Search Results

Search found 16246 results on 650 pages for 'free books'.

Page 575/650 | < Previous Page | 571 572 573 574 575 576 577 578 579 580 581 582  | Next Page >

  • How can I declare and initialize an array of pointers to a structure in C?

    - by worlds-apart89
    I have a small assignment in C. I am trying to create an array of pointers to a structure. My question is how can I initialize each pointer to NULL? Also, after I allocate memory for a member of the array, I can not assign values to the structure to which the array element points. #include <stdio.h> #include <stdlib.h> typedef struct list_node list_node_t; struct list_node { char *key; int value; list_node_t *next; }; int main() { list_node_t *ptr = (list_node_t*) malloc(sizeof(list_node_t)); ptr->key = "Hello There"; ptr->value = 1; ptr->next = NULL; // Above works fine // Below is erroneous list_node_t **array[10] = {NULL}; *array[0] = (list_node_t*) malloc(sizeof(list_node_t)); array[0]->key = "Hello world!"; //request for member ‘key’ in something not a structure or union array[0]->value = 22; //request for member ‘value’ in something not a structure or union array[0]->next = NULL; //request for member ‘next’ in something not a structure or union // Do something with the data at hand // Deallocate memory using function free return 0; }

    Read the article

  • Compiling Objective-C project on Linux (Ubuntu)

    - by Alex
    How to make an Objective-C project work on Ubuntu? My files are: Fraction.h #import <Foundation/NSObject.h> @interface Fraction: NSObject { int numerator; int denominator; } -(void) print; -(void) setNumerator: (int) n; -(void) setDenominator: (int) d; -(int) numerator; -(int) denominator; @end Fraction.m #import "Fraction.h" #import <stdio.h> @implementation Fraction -(void) print { printf( "%i/%i", numerator, denominator ); } -(void) setNumerator: (int) n { numerator = n; } -(void) setDenominator: (int) d { denominator = d; } -(int) denominator { return denominator; } -(int) numerator { return numerator; } @end main.m #import <stdio.h> #import "Fraction.h" int main( int argc, const char *argv[] ) { // create a new instance Fraction *frac = [[Fraction alloc] init]; // set the values [frac setNumerator: 1]; [frac setDenominator: 3]; // print it printf( "The fraction is: " ); [frac print]; printf( "\n" ); // free memory [frac release]; return 0; } I've tried two approaches to compile it: Pure gcc: $ sudo apt-get install gobjc gnustep gnustep-devel $ gcc `gnustep-config --objc-flags` -o main main.m -lobjc -lgnustep-base /tmp/ccIQKhfH.o:(.data.rel+0x0): undefined reference to `__objc_class_name_Fraction' I created a GNUmakefile Makefile: include ${GNUSTEP_MAKEFILES}/common.make TOOL_NAME = main main_OBJC_FILES = main.m include ${GNUSTEP_MAKEFILES}/tool.make ... and ran: $ source /usr/share/GNUstep/Makefiles/GNUstep.sh $ make Making all for tool main... Linking tool main ... ./obj/main.o:(.data.rel+0x0): undefined reference to `__objc_class_name_Fraction' So in both cases compiler gets stuck at undefined reference to `__objc_class_name_Fraction' Do you have and idea how to resolve this issue?

    Read the article

  • Which is the better C# class design for dealing with read+write versus readonly

    - by DanM
    I'm contemplating two different class designs for handling a situation where some repositories are read-only while others are read-write. (I don't foresee any need to a write-only repository.) Class Design 1 -- provide all functionality in a base class, then expose applicable functionality publicly in sub classes public abstract class RepositoryBase { protected virtual void SelectBase() { // implementation... } protected virtual void InsertBase() { // implementation... } protected virtual void UpdateBase() { // implementation... } protected virtual void DeleteBase() { // implementation... } } public class ReadOnlyRepository : RepositoryBase { public void Select() { SelectBase(); } } public class ReadWriteRepository : RepositoryBase { public void Select() { SelectBase(); } public void Insert() { InsertBase(); } public void Update() { UpdateBase(); } public void Delete() { DeleteBase(); } } Class Design 2 - read-write class inherits from read-only class public class ReadOnlyRepository { public void Select() { // implementation... } } public class ReadWriteRepository : ReadOnlyRepository { public void Insert() { // implementation... } public void Update() { // implementation... } public void Delete() { // implementation... } } Is one of these designs clearly stronger than the other? If so, which one and why? P.S. If this sounds like a homework question, it's not, but feel free to use it as one if you want :)

    Read the article

  • ASP MVC - Routing Required?

