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  • fetch value of ipaddress

    - by neha soni
    i want to get ipaddress of mycomputer in a variable this statement prints ipaddress of my computer but i want to assign it in a varible how can i fetch the value of ipaddress from inet_ntoa(inaddrr(ifr_addr.sa_data)) into an variable ip of char* type . printf("IP Address: %s\n", inet_ntoa(inaddrr(ifr_addr.sa_data)));

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  • How to return a single variable from a CUDA kernel function?

    - by Pooya
    I have a CUDA search function which calculate one single variable. How can I return it back. global void G_SearchByNameID(node* Node, long nodeCount, long start,char* dest, long answer){ answer = 2; } cudaMemcpy(h_answer, d_answer, sizeof(long), cudaMemcpyDeviceToHost); cudaFree(d_answer); for both of these lines I get this error: error: argument of type "long" is incompatible with parameter of type "const void *"

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  • c# interop with ghostscript

    - by yodaj007
    I'm trying to access some Ghostscript functions like so: [DllImport(@"C:\Program Files\GPLGS\gsdll32.dll", EntryPoint = "gsapi_revision")] public static extern int Foo(gsapi_revision_t x, int len); public struct gsapi_revision_t { [MarshalAs(UnmanagedType.LPTStr)] string product; [MarshalAs(UnmanagedType.LPTStr)] string copyright; long revision; long revisiondate; } public static void Main() { gsapi_revision_t foo = new gsapi_revision_t(); Foo(foo, Marshal.SizeOf(foo)); This corresponds with these definitions from the iapi.h header from ghostscript: typedef struct gsapi_revision_s { const char *product; const char *copyright; long revision; long revisiondate; } gsapi_revision_t; GSDLLEXPORT int GSDLLAPI gsapi_revision(gsapi_revision_t *pr, int len); But my code is reading nothing into the string fields. If I add 'ref' to the function, it reads gibberish. However, the following code reads in the data just fine: public struct gsapi_revision_t { IntPtr product; IntPtr copyright; long revision; long revisiondate; } public static void Main() { gsapi_revision_t foo = new gsapi_revision_t(); IntPtr x = Marshal.AllocHGlobal(20); for (int i = 0; i < 20; i++) Marshal.WriteInt32(x, i, 0); int result = Foo(x, 20); IntPtr productNamePtr = Marshal.ReadIntPtr(x); IntPtr copyrightPtr = Marshal.ReadIntPtr(x, 4); long revision = Marshal.ReadInt64(x, 8); long revisionDate = Marshal.ReadInt64(x, 12); byte[] dest = new byte[1000]; Marshal.Copy(productNamePtr, dest, 0, 1000); string name = Read(productNamePtr); string copyright = Read(copyrightPtr); } public static string Read(IntPtr p) { List<byte> bits = new List<byte>(); int i = 0; while (true) { byte b = Marshal.ReadByte(new IntPtr(p.ToInt64() + i)); if (b == 0) break; bits.Add(b); i++; } return Encoding.ASCII.GetString(bits.ToArray()); } So what am I doing wrong with marshaling?

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  • Strange behavior of move with strings

