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  • How to make placeholder varablies in jquery validate 1.7?

    - by chobo2
    Hi I am using jquery 1.4.2 and jquery validate 1.7(http://bassistance.de/jquery-plugins/jquery-plugin-validation/) Say I have this example that I just grabbed off some random site(http://www.webreference.com/programming/javascript/jquery/form_validation/) 8 <script type="text/javascript"> 9 $(document).ready(function() { 10 $("#form1").validate({ 11 rules: { 12 name: "required",// simple rule, converted to {required:true} 13 email: {// compound rule 14 required: true, 15 email: true 16 }, 17 url: { 18 url: true 19 }, 20 comment: { 21 required: true 22 } 23 }, 24 messages: { 25 comment: "Please enter a comment." 26 } 27 }); 28 }); 29 </script> now is it possible to do something like this 10 $("#form1").validate({ var NameHolder = "name" 11 rules: { 12 NameHolder: "required",// simple rule, converted to {required:true} 13 email: {// compound rule 14 required: true, 15 email: true So basically I want to make sort of a global variable to hold theses rule names( what correspond to the names on that html control). My concern is the names of html controls can change and it kinda sucks that I will have to go around and change it in many places of my code to make it work again. So basically I am wondering is there away to make a global variable to store this name. So if I need to change the name I only have to change it in one spot in my javascript file sort of the way stopping magic numbers ?

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  • What is wrong with accessing DBI directly?

    - by canavanin
    Hi everyone! I'm currently reading Effective Perl Programming (2nd edition). I have come across a piece of code which was described as being poorly written, but I don't yet understand what's so bad about it, or how it should be improved. It would be great if someone could explain the matter to me. Here's the code in question: sub sum_values_per_key { my ( $class, $dsn, $user, $password, $parameters ) = @_; my %results; my $dbh = DBI->connect( $dsn, $user, $password, $parameters ); my $sth = $dbh->prepare( 'select key, calculate(value) from my_table'); $sth->execute(); # ... fill %results ... $sth->finish(); $dbh->disconnect(); return \%results; } The example comes from the chapter on testing your code (p. 324/325). The sentence that has left me wondering about how to improve the code is the following: Since the code was poorly written and accesses DBI directly, you'll have to create a fake DBI object to stand in for the real thing. I have probably not understood a lot of what the book has so far been trying to teach me, or I have skipped the section relevant for understanding what's bad practice about the above code... Well, thanks in advance for your help!

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  • Syntactical analysis with Flex/Bison part 2

    - by Imran
    Hallo, I need help in Lex/Yacc Programming. I wrote a compiler for a syntactical analysis for inputs of many statements. Now i have a special problem. In case of an Input the compiler gives the right output, which statement is uses, constant operator or a jmp instructor to which label, now i have to write so, if now a if statement comes, first the first command (before the else) must be give out when the assignment of the if is yes then it must jump to the end because the command after the else isnt needed, so after this jmp then the second command must be give out. I show it in an example maybe you understand what i mean. Input adr. Output if(x==0) 10 if(x==0) Wait 5 20 WAIT 5 else 30 JMP 50 Wait 1 40 WAIT 1 end 50 END like so. I have an idea, maybe i can do it whith a special if statement like IF exp jmp_stmt_end stmt_seq END when the if statement is given in the input the compiler has to recognize the end ofthe statement and like my jmp_stmt in my compiler ( you have to download the files from http://bitbucket.org/matrix/changed-tiny) only to jump to the end. I hope you understand my problem.thanks.

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  • How much memory I would need for something like this?

    - by Vdas Dorls
    If I create social portal similar to Twitter (not exactly twitter, but similar in my country), how much space would I need for images? I guess with 100 gb of disk space it won't be enough, so could you please give me some information how much I would exactly need? And is there any suggestions how should I add the profile images? Is there any tactics from programming side, when I could save some space uploading and hosting images for profile users? I guess, each time user changes images, it would be good to delete the previous image, correctly? In additional, how much disk space would be needed for 1000000 user profiles, if we have like 15 default images, and part of the users won't upload their own images, but use some of the default ones. So 3 questions - How much disk space I would need to hold a good social portal? Is there any suggested way to deal with pictures with PHP to save disk space? How much disk space would be needed for 1000000 user profile, if we have like 15 default images and part of the users won't upload their own, but instead use one of the 15 default images?

