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  • Where can a self-teacher learn general good programming habits and conventions?

    - by lucid
    A few mistakes and general childishness in early adulthood have left me in a situation where I work a menial job, with no possibility (in the near future) of attending school. I aspire to one day work in the programming field (gaming specifically), after proving myself on the indie end of things. I've gotten very confident in C++, java, and python, and I find I'm able to solve any problem I want either from previous experience, or from scouring the web for help. The solutions work, and with each attempt they become more readable, maintainable, and extensible. But this is because I'm learning from mistakes and bad programming and design habits I feel I might have avoided with actual schooling. General tips like: "if it's hard to read or getting long, or you're writing it twice, it should be in one or more functions." or "design all your classes before you start coding, so you don't have to rewrite classes later when you discover an unforeseen dependency" Is there a good book or website for learning general good programming practices and design habits? Also, naming and format conventions. I realize sometimes development houses have their own conventions, but things like "Classes in python usually have the first letter of each word capitalized". I'd like to be able to show some source code to a potential employer, and be prepared when for what's expected on a team. Is there some central database of naming and formatting conventions somewhere? Also, feel free to give any thoughts on whether or not the self-teach, garner some indie sales, use them as your resume' route is realistic

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  • segmentation fault in file operations in c

    - by mekasperasky
    #include<stdio.h> /* this is a lexer which recognizes constants , variables ,symbols, identifiers , functions , comments and also header files . It stores the lexemes in 3 different files . One file contains all the headers and the comments . Another file will contain all the variables , another will contain all the symbols. */ int main() { int i; char a,b[20],c; FILE *fp1; fp1=fopen("source.txt","r"); //the source file is opened in read only mode which will passed through the lexer //now lets remove all the white spaces and store the rest of the words in a file if(fp1==NULL) { perror("failed to open source.txt"); //return EXIT_FAILURE; } i=0; while(1) { a=fgetc(fp1); if(a !="") { b[i]=a; } else { fprintf(fp1, "%.20s\n", b); i=0; continue; } i=i+1; /*Switch(a) { case EOF :return eof; case '+':sym=sym+1; case '-':sym=sym+1; case '*':sym=sym+1; case '/':sym=sym+1; case '%':sym=sym+1; case ' */ } return 0; } how does this code end up in segmentation fault?

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  • Eclipse PDT "tips" ?

    - by Pascal MARTIN
    Hi ! (Yes, this is a quite opened and general and subjective question -- it's by design, cause I want tips you think are great !) I'm using Eclipse PDT 2.1 to work in PHP, either for small and/or big projects -- I've been doing so for quite some times, now, actually (since before 1.0 stable, if I remember well)... I was wondering if any of you did know "tips" to be more efficient. Let met explain more in details : I know about things like plugins like Aptana (better editor for JS/CSS), Subversive (for SVN access), RSE, Filesync, integrating Xdebug's debugger, ... What I mean by "tips" is more some little things you discovered one day and since use all the time -- and allow you to be more efficient in your PHP projects. Some examples of "tips" that come to my mind, and that already know and use : ctrl+space to open the list of suggestions for functions / variables names ctrl+shift+R (navigate > open resource) to open a popup which show only files which names contain what you type ; ie, quick opening of files this one might be the perfect example : I know this one is not often known by coworkers and they find it as useful as I do ; so, I guess there might be lots of other things like this one I don't know myself ^^ ctrl+M to switch to full-screen view for the editor (instead of double-click on tabs bar) shift+F2 while on a function name, to open it's page if the PHP manual in a browser Attention Mac Users use Command instead Control. I guess you get the point ; but I'm really open to any suggestion (be it eclipse-related in general, of more PHP/PDT-specific) that can help be be more efficient :-) Anyway, thanks in advance for your help !