    - by evo_9
    I've been reading up on MVC2 which came in VS2010 and it sounds pretty interesting. I'm actually in the middle of a large multi-tenant application project, and have just started coding the UI. I'm considering changing to MVC as I'm not that far along at this point. I have some questions about the Routing capabilities, namely are they required to use MVC or can I more or less ignore Routing? Or do I have to setup a default routing record that will make things work like standard ASPX (as far as routing alone is concerned)? The reason why I don't want to use Routing is because I've already defined a custom URL 'rewrite' mechanism of my own (which fires on session_start). In addition, I'm using jquery and opens-standards for the entire UI, and MVC's aspx overhead-free approach seems like a better fit based on how I've already started to build the application (I am not using viewstate at all, for example). I guess my big concern is whether the routing can be ignored, of if I will have to re-implement my custom URL rewriting to work with MVC, and if that's the case, how would I do that? As a new Routing routine, or stick with the session_start (if that's even possible?). Lastly, I don't want to use anything even remotely 'intelligent/readable' for the url - for a site like StackOverflow, the readability of the URL is a positive, but the opposite is true if it's not a public website like this one. In fact, it would seem to me that the more friendly MVC routing URL (which indirectly show method names) could pose a security risk on a private, non-public website app like I'm developing. For all these reasons I would love to use the lightweight aspects of MVC but skip the Routing entirely - is this possible?

    Read the article

  • Google App Engine, parsedatetime and TimeZones

    - by Ron
    Hey guys, I'm working on a Google App Engine / Django app and I encountered the following problem: In my html I have an input for time. The input is free text - the user types "in 1 hour" or "tomorrow at 11am". The text is then sent to the server in AJAX, which parses it using this python library: http://code.google.com/p/parsedatetime/. Once parsed, the server returns an epoch timestamp of the time. Here is the problem - Google App Engine always runs on UTC. Therefore, lets say that the local time is now 11am and the UTC time is 2am. When I send "now" to the server it will return "2am", which is good because I want the date to be received in UTC time. When I send "in 1 hour" the server will return "3am" which is good, again. However, when I send "at noon" the server will return "12pm" because it thinks that I'm talking about noon UTC - but really I need it to return 3am, which is noon for the request sender.. I can pass on the TZ of the browser that sends the request, but that wont really help me - the parsedatetime library wont take a timezone argument (correct me if I'm wrong). Is there a walk around this? Maybe setting the environments TZ somehow? Thanks!

    Read the article

  • Improve speed of a JOIN in MySQL

    - by ran2
    Dear all, I know there a similar threads around, but this is really the first time I realize that query speed might affect me - so it´s not that easy for me to really make the transfer from other folks problems. That being said I have using the following query successfully with smaller data, but if I use it on what are mildly large tables (about 120,000 records). I am waiting for hours. INSERT INTO anothertable (id,someint1,someint1,somevarchar1,somevarchar1) SELECT DISTINCT md.id,md.someint1,md.someint1,md.somevarchar1,pd.somevarchar1 from table1 AS md JOIN table2 AS pd ON (md.id = pd.id); Tables 1 and 2 contain about 120,000 records. The query has been running for almost 2 hours right now. Is this normal? Do I just have to wait. I really have no idea, but I am pretty sure that one could do it better since it´s my very first try. I read about indexing, but dont know yet what to index in my case? Thanks for any suggestions - feel free to point my to the very beginners guides ! best matt