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  • Static code analysis for new language. Where to start?

    - by tinny
    I just been given a new assignment which looks like its going to be an interesting challenge. The customer is wanting a code style checking tool to be developed for their internal (soon to be open sourced) programming language which runs on the JVM. The language syntax is very Java like. The customer basically wants me to produce something like checkstyle. So my question is this, how would you approach this problem? Given a clean slate what recommendations would you make to the customer? I think I have 3 options Write something from scratch. Id prefer not to do this as it seems like this sort of code analysis tool problem has been solved so many times that there must be a more "framework" or "platform" orientated approach. Fork an existing code style checking tool and modify the parsing to fit with this new language etc etc Extend or plug into an existing static code analysis tool. (maybe write a plugin for Yasca?) Maybe you would like to share your experiences in this area? Thanks for reading

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  • c++ callback syntax in a class

    - by Mr Bell
    I am trying to figure out the syntax to register a callback with this 3rd party software. I think it is probably a basic question, I just am not too familiar with c++. They have a method for registering a callback function so their code can call a function in my code when an event happens. They provided a working example that registers the callback from the main file, but I want to know how to do it when working inside a class Their method signature: smHTRegisterHeadPoseCallback(smEngineHandle engine_handle, void *user_data, smHTHeadPoseCallback callback_fun); Working example from the main file: void STDCALL receiveHeadPose(void *,smEngineHeadPoseData head_pose, smCameraVideoFrame video_frame) { ... } void main() { ... smHTRegisterHeadPoseCallback(engine_handle,0,receiveHeadPose) ... } But I want to use this from my class MyClass.h class FaceEngine { public: void STDCALL receiveFaceData(void *, smEngineFaceData face_data, smCameraVideoFrame video_frame); ... MyClass.cpp void FaceEngine::Start(void) { rc = smHTRegisterFaceDataCallback(hFaceAPIEngine,0,&FaceEngine::receiveFaceData); ... Results in this compiler error: Error 1 error C2664: 'smHTRegisterFaceDataCallback' : cannot convert parameter 3 from 'void (__stdcall FaceEngine::* )(void *,smEngineFaceData,smCameraVideoFrame)' to 'smHTFaceDataCallback' d:\stuff\programming\visual studio 2008\projects\tut02_vertices\faceengine.cpp 43 Beard If my question isn't clear please let me know how I can clarify.

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  • how does one _model_ data from relational databases in clojure ?

    - by sandeep
    I have asked this question on twitter as well the #clojure IRC channel, yet got no responses. There have been several articles about Clojure-for-Ruby-programmers, Clojure-for-lisp-programmers.. but what is the missing part is Clojure for ActiveRecord programmers . There have been articles about interacting with MongoDB, Redis, etc. - but these are key value stores at the end of the day. However, coming from a Rails background, we are used to thinking about databases in terms of inheritance - has_many, polymorphic, belongs_to, etc. The few articles about Clojure/Compojure + MySQL (ffclassic) - delve right into sql. Of course, it might be that an ORM induces impedence mismatch, but the fact remains that after thinking like ActiveRecord, it is very difficult to think any other way. I believe that relational DBs, lend themselves very well to the object-oriented paradigm because of them being , essentially, Sets. Stuff like activerecord is very well suited for modelling this data. For e.g. a blog - simply put class Post < ActiveRecord::Base has_many :comments end class Comment < ActiveRecord::Base belongs_to :post end How does one model this in Clojure - which is so strictly anti-OO ? Perhaps the question would have been better if it referred to all functional programming languages, but I am more interested from a Clojure standpoint (and Clojure examples)

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  • Shared Memory and Process Sempahores (IPC)

    - by fsdfa
    This is an extract from Advanced Liniux Programming: Semaphores continue to exist even after all processes using them have terminated. The last process to use a semaphore set must explicitly remove it to ensure that the operating system does not run out of semaphores.To do so, invoke semctl with the semaphore identifier, the number of semaphores in the set, IPC_RMID as the third argument, and any union semun value as the fourth argument (which is ignored).The effective user ID of the calling process must match that of the semaphore’s allocator (or the caller must be root). Unlike shared memory segments, removing a semaphore set causes Linux to deallocate immediately. If a process allocate a shared memory, and many process use it and never set to delete it (with shmctl), if all them terminate, then the shared page continues being available. (We can see this with ipcs). If some process did the shmctl, then when the last process deattached, then the system will deallocate the shared memory. So far so good (I guess, if not, correct me). What I dont understand from that quote I did, is that first it say: "Semaphores continue to exist even after all processes using them have terminated." and then: "Unlike shared memory segments, removing a semaphore set causes Linux to deallocate immediately."

