.frame.size.width, signature.frame.size.height)]; CGContextSetLineCap(UIGraphicsGetCurrentContext(), kCGLineCapRound); CGContextSetLineWidth(UIGraphicsGetCurrentContext(), 5.0); CGContextSetRGBStrokeColor(UIGraphicsGetCurrentContext(), 1.0, 0.0, 0.0, 1.0); CGContextMoveToPoint(UIGraphicsGetCurrentContext(), lastPoint.x, lastPoint.y); CGContextAddLineToPoint(UIGraphicsGetCurrentContext(), lastPoint.x, lastPoint.y); CGContextStrokePath(UIGraphicsGetCurrentContext()); CGContextFlush(UIGraphicsGetCurrentContext()); drawImage.image = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext() The issue I am having is that the drawing is not only is the drawing not in line with the pointer when in use in the simulator, the image is going outside of the designated UIView compontent and is getting smaller/out of focus the more I draw, as you can see in this image: And after a few lines, showing the boundaries of the exact are of where I can draw: Any ideas on what's happening here? lastPoint.y is defined as: lastPoint.y -= 20; Any ideas on what on earth is happening here?

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  • OSMF seek with Amazon Cloudfront

    - by giorrrgio
    I've written a little OSMF player that streams via RTMP from Amazon Cloudfront. There's a known issue, the mp3 duration is not correctly readed from metadata and thus the seek function is not working. I know there's a workaround implying the use of getStreamLength function of NetConnection, which I successfully implemented in a previous non-OSMF player, but now I don't know how and when to call it, in terms of OSMF Events and Traits. This code is not working: protected function initApp():void { //the pointer to the media var resource:URLResource = new URLResource( STREAMING_PATH ); // Create a mediafactory instance mediaFactory = new DefaultMediaFactory(); //creates and sets the MediaElement (generic) with a resource and path element = mediaFactory.createMediaElement( resource ); var loadTrait:NetStreamLoadTrait = element.getTrait(MediaTraitType.LOAD) as NetStreamLoadTrait; loadTrait.addEventListener(LoaderEvent.LOAD_STATE_CHANGE, _onLoaded); player = new MediaPlayer( element ); //Marker 5: Add MediaPlayer listeners for media size and current time change player.addEventListener( DisplayObjectEvent.MEDIA_SIZE_CHANGE, _onSizeChange ); player.addEventListener( TimeEvent.CURRENT_TIME_CHANGE, _onProgress ); initControlBar(); } private function onGetStreamLength(result:Object):void { Alert.show("The stream length is " + result + " seconds"); duration = Number(result); } private function _onLoaded(e:LoaderEvent):void { if (e.newState == LoadState.READY) { var loadTrait:NetStreamLoadTrait = player.media.getTrait(MediaTraitType.LOAD) as NetStreamLoadTrait; if (loadTrait && loadTrait.netStream) { var responder:Responder = new Responder(onGetStreamLength); loadTrait.connection.call("getStreamLength", responder, STREAMING_PATH); } } }

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  • va_arg with pointers

    - by Yktula
    I want to initialize a linked list with pointer arguments like so: /* * Initialize a linked list using variadic arguments * Returns the number of structures initialized */ int init_structures(struct structure *first, ...) { struct structure *s; unsigned int count = 0; va_list va; va_start(va, first); for (s = first; s != NULL; s = va_arg(va, (struct structure *))) { if ((s = malloc(sizeof(struct structure))) == NULL) { perror("malloc"); exit(EXIT_FAILURE); } count++; } va_end(va); return count; } The problem is that clang errors type name requires a specifier or qualifier at va_arg(va, (struct structure *)), and says that the type specifier defaults to int. It also notes instantiated form at (struct structure *) and struct structure *. This, what seems to be getting assigned to s is int (struct structure *). It compiles fine when parentheses are removed from (struct structure *), but the structures that are supposed to be initialized are inaccessible. Why is int assumed when parentheses are around the type argument passed to va_arg? How can I fix this?