    Read the article

  • Close TCP connection when owner process is already killed

    - by Otiel
    I have a Windows service that - when it starts - opens some WCF services to listen on the 8000 port. It happens that this service crashes sometimes. When it does, the TCP connection is not released, thus causing my service to throw an exception if I try to start it again: AddressAlreadyInUseException: There is already a listener on IP endpoint 0.0.0.0:8000 Some observations: When running CurrPorts or netstat -ano, I can see that the 8000 port is still in use (in LISTENING state) and is owned by the Process ID XXX that corresponded to my service process ID. But my service has already crashed, and does not appear in the Task Manager anymore. Thus I can't kill the process to free the port! Of course, running taskkill /PID XXX returns: ERROR: The process "XXX" not found. When running CurrPorts or netstat -b, I can see that the process name involved in creating the listening port is System, and not as MyService.exe (whereas it is MyService.exe when my service is running). I tried to use CurrPorts to close the connection, but I always get the following error message: Failed to close one or more TCP connections. Be aware that you must run this tool as admin in order to close TCP connections. (Useless to say, I do run CurrPorts as Administrator...) TCPView is not much help either: the process name associated to the 8000 port is <non-existent>, and doing "End process" or "Close connection" has no effect. I tried to see if there was not a child process associated with the PID XXX using Process Explorer, but no luck here. If I close my service properly (before it crashes), the TCP connection is correctly released. This is normal, as I close the WCF service hosts in the OnStop() event of my service. The only way I found to release the connection is to restart the server (which is not convenient in a production environment as you can guess). Waiting does not help, the TCP connection is never released. How can I close the connection without restarting the Windows server? PS: found some questions extremely similar to mine.

    Read the article

  • Building a ctypes-"based" C library with distutils

    - by Robie Basak
    Following this recommendation, I have written a native C extension library to optimise part of a Python module via ctypes. I chose ctypes over writing a CPython-native library because it was quicker and easier (just a few functions with all tight loops inside). I've now hit a snag. If I want my work to be easily installable using distutils using python setup.py install, then distutils needs to be able to build my shared library and install it (presumably into /usr/lib/myproject). However, this not a Python extension module, and so as far as I can tell, distutils cannot do this. I've found a few references to people other people with this problem: Someone on numpy-discussion with a hack back in 2006. Somebody asking on distutils-sig and not getting an answer. Somebody asking on the main python list and being pointed to the innards of an existing project. I am aware that I can do something native and not use distutils for the shared library, or indeed use my distribution's packaging system. My concern is that this will limit usability as not everyone will be able to install it easily. So my question is: what is the current best way of distributing a shared library with distutils that will be used by ctypes but otherwise is OS-native and not a Python extension module? Feel free to answer with one of the hacks linked to above if you can expand on it and justify why that is the best way. If there is nothing better, at least all the information will be in one place.

    Read the article

  • Secure web module for paid subscribtion

    - by DarkJaff
    Hello everyone, I'm building a website (a community web site like digg) but we will soon release a new feature that people will need to pay for. Right now, our website is in pure C# in .NET, very simple pages with some AJAX. When the member log in, there is no HTTPS. Everything is check with session and the internal validation that I do. What we need, is that when the people are logged in, they can click on a link a proceed to a payment (Paypal, credit card, etc). After the payment is done, the "billing module" will return a value to my site to validate that the payment is done so the account will be flagged as "paying member". I'm guessing this is the way to do, maybe I'm wrong! So my questions are: -What is the name of this kind of billing module? (I will do some research on that) -Do you know any ready to go module that does this kind of thing? -(I push my luck) Do you know any FREE module that do this kind of things. If something is not clear, don't hesitate to ask question :) Thanks a lot! DarkJaff