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  • Disable validation in an object in Ruby on Rails

    - by J. Pablo Fernández
    I have an object which whether validation happens or not should depend on a boolean, or in another way, validation is optional. I haven't found a clean way to do it. What I'm currently doing is this (disclaimer: you cannot unsee, leave this page if you are too sensitive): def valid? if perform_validation super else super # Call valid? so that callbacks get called and things like encrypting passwords and generating salt in before_validation actually happen errors.clear # but then clear the errors true # and claim ourselves to be valid. This is super hacky! end end Any better ways? Before you point to the :if argument of many validations, this is for a user model which is using authlogic so it has a lot of validation rules. You can stop reading here if you belive me. If you don't, authlogic already sets some :ifs like: :if => :email_changed? which I have to turn into :if => Proc.new {|user| user.email_changed? and user.perform_validation} and in some other cases, since I'm also using authlogic-oid (OpenID) I just don't have control over the :if, authlogic-oid sets it in a way I cannot change it (in time) without further monkey patching. So I have to override seemingly unrelated functions, catch exceptions if a method doesn't exist, etc. The previous hacky solution if the best of my two attempts.

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  • What is a fast way to set debugging code at a given line in a function?

    - by Josh O'Brien
    Preamble: R's trace() is a powerful debugging tool, allowing users to "insert debugging code at chosen places in any function". Unfortunately, using it from the command-line can be fairly laborious. As an artificial example, let's say I want to insert debugging code that will report the between-tick interval calculated by pretty.default(). I'd like to insert the code immediately after the value of delta is calculated, about four lines up from the bottom of the function definition. (Type pretty.default to see where I mean.) To indicate that line, I need to find which step in the code it corresponds to. The answer turns out to be step list(c(12, 3, 3)), which I zero in on by running through the following steps: as.list(body(pretty.default)) as.list(as.list(body(pretty.default))[[12]]) as.list(as.list(as.list(body(pretty.default))[[12]])[[3]]) as.list(as.list(as.list(body(pretty.default))[[12]])[[3]])[[3]] I can then insert debugging code like this: trace(what = 'pretty.default', tracer = quote(cat("\nThe value of delta is: ", delta, "\n\n")), at = list(c(12,3,3))) ## Try it a <- pretty(c(1, 7843)) b <- pretty(c(2, 23)) ## Clean up untrace('pretty.default') Questions: So here are my questions: Is there a way to print out a function (or a parsed version of it) with the lines nicely labeled by the steps to which they belong? Alternatively, is there another easier way, from the command line, to quickly set debugging code for a specific line within a function? Addendum: I used the pretty.default() example because it is reasonably tame, but with real/interesting functions, repeatedly using as.list() quickly gets tiresome and distracting. Here's an example: as.list(as.list(as.list(as.list(as.list(as.list(as.list(as.list(as.list(body(# model.frame.default))[[26]])[[3]])[[2]])[[4]])[[3]])[[4]])[[4]])[[4]])[[3]]

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  • Resizing a GLJPanel with JOGL causes my model to disappear.

    - by badcodenotreat
    I switched over to using a GLJPanel from a GLCanvas to avoid certain flickering issues, however this has created several unintended consequences of it's own. From what I've gleaned so far, GLJPanel calls GLEventListener.init() every time it's resized which either resets various openGL functions i've enabled in init() (depth test, lighting, etc...) if i'm lucky, or completely obliterates my model if i'm not. I've tried debugging it but I'm not able to correct this behavior. This is my init() function: gl.glShadeModel( GL.GL_SMOOTH ); gl.glEnable( GL.GL_DEPTH_TEST ); gl.glDepthFunc( GL.GL_LEQUAL ); gl.glDepthRange( zNear, zFar ); gl.glDisable( GL.GL_LINE_SMOOTH ); gl.glEnable(GL.GL_NORMALIZE); gl.glEnable( GL.GL_BLEND ); gl.glBlendFunc( GL.GL_SRC_ALPHA, GL.GL_ONE_MINUS_SRC_ALPHA ); // set up the background color gl.glClearColor( ((float)backColor.getRed () / 255.0f), ((float)backColor.getGreen() / 255.0f), ((float)backColor.getBlue () / 255.0f), 1.0f); gl.glEnable ( GL.GL_LIGHTING ); gl.glLightfv( GL.GL_LIGHT0, GL.GL_AMBIENT, Constants.AMBIENT_LIGHT, 0 ); gl.glLightfv( GL.GL_LIGHT0, GL.GL_DIFFUSE, Constants.DIFFUSE_LIGHT, 0 ); gl.glEnable ( GL.GL_LIGHT0 ); gl.glTexEnvf( GL.GL_TEXTURE_ENV, GL.GL_TEXTURE_ENV_MODE, GL.GL_MODULATE ); gl.glHint( GL.GL_PERSPECTIVE_CORRECTION_HINT, GL.GL_NICEST ); // code to generate model Is there any way around this other than removing everything from init(), adding it to my display() function? Given the behavior of init() and reshape() for GLJPanel, i'm not sure if that will fix it either.