    - by Umair Ahmed
    I am testing some enhanced string related functions with which I am trying to use move as a way to copy strings around for faster, more efficient use without delving into pointers. While testing a function for making a delimited string from a TStringList, I encountered a strange issue. The compiler referenced the bytes contained through the index when it was empty and when a string was added to it through move, index referenced the characters contained. Here is a small downsized barebone code sample:- unit UI; interface uses System.SysUtils, System.Types, System.UITypes, System.Rtti, System.Classes, System.Variants, FMX.Types, FMX.Controls, FMX.Forms, FMX.Dialogs, FMX.Layouts, FMX.Memo; type TForm1 = class(TForm) Results: TMemo; procedure FormCreate(Sender: TObject); end; var Form1: TForm1; implementation {$R *.fmx} function StringListToDelimitedString ( const AStringList: TStringList; const ADelimiter: String ): String; var Str : String; Temp1 : NativeInt; Temp2 : NativeInt; DelimiterSize : Byte; begin Result := ' '; Temp1 := 0; DelimiterSize := Length ( ADelimiter ) * 2; for Str in AStringList do Temp1 := Temp1 + Length ( Str ); SetLength ( Result, Temp1 ); Temp1 := 1; for Str in AStringList do begin Temp2 := Length ( Str ) * 2; // Here Index references bytes in Result Move ( Str [1], Result [Temp1], Temp2 ); // From here the index seems to address characters instead of bytes in Result Temp1 := Temp1 + Temp2; Move ( ADelimiter [1], Result [Temp1], DelimiterSize ); Temp1 := Temp1 + DelimiterSize; end; end; procedure TForm1.FormCreate(Sender: TObject); var StrList : TStringList; Str : String; begin // Test 1 : StringListToDelimitedString StrList := TStringList.Create; Str := ''; StrList.Add ( 'Hello1' ); StrList.Add ( 'Hello2' ); StrList.Add ( 'Hello3' ); StrList.Add ( 'Hello4' ); Str := StringListToDelimitedString ( StrList, ';' ); Results.Lines.Add ( Str ); StrList.Free; end; end. Please devise a solution and if possible, some explanation. Alternatives are welcome too.

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  • Streaming binary data to WCF rest service gives Bad Request (400) when content length is greater than 64k

    - by Mikey Cee
    I have a WCF service that takes a stream: [ServiceContract] public class UploadService : BaseService { [OperationContract] [WebInvoke(BodyStyle=WebMessageBodyStyle.Bare, Method=WebRequestMethods.Http.Post)] public void Upload(Stream data) { // etc. } } This method is to allow my Silverlight application to upload large binary files, the easiest way being to craft the HTTP request by hand from the client. Here is the code in the Silverlight client that does this: const int contentLength = 64 * 1024; // 64 Kb var request = (HttpWebRequest)WebRequest.Create("http://localhost:8732/UploadService/"); request.AllowWriteStreamBuffering = false; request.Method = WebRequestMethods.Http.Post; request.ContentType = "application/octet-stream"; request.ContentLength = contentLength; using (var outputStream = request.GetRequestStream()) { outputStream.Write(new byte[contentLength], 0, contentLength); outputStream.Flush(); using (var response = request.GetResponse()); } Now, in the case above, where I am streaming 64 kB of data (or less), this works OK and if I set a breakpoint in my WCF method, and I can examine the stream and see 64 kB worth of zeros - yay! The problem arises if I send anything more than 64 kB of data, for instance by changing the first line of my client code to the following: const int contentLength = 64 * 1024 + 1; // 64 kB + 1 B This now throws an exception when I call request.GetResponse(): The remote server returned an error: (400) Bad Request. In my WCF configuration I have set maxReceivedMessageSize, maxBufferSize and maxBufferPoolSize to 2147483647, but to no avail. Here are the relevant sections from my service's app.config: <service name="UploadService"> <endpoint address="" binding="webHttpBinding" bindingName="StreamedRequestWebBinding" contract="UploadService" behaviorConfiguration="webBehavior"> <identity> <dns value="localhost" /> </identity> </endpoint> <host> <baseAddresses> <add baseAddress="http://localhost:8732/UploadService/" /> </baseAddresses> </host> </service> <bindings> <webHttpBinding> <binding name="StreamedRequestWebBinding" bypassProxyOnLocal="true" useDefaultWebProxy="false" hostNameComparisonMode="WeakWildcard" sendTimeout="00:05:00" openTimeout="00:05:00" receiveTimeout="00:05:00" maxReceivedMessageSize="2147483647" maxBufferSize="2147483647" maxBufferPoolSize="2147483647" transferMode="StreamedRequest"> <readerQuotas maxArrayLength="2147483647" maxStringContentLength="2147483647" /> </binding> </webHttpBinding> </bindings> <behaviors> <endpointBehaviors> <behavior name="webBehavior"> <webHttp /> </behavior> <endpointBehaviors> </behaviors> How do I make my service accept more than 64 kB of streamed post data?

