Search Results

Search found 15377 results on 616 pages for 'socket programming'.

Page 90/616 | < Previous Page | 86 87 88 89 90 91 92 93 94 95 96 97  | Next Page >

  • What are some good resources for creating a game engine in XNA?

    - by Glasser
    I'm currently a student game programmer working on an indie project. We have a team of eleven people (five programmers, four artists, and two audio designers) aboard, all working hard to help design this game. We've been meeting for months now and so far we have a pretty buffed out Game Design Document as well as much audio/visual concept art. Our programmers are itching to progress on our own end. Each person in our programming team is well versed in C++, but is very familiar with C#. We have enough experience and skill that we're confident that we will be successful with our game, and we're looking to build our own game engine in XNA as it seems like it would be worth our time and effort in the end. The game itself will be a 2D beat 'em up style game to be released over xbox live and the PC. It's play style will be similar to that of Castle Crashers or Scott Pilgrim vs The World. We want to design the game engine to allow us to better implement our assets into the game as well as to simplify the creation of design elements/mechanics. Currently between our programmers, we have books such as "XNA 4.0" and "Game Coding Complete, Third Edition," but we'd still like more information on both XNA and (especially) building a game engine from scratch. What are any other good books, websites, or resources we could use to further map out and program our game engine?

    Read the article

  • Can too much abstraction be bad?

    - by m3th0dman
    As programmers I feel that our goal is to provide good abstractions on the given domain model and business logic. But where should this abstraction stop? How to make the trade-off between abstraction and all it's benefits (flexibility, ease of changing etc.) and ease of understanding the code and all it's benefits. I believe I tend to write code overly abstracted and I don't know how good is it; I often tend to write it like it is some kind of a micro-framework, which consists of two parts: Micro-Modules which are hooked up in the micro-framework: these modules are easy to be understood, developed and maintained as single units. This code basically represents the code that actually does the functional stuff, described in requirements. Connecting code; now here I believe stands the problem. This code tends to be complicated because it is sometimes very abstracted and is hard to be understood at the beginning; this arises due to the fact that it is only pure abstraction, the base in reality and business logic being performed in the code presented 1; from this reason this code is not expected to be changed once tested. Is this a good approach at programming? That it, having changing code very fragmented in many modules and very easy to be understood and non-changing code very complex from the abstraction POV? Should all the code be uniformly complex (that is code 1 more complex and interlinked and code 2 more simple) so that anybody looking through it can understand it in a reasonable amount of time but change is expensive or the solution presented above is good, where "changing code" is very easy to be understood, debugged, changed and "linking code" is kind of difficult. Note: this is not about code readability! Both code at 1 and 2 is readable, but code at 2 comes with more complex abstractions while code 1 comes with simple abstractions.

    Read the article

  • Breaking up classes and methods into smaller units

    - by micahhoover
    During code reviews a couple devs have recommended I break up my methods into smaller methods. Their justification was (1) increased readability and (2) the back trace that comes back from production showing the method name is more specific to the line of code that failed. There may have also been some colorful words about functional programming. Additionally I think I may have failed an interview a while back because I didn't give an acceptable answer about when to break things up. My inclination is that when I see a bunch of methods in a class or across a bunch of files, it isn't clear to me how they flow together, and how many times each one gets called. I don't really have a good feel for the linearity of it as quickly just by eye-balling it. The other thing is a lot of people seem to place a premium of organization over content (e.g. 'Look at how organized my sock drawer is!' Me: 'Overall, I think I can get to my socks faster if you count the time it took to organize them'). Our business requirements are not very stable. I'm afraid that if the classes/methods are very granular it will take longer to refactor to requirement changes. I'm not sure how much of a factor this should be. Anyway, computer science is part art / part science, but I'm not sure how much this applies to this issue.

    Read the article

  • Have there been attempts to make object containers that search for valid programs by auto wiring compatible components?

    - by Aaron Anodide
    I hope this post isn't too "Fringe" - I'm sure someone will just kill it if it is :) Three things made me want to reach out about this now: Decoupling is so in the forefront of design. TDD inspires the idea that it doesn't matter how a program comes to exist as long as it works. Seeing how often the adapter pattern is applied to achieve (1). I'm almost sure this has been tried from a memory of reading about it around the year 2000 or so. If I had to guess, it was maybe about and earlier version of the Java Spring framework. At this time we were not so far from days when the belief was that computer programs could exhibit useful emergent behavior. I think the article said it didn't work, but it didn't say it was impossible. I wonder if since then it has been deemed impossible or simply an illusion due to a false assumption of similarity between a brain and a CPU. I know this illusion existed because I had an internship in 1996 where I programmed neural nets that were supposedly going to exhibit "brain damage". STILL, after all that, I'm sitting around this morning and not able to shake the idea that it should be possible to have a method of programming to allow autonomous components to find each other, attempt to collaborate and their outputs evaluated against a set desired results.

    Read the article

  • What's the right/standard way of achieving separation of concerns?

    - by Ghanima
    Some background: I want to start developing games, and taking some of the advice given in this site, I've started with something simple and familiar, such as pong, tetris, etc. I want to take as much time as needed to make sure that I have the basics right before moving on to something bigger. I have medium programming experience but I realize making games is a different thing. I find myself wondering many things like should this be in a separate class? Should this module handle this stuff or is it better to let other modules have that kind of functionality? For example, the bouncing of a ball in pong, right now is handled in the ball module, but maybe it's better that some other module did it. Right now I have different modules: one for the graphics, one for the game logic, and others for the objects (depending on the kind of movement required, not all the objects are alike). I know I am asking a lot, any tips you have will be very much appreciated. Short question: What's the right or standard way of separating the modules? What have you found most effective? Is it enough to just keep the drawing (graphics) and the logic separate? Is it necessary to have a lot of classes? (for example for the objects in the game, to handle the movement, etc)

    Read the article

  • is wisdom of what happens 'behind scenes' (in compiler, external DLLs etc.) important?