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  • How can I determine PerlLogHandler performance impact?

    - by Timmy
    I want to create a custom Apache2 log handler, and the template that is found on the apache site is: #file:MyApache2/LogPerUser.pm #--------------------------- package MyApache2::LogPerUser; use strict; use warnings; use Apache2::RequestRec (); use Apache2::Connection (); use Fcntl qw(:flock); use File::Spec::Functions qw(catfile); use Apache2::Const -compile => qw(OK DECLINED); sub handler { my $r = shift; my ($username) = $r->uri =~ m|^/~([^/]+)|; return Apache2::Const::DECLINED unless defined $username; my $entry = sprintf qq(%s [%s] "%s" %d %d\n), $r->connection->remote_ip, scalar(localtime), $r->uri, $r->status, $r->bytes_sent; my $log_path = catfile Apache2::ServerUtil::server_root, "logs", "$username.log"; open my $fh, ">>$log_path" or die "can't open $log_path: $!"; flock $fh, LOCK_EX; print $fh $entry; close $fh; return Apache2::Const::OK; } 1; What is the performance cost of the flocks? Is this logging process done in parallel, or in serial with the HTTP request? In parallel the performance would not matter as much, but I wouldn't want the user to wait another split second to add something like this.

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  • How to change the date/time in Python for all modules?

    - by Felix Schwarz
    When I write with business logic, my code often depends on the current time. For example the algorithm which looks at each unfinished order and checks if an invoice should be sent (which depends on the no of days since the job was ended). In these cases creating an invoice is not triggered by an explicit user action but by a background job. Now this creates a problem for me when it comes to testing: I can test invoice creation itself easily However it is hard to create an order in a test and check that the background job identifies the correct orders at the correct time. So far I found two solutions: In the test setup, calculate the job dates relative to the current date. Downside: The code becomes quite complicated as there are no explicit dates written anymore. Sometimes the business logic is pretty complex for edge cases so it becomes hard to debug due to all these relative dates. I have my own date/time accessor functions which I use throughout my code. In the test I just set a current date and all modules get this date. So I can simulate an order creation in February and check that the invoice is created in April easily. Downside: 3rd party modules do not use this mechanism so it's really hard to integrate+test these. The second approach was way more successful to me after all. Therefore I'm looking for a way to set the time Python's datetime+time modules return. Setting the date is usually enough, I don't need to set the current hour or second (even though this would be nice). Is there such a utility? Is there an (internal) Python API that I can use?

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  • php and mysql listing databases and looping through results

    - by Jacksta
    Beginner help needed :) I am doign an example form a php book which lists tables in databases. I am getting an error on line 36: $db_list .= "$table_list"; <?php //connect to database $connection = mysql_connect("localhost", "admin_cantsayno", "cantsayno") or die(mysql_error()); //list databases $dbs = @mysql_list_dbs($connection) or die(mysql_error()); //start first bullet list $db_list = "<ul>"; $db_num = 0; //loop through results of functions while ($db_num < mysql_num_rows($dbs)) { //get database names and make each a list point $db_names[$db_num] = mysql_tablename($dbs, $db_num); $db_list .= "<li>$db_names[$db_num]"; //get table names and make another list $tables = @mysql_list_tables($db_names[$db_num]) or die(mysql_error()); $table_list = "<ul>"; $table_num = 0; //loop through results of function while ($table_num < mysql_num_rows($tables)){ //get table names and make each bullet point $table_names[$table_num] = mysql_tablename($tables, $table_num); $table_list .= "<li>$table_names[$table_num]"; $table_num++; } //close inner bullet list and increment number to continue $table_list .= "</ul>" $db_list .= "$table_list"; $db_num++; } //close outer bullet list $db_list .= "</ul>"; ?> <html> <head> <title>MySQL Tables</title> </head> <body> <p><strong>Data bases and tables on local host</strong></p> <? echo "$db_list"; ?> </body>