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  • List local printers

    - by vladimir
    hi all, i am using this routine to list the local printers installed on on a machine... var p: pointer; hpi: _PRINTER_INFO_2A; hGlobal: cardinal; dwNeeded, dwReturned: DWORD; bFlag: boolean; i: dword; begin p := nil; EnumPrinters(PRINTER_ENUM_LOCAL, nil, 2, p, 0, dwNeeded, dwReturned); if (dwNeeded = 0) then exit; GetMem(p,dwNeeded); if (p = nil) then exit; bFlag := EnumPrinters(PRINTER_ENUM_LOCAL, nil, 2, p, dwneeded, dwNeeded, dwReturned); if (not bFlag) then exit; CbLblPrinterPath.Properties.Items.Clear; for i := 0 to dwReturned - 1 do begin CbLblPrinterPath.Properties.Items.Add(TPrinterInfos(p^)[i].pPrinterName); end; FreeMem(p); TPrinterInfos(p^)[i].pPrinterName returns a 'P' for printer name. i have a PdfCreator installed as a printer. TPrinterInfos is an array of _PRINTER_INFO_2A. how can i fix this?

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  • C# Web Service gets stuck waiting for lock, does not return

    - by blue
    We have a C#(2.0) application which talks to our server(in java) via web services. Lately we have started seeing following behavior in (ONLY)one of our lab machines(XP): Once in a while(every few days), one of the webservice request will just get stuck, will not return or timeout. Following is the stacktrace where it seem to be stuck. Have no clue what is going on here. Any pointer would be of great help. ESP EIP 05eceeec 7c90eb94 [GCFrame: 05eceeec] 05ecefbc 7c90eb94 [HelperMethodFrame_1OBJ: 05ecefbc] System.Threading.Monitor.Enter(System.Object) 05ecf014 7a5b0034 System.Net.ConnectionGroup.Disassociate(System.Net.Connection) 05ecf040 7a5aeaa7 System.Net.Connection.PrepareCloseConnectionSocket(System.Net.ConnectionReturnResult ByRef) 05ecf0a4 7a5ac0e1 System.Net.Connection.ReadStartNextRequest(System.Net.WebRequest, System.Net.ConnectionReturnResult ByRef) 05ecf0e8 7a5b1119 System.Net.ConnectStream.CallDone(System.Net.ConnectionReturnResult) 05ecf0fc 7a5b3b5a System.Net.ConnectStream.ReadChunkedSync(Byte[], Int32, Int32) 05ecf114 7a5b2b90 System.Net.ConnectStream.ReadWithoutValidation(Byte[], Int32, Int32, Boolean) 05ecf160 7a5b29cc System.Net.ConnectStream.Read(Byte[], Int32, Int32) 05ecf1a0 79473cab System.IO.StreamReader.ReadBuffer(Char[], Int32, Int32, Boolean ByRef) 05ecf1c4 79473bd6 System.IO.StreamReader.Read(Char[], Int32, Int32) 05ecf1e8 69c29119 System.Xml.XmlTextReaderImpl.ReadData() 05ecf1f8 69c2ad70 System.Xml.XmlTextReaderImpl.ParseDocumentContent() 05ecf20c 69c292d7 System.Xml.XmlTextReaderImpl.Read() 05ecf21c 69c2929d System.Xml.XmlTextReader.Read() 05ecf220 6991b3e7 System.Web.Services.Protocols.SoapHttpClientProtocol.ReadResponse(System.Web.Services.Protocols.SoapClientMessage, System.Net.WebResponse, System.IO.Stream, Boolean) 05ecf268 69919ed1 System.Web.Services.Protocols.SoapHttpClientProtocol.Invoke(System.String, System.Object[])

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  • Make an element visible to the user but invisible to events

    - by Acorn
    I'm not quite sure how to describe what I'm looking to do, but I'll do my best. At the moment I have a parent <div>, with absolutely positioned child <div>s within it, and I'm tracking the mouse pointer location coordinates relative to the element your mouse is over. At the moment, when I mouse over my child <div>s, I get the mouse location relative to them, but I want the coordinates to be relative the the parent <div> even when mousing over the child elements. So I basically want the child elements to be visible, but transparent to the mousemove, so I want the mousemove to go straight through to the parent element. How would I do this? Do I maybe need to somehow make the parent <div> be in the forground but still have the child <div>s show through? or make a transparent <div> overlay just to get the mouse coordinates? Here's a link to the page I'm experimenting on: http://acorn.host22.com/mouse.html