    - by I_Question_Things_Deeply
    I have been a computer-fanatic for almost a decade now. I've always loved and wondered how computers work, even from the purest, lowest hardware level to the very smallest pixel on the screen, and all the software around that. That seems to be my problem though ... as I try to write code (I'm pretty fluent at C++) I always sit there enormous amounts of time in front of a text-editor wondering how every line, statement, datum, function, etc. will correspond to every Assembly and machine instruction performed to do absolutely everything necessary for the kernel to allocate memory to run my compiled program, and all of the other hardware being used as well. For example ... I would write cout << "Before memory changed" << endl; and run the debugger to get the Assembly for this, and then try and reverse disassemble the Assembly to machine code based on my ISA, and then research every .dll, library file, linked library, linking process, linker source code of the program, the make file, the kernel I'm using's steps of processing this compilation, the hardware's part aside from the processor (e.g. video card, sound card, chipset, cache latency, byte-sized registers, calling convention use, DDR3 RAM and disk drive, filesystem functioning and so many other things). Am I going about programming wrong? I mean I feel I should know everything that goes on underneath English syntax on a computer program. But the problem is that the more I research every little thing the less I actually accomplish at all. I can never finish anything because of this mentality, yet I feel compelled to know everything... what should I do?

    Read the article

  • What language available on commodity web hosts would suit a C# developer? [closed]

    - by billpg
    Recognising its ubiquity on commodity web hosting services, I tried developing in PHP a few years ago. I really didn't like it, later deciding that life was too short for PHP. (In brief, having to put $ on variable names; mis-spelt variable names become new variables; converting non-numeric strings to integers without complaint; the need for an "and this time I mean it" comparison operator.) In my ideal world, commodity web hosts would all support C#/ASP.NET, my preferred web-development language and framework, but this is not my ideal world. Even Mono has barely made a dent on Linux based hosts. However, last time I moaned about PHP's ubiquity, someone followed up that this was no longer the case, and that many other languages are now commonly usable on web hosts too. What programming language; a. Would suit a developer who prefers C#. b. Is available to run on many web hosts.

    Read the article

  • What is the best objective way to measure language popularity trends? (What's better than TIOBE?)

    - by Eric Wilson
    The best way to get data on computer language popularity that I know is the TIOBE index. But everyone knows that TIOBE is hopelessly flawed. (If someone provides a link to support this, I'll add it here.) So is there any data on programming language popularity that is generally considered meaningful? The only other option I know is to look at the trends at indeed.com, which is inherently flawed, being based on job postings. It isn't like I would make a future language decision solely based on an index, but it might provide a useful balance to the skewed perspective one obtains by talking to ones friends and colleagues. To illustrate that bias, I'll point out that based on the experience of those I personally know, the only languages used professionally today (in order of popularity) are Java, C#, Groovy, JavaScript, Ruby, Objective C, and Perl. (Though it is evident that C, C++ and PHP were used in the past.) So my question is, everyone bashes TIOBE, but is there anything else? If so, can anyone explain how we know the alternative has better methodology? Thanks.

    Read the article

  • Classes as a compilation unit

    - by Yannbane
    If "compilation unit" is unclear, please refer to this. However, what I mean by it will be clear from the context. Edit: my language allows for multiple inheritance, unlike Java. I've started designing+developing my own programming language for educational, recreational, and potentially useful purposes. At first, I've decided to base it off Java. This implied that I would have all the code be written inside classes, and that code compiles to classes, which are loaded by the VM. However, I've excluded features such as interfaces and abstract classes, because I found no need for them. They seemed to be enforcing a paradigm, and I'd like my language not to do that. I wanted to keep the classes as the compilation unit though, because it seemed convenient to implement, familiar, and I just liked the idea. Then I noticed that I'm basically left with a glorified module system, where classes could be used either as "namespaces", providing constants and functions using the static directive, or as templates for objects that need to be instantiated ("actual" purpose of classes in other languages). Now I'm left wondering: what are the benefits of having classes as compilation units? (Also, any general commentary on my design would be much appreciated.)

    Read the article

  • Using foldr to append two lists together (Haskell)

    - by Luke Murphy
    I have been given the following question as part of a college assignment. Due to the module being very short, we are using only a subset of Haskell, without any of the syntactic sugar or idiomatic shortcuts....I must write: append xs ys : The list formed by joining the lists xs and ys, in that order append (5:8:3:[]) (4:7:[]) => 5:8:3:4:7:[] I understand the concept of how foldr works, but I am only starting off in Functional programming. I managed to write the following working solution (hidden for the benefit of others in my class...) : However, I just can't for the life of me, explain what the hell is going on!? I wrote it by just fiddling around in the interpreter, for example, the following line : foldr (\x -> \y -> x:y) [] (2:3:4:[]) which returned [2:3:4] , which led me to try, foldr (\x -> \y -> x:y) (2:3:4:[]) (5:6:7:[]) which returned [5,6,7,2,3,4] so I worked it out from there. I came to the correct solution through guess work and a bit of luck... I am working from the following definition of foldr: foldr = \f -> \s -> \xs -> if null xs then s else f (head xs) (foldr f s (tail xs) ) Can someone baby step me through my correct solution? I can't seem to get it....I already have scoured the web, and also read a bunch of SE threads, such as How foldr works

    Read the article

  • Should I be concerned that I can't program very fast without Google? [closed]

    - by seth
    Possible Duplicate: Google is good or bad for programmer? I'm currently in college to be a software engineer, and one of the main principles taught to us is how to learn for ourselves, and how to search the web when we have a doubt. This leads to a proactive attitude - when I need something, I go get it. Recently, I started wondering how much development would I be able to do without internet access and the answer bugged me quite a bit. I know the concept of the languages and how to use them, but I was amazed by how "slow" things were without having the Google to help in the development. Most of the problems I have are related to specific syntax. For example, reading and writing to a file in Java. I have done this about a dozen times in my life, yet every time I need to do it, I end up googling "read file java" and refreshing my memory. I completely understand the code and fully understand what it does, but I am sure that without Google it would take me a few tries to get the code correct. Is this normal? Should I be worried and try to change something in my programming behaviour?