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  • JMeter CSV Data Set is corrupting Japanese strings stored as proper UTF-8, I get Question Marks instead

    - by Mark Bennett
    I read in search terms from a simple text file to send to a search engine. It works fine in English, but gives me ???? for any Japanese text. Text with mixed English and Japanese does show the English text, so I know it's reading it. What I'm seeing: Input text: Snow Leopard ??????????????? Turns into: Snow Leopard ??????????????? This is in my POST field of an HTTP. If I set JMeter to encode the data, it just puts in the percent sequence for question marks. Interesting note: In the example above there are 15 Japanese characters, and then 15 question marks, so at some point it's being seen as full characters and not just bytes. About the Data: The CSV file is very simple in structure. There's only one field / one column, which I name TERM, and later use as ${TERM} I don't really need full CSV because it's only one string per line. There's no commas or quotes. When I run the Unix "file" command on the file, it says UTF-8 text. I've also verified it in command line and graphical mode on two machines. JMeter CSV Dataset Config: Filename: japanese-searches.csv File encoding: UTF-8 (also tried without) Variable names: TERM Delimiter: , Allow Quoted Data: False (I also tried True, different, but still wrong) Recycle at EOF: True Stop at EOF: False Staring mode: All threads A few things I've tried: Tried Allow quoted Data. It changed to other strange characters. -Dfile.encoding=UTF-8 Tried encoding the POST, but it just turned into a bunch of %nn for question marks And I'm not sure how "debug" just after the each line of the CSV is read in. I think it's corrupted right away, but I'm not sure. If it's only mangled when I reference it, then instead of ${TERM} perhaps there's some other "to bytes" function call. I'll start checking into that. I haven't done anything with the JMeter functions yet.

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  • Visual Studio project remains "stuck" when stopped

    - by Traveling Tech Guy
    Hi, Currently developing a connector DLL to HP's Quality Center. I'm using their (insert expelative) COM API to connect to the server. An Interop wrapper gets created automatically by VStudio. My solution has 2 projects: the DLL and a tester application - essentially a form with buttons that call functions in the DLL. Everything works well - I can create defects, update them and delete them. When I close the main form, the application stops nicely. But when I call a function that returns a list of all available projects (to fill a combo box), if I close the main form, VStudio still shows the solution as running and I have to stop it. I've managed to pinpoint a single function in my code that when I call, the solution remains "hung" and if I don't, it closes well. It's a call to a property in the TDC object get_VisibleProjects that returns a List (not the .Net one, but a type in the COM library) - I just iterate over it and return a proper list (that I later use to fill the combo box): public List<string> GetAvailableProjects() { List<string> projects = new List<string>(); foreach (string project in this.tdc.get_VisibleProjects(qcDomain)) { projects.Add(project); } return projects; } My assumption is that something gets retained in memory. If I run the EXE outside of VStudio it closes - but who knows what gets left behind in memory? My question is - how do I get rid of whatever calling this property returns? Shouldn't the GC handle this? Do I need to delve into pointers? Things I've tried: getting the list into a variable and setting it to null at the end of the function Adding a destructor to the class and nulling the tdc object Stepping through the tester function application all the way out, whne the form closes and the Main function ends - it closes, but VStudio still shows I'm running. Thanks for your assistance!

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  • Xlib.h and Xutil.h not found in Eclipse, how can I fix this?

    - by eclipseNoob
    Hi, I'm a newbie to Eclipse IDE for C/C++ development. I just installed MingW and set it up as my system's environment variable. I am trying to make an application that uses the X library but eclipse cant seem to find it. Eclipse works with any other simple standard library functions but it cant find the X library. Please Help! Here's a sample code snippet that's failing: #include <stdio.h> #include <X11/Xlib.h> // Can't find this #include <X11/Xutil.h> // Or this... int main() { printf("Hello"); return 0; } Do I have to download the X library from somewhere? If so then from where and where do I paste it to? Please tell me what to do in order for me to start coding using the Xlib in Eclipse. If you find any useful links, please dont hesitate to post. Thanks.