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  • Print an array elements

    - by 1ace1
    Hello guys, this is my first post and im still a beginner in the programming world so bare with me. I just created an array with 100 initialized values and i want to print out 10 elements on each line so it would be somthing like this 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 ...26 this is the code i used and i managed to do it for the first 10 elements but i couldnt figure out how to do it for the rest public static void main(String[] args) { int[] numbers = { 0,1,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17}; int i, count = 0; for (i = 0; i < numbers.length; i++) { System.out.print(numbers[i] + " "); count++; if (count == 9) for (i = 9; i < numbers.length; i++) System.out.println(numbers[i] + " "); } } thanks!

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  • Rails: creating a custom data type, to use with generator classes and a bunch of questions related t

    - by Shyam
    Hi, After being productive with Rails for some weeks, I learned some tricks and got some experience with the framework. About 10 days ago, I figured out it is possible to build a custom data type for migrations by adding some code in the Table definition. Also, after learning a bit about floating points (and how evil they are) vs integers, the money gem and other possible solutions, I decided I didn't WANT to use the money gem, but instead try to learn more about programming and finding a solution myself. Some suggestions said that I should be using integers, one for the whole numbers and one for the cents. When playing in script/console, I discovered how easy it is to work with calculations and arrays. But, I am talking to much (and the reason I am, is to give some sufficient background). Right now, while playing with the scaffold generator (yes, I use it, because I like they way I can quickly set up a prototype while I am still researching my objectives), I like to use a DRY method. In my opinion, I should build a custom "object", that can hold two variables (Fixnum), one for the whole, one for the cents. In my big dream, I would be able to do the following: script/generate scaffold Cake name:string description:text cost:mycustom Where mycustom should create two integer columns (one for wholes, one for cents). Right now I could do this by doing: script/generate scaffold Cake name:string description:text cost_w:integer cost_c:integer I had also had an idea that would be creating a "cost model", which would hold two columns of integers and create a cost_id column to my scaffold. But wouldn't that be an extra table that would cause some kind of performance penalty? And wouldn't that be defy the purpose of the Cake model in the first place, because the costs are an attribute of individual Cake entries? The reason why I would want to have such a functionality because I am thinking of having multiple "costs" inside my rails application. Thank you for your feedback, comments and answers! I hope my message got through as understandable, my apologies for incorrect grammar or weird sentences as English is not my native language.

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  • PHP Commercial Project Function define

    - by Shiro
    Currently I am working with a commercial project with PHP. I think this question not really apply to PHP for all programming language, just want to discuss how your guys solve it. I work in MVC framework (CodeIgniter). all the database transaction code in model class. Previously, I seperate different search criteria with different function name. Just an example function get_student_detail_by_ID($id){} function get_student_detail_by_name($name){} as you can see the function actually can merge to one, just add a parameter for it. But something you are rushing with project, you won't look back previously got what similar function just make some changes can meet the goal. In this case, we found that there is a lot function there and hard to maintenance. Recently, we try to group the entity to one ultimate search something like this function get_ResList($is_row_count=FALSE, $record_start=0, $arr_search_criteria='', $paging_limit=20, $orderby='name', $sortdir='ASC') we try to make this function to fit all the searching criteria. However, our system getting bigger and bigger, the search criteria not more 1-2 tables. It require join with other table with different purpose. What we had done is using IF ELSE, if(bla bla bla) { $sql_join = JOIN_SOME_TABLE; $sql_where = CONDITION; } at the end, we found that very hard to maintance the function. it is very hard to debug as well. I would like to ask your opinion, what is the commercial solution they solve this kind of issue, how to define a function and how to revise it. I think this is link project management skill. Hope you willing to share with us. Thanks.