    Read the article

  • a question related to URL

    - by Robert
    Dear all,Now i have this question in my java program,I think it should be classified as URL problem,but not 100% sure.If you think I am wrong,feel free to recategorize this problem,thanks. I would state my problem as simply as possible. I did a search on the famouse Chinese search engine baidu.com for a Chinese key word "???" (Obama in English),and the way I do that is to pass a URL (in a Java Program)to the browser like: http://news.baidu.com/ns?word=??? and it works perfectly just like I input the "???”keyword in the text field on baidu.com. However,now my advisor wants another thing.Since he can not read the Chinese webpages,but he wants to make sure the webpages I got from Baidu.com is related to "Obama",he asked me to google translate it back,i.e,using google translate and translate the Chinese webpage to English one. This sounds straightforward.However,I met my problem here. If I simply pass the URL "http://news.baidu.com/ns?word=???" into Google Translate and tick "Chinese to English" translating option,the result looks awful.(I don't know the clue here,maybe related to Chinese character encoding). Alternatively,if now my browser opens ""http://news.baidu.com/ns?word=???" webpage,but I click on the "????" button (that simply means "search"),you will notice the URL will get changed,now if I pass this URL into the Google translate and do the same thing,the result works much better. I hope I am not making this problem sound too complicated,and I appologize for some Chinese words invovled,but I really need your guys' help here.Becasue I did all this in a Java program,I couldn't figure out how to realize that "????"(pressing search button) step then get the new URL.If I could get that new URL,things are easy,I could just call Google translate in my Java code,and pops out the new window to show my advisor. Please share any of your idea or thougts here.Thanks a lot. Robert

    Read the article

  • Lazarus Pascal - DB Connection - clarification

    - by itsols
    The following code is from the docs here: Program ConnectDB var AConnection : TSQLConnection; Procedure CreateConnection; begin AConnection := TIBConnection.Create(nil); AConnection.Hostname := 'localhost'; AConnection.DatabaseName := '/opt/firebird/examples/employee.fdb'; AConnection.UserName := 'sysdba'; AConnection.Password := 'masterkey'; end; begin CreateConnection; AConnection.Open; if Aconnection.Connected then writeln('Succesful connect!') else writeln('This is not possible, because if the connection failed, ' + 'an exception should be raised, so this code would not ' + 'be executed'); AConnection.Close; AConnection.Free; end. The main body of the code makes sense to me BUT I don't get where TSQLConnection came from. I cannot use CTRL + Space to autocomplete it either, which means my program has no reference to it. I'm trying to connect to Postgres by the way. Can someone please state what TSQLConnection is? Thanks!

    Read the article

  • c++ function scope

    - by Myx
    I have a main function in A.cpp which has the following relevant two lines of code: B definition(input_file); definition.Print(); In B.h I have the following relevant lines of code: class B { public: // Constructors B(void); B(const char *filename); ~B(void); // File input int ParseLSFile(const char *filename); // Debugging void Print(void); // Data int var1; double var2; vector<char* > var3; map<char*, vector<char* > > var4; } In B.cpp, I have the following function signatures (sorry for being redundant): B::B(void) : var1(-1), var2(numeric_limits<double>::infinity()) { } B::B(const char *filename) { B *def = new B(); def->ParseLSFile(filename); } B::~B(void) { // Free memory for var3 and var 4 } int B::ParseLSFile(const char *filename) { // assign var1, var2, var3, and var4 values } void B::Print(void) { // print contents of var1, var2, var3, and var4 to stdout } So when I call Print() from within B::ParseLSFile(...), then the contents of my structures print correctly to stdout. However, when I call definition.Print() from A.cpp, my structures are empty or contain garbage. Can anyone recommend the correct way to initialize/pass my structures so that I can access them outside of the scope of my function definition? Thanks.

    Read the article

  • FogBugz On Demand + online source control at low/no cost?

    - by quux
    I have a project in the free hosted FogBugz On Demand (FOD) product right now. This is great for feature/issue tracking. But I've been working from a codebase that is solely on my development machine. I'd like to collaborate with another guy who is thousands of miles from me. So we need a source control solution (SCM)! I use Visual Studio (2005, but can upgrade to later versions as needed). I am aware that FogBugz can integrate with a number of source control systems. So now the question is: which online SCM products can integrate well with FOD and VS? And which ones do so well at low or no cost, for a small code repository. And where might I find a proven recipe for putting this together. I'm open to other solutions which provide the same functionality. Please don't suggest Trac - I regard it highly, but I want the features of FOB (especially the evidence based scheduling) in my issue tracking solution. So really, I need to combine FOB + VS + some online SCM product into a low or no cost solution for two coders to collaborate on.