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  • strange memory error when deleting object from Core Data

    - by llloydxmas
    I have an application that downloads an xml file, parses the file, and creates core data objects while doing so. In the parse code I have a function called 'emptydatacontext' that removes all items from Core Data before creating replacements from the xml file. This method looks like this: -(void) emptyDataContext { NSMutableArray* mutableFetchResults = [CoreDataHelper getObjectsFromContext:@"Condition" :@"road" :NO :managedObjectContext]; NSFetchRequest * allCon = [[NSFetchRequest alloc] init]; [allCon setEntity:[NSEntityDescription entityForName:@"Condition" inManagedObjectContext:managedObjectContext]]; NSError * error = nil; NSArray * conditions = [managedObjectContext executeFetchRequest:allCon error:&error]; [allCon release]; for (NSManagedObject * condition in conditions) { [managedObjectContext deleteObject:condition]; } } The first time this runs it deletes all objects and functions as it should - creating new objects from the xml file. I created a 'update' button that starts the exact same process of retrieving the file the preceeding as it did the first time. All is well until its time to delete the core data objects again. This 'deleteObject' call creates a "EXC_BAD_ACCESS" error each time. This only happens on the second time through. See this image for the debugger window as it appears when walking through the deletion FOR loop on the second iteration. Conditions is the fetched array of 7 objects with the objects below. Condition should be an individual condition. link text As you can see 'condition' does not match any of the objects in the 'conditions' array. I'm sure this is why I'm getting the memory access errors. Just not sure why this fetch (or the FOR) is returning a wrong reference. All the code that successfully performes this function on the first iteration is used in the second but with very different results. Thanks in advance for the help!

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  • How to report progress of a JavaScript function?

    - by LambyPie
    I have a JavaScript function which is quite long and performs a number of tasks, I would like to report progress to the user by updating the contents of a SPAN element with a message as I go. I tried adding document.getElementById('spnProgress').innerText = ... statements throughout the function code. However, whilst the function is executing the UI will not update and so you only ever see the last message written to the SPAN which is not very helpful. My current solution is to break the task up into a number of functions, at the end of each I set the SPAN message and then "trigger" the next one with a window.setTimeout call with a very short delay (say 10ms). This yields control and allows the browser to repaint the SPAN with the updated message before starting the next step. However I find this very messy and difficult to follow the code, I'm thinking there must be a better way. Does anyone have any suggestions? Is there any way to force the SPAN to repaint without having to leave the context of the function? Thanks

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  • linear combinations in python/numpy

    - by nmaxwell
    greetings, I'm not sure if this is a dumb question or not. Lets say I have 3 numpy arrays, A1,A2,A3, and 3 floats, c1,c2,c3 and I'd like to evaluate B = A1*c1+ A2*c2+ A3*c3 will numpy compute this as for example, E1 = A1*c1 E2 = A2*c2 E3 = A3*c3 D1 = E1+E2 B = D1+E3 or is it more clever than that? In c++ I had a neat way to abstract this kind of operation. I defined series of general 'LC' template functions, LC for linear combination like: template<class T,class D> void LC( T & R, T & L0,D C0, T & L1,D C1, T & L2,D C2) { R = L0*C0 +L1*C1 +L2*C2; } and then specialized this for various types, so for instance, for an array the code looked like for (int i=0; i<L0.length; i++) R.array[i] = L0.array[i]*C0 + L1.array[i]*C1 + L2.array[i]*C2; thus avoiding having to create new intermediate arrays. This may look messy but it worked really well. I could do something similar in python, but I'm not sure if its nescesary. Thanks in advance for any insight. -nick

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  • Visual Studio and .NET programming