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  • Can you open a form or window in an Outlook Addin (VSTO)

    - by dontpanic
    Hi, I am new to VSTO programming. I have created a basic addin for Outlook 2007 that monitors a folder containing XML text files which it opens and then sends them as an email, then deletes them. this all works fine. I want the user to be able to configure certain settings for the way the addin/program will operate, such as the folder that it will monitor, and other things. The logical way to do this is to create a menu item in the addin (which I have also done) that opens a windows form (or XAML window) that allows them to enter the parameters. In my addin I added a new item Windows Form, which worked, and the designer opened. However, in my addin code I cannot open the form. The Show() method normally associated with form objects is not available. Is this simply something you cannot do, or am I just doing it the wrong way? I have read about Outlook form regions, but these seemed to be attached to outlook items such as a new email, task, appointment etc... there doesnt seem to be a way to create a form region that can be opened in the main window of Outlook. Ideally, I would like to go with my original method of opening a new window from a menu item, but if this isnt possible I would like to hear other solutions. Thanks, Will.

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  • Combining the jquery Calendar picker with the jquery validation and getting them to play nice?

    - by MBonig
    I'm just starting to get into jquery/javascript programming so this may be a beginner question but I sure can't seem to find anything about it. I have a text field on a form. I've used the JQuery UI Calendar picker to make data entry better. I've also added jquery validation to ensure that if the user enters the date by hand that it's still valid. Here is the html: <input class="datepicker" id="Log_ServiceStartTime_date" name="Log_ServiceStartTime_date" type="text" value="3/16/2010"></input> and javascript: $('form').validate(); $('#Log_ServiceStartTime_date').rules('add','required'); $('#Log_ServiceStartTime_date').rules('add','date'); the problem I'm having is this: If a user puts in a bad date, or no date at all, the validation correctly kicks in and the error description displays. However, if the user clicks on the textbox to bring up the calendar picker and selects a date, the date fills into the field but the validation does not go away. If the user clicks into the textbox and then back out, the validation correctly goes away. How can I get the calendar picker to kick off the validation routine once a date is selected? thanks

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  • A Newbie question regarding Software Development

    - by Sharif
    Hi, I'm going to complete my B.pharm (Hons.) degree and, you know, I don't have much knowledge about programing. I was wondering to build a software on my own. Could you guys tell me what to learn first for that? Is it too hard for a student of other discipline to build a software? Let me know please. The software I want to make is like a dictionary (or more specifically like "Physician's Desk Reference"). It should find the generic name, company name, indication, price etc. of a drug when I enter the brand name and vice versa. To build a software like that what programing language could help me most and what (and how many) language should I learn first? In my country, there is no practice of Community pharmacy (most of the pharmacy stores are run by unskilled people), that's why this type of thing could help them sell drugs. Would you please tell me what I'm to do and how tough it is? I'm very keen to learn programming. Thanks in advance NB: I started this post in ASKREDDIT section but it seems that was not the right place for poll type question, so I post it again in this section

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  • Midiplayer stops playing sounds after 16 notes.

    - by user349673
    Hi. I am currently programming a Piano Keyboard editor, much like the one you can find in Cubase, Logic, Reason etc.. I have this big grid, double array new int [13][9], which makes it 13 rows, 9 columns. The first column [0-12][0] is the Keyboard, at the top there's "high C" (midi note 72) and at the bottom there's "low C" (midi note 60). That column is an array of JButtons and when you press for example "low C", note 60 is being played by the Synthesizer. I've gotten this to work pretty OK as for now, but one problem I have is that I can only play 16 notes in a row, then it's like the Synthesizer shuts down or something. Do you guys have ANY idea of what the problem is? A bit of the code: import java.awt.*; import javax.swing.*; import java.awt.event.*; import java.util.*; import javax.sound.midi.*; actionPerformed(ActionEvent ae){ for(int i = 0; i<13; i++){ if(o== instr[i]){//instr is the button array SpelaTangent(i); } } } public void SpelaTangent(int tangent){ int [] klaviatur = new int[13]; for(int i = 0; i<13; i++){ klaviatur[i] = (72-i); } try { Synthesizer synth = MidiSystem.getSynthesizer(); synth.open(); final MidiChannel[] mc = synth.getChannels(); Instrument[] instrument = synth.getDefaultSoundbank().getInstruments(); synth.loadInstrument(instrument[1]); mc[0].noteOn(klaviatur[tangent],350); mc[0].noteOff(klaviatur[tangent],350); } catch (MidiUnavailableException e) {} } Help is very much appreciated!