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  • using string to read file - XCode

    - by Fernando
    The following does not work and gives me a SIGABRT when I run in the debugger: std::ifstream inFile; inFile.open("/Users/fernandonewyork/inputText.txt"); cout << inFile << endl; vector<string> inText; if (inFile) { string s4; while (inFile>>s4) { inText.push_back(s4); } } inFile.close(); The following does: std::ifstream inFile; inFile.open("/Users/fernandonewyork/inputText.txt"); cout << inFile << endl; vector<string> inText; if (inFile) { string s4("This is no lnger an empty string"); while (inFile>>s4) { inText.push_back(s4); } } inFile.close(); I was under the impression I was able to simply use s4 without having to worry about any space considerations, or is something else happening here? This is the full error I get from the top code: malloc: * error for object 0x100010a20: pointer being freed was not allocated * set a breakpoint in malloc_error_break to debug Program received signal: “SIGABRT”.

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  • JQuery drag, drop and save via cookie - how to?

    - by RussP
    Sorry to be back folks, but you guys & girls seem to know much more about this than I do ... anyhow, here is my question/problem I want to use drag, drop, sort (the interface plugin does me even though I have read it's out of date? but have looked at UI and to be honest is not clear and to me appears heavier than interface?) Anyhow, how do I set a cookie to save positions from this: $(document).ready( function () { $('a.closeEl').bind('click', toggleContent); $('div.groupWrapper').Sortable( { accept: 'groupItem', helperclass: 'sortHelper', activeclass : 'sortableactive', hoverclass : 'sortablehover', handle: 'div.itemHeader', tolerance: 'pointer', onChange : function(ser) { }, onStart : function() { $.iAutoscroller.start(this, document.getElementsByTagName('body')); }, onStop : function() { $.iAutoscroller.stop(); } } ); } ); var toggleContent = function(e) { var targetContent = $('div.itemContent', this.parentNode.parentNode); if (targetContent.css('display') == 'none') { targetContent.slideDown(300); $(this).html('[-]'); } else { targetContent.slideUp(300); $(this).html('[+]'); } return false; }; var ser = function (s) { serial = $.SortSerialize(s); alert(serial.hash); }; which is the "standard" interface demo, PLUS How do I then get to read that cookie so that when I next visit the page the order is as I set it in the cookie? Hopefully from that I can work out the rest .......? Thanks for help in advance.

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  • c++ File input/output

    - by Myx
    Hi: I am trying to read from a file using fgets and sscanf. In my file, I have characters on each line of the while which I wish to put into a vector. So far, I have the following: FILE *fp; fp = fopen(filename, "r"); if(!fp) { fprintf(stderr, "Unable to open file %s\n", filename); return 0; } // Read file int line_count = 0; char buffer[1024]; while(fgets(buffer, 1023, fp)) { // Increment line counter line_count++; char *bufferp = buffer; ... while(*bufferp != '\n') { char *tmp; if(sscanf(bufferp, "%c", tmp) != 1) { fprintf(stderr, "Syntax error reading axiom on " "line %d in file %s\n", line_count, filename); return 0; } axiom.push_back(tmp); printf("put %s in axiom vector\n", axiom[axiom.size()-1]); // increment buffer pointer bufferp++; } } my axiom vector is defined as vector<char *> axiom;. When I run my program, I get a seg fault. It happens when I do the sscanf. Any suggestions on what I'm doing wrong?

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  • How safe and reliable are C++ String Literals?