    - by Vit
    Hi, I just want to ask wheather I am right or not about .NET. So, .NET is new framework that enables you to easily implement new and old windows functions. It is similiar to java in the way that its also compiled into "bytecode", but its name is Common Language Infrastructure, or CLI. This language is interpreted by .NET Framework, so code generated by programming using .NET cannot be executed directly by CPU. Now, few languages can be compiled to CLI. First, it was Microsoft-developed C#, than J#, C++ others. I suspect that this is in general right, at least I hope I understand it right. But, what I am still missing is, can you write to machine code compiled code in C#? And, if using Visual Studio 2005, when I select Win32 project, it is compiled into machine code, so only thing you need to run this apps are windows dynamic-link libraries, since static libraries code is implemented into app durink linking phase. And those dynamic-link libraries are implemented in every windows installation, or provided by DirectX installations. But when I select CLR in Visual Studio 2005, than app is compiled into CLI code, and it first executes .NET framework, and than .NET framework executes that program, since its not in machine code. So, I am right? I ask becouse you can read these infos on the internet, but I have noone to tell me wheather I understand it right or not. Thanks.

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  • How to easily map c++ enums to strings

    - by Roddy
    I have a bunch of enum types in some library header files that I'm using, and I want to have a way of converting enum values to user strings - and vice-versa. RTTI won't do it for me, because the 'user strings' need to be a bit more readable than the enumerations. A brute force solution would be a bunch of functions like this, but I feel that's a bit too C-like. enum MyEnum {VAL1, VAL2,VAL3}; String getStringFromEnum(MyEnum e) { switch e { case VAL1: return "Value 1"; case VAL2: return "Value 2"; case VAL1: return "Value 3"; default: throw Exception("Bad MyEnum"); } } I have a gut feeling that there's an elegant solution using templates, but I can't quite get my head round it yet. UPDATE: Thanks for suggestions - I should have made clear that the enums are defined in a third-party library header, so I don't want to have to change the definition of them. My gut feeling now is to avoid templates and do something like this: char * MyGetValue(int v, char *tmp); // implementation is trivial #define ENUM_MAP(type, strings) char * getStringValue(const type &T) \ { \ return MyGetValue((int)T, strings); \ } ; enum eee {AA,BB,CC}; - exists in library header file ; enum fff {DD,GG,HH}; ENUM_MAP(eee,"AA|BB|CC") ENUM_MAP(fff,"DD|GG|HH") // To use... eee e; fff f; std::cout<< getStringValue(e); std::cout<< getStringValue(f);

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  • Matab - Trace contour line between two different points

    - by Graham
    Hi, I have a set of points represented as a 2 row by n column matrix. These points make up a connected boundary or edge. I require a function that traces this contour from a start point P1 and stop at an end point P2. It also needs to be able trace the contour in a clockwise or anti-clockwise direction. I was wondering if this can be achieved by using some of matlabs functions. I have tried to write my own function but this was riddled with bugs and I have also tried using bwtraceboundary and indexing however this has problematic results as the points within the matrix are not in the order that create the contour. Thank you in advance for any help. Btw, I have included a link to a plot of the set of points. It is half the outline of a hand. The function would ideally trace the contour from ether the red star to the green triangle. Returning the points in order of traversal.

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  • How to redirect registry access of a dll loaded by my program

    - by dummzeuch
    I have got a dll that I load in my program which reads and writes its settings to the registry (hkcu). My program changes these settings prior to loading the dll so it uses the settings my program wants it to use which works fine. Unfortunately I need to run several instances of my program with different settings for the dll. Now the approach I have used so far no longer works reliably because it is possible for one instance of the program to overwrite the settings that another instance just wrote before the dll has a chance to read them. I haven't got the source of the dll in question and I cannot ask the programmer who wrote it to change it. One idea I had, was to hook registry access functions and redirect them to a different branch of the registry which is specific to the instance of my program (e.g. use the process id as part of the path). I think this should work but maybe you have got a different / more elegant. In case it matters: I am using Delphi 2007 for my program, the dll is probably written in C or C++.

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  • How to update GUI thread/class from worker thread/class?