    Read the article

  • Looping through a file in VB.NET

    - by Ousman
    I am writing a VB.NET program and I'm trying to accomplish the following: Read and loop through a text file line by line Show the event of the loop on a textbox or label until a button is pressed The loop will then stop on any number that happened to be at the loop event and When a button is pressed again the loop will continue. Code Imports System.IO Public Class Form1 'Dim nFileNum As Integer = FreeFile() ' Get a free file number Dim strFileName As String = "C:\scb.txt" Dim objFilename As FileStream = New FileStream(strFileName, _ FileMode.Open, FileAccess.Read, FileShare.Read) Dim objFileRead As StreamReader = New StreamReader(objFilename) 'Dim lLineCount As Long 'Dim sNextLine As String Private Sub btStart_Click(ByVal sender As System.Object, _ ByVal e As System.EventArgs) _ Handles btStart.Click Try If objFileRead.ReadLine = Nothing Then MsgBox("No Accounts Available to show!", _ MsgBoxStyle.Information, _ MsgBoxStyle.DefaultButton2 = MsgBoxStyle.OkOnly) Return Else Do While (objFileRead.Peek() > -1) Loop lblAccounts.Text = objFileRead.ReadLine() 'objFileRead.Close() 'objFilename.Close() End If Catch ex As Exception MessageBox.Show(ex.Message) Finally 'objFileRead.Close() 'objFilename.Close() End Try End Sub Private Sub Form1_Load(ByVal sender As System.Object, _ ByVal e As System.EventArgs) _ Handles MyBase.Load End Sub End Class Problem I'm able to read the text file but my label will only loop if I hit the start button. It goes to the next line, but I want it to continue to loop through the entire file until I hit a button telling it to stop.

    Read the article

  • Exposed onsite vs IFD deployments for MS Dynamics CRM

    - by Greg McGuffey
    I'm working for the first time on a MS Dyanmics CRM 4.0 project. Our company has a high number of remote employees and even more remote consultants. As such it will be necessary to make the CRM solution available over the internet. As near as I can tell, I have three options: Have everyone use a VPN to access an intranet site (typical onsite deployment). However, we have found that VPNs are far from trouble free and cause many support issues. We avoid them like the plague. Use IFD to expose the CRM on the internet. I don't know much about this except that the URL will be different than the onsite URL, which could cause some headaches (see below). Expose the CRM site by opening the site to the internet, using SSL to encrypt traffic. We currently do this with our MS sharepoint sites. I'm not sure how secure this would be (one of the reasons for this question). I'd like to avoid using both the onsite intranet deployment and the IFD together for a couple of reasons. One of the requests for the solution is use email to notify users that they've been assigned a task, and include the URL to the task within the email. For this reason. If both deployments are used, then I'll need to include two URLs and the user would need to know which to use. Which leads to the second reason, the main users of the solution split time between being in the office and being remote. Thus they would need to access the solution two different ways, and know when to use which. Bad. So, what are the advantages/disadvantages of any of these methods? Any other options? Is there any issue using IFD from within the intranet? Security issues? Thanks!