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  • How do I call a static bool method in main.m

    - by AaronG
    This is Objective-C, in Xcode for the iPhone. I have a method in main.m: int main(int argc, char *argv[]) { NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init]; //I want to call the method here// int retVal = UIApplicationMain(argc, argv, nil, nil); [pool release]; return retVal; } static BOOL do_it_all () { //code here// } How do I call the do_it_all method from main.m?

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  • Ajax to read updated values from XML

    - by punit
    I am creating file upload progress bar. I have a CGI script which copies the data, and here I increment the progress bar value by ONE after certain iterations. I am storing the incremented value in XML file (I also tried using plain text file). On the other side I have ajax reading incremented value from xml and depending on that it increments the DIV element. However, what happens here is, it seems to me that although the ajax reads all the incremented values but it processes it after the CGI has finished execution. That is progress bar starts execution once the file copying and other stuff in CGI is completed. My code is: AJAX:::: function polling_start() { //GETS CALLED WHEN USER HITS FILE UPLOAD BUTTON intervalID = window.setInterval(send_request,100); } window.onload = function (){ request = initXMLHttpClient(); request.overrideMimeType('text/xml'); progress = document.getElementById('progress'); } function initXMLHttpClient() { if (window.XMLHttpRequest){ // code for IE7+, Firefox, Chrome, Opera, Safari xmlhttp = new XMLHttpRequest(); } else{ // code for IE6, IE5 xmlhttp = new ActiveXObject("Microsoft.XMLHTTP"); } return xmlhttp } function send_request() { request.open("GET","progress_bar.xml",true); request.onreadystatechange = request_handler; request.send(); } function request_handler() { if (request.readyState == 4 && request.status == 200) { var level=request.responseXML.getElementsByTagName('PROGRESS')[0].firstChild; progress.style.width = progress.innerHTML = level.nodeValue + '%'; progress.style.backgroundColor = "green"; } } /****ON SERVER SIDE*********/ char xmlDat1[] = "<DOCUMENT><PROGRESS>"; char xmlDat2[] = "</PROGRESS></DOCUMENT>"; fptr = fopen("progress_bar.xml", "w"); .........OTHER STUFF.............................. ................................. if(i == inc && j<=100) { fprintf(fptr, "%s\n", "\n\n\n]"); //fprintf(fptr, "%s\n", ""); fprintf(fptr, "%s", xmlDat1); // fprintf(fptr, "%d" ,j); fprintf(fptr, "%s" ,xmlDat2); fseek(fptr, 0, SEEK_SET); /*fprintf(fptr, "%d" ,j); fseek(fptr, 0, SEEK_SET);*/ i = 0; //sleep(1); j++; } (I also tried to write in .text, but same response) Any quick response would be appreciable.

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  • Sharepoint InputFormTextBox: cannot change text color

    - by Mina Samy
    Hi all I have a custom sharepoint aspx form that has an InputFormTextBox with RichText property set to true. In browser when I change the color of the text I receive a javascript error: Message: 'g_elemRTELastTextAreaConverted' is null or not an object Line: 2509 Char: 3 Code: 0 URI: http://myhost/_layouts/1033/form.js what can be the reason for this

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  • gcc/g++: error when compiling large file