    Read the article

  • batch: comparing filenames and renaming [migrated]

    - by user2978770
    i'm new to both this platform and batch programming and i'm slowly but steadily driving crazy :-( I'm studying in Germany and just started on a bigger project that mainly consists of analyzing data and finding algorithms in order to maintain a certain function of a system. In order to get started i got a bunch of recorded data that, unfortunately, is not consistent when i comes to naming. Normally all files (all in one folder) should start with SPY.SPYNODE.SIDE and then go on with the specific names for each values or variables. However, the data logger messed it up a couple of times and gives weird names like SP0E1A~1.csv (all files are .csv-files). An that's when i figured in stead of renaming a couple of thousand files manually i could "easily" use a simple batch file to do that job for name. And that's exactly when I started to go crazy :-) So far i came up with the following: FOR /R %%i in (%CD%) DO ( set file1=%%i if not %file1%=="SPY.SPYNODE.SIDE" DO ( set /p "filename" < %file1% rename %file1% %filename% ) ) So what i want it to do is this (in pseudo) look through the whole folder and every file save the filename in variable file1 if file1 partially equals SPY.SPYNODE.SIDE open the file and save the first line (which contains the correct name of the file) in variable filename rename the file with the correct filename But so far it doesn't really work and i don't know why. Could anybody give me a hint or some advice how i should proceed? I really appreciate any kind of help!

    Read the article

  • What is the most concise, unambiguous syntax for operator associated methods (for overloading etc.) that doesn't pollute the namespace?

    - by Doug Treadwell
    Python tends to add double underscores before its built-in or overloadable operator methods, like __add(), whereas C++ requires declaring overloaded operators as operator + (Thing& thing) { /* code */ } for example. Personally I like the operator syntax because it seems to be more explicit and keeps these operator overloading methods separated from other methods without introducing weird prefix notation. What are your thoughts? Also, what about the case of built-in methods that are needed for the programming language to work properly? Is name mangling (like adding __ prefix or sys or something) the best solution here? What do you think about having another type of method declaration, like ... "system method" for lack of creativity at the moment. So there would be two kinds of declarations: int method_name() { ... } system int method_name() { ... } ... and the call would need to be different to distinguish between them. obj.method_name(); vs obj:method_name(); perhaps, assuming a language where : can be unambiguously used in this situation. obj.method_name() vs obj.(system method_name)() Sure, the latter is ugly, but the idea is to make the common case simple and system stuff should be kept out of the way. Maybe the Objective-C notation of method calls? [obj method_name]? Are there more alternatives? Please make suggestions.

    Read the article

  • I need a decent alternative to c++ [closed]

    - by wxiiir
    I've learned php and c++, i will list the things i liked and didn't liked on each of them, how i decided to learn them in the first place and why i feel the need to learn a decent alternative to c++, i'm not a professional programmer and only do projects for myself. PHP - Decided to learn because i wanted to build a dynamic website, that i did and turned out very good, i even coded a 'not so basic' search engine for it that would display the results 'google style' and really fast, pretty cool stuff. PROS - Pretty consistent syntax for all stuff (minor caveats), great functionality, a joy for me to code in it (it seems to 'know' what i want it to do and just does it) CONS - Painfully slow for number crunching (which takes me to c++ that i only learned because i wanted to do some number crunching and it had to be screaming fast) C++ - Learned because number crunching was so slow in php and manipulating large amounts of data was very difficult, i thought, it's popular programming language and all, and tests show that it's fast, the basic stuff resemble php so it shouldn't be hard to pick up PROS - It can be used to virtually anything, very very fast CONS - Although fun to code at the start, if i need to do something out of the ordinary, memory allocation routines, pointer stuff, stack sizes etc... will get me tired really quick, syntax is a bit inconsistent some times (more caveats) I guess that from what i wrote you guys will understand what i'm looking for, there are thousands of languages out there, it's likely that one of them will suit my needs, i've been seeing stuff today and a friend of mine that is a professional programmer tried OCaml and Fortran and said that both are fast for numerical stuff, i've been inclined to test Fortran, but i need some more input because i want to have some other good 'candidates' to choose from, for example the python syntax seemed great to me, but then i found out from some tests that it was a lot slower than c++ and i simply don't want to twiddle my thumbs all day.

    Read the article

  • Is there a website that scrapes job postings to determine the popularity of web technologies? [closed]

    - by dB'
    I'm often in a position where I need to choose between a number of web technologies. These technologies might be programming languages, or web application frameworks, or types of databases, or some other kind of toolkit used by programmers. More often than not, after some doing research, I end up with a list of contenders that are all equally viable. They're all powerful enough to solve my problem, they're all popular and well supported, and they're all equally familiar/unfamiliar to me. There's no obvious rationale by which to choose between them. Still, I need to pick one, so at this point I usually ask myself a hypothetical question: which one of these technologies, if I invest in learning it, would be most helpful to me in a job search? Where can I go on the internet to answer this question? Is there a website/service that scrapes the texts of worldwide job postings and would allow me to compare, say, the number of employers looking for expertise in technology x vs. technology y? (Where x and y are Rails vs. Djando, Java vs. Python, Brainfuck vs. LOLCode, etc.)