    Read the article

  • G++ Multi-platform memory leak detection tool

    - by indyK1ng
    Does anyone know where I can find a memory memory leak detection tool for C++ which can be either run in a command line or as an Eclipse plug-in in Windows and Linux. I would like it to be easy to use. Preferably one that doesn't overwrite new(), delete(), malloc() or free(). Something like GDB if its gonna be in the command line, but I don't remember that being used for detecting memory leaks. If there is a unit testing framework which does this automatically, that would be great. This question is similar to other questions (such as http://stackoverflow.com/questions/283726/memory-leak-detection-under-windows-for-gnu-c-c ) however I feel it is different because those ask for windows specific solutions or have solutions which I would rather avoid. I feel I am looking for something a bit more specific here. Suggestions don't have to fulfill all requirements, but as many as possible would be nice. Thanks. EDIT: Since this has come up, by "overwrite" I mean anything which requires me to #include a library or which otherwise changes how C++ compiles my code, if it does this at run time so that running the code in a different environment won't affect anything that would be great. Also, unfortunately, I don't have a Mac, so any suggestions for that are unhelpful, but thank you for trying. My desktop runs Windows (I have Linux installed but my dual monitors don't work with it) and I'd rather not run Linux in a VM, although that is certainly an option. My laptop runs Linux, so I can use that tool on there, although I would definitely prefer sticking to my desktop as the screen space is excellent for keeping all of the design documentation and requirements in view without having to move too much around on the desktop. NOTE: While I may try answers, I won't mark one as accepted until I have tried the suggestion and it is satisfactory. EDIT2: I'm not worried about the cross-platform compatibility of my code, it's a command line application using just the C++ libraries.

    Read the article

  • fullcalendar events from REST-ful php server.

    - by biagidp
    I've written a very simple RESTful php server (my first experiment with REST, so feel free to make suggestions) to respond to the fullcalendar events callback. It produces exactly the same string output as the json-events.php file in the fullcalendar json example, but for some reason fullcalendar will not accept my server's output. I've tried messing with the headers because they're different from the ones produced by json-events.php, but I'm not really sure what's awry there, if anything. The code for the server is below: <?php class Listener{ function __construct() { $this->getResource(); $this->buildResponse(); } function getResource(){ $parts = explode('/', $_SERVER["REQUEST_URI"]); $script_name = end(explode('/', $_SERVER["SCRIPT_NAME"])); $this->resource = $parts[array_search($script_name, $parts) + 1]; $this->resource_id = $parts[array_search($script_name, $parts) + 2]; } function buildResponse(){ $method = strtolower($_SERVER["REQUEST_METHOD"]); $this->response_string = $method . ucwords($this->resource); } function getResponse(){ return $this->response_string; } } $listener = new Listener(); $thing = $listener->getResponse(); #$thing(); function getEvents(){ $year = date('Y'); $month = date('m'); echo json_encode(array( array( 'id' => 111, 'title' => "Event1", 'start' => "$year-$month-10", 'url' => "http://yahoo.com/" ), array( 'id' => 222, 'title' => "Event2", 'start' => "$year-$month-20", 'end' => "$year-$month-22", 'url' => "http://yahoo.com/" ) )); } ?> Any input, help or suggestions would be greatly appreciated! Thanks, David

    Read the article

  • BeautifulSoup HTMLParseError. What's wrong with this?

    - by user1915496
    This is my code: from bs4 import BeautifulSoup as BS import urllib2 url = "http://services.runescape.com/m=news/recruit-a-friend-for-free-membership-and-xp" res = urllib2.urlopen(url) soup = BS(res.read()) other_content = soup.find_all('div',{'class':'Content'})[0] print other_content Yet an error comes up: /Library/Python/2.7/site-packages/bs4/builder/_htmlparser.py:149: RuntimeWarning: Python's built-in HTMLParser cannot parse the given document. This is not a bug in Beautiful Soup. The best solution is to install an external parser (lxml or html5lib), and use Beautiful Soup with that parser. See http://www.crummy.com/software/BeautifulSoup/bs4/doc/#installing-a-parser for help. "Python's built-in HTMLParser cannot parse the given document. This is not a bug in Beautiful Soup. The best solution is to install an external parser (lxml or html5lib), and use Beautiful Soup with that parser. See http://www.crummy.com/software/BeautifulSoup/bs4/doc/#installing-a-parser for help.")) Traceback (most recent call last): File "web.py", line 5, in <module> soup = BS(res.read()) File "/Library/Python/2.7/site-packages/bs4/__init__.py", line 172, in __init__ self._feed() File "/Library/Python/2.7/site-packages/bs4/__init__.py", line 185, in _feed self.builder.feed(self.markup) File "/Library/Python/2.7/site-packages/bs4/builder/_htmlparser.py", line 150, in feed raise e I've let two other people use this code, and it works for them perfectly fine. Why is it not working for me? I have bs4 installed...