    - by Alexander
    Hi, I have a auto-generated C++ source file, around 40 MB in size. It largely consists of push_back commands for some vectors and string constants that shall be pushed. When I try to compile this file, g++ exits and says that it couldn't reserve enough virtual memory (around 3 GB). Googling this problem, I found that using the command line switches --param ggc-min-expand=0 --param ggc-min-heapsize=4096 may solve the problem. They, however, only seem to work when optimization is turned on. 1) Is this really the solution that I am looking for? 2) Or is there a faster, better (compiling takes ages with these options acitvated) way to do this? Best wishes, Alexander Update: Thanks for all the good ideas. I tried most of them. Using an array instead of several push_back() operations reduced memory usage, but as the file that I was trying to compile was so big, it still crashed, only later. In a way, this behaviour is really interesting, as there is not much to optimize in such a setting -- what does the GCC do behind the scenes that costs so much memory? (I compiled with deactivating all optimizations as well and got the same results) The solution that I switched to now is reading in the original data from a binary object file that I created from the original file using objcopy. This is what I originally did not want to do, because creating the data structures in a higher-level language (in this case Perl) was more convenient than having to do this in C++. However, getting this running under Win32 was more complicated than expected. objcopy seems to generate files in the ELF format, and it seems that some of the problems I had disappeared when I manually set the output format to pe-i386. The symbols in the object file are by standard named after the file name, e.g. converting the file inbuilt_training_data.bin would result in these two symbols: binary_inbuilt_training_data_bin_start and binary_inbuilt_training_data_bin_end. I found some tutorials on the web which claim that these symbols should be declared as extern char _binary_inbuilt_training_data_bin_start;, but this does not seem to be right -- only extern char binary_inbuilt_training_data_bin_start; worked for me.

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  • QPlainTextEdit segmentation fault

    - by Alexander
    Hi, All! I have some Qt application with QPlainTextEdit in Tab widget. When try to make a pointer on it QPlainTextEdit *w = (QPlainTextEdit*)ui->tabWidget->widget(0) and call a document() method w->document() I get a segfault. But if i call document directly, e.g. ui-mainEdit-document(), then everything works fine. Can anybody explain me why it happens?

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  • How to launch a Windows service network process to listen to a port on a localhost socket that is vi

    - by rwired
    Here's the code (in a standard TService in Delphi): const ProcessExe = 'MyNetApp.exe'; function RunService: Boolean; var StartInfo : TStartupInfo; ProcInfo : TProcessInformation; CreateOK : Boolean; begin CreateOK := false; FillChar(StartInfo,SizeOf(TStartupInfo),#0); FillChar(ProcInfo,SizeOf(TProcessInformation),#0); StartInfo.cb := SizeOf(TStartupInfo); CreateOK := CreateProcess(nil, PChar(ProcessEXE),nil,nil,False, CREATE_NEW_PROCESS_GROUP+NORMAL_PRIORITY_CLASS, nil, PChar(InstallDir), StartInfo, ProcInfo); CloseHandle(ProcInfo.hProcess); CloseHandle(ProcInfo.hThread); Result := CreateOK; end; procedure TServicel.ServiceExecute(Sender: TService); const IntervalsBetweenRuns = 4; //no of IntTimes between checks IntTime = 250; //ms var Count: SmallInt; begin Count := IntervalsBetweenRuns; //first time run immediately while not Terminated do begin Inc(Count); if Count >= IntervalsBetweenRuns then begin Count := 0; //We check to see if the process is running, //if not we run it. That's all there is to it. //if ProcessEXE crashes, this service host will just rerun it if processExists(ProcessEXE)=0 then RunService; end; Sleep(IntTime); ServiceThread.ProcessRequests(False); end; end; MyNetApp.exe is a SOCKS5 proxy listening on port 9870. Users configure their browser to this proxy which acts as a secure-tunnel/anonymizer. All works perfectly fine on 2000/XP/2003, but on Vista/Win7 with UAC the service runs in Session0 under LocalSystem and port 9870 doesn't show up in netstat for the logged-in user or Administrator. Seems UAC is getting in my way. Is there something I can do with the SECURITY_ATTRIBUTES or CreateProcess, or is there something I can do with CreateProcessAsUser or impersonation to ensure that a network socket on a service is available to logged-in users on the system (note, this app is for mass deployment, I don't have access to user credentials, and require the user elevate their privileges to install a service on Vista/Win7)

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  • C# : MS Chart : SeriesCollection -> InvalidCastException?