    - by user315182
    First question here so hello everyone. The requirement I'm working on is a small test application that communicates with an external device over a serial port. The communication can take a long time, and the device can return all sorts of errors. The device is nicely abstracted in its own class that the GUI thread starts to run in its own thread and has the usual open/close/read data/write data basic functions. The GUI is also pretty simple - choose COM port, open, close, show data read or errors from device, allow modification and write back etc. The question is simply how to update the GUI from the device class? There are several distinct types of data the device deals with so I need a relatively generic bridge between the GUI form/thread class and the working device class/thread. In the GUI to device direction everything works fine with [Begin]Invoke calls for open/close/read/write etc. on various GUI generated events. I've read the thread here (How to update GUI from another thread in C#?) where the assumption is made that the GUI and worker thread are in the same class. Google searches throw up how to create a delegate or how to create the classic background worker but that's not at all what I need, although they may be part of the solution. So, is there a simple but generic structure that can be used? My level of C# is moderate and I've been programming all my working life, given a clue I'll figure it out (and post back)... Thanks in advance for any help.

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  • How to implement a 'safe' periodical executer without using the Rails helpers?

    - by Robbie
    I am very new to Ruby on Rails and was never really big on writing JavaScript, so the built in helpers were like a tiny silce of heaven. However I have recently learned that using the helper methods creates "obtrusive javascript" so I am doing a tiny bit of refactoring to get all this messy code out of my view. I'm also using the Prototype API to figure out what all these functions do. Right now, I have: <%= periodically_call_remote(:url => {:action => "tablerefresh", :id => 1 }, :frequency => '5', :complete => "load('26', 'table1', request.responseText)")%> Which produces: <script type="text/javascript"> //<![CDATA[ new PeriodicalExecuter(function() {new Ajax.Request('/qrpsdrail/grids/tablerefresh/1', {asynchronous:true, evalScripts:true, onComplete:function(request){load('26', 'table1', request.responseText)}, parameters:'authenticity_token=' + encodeURIComponent('dfG7wWyVYEpelfdZvBWk7MlhzZoK7VvtT/HDi3w7gPM=')})}, 5) //]]> </script> My concern is that the "encodeURIComponent" and the presence of "authenticity_token" are generated by Rails. I'm assuming these are used to assure the validity of a request. (Ensuring a request comes from a currently active session?) If that is the case, how can I implement this in application.js 'safely'? It seems that the built in method, although obtrusive, does add some beneficial security. Thanks, in advance, to all who answer.

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  • Socket Read In Multi-Threaded Application Returns Zero Bytes or EINTR (-1)

    - by user309670
    Hi. Am a c-coder for a while now - neither a newbie nor an expert. Now, I have a certain daemoned application in C on a PPC Linux. I use PHP's socket_connect as a client to connect to this service locally. The server uses epoll for concurrent connections via a Unix socket. A user submitted string is parsed for certain characters/words using strstr() and if found, spawns 4 joinable threads to different websites simultaneously. I use socket, connect, write and read, to interact with the said webservers via TCP on port 80 in each thread. All connections and writes seems successful. Reads to the webserver sockets fail however, with either (A) all 3 threads seem to hang, and only one thread returns -1 and errno is set to 104. The responding thread takes like 10 minutes - an eternity long:-(. *I read somewhere that the 104 (is EINTR) suggests that ...'the connection was reset by peer', or (B) 0 bytes from 3 threads, and only 1 of the 4 threads actually returns some data. Isn't the socket read/write thread-safe? Otherwise, use thread-safe (and reentrant) libc functions such as strtok_r, gethostbyname_r, etc. *I doubt that the said webhosts are actually resetting the connection, because when I run a single-threaded standalone (everything else equal) all things works perfectly right. There's a second problem too (oops), I can't write back to the client who connect to my epoll-ed Unix socket. My daemon application will hang and hog CPU 100% for ever. Yet nothing is written to the clients end. Am sure the client (a very typical PHP socket application) hasn't closed the connection whenever this is happening - no error(s) detected either. I cannot figure-out whatever is wrong even with Valgrind or GDB

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  • SWIG interface to receive an opaque struct reference in Java through function argument