    Read the article

  • Are my negative internship experiences representative of the real world? [closed]

    - by attemptAtAnonymity
    I'm curious if my current experiences as an intern are representative of actual industry. As background, I'm through the better part of two computing majors and a math major at a major university; I've aced every class and adored all of them, so I'd like to think that I'm not terrible at programming. I got an internship with one of the major software companies, and half way through now I've been shocked at the extraordinarily low quality of code. Comments don't exist, it's all spaghetti code, and everything that could be wrong is even worse. I've done a ton of tutoring/TAing, so I'm very used to reading bad code, but the major industry products I've been seeing trump all of that. I work 10-12 hours a day and never feel like I'm getting anywhere, because it's endless hours of trying to figure out an undocumented API or determine the behavior of some other part of the (completely undocumented) product. I've left work hating the job every day so far, and I desperately want to know if this is what is in store for the rest of my life. Did I draw a short straw on internships (the absurdly large paychecks imply that it's not a low quality position), or is this what the real world is like?

    Read the article

  • Requiring a specific order of compilaiton

    - by Aber Kled
    When designing a compiled programming language, is it a bad idea to require a specific order of compilation of separate units, according to their dependencies? To illustrate what I mean, consider C. C is the opposite of what I'm suggesting. There are multiple .c files, that can all depend on each other, but all of these separate units can be compiled on their own, in no particular order - only to be linked together into a final executable later. This is mostly due to header files. They enable separate units to share information with each other, and thus the units are able to be compiled independently. If a language were to dispose of header files, and only keep source and object files, then the only option would be to actually include the unit's meta-information in the unit's object file. However, this would mean that if the unit A depends on the unit B, then the unit B would need to be compiled before unit A, so unit A could "import" the unit B's object file, thus obtaining the information required for its compilation. Am I missing something here? Is this really the only way to go about removing header files in compiled languages?

    Read the article

  • Are my negative internship experiences respresentative of the real world?

    - by attemptAtAnonymity
    I'm curious if my current experiences as an intern are representative of actual industry. As background, I'm through the better part of two computing majors and a math major at a major university; I've aced every class and adored all of them, so I'd like to think that I'm not terrible at programming. I got an internship with one of the major software companies, and half way through now I've been shocked at the extraordinarily low quality of code. Comments don't exist, it's all spaghetti code, and everything that could be wrong is even worse. I've done a ton of tutoring/TAing, so I'm very used to reading bad code, but the major industry products I've been seeing trump all of that. I work 10-12 hours a day and never feel like I'm getting anywhere, because it's endless hours of trying to figure out an undocumented API or determine the behavior of some other part of the (completely undocumented) product. I've left work hating the job every day so far, and I desperately want to know if this is what is in store for the rest of my life. Did I draw a short straw on internships (the absurdly large paychecks imply that it's not a low quality position), or is this what the real world is like?

    Read the article

  • I was stuck in implementing Simple Ftp with Winsock [migrated]