    - by DoctorT
    So, I'm wanting to get a better grasp on how string literals in C++ work. I'm mostly concerned with situations where you're assigning the address of a string literal to a pointer, and passing it around. For example: char* advice = "Don't stick your hands in the toaster."; Now lets say I just pass this string around by copying pointers for the duration of the program. Sure, it's probably not a good idea, but I'm curious what would actually be going on behind the scenes. For another example, let's say we make a function that returns a string literal: char* foo() { // function does does stuff return "Yikes!"; // somebody's feeble attempt at an error message } Now lets say this function is called very often, and the string literal is only used about half the time it's called: // situation #1: it's just randomly called without heed to the return value foo(); // situation #2: the returned string is kept and used for who knows how long char* retVal = foo(); In the first situation, what's actually happening? Is the string just created but not used, and never deallocated? In the second situation, is the string going to be maintained as long as the user finds need for it? What happens when it isn't needed anymore... will that memory be freed up then (assuming nothing points to that space anymore)? Don't get me wrong, I'm not planning on using string literals like this. I'm planning on using a container to keep my strings in check (probably std::string). I'm mostly just wanting to know if these situations could cause problems either for memory management or corrupted data.

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  • scanf segfaults and various other anomalies inside while loop

    - by Shadow
    while(1){ //Command prompt char *command; printf("%s>",current_working_directory); scanf("%s",command);<--seg faults after input has been received. printf("\ncommand:%s\n",command); } I am getting a few different errors and they don't really seem reproducible(except for the segfault at this point .<). This code worked fine about 10 minutes ago, then it infinite looped the printf command and now it seg faults on the line mentioned above. The only thing I changed was scanf("%s",command); to what it currently is. If I change the command variable to be an array it works, obviously this is because the storage is set aside for it. 1) I got prosecuted about telling someone that they needed to malloc a pointer* (But that usually seems to solve the problem such as making it an array) 2) the command I am entering is "magic" 5 characters so there shouldn't be any crazy stack overflow. 3) I am running on mac OSX 10.6 with newest version of xCode(non-OS4) and standard gcc 4) this is how I compile the program: gcc --std=c99 -W sfs.c Just trying to figure out what is going on. Being this is for a school project I am never going to have to see again, I will just code some noob work around that would make my boss cry :) But for afterwards I would love to figure out why this is happening and not just make some fix for it, and if there is some fix for it why that fix works.

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  • Jquery grid overlay in wordpress

    - by Anders Kitson
    I am adding this simple plugin that I have working in a static html site, and am trying to add it to a wordpress development site based off of 960 gs. The jquery code links are correct but the console gives me this error "Uncaught TypeError: Cannot call method 'addGrid' of null" I got the code from this turtorial http://www.badlydrawntoy.com/2009/04/21/960gs-grid-overlay-a-jquery-plugin/ Here is the code I am using /*<![CDATA[*/ // onload $(function() { $("body").addGrid(12, {img_path: 'img/'}); }); /*]]>*/ Here is the code for the plugin /* * @ description: Plugin to display 960.gs gridlines See http://960.gs/ * @author: badlyDrawnToy sharp / http://www.badlydrawntoy.com * @license: Creative Commons License - ShareAlike http://creativecommons.org/licenses/by-sa/3.0/ * @version: 1.0 20th April 2009 */ (function($){$.fn.addGrid=function(cols,options){var defaults={default_cols:12,z_index:999,img_path:'/images/',opacity:.6};var opts=$.extend(defaults,options);var cols=cols!=null&&(cols===12||cols===16)?cols:12;var cols=cols===opts.default_cols?'12_col':'16_col';return this.each(function(){var $el=$(this);var height=$el.height();var wrapper=$('<div id="'+opts.grid_id+'"/>').appendTo($el).css({'display':'none','position':'absolute','top':0,'z-index':(opts.z_index-1),'height':height,'opacity':opts.opacity,'width':'100%'});$('<div/>').addClass('container_12').css({'margin':'0 auto','width':'960px','height':height,'background-image':'url('+opts.img_path+cols+'.png)','background-repeat':'repeat-y'}).appendTo(wrapper);$('<div>grid on</div>').appendTo($el).css({'position':'absolute','top':0,'left':0,'z-index':opts.z_index,'background':'#222','color':'#fff','padding':'3px 6px','width':'40px','text-align':'center'}).hover(function(){$(this).css("cursor","pointer");},function(){$(this).css("cursor","default");}).toggle(function(){$(this).text("grid off");$('#'+opts.grid_id).slideDown();},function(){$(this).text("grid on");$('#'+opts.grid_id).slideUp();});});};})(jQuery);

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  • Inheritance inside a template - public members become invisible?