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  • How can I obtain the local TCP port and IP Address of my client program?

    - by Dr Dork
    Hello! I'm prepping for a simple work project and am trying to familiarize myself with the basics of socket programming in a Unix dev environment. At this point, I have some basic server side code and client side code setup to communicate. Currently, my client code successfully connects to the server code and the server code sends it a test message, then both quit out. Perfect! That's exactly what I wanted to accomplish. Now I'm playing around with the functions used to obtain info about the two environments (server and client). I'd like to obtain the local IP address and dynamically assigned TCP port of the client. The function I've found to do this is getsockname()... //setup the socket if ((sockfd = socket(p->ai_family, p->ai_socktype, p->ai_protocol)) == -1) { perror("client: socket"); continue; } //Retrieve the locally-bound name of the specified socket and store it in the sockaddr structure sa_len = sizeof(sa); getsock_check = getsockname(sockfd,(struct sockaddr *)&sa,(socklen_t *)&sa_len) ; if (getsock_check== -1) { perror("getsockname"); exit(1); } printf("Local IP address is: %s\n", inet_ntoa(sa.sin_addr)); printf("Local port is: %d\n", (int) ntohs(sa.sin_port)); but the output is always zero... Local IP address is: 0.0.0.0 Local port is: 0 does anyone see anything I might be or am definitely doing wrong? Thanks so much in advance for all your help!

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  • How do you make life easier for yourself when developing a really large database

    - by Hannes de Jager
    I am busy developing 2 web based systems with MySql databases and the amount of tables/views/stored routines is really becoming a lot and it is more and more challenging to handle the complexity. Now in programming languages we have namespacing e.g. Java packages, C++ namespaces to partition the software, grouping it together to make things more understandable. Databases on the other hand have more of a flat structure (MySql at least) e.g. tables and stored procedures are on the same level. So one have to be more creative, creating naming conventions, perhaps use more than one database or using tools to visualize things. What methods do you use to ease the pain? To be effective while developing your databases? To not get lost in a sea of tables and fields and stored procs? Feel free to mention tools you use also, but try to restrict it to open source and preferably Linux solutions if thats OK. b.t.w How many tables would a database have to be considered large in terms of design?

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  • Neural Networks or Human-computer interaction

    - by Shahin
    I will be entering my third year of university in my next academic year, once I've finished my placement year as a web developer, and I would like to hear some opinions on the two modules in the Title. I'm interested in both, however I want to pick one that will be relevant to my career and that I can apply to systems I develop. I'm doing an Internet Computing degree, it covers web development, networking, database work and programming. Though I have had myself set on becoming a web developer I'm not so sure about that any more so am trying not to limit myself to that area of development. I know HCI would help me as a web developer, but do you think it's worth it? Do you think Neural Network knowledge could help me realistically in a system I write in the future? Thanks. EDIT: Hi guys, I thought it would be useful to follow-up with what I decided to do and how it's worked out. I picked Artificial Neural Networks over HCI, and I've really enjoyed it. Having a peek into cognitive science and machine learning has ignited my interest for the subject area, and I will be hoping to take on a postgraduate project a few years from now when I can afford it. I have got a job which I am starting after my final exams (which are in a few days) and I was indeed asked if I had done a module in HCI or similar. It didn't seem to matter, as it isn't a front-end developer position! I would recommend taking the module if you have it as an option, as well as any module consisting of biological computation, it will open up more doors should you want to go onto postgraduate research in the future. Thanks again, Shahin

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  • Using boost asio for pub/sub style tcp in a game loop

    - by unohoo
    I have been reading through the boost asio documentation for a couple of hours now, and while I think the documentation is really great, I am still left a bit confused on how to implement the system that I need. I have to stream info, from a game engine, to a list of computers over tcp. One snag is that, unlike traditional pub/sub, the computer that does the distribution of info is actually the computer that has to connect to the subscribers as well (instead of the subscribers registering with the publisher). This is done via a config file - a list of ip's/ports along with the data that they each require. The subscribers listen, but do not know the ip of the publisher. (As a side note, I'm quite new to network programming, so maybe I'm missing something .. but it's strange that I do not find much information regarding this style of "inverted" client-server model..) I am looking for suggestions for the implementation of such a system using boost asio. Of course I have to integrate the networking into an already existing engine, so with regards to that: What would be a good way to handle messages being sent to multiple computers every frame? Use async_write, call io_service.run and then reset every frame? Would having io_service.run have its own thread be better? Or should I just use threads and use blocking writes?