    - by user67449
    I want to implement a SimpleFtp with Winsock. But I was stuck in the maybe the file stream reading and writing. This is the Server. #include <WinSock2.h> #include <memory.h> #include <stdio.h> #include <iostream> using namespace std; #pragma comment(lib, "ws2_32.lib") #define MAX_FILE_NAME 100 #define DATA_PACK_SIZE 80*1000 // ??DataPack?????80KB #define SOCKKET_BUFFER_SIZE 80*1000 // socket??? #define FILE_BUFFER_SIZE DATA_PACK_SIZE-MAX_FILE_NAME-4*sizeof(int)-sizeof(u_long) //?????,??,??????content????? #define CONTENT_SIZE FILE_BUFFER_SIZE // DataPack?????content??? // Define a structure to hold the content of a file typedef struct FilePack{ char fName[MAX_FILE_NAME]; // File's name int fLen; // File's length int packNum; // Number of the DataPack int packLen; // DataPack's length int packCount; int contenLen; // the content length the DataPack actually holds u_long index; // ?????????? char content[CONTENT_SIZE]; // DataPack?????? }DataPack, *pDataPack; void WinsockInitial(){ WSADATA wsaData; WORD wVersionRequested; int err; wVersionRequested=MAKEWORD(2,2); err=WSAStartup(wVersionRequested, &wsaData); if(err!=0){ cout<<"Error at WSAStartup()."<<endl; exit(0); } if( LOBYTE(wsaData.wVersion)!=2 || HIBYTE(wsaData.wVersion)!=2 ){ cout<<"Error at version of Winsock. "<<endl; WSACleanup(); exit(0); } } void SockBind(SOCKET sock, int port, sockaddr_in &addrsock){ addrsock.sin_family=AF_INET; addrsock.sin_port=htons(port); addrsock.sin_addr.S_un.S_addr=htonl(INADDR_ANY); if( bind(sock, (sockaddr*)&addrsock, sizeof(addrsock)) == SOCKET_ERROR ){ cout<<"Error at bind(). Error: "<<GetLastError()<<endl; closesocket(sock); WSACleanup(); exit(0); } } void SockListen(SOCKET sock, int bak){ int err=listen(sock, bak); if(err==SOCKET_ERROR){ cout<<"Error at listen()."<<WSAGetLastError()<<endl; closesocket(sock); WSACleanup(); exit(0); } } int SockSend(DataPack &dataPack, SOCKET sock, char *sockBuf){ int bytesLeft=0, bytesSend=0; int idx=0; bytesLeft=sizeof(dataPack); // ?DataPack?????sockBuf??? memcpy(sockBuf, &dataPack, sizeof(dataPack)); while(bytesLeft>0){ bytesSend=send(sock, &sockBuf[idx], bytesLeft, 0); if(bytesSend==SOCKET_ERROR){ cout<<"Error at send()."<<endl; return 1; } bytesLeft-=bytesSend; idx+=bytesSend; } return 0; } int GetFileLen(FILE *fp){ // ?????? if(fp==NULL){ cout<<"Invalid argument. Error at GetFileLen()."<<endl; exit(0); } fseek(fp, 0, SEEK_END); int tempFileLen=ftell(fp); fseek(fp, 0, SEEK_SET); return tempFileLen; } int main(){ int err; sockaddr_in addrServ; int port=8000; // Initialize Winsock WinsockInitial(); // Create a socket SOCKET sockListen=socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); if(sockListen==INVALID_SOCKET){ cout<<"Error at socket()."<<endl; WSACleanup(); return 1; } // Bind the socket. SockBind(sockListen, port, addrServ); // Listen for incoming connection requests cout<<"Waiting for incoming connection requests..."<<endl; SockListen(sockListen, 5); // Accept the connection request. sockaddr_in addrClient; int len=sizeof(addrClient); SOCKET sockConn=accept(sockListen, (sockaddr*)&addrClient, &len); if(sockConn!=INVALID_SOCKET){ cout<<"Connected to client successfully."<<endl; } // Set the buffer size of socket char sockBuf[SOCKKET_BUFFER_SIZE]; int nBuf=SOCKKET_BUFFER_SIZE; int nBufLen=sizeof(nBuf); err=setsockopt(sockConn, SOL_SOCKET, SO_SNDBUF, (char*)&nBuf, nBufLen); if(err!=0){ cout<<"Error at setsockopt(). Failed to set buffer size for socket."<<endl; exit(0); } //??????????? err = getsockopt(sockConn, SOL_SOCKET, SO_SNDBUF, (char*)&nBuf, &nBufLen); if( SOCKKET_BUFFER_SIZE != nBuf){ cout<<"Error at setsockopt(). ?socket????????"<<endl; closesocket(sockListen); closesocket(sockConn); WSACleanup(); exit(0); } //------------------------------------------------------------------------// DataPack dataPackSend; memset(&dataPackSend, 0, sizeof(dataPackSend)); int bytesRead; int bytesLeft; int bytesSend; int packCount; // Counts how many DataPack needed FILE *frp; // Used to read if(strcpy_s(dataPackSend.fName, "music.mp3")!=0){ cout<<"Error at strcpy_s()."<<endl; return 1; } // Open the file in read+binary mode err=fopen_s(&frp, dataPackSend.fName, "rb"); if(err!=0){ cout<<"Error at fopen_s()."<<endl; return 1; } char fileBuf[FILE_BUFFER_SIZE]; // Set the buffer size of File if(setvbuf(frp, fileBuf, _IONBF, FILE_BUFFER_SIZE)!=0){ cout<<"Error at setvbuf().Failed to set buffer size for file."<<endl; closesocket(sockListen); closesocket(sockConn); WSACleanup(); exit(0); } // Get file's length int fileLen=GetFileLen(frp); cout<<"File ???:"<<fileLen<<" bytes."<<endl; // Calculate how many DataPacks needed packCount=ceil( (double)fileLen/CONTENT_SIZE ); cout<<"File Length: "<<fileLen<<" "<<"Content Size: "<<CONTENT_SIZE<<endl; cout<<"???"<<packCount<<" ?DataPack"<<endl; int i=0; for(i=0; i<packCount; i++){ //?????dataPackSend????? memset(&dataPackSend, 0, sizeof(dataPackSend)); // Fill the dataPackSend if(strcpy_s(dataPackSend.fName, "abc.txt")!=0){ cout<<"Error at strcpy_s()."<<endl; return 1; } dataPackSend.packLen=DATA_PACK_SIZE; dataPackSend.fLen=fileLen; dataPackSend.packCount=packCount; if( packCount==1 ){ //??DataPack??? bytesRead=fread(fileBuf, 1, dataPackSend.fLen, frp); dataPackSend.contenLen=dataPackSend.fLen; memcpy(dataPackSend.content, fileBuf, bytesRead); dataPackSend.packNum=0; //???????DataPack // ?????dataPackSend?Client? if( SockSend(dataPackSend, sockConn, sockBuf)==0 ){ cout<<"??? "<<dataPackSend.packNum<<" ?DataPack"<<endl; } }else if( packCount>1 && i<(packCount-1) ){ // ???