    - by HeinrichStack
    What is the correct way to get the Series of a char in PPT 2010. I tried PowerPoint.SeriesCollection mySeriesCollection = (PowerPoint.SeriesCollection) myChart.SeriesCollection(1); throws the following exception Exception Type: System.InvalidCastException Further, What is the correct call in C# to get the series of a chart ? If I try this way: PowerPoint.Series mySeries = (PowerPoint.Series)myChart.SeriesCollection.Item(1); I get the following compile error : error CS0119: 'Microsoft.Office.Interop.PowerPoint.Chart.SeriesCollection(object)' is a 'method', which is not valid in the given context

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  • Is it possible to build a WinForm app (or another type of .NET app) which allows me to interact with

    - by RoboShop
    I'm learning Chinese at the moment and I have gotten my hand on a Chinese dictionary definition. Now I would like to make an interface. All I really want the application to do is when I point my mouse pointer over any text on the screen (in any window), it would identify the text I am pointing at and then display a small form over it, which would the chinese transaction. Is that possible to do? Can WinForms apps interact with windows outside of it's own application?

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  • Any tips on reducing wxWidgets application code size?

    - by Billy ONeal
    I have written a minimal wxWidgets application: stdafx.h #define wxNO_REGEX_LIB #define wxNO_XML_LIB #define wxNO_NET_LIB #define wxNO_EXPAT_LIB #define wxNO_JPEG_LIB #define wxNO_PNG_LIB #define wxNO_TIFF_LIB #define wxNO_ZLIB_LIB #define wxNO_ADV_LIB #define wxNO_HTML_LIB #define wxNO_GL_LIB #define wxNO_QA_LIB #define wxNO_XRC_LIB #define wxNO_AUI_LIB #define wxNO_PROPGRID_LIB #define wxNO_RIBBON_LIB #define wxNO_RICHTEXT_LIB #define wxNO_MEDIA_LIB #define wxNO_STC_LIB #include <wx/wxprec.h> Minimal.cpp #include "stdafx.h" #include <memory> #include <wx/wx.h> class Minimal : public wxApp { public: virtual bool OnInit(); }; IMPLEMENT_APP(Minimal) DECLARE_APP(Minimal) class MinimalFrame : public wxFrame { DECLARE_EVENT_TABLE() public: MinimalFrame(const wxString& title); void OnQuit(wxCommandEvent& e); void OnAbout(wxCommandEvent& e); }; BEGIN_EVENT_TABLE(MinimalFrame, wxFrame) EVT_MENU(wxID_ABOUT, MinimalFrame::OnAbout) EVT_MENU(wxID_EXIT, MinimalFrame::OnQuit) END_EVENT_TABLE() MinimalFrame::MinimalFrame(const wxString& title) : wxFrame(0, wxID_ANY, title) { std::auto_ptr<wxMenu> fileMenu(new wxMenu); fileMenu->Append(wxID_EXIT, L"E&xit\tAlt-X", L"Terminate the Minimal Example."); std::auto_ptr<wxMenu> helpMenu(new wxMenu); helpMenu->Append(wxID_ABOUT, L"&About\tF1", L"Show the about dialog box."); std::auto_ptr<wxMenuBar> bar(new wxMenuBar); bar->Append(fileMenu.get(), L"&File"); fileMenu.release(); bar->Append(helpMenu.get(), L"&Help"); helpMenu.release(); SetMenuBar(bar.get()); bar.release(); CreateStatusBar(2); SetStatusText(L"Welcome to wxWidgets!"); } void MinimalFrame::OnAbout(wxCommandEvent& e) { wxMessageBox(L"Some text about me!", L"About", wxOK, this); } void MinimalFrame::OnQuit(wxCommandEvent& e) { Close(); } bool Minimal::OnInit() { std::auto_ptr<MinimalFrame> mainFrame( new MinimalFrame(L"Minimal wxWidgets Application")); mainFrame->Show(); mainFrame.release(); return true; } This minimal program weighs in at 2.4MB! (Executable compression drops this to half a MB or so but that's still HUGE!) (I must statically link because this application needs to be single-binary-xcopy-deployed, so both the C runtime and wxWidgets itself are set for static linking) Any tips on cutting this down? (I'm using Microsoft Visual Studio 2010)

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  • How to handle an array of pointers in Objective-C

    - by DougW
    I figured out the answer to this question, but I couldn't find the solution on here, so posting it for posterity. So, in Objective-C, how do you create an object out of a pointer in order to store it in objective-c collections (NSArray, NSDictionary, NSSet, etc) without reverting to regular C?