    - by Juliano
    I'm trying to use inheritance among classes defined inside a class template (inner classes). However, the compiler (GCC) is refusing to give me access to public members in the base class. Example code: template <int D> struct Space { struct Plane { Plane(Space& b); virtual int& at(int y, int z) = 0; Space& space; /* <= this member is public */ }; struct PlaneX: public Plane { /* using Plane::space; */ PlaneX(Space& b, int x); int& at(int y, int z); const int cx; }; int& at(int x, int y, int z); }; template <int D> int& Space<D>::PlaneX::at(int y, int z) { return space.at(cx, y, z); /* <= but it fails here */ }; Space<4> sp4; The compiler says: file.cpp: In member function ‘int& Space::PlaneX::at(int, int)’: file.cpp:21: error: ‘space’ was not declared in this scope If using Plane::space; is added to the definition of class PlaneX, or if the base class member is accessed through the this pointer, or if class Space is changed to a non-template class, then the compiler is fine with it. I don't know if this is either some obscure restriction of C++, or a bug in GCC (GCC versions 4.4.1 and 4.4.3 tested). Does anyone have an idea?

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  • Modelling in Agile Development

    - by bertzzie
    I'm writing a bachelor dissertation report where I'm developing a system with Agile methodology. Given that the development is an one man show, of course the "Agile" I did was not really agile at all (from my understanding at least). So I want some perspective from SO crowds, who is of course a professional, real world, developer with tons of experience. I think real world experience is better than the theory and experiments that I did. My question is: Do we model during development time when using Agile? UML? DFD? Or a Functional Specification is enough1? If modelling is not really necessary, what do we use to communicate to the user, as the user almost always won't understand UML or DFD? For my system, I use UI & UX Design with heavy prototyping, but then I don't have time to draw UML any more. Which one is better? 1 http://www.joelonsoftware.com/articles/fog0000000036.html I hope the question's not "subjective and argumentative" as I know this question exist because of my lack of understanding in the agile development. If it is, could someone just give me a pointer or reference about that? Possible duplicate: Do you use UML in Agile development practices?

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  • How can I get type information at runtime from a DMP file in a Windbg extension?

    - by pj4533
    This is related to my previous question, regarding pulling objects from a dmp file. As I mentioned in the previous question, I can successfully pull object out of the dmp file by creating wrapper 'remote' objects. I have implemented several of these so far, and it seems to be working well. However I have run into a snag. In one case, a pointer is stored in a class, say of type 'SomeBaseClass', but that object is actually of the type 'SomeDerivedClass' which derives from 'SomeBaseClass'. For example it would be something like this: MyApplication!SomeObject +0x000 field1 : Ptr32 SomeBaseClass +0x004 field2 : Ptr32 SomeOtherClass +0x008 field3 : Ptr32 SomeOtherClass I need someway to find out what the ACTUAL type of 'field1' is. To be more specific, using example addresses: MyApplication!SomeObject +0x000 field1 : 0cae2e24 SomeBaseClass +0x004 field2 : 0x262c8d3c SomeOtherClass +0x008 field3 : 0x262c8d3c SomeOtherClass 0:000> dt SomeBaseClass 0cae2e24 MyApplication!SomeBaseClass +0x000 __VFN_table : 0x02de89e4 +0x038 basefield1 : (null) +0x03c basefield2 : 3 0:000> dt SomeDerivedClass 0cae2e24 MyApplication!SomeDerivedClass +0x000 __VFN_table : 0x02de89e4 +0x038 basefield1 : (null) +0x03c basefield2 : 3 +0x040 derivedfield1 : 357 +0x044 derivedfield2 : timecode_t When I am in WinDbg, I can do this: dt 0x02de89e4 And it will show the type: 0:000> dt 0x02de89e4 SomeDerivedClass::`vftable' Symbol not found. But how do get that inside an extension? Can I use SearchMemory() to look for 'SomeDerivedClass::`vftable'? If you follow my other question, I need this type information so I know what type of wrapper remote classes to create. I figure it might end up being some sort of case-statement, where I have to match a string to a type? I am ok with that, but I still don't know where I can get that string that represents the type of the object in question (ie SomeObject-field1 in the above example).

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