(???????) bytesRead=fread(fileBuf, 1, CONTENT_SIZE, frp); dataPackSend.contenLen=CONTENT_SIZE; memcpy(dataPackSend.content, fileBuf, bytesRead); dataPackSend.packNum=i; //?dataPackSend??????Client? if( SockSend(dataPackSend, sockConn, sockBuf)==0 ){ cout<<"??? "<<dataPackSend.packNum<<" ?DataPack."<<endl; } }else{ // ????? bytesRead=fread(fileBuf, 1, (dataPackSend.fLen-i*CONTENT_SIZE), frp); dataPackSend.contenLen=dataPackSend.fLen-i*CONTENT_SIZE; memcpy(dataPackSend.content, fileBuf, bytesRead); dataPackSend.packNum=i; //?dataPackSend???Client? if( SockSend(dataPackSend, sockConn, sockBuf)==0 ){ cout<<"??? "<<dataPackSend.packNum<<" ?DataPack."<<endl; } } } fclose(frp); closesocket(sockListen); closesocket(sockConn); WSACleanup(); return 0; } And this is Client. #include <WinSock2.h> #include <memory.h> #include <stdio.h> #include <iostream> using namespace std; #pragma comment(lib, "ws2_32.lib") #define MAX_FILE_NAME 100 #define DATA_PACK_SIZE 80*1000 // ??DataPack?????80KB #define SOCKKET_BUFFER_SIZE 80*1000 // socket??? #define FILE_BUFFER_SIZE DATA_PACK_SIZE-MAX_FILE_NAME-4*sizeof(int)-sizeof(u_long) //?????,??,??????content????? #define CONTENT_SIZE FILE_BUFFER_SIZE // DataPack?????content??? // Define a structure to hold the content of a file typedef struct FilePack{ char fName[MAX_FILE_NAME]; // File's name int fLen; // File's length int packNum; // Number of the DataPack int packLen; // DataPack's length int packCount; //DataPack??? int contenLen; // the content length the DataPack actually holds u_long index; // ?????????? char content[CONTENT_SIZE]; // DataPack?????? }DataPack, *pDataPack; void WinsockInitial(){ WSADATA wsaData; WORD wVersionRequested; int err; wVersionRequested=MAKEWORD(2,2); err=WSAStartup(wVersionRequested, &wsaData); if(err!=0){ cout<<"Error at WSAStartup()."<<endl; exit(0); } if( LOBYTE(wsaData.wVersion)!=2 || HIBYTE(wsaData.wVersion)!=2 ){ cout<<"Error at version of Winsock. "<<endl; WSACleanup(); exit(0); } } int SockRecv(SOCKET sock, char *sockBuf){ int bytesLeft, bytesRecv; int idx=0; bytesLeft=DATA_PACK_SIZE; while(bytesLeft>0){ bytesRecv=recv(sock, &sockBuf[idx], bytesLeft, 0); if(bytesRecv==SOCKET_ERROR){ cout<<"Error at recv()."<<endl; return 1; } bytesLeft-=bytesRecv; idx+=bytesRecv; } return 0; } int main(){ int err; sockaddr_in addrServ; int port=8000; // Initialize Winsock WinsockInitial(); // Create a socket SOCKET sockClient=socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); if(sockClient==INVALID_SOCKET){ cout<<"Error at socket()."<<endl; WSACleanup(); return 1; } // Set the buffer size of socket char sockBuf[SOCKKET_BUFFER_SIZE]; int nBuf=SOCKKET_BUFFER_SIZE; int nBufLen=sizeof(nBuf); err=setsockopt(sockClient, SOL_SOCKET, SO_RCVBUF, (char*)&nBuf, nBufLen); if(err!=0){ cout<<"Error at setsockopt(). Failed to set buffer size for socket."<<endl; exit(0); } //??????????? err = getsockopt(sockClient, SOL_SOCKET, SO_RCVBUF, (char*)&nBuf, &nBufLen); if( SOCKKET_BUFFER_SIZE != nBuf){ cout<<"Error at getsockopt(). ?socket????????"<<endl; closesocket(sockClient); WSACleanup(); exit(0); } // Connect to the Server addrServ.sin_family=AF_INET; addrServ.sin_port=htons(port); addrServ.sin_addr.S_un.S_addr=inet_addr("127.0.0.1"); err=connect(sockClient, (sockaddr*)&addrServ, sizeof(sockaddr)); if(err==SOCKET_ERROR){ cout<<"Error at connect()."<<GetLastError()<<endl; closesocket(sockClient); WSACleanup(); return 1; }else{ cout<<"Connected to the FTP Server successfully."<<endl; } /* int i=0; int bytesRecv, bytesLeft, bytesWrite; int packCount=0, fLen=0; DataPack dataPackRecv; //?????? SockRecv(sockClient, sockBuf); memcpy(&dataPackRecv, sockBuf, sizeof(dataPackRecv)); cout<<"???? "<<dataPackRecv.packNum<<" ?DataPack."<<endl; cout<<"?DataPack??fName????: "<<dataPackRecv.fName<<endl; //??????? packCount=dataPackRecv.packCount; cout<<"?? "<<packCount<<" ?DataPack."<<endl; fLen=dataPackRecv.fLen; // Create a local file to write into FILE *fwp; err=fopen_s(&fwp, dataPackRecv.fName, "wb"); if(err!=0){ cout<<"Error at creat fopen_s(). Failed to create a local file to write into."<<endl; return 1; } // Set the buffer size of File char fileBuf[FILE_BUFFER_SIZE]; if(setvbuf(fwp, fileBuf, _IONBF, FILE_BUFFER_SIZE)!=0){ cout<<"Error at setvbuf().Failed to set buffer size for file."<<endl; memset(fileBuf, 0, sizeof(fileBuf)); closesocket(sockClient); WSACleanup(); exit(0); } //???????content???? memcpy(fileBuf, dataPackRecv.content, sizeof(dataPackRecv.content)); bytesWrite=fwrite(fileBuf, 1, sizeof(fileBuf), fwp); if(bytesWrite<sizeof(fileBuf)){ cout<<"Error at fwrite(). Failed to write the content of dataPackRecv to local file."<<endl; } //?????packCount-1????????????????? for(int i=1; i<packCount; i++){ // ????????? memset(sockBuf, 0, sizeof(sockBuf)); memset(&dataPackRecv, 0, sizeof(dataPackRecv)); memset(fileBuf, 0, sizeof(fileBuf)); SockRecv(sockClient, sockBuf); memcpy(&dataPackRecv, sockBuf, sizeof(dataPackRecv)); cout<<"???? "<<dataPackRecv.packNum<<" ?DataPack."<<endl; //???? memcpy(fileBuf, dataPackRecv.content, dataPackRecv.contenLen); bytesWrite=fwrite(fileBuf, 1, dataPackRecv.contenLen, fwp); if(bytesWrite<dataPackRecv.contenLen){ cout<<"Error at fwrite(). Failed to write the content of dataPackRecv to local file."<<endl; } } if( (i+1)==packCount ){ cout<<"??DataPack????????!"<<endl; } fclose(fwp); closesocket(sockClient); WSACleanup(); return 0;*/ }