    - by Beeo
    I am trying to use SWIG in order to use the Spotify API (libspotify) for Android: https://developer.spotify.com/technologies/libspotify/ I am having trouble defining the SWIG interface file to be able to successfully call the following native C function: sp_error sp_session_create(const sp_session_config * config, sp_session ** sess); Which in C would be called like this: //config struct defined previously sp_session *sess; sp_session_create(&config, &sess); But in Java I would need to call it like this: //config object defined previously sp_session javaSess = new sp_session(); sp_session_create(config, javaSess); sp_session is an opaque struct and is only defined in libspotify's API.h file as: typedef struct sp_session sp_session; I'm expecting the libspotify library to create it and give me a reference to it. The only thing I need that reference for then is to pass to other functions in the API. I believe the answer lies within the SWIG interface and typemaps, but I have been unsuccessful in trying to apply the examples I found in the documentation: http://www.swig.org/Doc2.0/SWIGDocumentation.html#Java_struct_pointer_pointer `http://www.swig.org/Doc2.0/SWIGDocumentation.html#Java_using_typemaps_return_arguments Help!

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  • Using parameterized function calls in SELECT statements. SQL Server

    - by geekzlla
    I have taken over some code from a previous developer and have come across this SQL statement that calls several SQL functions. As you can see, the function calls in the select statement pass a parameter to the function. How does the SQL statement know what value to replace the variable with? For the below sample, how does the query engine know what to replace nDeptID with when it calls, fn_SelDeptName_DeptID(nDeptID) nDeptID IS a column in table Note. SELECT STATEMENT: SELECT nCustomerID AS [Customer ID], nJobID AS [Job ID], dbo.fn_SelDeptName_DeptID(nDeptID) AS Department, nJobTaskID AS JobTaskID, dbo.fn_SelDeptTaskDesc_OpenTask(nJobID, nJobTaskID) AS Task, nStandardNoteID AS StandardNoteID, dbo.fn_SelNoteTypeDesc(nNoteID) AS [Note Type], dbo.fn_SelGPAStandardNote(nStandardNoteID) AS [Standard Note], nEntryDate AS [Entry Date], nUserName as [Added By], nType AS Type, nNote AS Note FROM Note WHERE nJobID = 844261 ORDER BY nJobID, Task, [Entry Date] ====================== Function fn_SelDeptName_DeptID: ALTER FUNCTION [dbo].[fn_SelDeptName_DeptID] (@iDeptID int) RETURNS varchar(25) -- Used by DataCollection for Job Tracking -- if the Deptartment isnt found return an empty string BEGIN -- Return the Department name for the given DeptID. DECLARE @strDeptName varchar(25) IF @iDeptID = 0 SET @strDeptName = '' ELSE BEGIN SET @strDeptName = (SELECT dName FROM Department WHERE dDeptID = @iDeptID) IF (@strDeptName IS NULL) SET @strDeptName = '' END RETURN @strDeptName END ========================== Thanks in advance.

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  • Initialize Static Array of Structs in C

    - by russell_h
    I implementing a card game in C. There are lots of types of cards and each has a bunch of information, including some actions that will need to be individually scripted associated with it. Given a struct like this (and I'm not certain I have the syntax right for the function pointer) struct CARD { int value; int cost; // This is a pointer to a function that carries out actions unique // to this card int (*do_actions) (struct GAME_STATE *state, int choice1, int choice2); }; I would like to initialize a static array of these, one for each card. I'm guessing this would look something like this int do_card0(struct GAME_STATE *state, int choice1, int choice2) { // Operate on state here } int do_card1(struct GAME_STATE *state, int choice1, int choice2) { // Operate on state here } extern static struct cardDefinitions[] = { {0, 1, do_card0}, {1, 3, do_card1} }; Will this work, and am I going about this the right way at all? I'm trying to avoid huge numbers of switch statements. Do I need to define the 'do_cardN' functions ahead of time, or is there some way to define them inline in the initialization of the struct (something like a lambda function in python)? I'll need read-only access to cardDefinitions from a different file - is 'extern static' correct for that? I know this is a lot of questions rolled into one but I'm really a bit vague about how to go about this. Thanks.

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