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  • Why doesn't my test run tearDownAfterTestClass when it fails

    - by Memor-X
    in a test i am writing the setUpBeforeTests creates a new customer in the database who is then used to perform the tests with so naturally when i finish the test i should get rid of this test customer in tearDownAfterTestClass so that i can create then anew when i rerun the test and not get any false positives how when the tests all run fine i have no problem but if a test fails and i go to rerun it my setUpBeforeTests fails because i check for mysql errors in it like this try { if(!mysqli_query($connection,$query)) { $this->assertTrue(false); } } catch (Exception $exc) { $msg = '[tearDownAfterTestClass] Exception Error' . PHP_EOL . PHP_EOL; $msg .= 'Could not run query - '.mysqli_error($connection). PHP_EOL;; $this->fail($msg); } the error i get is that there is a primary key violation which is expected cause i'm trying to create a new customer using the same data (primary key is on email which is also used to log in) however that means when the test failed it didn't run tearDownAfterTestClass now i could just move everything in tearDownAfterTestClass to the start of setUpBeforeTests however to me that seems like bad programming since it defeates the purpose of even have tearDownAfterTestClass so i am wondering, why isn't my tearDownAfterTestClass running when a test fails NOTE: the database is a fundamental part of the system i'm testing and the database and system are on a separate development environment not the live one, the backup files for the database are almost 2 GBs and takes almost 1/2 an hour to restore, the purpose of the tear down is to remove any data we have added because of the test so that we don't have to restore the database every time we run the tests

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  • Why is debugging better in an IDE?

    - by Bill Karwin
    I've been a software developer for over twenty years, programming in C, Perl, SQL, Java, PHP, JavaScript, and recently Python. I've never had a problem I could not debug using some careful thought, and well-placed debugging print statements. I respect that many people say that my techniques are primitive, and using a real debugger in an IDE is much better. Yet from my observation, IDE users don't appear to debug faster or more successfully than I can, using my stone knives and bear skins. I'm sincerely open to learning the right tools, I've just never been shown a compelling advantage to using visual debuggers. Moreover, I have never read a tutorial or book that showed how to debug effectively using an IDE, beyond the basics of how to set breakpoints and display the contents of variables. What am I missing? What makes IDE debugging tools so much more effective than thoughtful use of diagnostic print statements? Can you suggest resources (tutorials, books, screencasts) that show the finer techniques of IDE debugging? Sweet answers! Thanks much to everyone for taking the time. Very illuminating. I voted up many, and voted none down. Some notable points: Debuggers can help me do ad hoc inspection or alteration of variables, code, or any other aspect of the runtime environment, whereas manual debugging requires me to stop, edit, and re-execute the application (possibly requiring recompilation). Debuggers can attach to a running process or use a crash dump, whereas with manual debugging, "steps to reproduce" a defect are necessary. Debuggers can display complex data structures, multi-threaded environments, or full runtime stacks easily and in a more readable manner. Debuggers offer many ways to reduce the time and repetitive work to do almost any debugging tasks. Visual debuggers and console debuggers are both useful, and have many features in common. A visual debugger integrated into an IDE also gives you convenient access to smart editing and all the other features of the IDE, in a single integrated development environment (hence the name).

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  • PHP Socket Server vs node.js: Web Chat