    Read the article

  • BindException with INTERNET permission requested

    - by Mondain
    I have seen several questions regarding SocketException when using Android, but none of them cover the BindException that I get even with the INTERNET permission specified in my manifest. Here is part of my manifest: <uses-permission android:name="android.permission.INTERNET"></uses-permission> <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"></uses-permission> <uses-permission android:name="android.permission.ACCESS_WIFI_STATE"></uses-permission> <uses-permission android:name="android.permission.READ_OWNER_DATA"></uses-permission> <uses-permission android:name="android.permission.READ_PHONE_STATE"></uses-permission> <uses-permission android:name="android.permission.ACCOUNT_MANAGER"></uses-permission> <uses-permission android:name="android.permission.AUTHENTICATE_ACCOUNTS"></uses-permission> Here is the relevant portion of my LogCat output: 04-22 14:49:06.117: DEBUG/MyLibrary(4844): Address to bind: 192.168.1.14 port: 843 04-22 14:49:06.197: WARN/System.err(4844): java.net.BindException: Permission denied (maybe missing INTERNET permission) 04-22 14:49:06.207: WARN/System.err(4844): at org.apache.harmony.luni.platform.OSNetworkSystem.socketBindImpl(Native Method) 04-22 14:49:06.207: WARN/System.err(4844): at org.apache.harmony.luni.platform.OSNetworkSystem.bind(OSNetworkSystem.java:107) 04-22 14:49:06.217: WARN/System.err(4844): at org.apache.harmony.luni.net.PlainSocketImpl.bind(PlainSocketImpl.java:184) 04-22 14:49:06.217: WARN/System.err(4844): at java.net.ServerSocket.bind(ServerSocket.java:414) 04-22 14:49:06.227: WARN/System.err(4844): at org.apache.harmony.nio.internal.ServerSocketChannelImpl$ServerSocketAdapter.bind(ServerSocketChannelImpl.java:213) 04-22 14:49:06.227: WARN/System.err(4844): at java.net.ServerSocket.bind(ServerSocket.java:367) 04-22 14:49:06.237: WARN/System.err(4844): at org.apache.harmony.nio.internal.ServerSocketChannelImpl$ServerSocketAdapter.bind(ServerSocketChannelImpl.java:283) 04-22 14:49:06.237: WARN/System.err(4844): at mylibrary.net.PolicyConnection$PolicyServerWorker.(PolicyConnection.java:201) I Really hope this is a simple problem and not something complicated by the fact that the binding is occurring within a worker thread on a port less than 1024. Update Looks as if this is a privileged port issue, anyone know how to bind to ports lower than 1024 in Android? SelectorProvider provider = SelectorProvider.provider(); try { ServerSocketChannel channel = provider.openServerSocketChannel(); policySocket = channel.socket(); Log.d("MyLibrary", "Address to bind: " + device.getAddress().getAddress() + " port: 843"); InetSocketAddress addr = new InetSocketAddress(InetAddress.getByName(device.getAddress().getAddress()), 843); policySocket.bind(addr); policySocket.setReuseAddress(true); policySocket.setReceiveBufferSize(256); } catch (Exception e) { e.printStackTrace(); }

    Read the article

  • Sockets receiving null (Android)

    - by Henrik
    I have a android app that is communicating with a server (written in java). Between these two parts I have established a Socket connection and want to send data. The problem I am having is that sometimes, for some users, the information that reaches the server is null. This works (for all phones, all users): Server: int a = Integer.parseInt(in.readLine()); int b = Integer.parseInt(in.readLine()); int c = Integer.parseInt(in.readLine()); int d = Integer.parseInt(in.readLine()); String checksum = in.readLine(); String model = in.readLine(); String device = in.readLine(); String name = in.readLine(); Client: out.println(a); out.println(b); out.println(c); out.println(d); out.println(hash); out.println(Build.MODEL); out.println(Build.DEVICE); String name = fixName(); out.print(name); out.flush(); This does not work (for some users): Server: int a = Integer.parseInt(in.readLine()); String checksum = in.readLine(); String model = in.readLine(); String device = in.readLine(); String name = in.readLine(); String msg = in.readLine(); int version = -1; String test = "hej"; try{ test = in.readLine(); version = Integer.parseInt(test); }catch(Exception e){ e.printStackTrace(); } Client: out.println(a); out.println(hash); out.println(Build.MODEL); out.println(Build.DEVICE); String name = fixName(); if(name == null) name = "John Doe"; out.println(name); String msg = fixMsg(); if(msg == null) name = "nada"; out.println(msg); out.println(curversion); out.flush(); Sometimes, in the second case, the name, msg, and version (the string test) are null at the server side. The catch is triggered because test is null. curversion,a are ints, the rest are strings. Any ideas?