    Read the article

  • Technology Plan - Which tools should I use?

    - by Armadillo
    Hi, Soon, I'll start my own software company. My primary product/solution will be a Billing/Invoice Software. In a near future, I pretend to expand this first module to an ERP. My app should be able to run as a stand-alone application and as a Web-based application (so there will be, probably two GUI for the same Database). My problem, now, is to choose the right tools; I'm talking about what programming language(s) should I use, what kind of database should I choose, and stuff like that. I'm primarily a VB6 programmer, so probably I'll choose the .net framework (vb/c#). But I'm seriously thinking about Java. Java has 2 "pros" that I really like: write once, run anywhere and it is free (I think...). I've been thinking about RIAs too, but I just don't have any substantial feedback about them... Then, I'll need a report tool. Crystal Reports? HTML based Reports? Other? Databases: I'm not sure if I should use SQL-Server Express or PostgreSQL (or other). I'd be happy to hear any comments and advices Thanks

    Read the article

  • Function parameters evaluation order: is undefined behaviour if we pass reference?

    - by bolov
    This is undefined behaviour: void feedMeValue(int x, int a) { cout << x << " " << a << endl; } int main() { int a = 2; int &ra = a; feedMeValue(ra = 3, a); return 0; } because depending on what parameter gets evaluated first we could call (3, 2) or (3, 3). However this: void feedMeReference(int x, int const &ref) { cout << x << " " << ref << endl; } int main() { int a = 2; int &ra = a; feedMeReference(ra = 3, a); return 0; } will always output 3 3 since the second parameter is a reference and all parameters have been evaluated before the function call, so even if the second parameter is evaluated before of after ra = 3, the function received a reference to a wich will have a value of 2 or 3 at the time of the evaluation, but will always have the value 3 at the time of the function call. Is the second example UB? It is important to know because the compiler is free to do anything if he detects undefined behaviour, even if I know it would always yield the same results. *Note: I think that feedMeReference(a = 3, a) is the exact same situation as feedMeReference(ra = 3, a). However it seems not everybody agrees, in the addition to having 2 completely different answers.

    Read the article

  • How to call functions inside a C dll which take pointers as arguments from C#

    - by AndrejaKo
    Hi people, this is my first post here! I'm trying to make a windows forms program using C# which will use a precompiled C library. It will access a smart card and provide output from it. For the library, I have a .dll, .lib and .h and no source. In the .h file there are several structs defined. Most interesting functions of the .dll expect pointers to allocated structs as arguments. I've been calling functions inside the .dll like this: For example function EID_API int WINAPI EidStartup(int nApiVersion); would be called like this [DllImport("CelikApi.dll")]//the name of the .dll public static extern int EidStartup(int nApiVersion); Now my problem is that I can't find equivalent of C's pointers which point to dynamically allocated structures in memory in C#, so I don't know what to pass as argument to functions which take C pointers. I don't have much experience in C#, but to me its use looked as the easiest way of making the program I need. I tried with C++, but Visual Studio 2010 doesn't have IntelliSense for C++/CLR. If you can point me to something better, feel free to do so.

    Read the article

  • Signable, streamable, "readable" archive format?

    - by alexvoda
    Is there any archive format that offers the following: be digitally sign-able with a digital certificate from a trusted source like Verisign - for preventing changes to the file (I am not referring to read only, but in case the file was changed it should no longer be signed telling the user this is not the original file) be stream-able - be able to be opened even if not all of the content has been transfered (also not strictly linearly) be "readable" - be able to read the data without extracting to a temporary folder (AFAIK if you open a file in a zip archive it is extracted first, and this stays true even for zip based formats like OOXML. This is not what I want) be portable - support on at least Windows, Linux and Mac OS X is a must, or at least future support be free of patents - Be open source - also preferably a license that allows commercial use(as far as i know GPL a share-alike licence so it doesn't allow comercial use, BSD on the other hand alows it) Note: Though it may come in handy eventually I can not think right now of a scenario that would require both point 1 and point 2 simultaneously. Or lets leave it a be able to check the signature only when the whole file was downloaded. I am not interested in: being able to be compressed being supported on legacy systems Does any existing archive format fit this description (tar evolutions like DAR and pax come to mind) ? If there is, are there programing libraries available for the above mentioned OSs? If not, would it be hard to create such a thing? EDIT: clarrified piont 5 EDIT 2: added a note to clarify point 1 and 2 P.S.: This is my first question on StackOverflow