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  • malloc_error_break

    - by milanjansari
    Hello, (4446,0xa0bc94e0) malloc: * error for object 0x1d153000: pointer being freed was not allocated * set a breakpoint in malloc_error_break to debug Cont does anyone idea above the error. i am trying to 2000 address contact dispaly in tableview that time i am getting error. Thank

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  • No middle-click scrolling in visual studio 2010?

    - by maxp
    Just as I started to assume this feature was ubiquitous(middle-clicking on a page, then scrolling speed/direction is relative to the distance of the pointer on the y-axis). I can't believe this hasn't been implemented into the text editor in vs2010, I used it all the time in 2005 and 2008. Has anyone managed to find a workaround or am I a minority user of this feature?

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  • Android problem: BufferedReader wont read whole stream into a string

    - by Levara
    Hi all! I'm making an android program that retrieves content of a webpage using HttpURLConnection. I'm new to both Java and Android. Problem is: Reader reads whole page source, but in the last while iteration it doesn't append to stringBuffer that last part. Using debbuger I have determined that, in the last loop iteration, string buff is created, but stringBuffer just doesnt append it. I need to parse retrieved content. Is there any better way to handle the content for parsing than using strings. I've read on numerous other sites that string size in Java is limited only by available heap size. Anyone know what could be the problem. Btw feel free to suggest any improvements to the code. Thanks! URL u; try { u = new URL("http://feeds.timesonline.co.uk/c/32313/f/440134/index.rss"); HttpURLConnection c = (HttpURLConnection) u.openConnection(); c.setRequestProperty("User-agent","Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 1.1.4322; InfoPath.1; .NET CLR 2.0.50727)"); c.setRequestMethod("GET"); c.setDoOutput(true); c.setReadTimeout(3000); c.connect(); StringBuffer stringBuffer = new StringBuffer(""); InputStream in = c.getInputStream(); InputStreamReader inp = new InputStreamReader(in); BufferedReader reader = new BufferedReader(inp); char[] buffer = new char[3072]; int len1 = 0; while ( (len1 = reader.read(buffer)) != -1 ) { String buff = new String(buffer,0,len1); stringBuffer.append(buff); } String stranica = new String(stringBuffer); c.disconnect(); reader.close(); inp.close(); in.close();

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  • C socket programming: connect() hangs

    - by Fantastic Fourier
    Hey all, I'm about to rip my hair out. I have this client that tries to connect to a server, everything seems to be fine, using gethostbyname(), socket(), bind(), but when trying toconnect()` it just hangs there and the server doesn't see anything from the client. I know that the server works because another client (also in C) can connect just fine. What causes the server to not see this incoming connection? I'm at the end of my wits here. The two different clients are pretty similar too so I'm even more lost. if (argc == 2) { host = argv[1]; // server address } else { printf("plz read the manual\n"); exit(1); } hserver = gethostbyname(host); if (hserver) { printf("host found: %p\n", hserver); printf("host found: %s\n", hserver->h_name ); } else { printf("host not found\n"); exit(1); } bzero((char * ) &server_address, sizeof(server_address)); // copy zeroes into string server_address.sin_family = AF_INET; server_address.sin_addr.s_addr = htonl(hserver->h_addr); server_address.sin_port = htons(SERVER_PORT); bzero((char * ) &client_address, sizeof(client_address)); // copy zeroes into string client_address.sin_family = AF_INET; client_address.sin_addr.s_addr = htonl(INADDR_ANY); client_address.sin_port = htons(SERVER_PORT); sockfd = socket(AF_INET, SOCK_STREAM, 0); if (sockfd < 0) exit(1); else { printf("socket is opened: %i \n", sockfd); info.sock_fd = sockfd; rv = fcntl(sockfd, F_SETFL, O_NONBLOCK); // socket set to NONBLOCK if(rv < 0) printf("nonblock failed: %i %s\n", errno, strerror(errno)); else printf("socket is set nonblock\n"); } timeout.tv_sec = 0; // seconds timeout.tv_usec = 500000; // micro seconds ( 0.5 seconds) setsockopt(sockfd, SOL_SOCKET, SO_RCVTIMEO, &timeout, sizeof(struct timeval)); rv = bind(sockfd, (struct sockaddr *) &client_address, sizeof(client_address)); if (rv < 0) { printf("MAIN: ERROR bind() %i: %s\n", errno, strerror(errno)); exit(1); } else printf("socket is bound\n"); rv = connect(sockfd, (struct sockaddr *) &server_address, sizeof(server_address)); printf("rv = %i\n", rv); if (rv < 0) { printf("MAIN: ERROR connect() %i: %s\n", errno, strerror(errno)); exit(1); } else printf("connected\n"); Any thoughts or insights are deeply greatly humongously appreciated. -Fourier