    Read the article

  • Udp server sending only 0 bytes of data

    - by mawia
    Hi all, This is a simple Udp server.I am trying to transmit data to some clients,but unfortunetly it is unable to transmit data.Though send is running quite successfully but it is returning with a return value meaning it has send nothing.On the client they are receiving but again obviously,zero bytes. void* UdpServerStreamToClients(void *fileToServe) { int sockfd,n=0,k; struct sockaddr_in servaddr,cliaddr; socklen_t len; char dataToSend[1000]; sockfd=socket(AF_INET,SOCK_DGRAM,0); bzero(&servaddr,sizeof(servaddr)); servaddr.sin_family = AF_INET; servaddr.sin_addr.s_addr=htonl(INADDR_ANY); servaddr.sin_port=htons(32000); bind(sockfd,(struct sockaddr *)&servaddr,sizeof(servaddr)); FILE *fp; if((fp=fopen((char*)fileToServe,"r"))==NULL) { printf("can not open file "); perror("fopen"); exit(1); } int dataRead=1; while(dataRead) { len = sizeof(cliaddr); if((dataRead=fread(dataToSend,1,500,fp))<0) { perror("fread"); exit(1); } //sleep(2); for(list<clientInfo>::iterator it=clients.begin();it!=clients.end();it++) { cliaddr.sin_family = AF_INET; inet_aton(inet_ntoa(it->addr.sin_addr),&cliaddr.sin_addr); cliaddr.sin_port = htons(it->udp_port); n=sendto(sockfd,dataToSend,sizeof(dataToSend),0,(struct sockaddr *)&cliaddr,len); cout<<"number of bytes send by udp: "<< n << endl; printf("SEND this message %d : %s to %s :%d \n",n,dataToSend,inet_ntoa(cliaddr.sin_addr), ntohs(cliaddr.sin_port)); } } } I am checking the value of sizeof(dataTosend) and it is pretty much as expected ie thousand ie the size of buffer. Are you people seeing some possible flaw in it. All of the help in this regard will be appreciated. Thanks!

    Read the article

  • How Would a Newborn Baby Learn Web Programming?

    - by Mugatu
    Hello all, I chose that title because I equate my knowledge of web programming and web development with that of a newborn. Here's the shortest version of my story and what I'm looking to do: A friend and I have been coming up with website ideas for a couple years, mostly just jotting them down whenever we come up with a good, useful idea when browsing the web. For the past 6 months we've hired a couple different programmers to make a couple of the sites for us, but have been disappointed with how it's gone. Been too slow and too many miscommunications for our liking. So like the saying goes if you want something done right do it yourself, we're going to do it ourselves. I know nothing about programming, I've never written a line of code in my life. I consider myself very good with math and about as logical as you can get, but I have zero real-life programming knowledge. The sites we want to make are all pretty 'Web 2.0'ish', meaning user-generated content, commenting on posts, pages that change on the fly, etc. So here are some of my questions for anyone who's been there before: Is there a language you'd recommend learning first? Something that is a good indicator how most other languages work? What web programming languages do you recommend learning first based on popularity both now and the future. I don't want to learn a language that's going to be outdated by the time I'm an expert at it. Any specific books you'd recommend? Any general advice you'd give to someone literally starting at square zero for coding who plans on being in it for the long haul? Thanks in advance for the help

    Read the article

  • How the reading from and writing to sockets are synchronized?

    - by Roman
    We create a socket. On one side of the socket we have a "server" and on another side there is a "client". Both, the server and client, can write to and read from the socket. It is what i understand. I do not understand the following things: If a server reads from the socket, does it see in the socket only those stuff which was written to the socket by the client? I mean if server writes something to the socket and than reads from the socket, will it (server) see in the socket the stuff it (server) wrote there? I hope not. Let's consider the following situation. A client write something to the socket and then it writes something new to the socket and then server reads from the socket. What will the server see there? Only the "new" stuff written by the client or both "new" and "old" one? If a client (or server) writes to the socket, can it see if the written information was received by other side? For example out.println("Hello, Server!") will return true it server received this message.

    Read the article

  • Round Table - Minimum Cost Algorithm

    - by 7Aces
    Problem Link - http://www.iarcs.org.in/zco2013/index.php/problems/ROUNDTABLE It's dinner time in Castle Camelot, and the fearsome Knights of the Round Table are clamouring for dessert. You, the chef, are in a soup. There are N knights, including King Arthur, each with a different preference for dessert, but you cannot afford to make desserts for all of them. You are given the cost of manufacturing each Knight's preferred dessert-since it is a round table, the list starts with the cost of King Arthur's dessert, and goes counter-clockwise. You decide to pick the cheapest desserts to make, such that for every pair of adjacent Knights, at least one gets his dessert. This will ensure that the Knights do not protest. What is the minimum cost of tonight's dinner, given this condition? I used the Dynamic Programming approach, considering the smallest of i-1 & i-2, & came up with the following code - #include<cstdio> #include<algorithm> using namespace std; int main() { int n,i,j,c,f; scanf("%d",&n); int k[n],m[n][2]; for(i=0;i<n;++i) scanf("%d",&k[i]); m[0][0]=k[0]; m[0][1]=0; m[1][0]=k[1]; m[1][1]=1; for(i=2;i<n;++i) { c=1000; for(j=i-2;j<i;++j) { if(m[j][0]<c) { c=m[j][0]; f=m[j][1];} } m[i][0]=c+k[i]; m[i][1]=f; } if(m[n-2][0]<m[n-1][0] && m[n-2][1]==0) printf("%d\n",m[n-2][0]); else printf("%d\n",m[n-1][0]); } I used the second dimension of the m array to store from which knight the given sequence started (1st or 2nd). I had to do this because of the case when m[n-2]<m[n-1] but the sequence started from knight 2, since that would create two adjacent knights without dessert. The problem arises because of the table's round shape. Now an anomaly arises when I consider the case - 2 1 1 2 1 2. The program gives an answer 5 when the answer should be 4, by picking the 1st, 3rd & 5th knight. At this point, I started to doubt my initial algorithm (approach) itself! Where did I go wrong?

    Read the article

< Previous Page | 86 87 88 89 90 91 92 93 94 95 96 97  | Next Page >