    Read the article

  • I'm trying to grasp the concept of creating a program that uses a SQL Server database, but I'm used

    - by Sergio Tapia
    How can I make a program use a SQL Server database, and have that program work on whatever computer it's installed on. If you've been following my string of questions today, you'd know that I'm making an open source and free Help Desk suite for small and medium businesses. The client application. The client application is a Windows Forms app. On installation and first launch on every client machine, it'll ask for the address of the main Help Desk server. The server. Here I plan to handle all incoming help requests, show them to the IT guys, and provide WCF services for the Client application to consume. My dilemma lies in that, I know how to make the program run on my local machine; but I'm really stumped on how to make this work for everyone who wants to download and install the server bit on their Windows Server. Would I have to make an SQL Script and have it run on the MS SQL server when a user wants to install the 'server' application? Many thanks to all for your valuable time and effort to teach me. It's really really appreciated. :) Edit: To clarify, each business will have their server completely separate from me. I will have no access whatsoever to them nor will they be in any way connected to me. (I don't know why I should clarify this :P ) So, assuming the have ABSOLUTELY NO DATABASE SERVER installed; what can I do?

    Read the article

  • Created files on Archos 5 invisible on Windows Xp

    - by user352042
    I am fairly new to Android and this is my first post so I apologise in advance if I am breaking protocol or posting to the wrong board. Please feel free to move this post to somewhere more appropriate if required. I am developing for the 160 Gb Archos 5 Internet tablet. Not ideal as a development platform I know, but customer requirements mean we have no choice. It is running Android 1.6. I have updated the device firmware to the most recent available. Updating the version of Android is not an option at this point. Part of my app's requirement is to write information out to .txt files on the external storage directory so that these can be copied over the USB connection to a Windows XP PC using the Mobile media device (MTP) mode. I have followed all instructions I have come across carefully, eg I check that the storage is available using the technique described at http://developer.android.com/guide/topics/data/data-storage.html#filesExternal. However, althoug the files are created succesfully on the device (I can browse them and open them using the device's File Explorer - they are fine), when I connect the device to a Windows XP computer none of the directories or files I created appear and the size of their parent files suggest they do not exist. I have tried running over the ADB, checked logcat, tried a (signed) release version and even written a second test application which just creates a folder (this behaves the same, ie it creates the folder but this is not visible in Windows Explorer) - nothing anywhere gives me any suggestion as to what the problem might be. If anyone has heard of this before or has any ideas as to what else | could try to fix it please get in touch! We do not have any other devices to test on at the moment, although I hope to remedy this soon, customer permitting.

    Read the article

  • Definition of the job titles involved in a software development process.

    - by Rafael Romão
    I have seen many job titles for people involved in a software development process, but never found a consensus about they mean. I know many of them are equivalent, and found some other questions about that here in SO, but I would like to know your definitions and comments about them. I want not only to know if there is really a consensus, but also to know if what I suppose to be a Software Architect, is really a Software Architect, and so on. The job titles I mean are: Developer; System Analyst; Programmer; Analyst Programmer; Software Engineer; Software Architect; Designer; Software Designer; Business Manager; Business Analyst; Program Manager; Project Manager; Development Manager; Tester; Support Analyst; Please, feel free to add more titles to this list in your answers. It would be very helpful.

    Read the article

< Previous Page | 571 572 573 574 575 576 577 578 579 580 581 582  | Next Page >