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  • Reading a child process's /proc/pid/mem file from the parent

    - by Amittai Aviram
    In the program below, I am trying to cause the following to happen: Process A assigns a value to a stack variable a. Process A (parent) creates process B (child) with PID child_pid. Process B calls function func1, passing a pointer to a. Process B changes the value of variable a through the pointer. Process B opens its /proc/self/mem file, seeks to the page containing a, and prints the new value of a. Process A (at the same time) opens /proc/child_pid/mem, seeks to the right page, and prints the new value of a. The problem is that, in step 6, the parent only sees the old value of a in /proc/child_pid/mem, while the child can indeed see the new value in its /proc/self/mem. Why is this the case? Is there any way that I can get the parent to to see the child's changes to its address space through the /proc filesystem? #include <fcntl.h> #include <stdbool.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <sys/types.h> #include <sys/stat.h> #include <sys/wait.h> #include <unistd.h> #define PAGE_SIZE 0x1000 #define LOG_PAGE_SIZE 0xc #define PAGE_ROUND_DOWN(v) ((v) & (~(PAGE_SIZE - 1))) #define PAGE_ROUND_UP(v) (((v) + PAGE_SIZE - 1) & (~(PAGE_SIZE - 1))) #define OFFSET_IN_PAGE(v) ((v) & (PAGE_SIZE - 1)) # if defined ARCH && ARCH == 32 #define BP "ebp" #define SP "esp" #else #define BP "rbp" #define SP "rsp" #endif typedef struct arg_t { int a; } arg_t; void func1(void * data) { arg_t * arg_ptr = (arg_t *)data; printf("func1: old value: %d\n", arg_ptr->a); arg_ptr->a = 53; printf("func1: address: %p\n", &arg_ptr->a); printf("func1: new value: %d\n", arg_ptr->a); } void expore_proc_mem(void (*fn)(void *), void * data) { off_t frame_pointer, stack_start; char buffer[PAGE_SIZE]; const char * path = "/proc/self/mem"; int child_pid, status; int parent_to_child[2]; int child_to_parent[2]; arg_t * arg_ptr; off_t child_offset; asm volatile ("mov %%"BP", %0" : "=m" (frame_pointer)); stack_start = PAGE_ROUND_DOWN(frame_pointer); printf("Stack_start: %lx\n", (unsigned long)stack_start); arg_ptr = (arg_t *)data; child_offset = OFFSET_IN_PAGE((off_t)&arg_ptr->a); printf("Address of arg_ptr->a: %p\n", &arg_ptr->a); pipe(parent_to_child); pipe(child_to_parent); bool msg; int child_mem_fd; char child_path[0x20]; child_pid = fork(); if (child_pid == -1) { perror("fork"); exit(EXIT_FAILURE); } if (!child_pid) { close(child_to_parent[0]); close(parent_to_child[1]); printf("CHILD (pid %d, parent pid %d).\n", getpid(), getppid()); fn(data); msg = true; write(child_to_parent[1], &msg, 1); child_mem_fd = open("/proc/self/mem", O_RDONLY); if (child_mem_fd == -1) { perror("open (child)"); exit(EXIT_FAILURE); } printf("CHILD: child_mem_fd: %d\n", child_mem_fd); if (lseek(child_mem_fd, stack_start, SEEK_SET) == (off_t)-1) { perror("lseek"); exit(EXIT_FAILURE); } if (read(child_mem_fd, buffer, sizeof(buffer)) != sizeof(buffer)) { perror("read"); exit(EXIT_FAILURE); } printf("CHILD: new value %d\n", *(int *)(buffer + child_offset)); read(parent_to_child[0], &msg, 1); exit(EXIT_SUCCESS); } else { printf("PARENT (pid %d, child pid %d)\n", getpid(), child_pid); printf("PARENT: child_offset: %lx\n", child_offset); read(child_to_parent[0], &msg, 1); printf("PARENT: message from child: %d\n", msg); snprintf(child_path, 0x20, "/proc/%d/mem", child_pid); printf("PARENT: child_path: %s\n", child_path); child_mem_fd = open(path, O_RDONLY); if (child_mem_fd == -1) { perror("open (child)"); exit(EXIT_FAILURE); } printf("PARENT: child_mem_fd: %d\n", child_mem_fd); if (lseek(child_mem_fd, stack_start, SEEK_SET) == (off_t)-1) { perror("lseek"); exit(EXIT_FAILURE); } if (read(child_mem_fd, buffer, sizeof(buffer)) != sizeof(buffer)) { perror("read"); exit(EXIT_FAILURE); } printf("PARENT: new value %d\n", *(int *)(buffer + child_offset)); close(child_mem_fd); printf("ENDING CHILD PROCESS.\n"); write(parent_to_child[1], &msg, 1); if (waitpid(child_pid, &status, 0) == -1) { perror("waitpid"); exit(EXIT_FAILURE); } } } int main(void) { arg_t arg; arg.a = 42; printf("In main: address of arg.a: %p\n", &arg.a); explore_proc_mem(&func1, &arg.a); return EXIT_SUCCESS; } This program produces the output below. Notice that the value of a (boldfaced) differs between parent's and child's reading of the /proc/child_pid/mem file. In main: address of arg.a: 0x7ffffe1964f0 Stack_start: 7ffffe196000 Address of arg_ptr-a: 0x7ffffe1964f0 PARENT (pid 20376, child pid 20377) PARENT: child_offset: 4f0 CHILD (pid 20377, parent pid 20376). func1: old value: 42 func1: address: 0x7ffffe1964f0 func1: new value: 53 PARENT: message from child: 1 CHILD: child_mem_fd: 4 PARENT: child_path: /proc/20377/mem CHILD: new value 53 PARENT: child_mem_fd: 7 PARENT: new value 42 ENDING CHILD PROCESS.

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  • Minimizing all open windows in C#

    - by Charlie Somerville
    I saw this C++ code on a forum which minimizes all open windows #define MIN_ALL 419 #define MIN_ALL_UNDO 416 int main(int argc, char* argv[]) { HWND lHwnd = FindWindow("Shell_TrayWnd",NULL); SendMessage(lHwnd,WM_COMMAND,MIN_ALL,0); Sleep(2000); SendMessage(lHwnd,WM_COMMAND,MIN_ALL_UNDO,0); return 0; } How can I access the FindWindow and SendMessage API function and the HWND type in C#.net?

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  • Need to add underscore to my regex

    - by TaMeR
    I suck at regular expression and just can't seem to figure this out. '/^[A-Za-z0-9](?:.[A-Za-z0-9]+)*$/' As it's right now it allows dots anytime after the first char and I like to add _ so that it allows both. Thanks

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  • How to download a folder of files from a web server using Delphi

    - by Brian Frost
    I've checked out the usefule link how to download a file from internet using Delphi and my question related but I would appreciate a pointer to get started. I need to be able to copy all files in a web server folder down to a local folder. I wont know how many files there are, or indeed whether there is an internet connection. Are there component(s) that would help me please? Or can I use Windows API? Thanks Brian

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