    - by Eliasdx
    I want to program a HTTP WebChat using long-held HTTP requests (Comet), ajax and websockets (depending on the browser used). Userdatabase is in mysql. Chat is written in PHP except maybe the chat stream itself which could also be written in javascript (node.js): I don't want to start a php process per user as there is no good way to send the chat messages between these php childs. So I thought about writing an own socket server in either PHP or node.js which should be able to handle more then 1000 connections (chat users). As a purely web developer (php) I'm not much familiar with sockets as I usually let web server care about connections. The chat messages won't be saved on disk nor in mysql but in RAM as an array or object for best speed. As far as I know there is no way to handle multiple connections at the same time in a single php process (socket server), however you can accept a great amount of socket connections and process them successive in a loop (read and write; incoming message - write to all socket connections). The problem is that there will most-likely be a lag with ~1000 users and mysql operations could slow the whole thing down which will then affect all users. My question is: Can node.js handle a socket server with better performance? Node.js is event-based but I'm not sure if it can process multiple events at the same time (wouldn't that need multi-threading?) or if there is just an event queue. With an event queue it would be just like php: process user after user. I could also spawn a php process per chat room (much less users) but afaik there are singlethreaded IRC servers which are also capable to handle thousands of users. (written in c++ or whatever) so maybe it's also possible in php. I would prefer PHP over Node.js because then the project would be php-only and not a mixture of programming languages. However if Node can process connections simultaneously I'd probably choose it.

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  • Deploy an hta file in an exe or msi file

    - by rjmunro
    I've written an HTA file frontend for our web app that allows the web app to run without web browser status bars etc, and allows it to access the local system for certain tasks. I need a way to deploy this to customers. I need an installer to supply an hta file, an ico file, and add a link to them in the start menu and on the users desktop. I looked at building an installer with NSIS, but I couldn't figure out how to assign the icon to the shortcuts - The icon had to be a standard HTA one. Can this be done with NSIS, or should I be using another installer? P.s. I've got no particular preference for NSIS, it's just something I once used a very long time ago. When I download stuff, I think I prefer them to be msi files that launch with windows installer (it feels more like downloading a .rpm or .deb on linux which I am used to) but I know nothing about how those are created. I'm a web/linux guy who knows very little about windows programming.

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  • Understanding the workflow of the messages in a generic server implementation in Erlang

    - by Chiron
    The following code is from "Programming Erlang, 2nd Edition". It is an example of how to implement a generic server in Erlang. -module(server1). -export([start/2, rpc/2]). start(Name, Mod) -> register(Name, spawn(fun() -> loop(Name, Mod, Mod:init()) end)). rpc(Name, Request) -> Name ! {self(), Request}, receive {Name, Response} -> Response end. loop(Name, Mod, State) -> receive {From, Request} -> {Response, State1} = Mod:handle(Request, State), From ! {Name, Response}, loop(Name, Mod, State1) end. -module(name_server). -export([init/0, add/2, find/1, handle/2]). -import(server1, [rpc/2]). %% client routines add(Name, Place) -> rpc(name_server, {add, Name, Place}). find(Name) -> rpc(name_server, {find, Name}). %% callback routines init() -> dict:new(). handle({add, Name, Place}, Dict) -> {ok, dict:store(Name, Place, Dict)}; handle({find, Name}, Dict) -> {dict:find(Name, Dict), Dict}. server1:start(name_server, name_server). name_server:add(joe, "at home"). name_server:find(joe). I tried so hard to understand the workflow of the messages. Would you please help me to understand the workflow of this server implementation during the executing of the functions: server1:start, name_server:add and name_server:find?

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  • Given a main function and a cleanup function, how (canonically) do I return an exit status in Bash/Linux?

    - by Zac B
    Context: I have a bash script (a wrapper for other scripts, really), that does the following pseudocode: do a main function if the main function returns: $returncode = $? #most recent return code if the main function runs longer than a timeout: kill the main function $returncode = 140 #the semi-canonical "exceeded allowed wall clock time" status run a cleanup function if the cleanup function returns an error: #nonzero return code exit $? #exit the program with the status returned from the cleanup function else #cleanup was successful .... Question: What should happen after the last line? If the cleanup function was successful, but the main function was not, should my program return 0 (for the successful cleanup), or $returncode, which contains the (possibly nonzero and unsuccessful) return code of the main function? For a specific application, the answer would be easy: "it depends on what you need the script for." However, this is more of a general/canonical question (and if this is the wrong place for it, kill it with fire): in Bash (or Linux in general) programming, do you typically want to return the status that "means" something (i.e. $returncode) or do you ignore such subjectivities and simply return the code of the most recent function? This isn't Bash-specific: if I have a standalone executable of any kind, how, canonically should it behave in these cases? Obviously, this is somewhat debatable. Even if there is a system for these things, I'm sure that a lot of people ignore it. All the same, I'd like to know. Cheers!

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