Search Results

Search found 4940 results on 198 pages for 'understanding'.

Page 120/198 | < Previous Page | 116 117 118 119 120 121 122 123 124 125 126 127  | Next Page >

• Can't edit IORegistryEntry

  - by yangumi

  Hi, I am creating a software on Mac and I would like to change the value of an IORegistryEntry. I can view it on the IORegistryExplorer, but I can't edit it. So it's my understanding that I have to edit it via code. Here is my code: CFMutableDictionaryRef matchingDict = IOServiceNameMatching("AppleUSBMultitouchDriver"); io_service_t service = IOServiceGetMatchingService(kIOMasterPortDefault, matchingDict); if(service) { CFStringRef manufacturer = IORegistryEntryCreateCFProperty(service, CFSTR("Manufacturer"), kCFAllocatorDefault,0); NSLog(@"%@", (NSString*)manufacturer); kern_return_t err = IORegistryEntrySetCFProperty(service, CFSTR("Manufacturer"), CFSTR("test")); NSLog(@"error = %d", err); } This will output 2010-04-10 16:09:09.015 Test[41548:a0f] Apple Inc. 2010-04-10 16:09:09.015 Test[41548:a0f] error = 0 But after I check the value in the IORegistryExplorer, it still doesn't change. Does anybody have any suggestions? Thank you

  Read the article

• Variable loss in redirected bash while loop

  - by James Hadley

  I have the following code for ip in $(ifconfig | awk -F ":" '/inet addr/{split($2,a," ");print a[1]}') do bytesin=0; bytesout=0; while read line do if [[ $(echo ${line} | awk '{print $1}') == ${ip} ]] then increment=$(echo ${line} | awk '{print $4}') bytesout=$((${bytesout} + ${increment})) else increment=$(echo ${line} | awk '{print $4}') bytesin=$((${bytesin} + ${increment})) fi done < <(pmacct -s | grep ${ip}) echo "${ip} ${bytesin} ${bytesout}" >> /tmp/bwacct.txt done Which I would like to print the incremented values to bwacct.txt, but instead the file is full of zeroes: 91.227.223.66 0 0 91.227.221.126 0 0 127.0.0.1 0 0 My understanding of Bash is that a redirected for loop should preserve variables. What am I doing wrong?

  Read the article

• How to get data in the servlet send via dojo.xhrPost

  - by snell

  > var xhrArgs = { > url: '/mum/proxy/http/localhost:8080/DemoProject/MyServlet', > postData:' MyDataToBeSend', > handleAs: 'text', > load: function(data) { }, > error: function(error) {alert(error);}}; var ret = > dojo.xhrGet(xhrArgs); Hi All, I have written the above code in Javascript to send data to a servlet. But I am not understanding how to get the postData in the servlet.

  Read the article

• c++ normalizing data sizes across systems

  - by Bocochoco

  I have a struct with three variables: two unsigned ints and an unsigned char. From my understanding, a c++ char is always 1 byte regardless of what operating system it is on. The same can't be said for other datatypes. I am looking for a way to normalize POD's so that when saved into a binary file, the resulting file is readable on any operating system that the code is compiled for. I changed my struct to use a 1-byte alignment by adding #pragma as follows: #pragma pack(push, 1) struct test { int a; } #pragma pack(pop) but that doesn't necessarily mean that int a is exactly 4 bytes on every os, I don't think? Is there a way to ensure that a file saved from my code will always be readable?

  Read the article

• Ideas for using R to create a T-shirt design (for useR 2010) ?

  - by Tal Galili

  There is now a competition for creating a T-shirt design for useR2010. Someone proposed the idea to use R for creating the T-shirt image. Which leads me to my questions: What type of images do you think might be fitting for this? How would you suggest to use R to create the images ? Would anyone here want to have a go at it? (p.s: I understand this is not a pure "programming" question. Yet it involves R programming, the understanding of R aesthetics, and some caring for the R community. I also understand I am at the risk of annoying people here with this question, so in case that happens - I deeply apologies! My only justification is that I am acting in good faith and in the purpose of having nice things for R users to enjoy, while learning something in the process) Related thread I once opened: http://stackoverflow.com/questions/2162131/how-can-i-learn-to-create-beautiful-infographics-with-connection-to-my-r-knowled

  Read the article

• Quick CPU ring mode protection question

  - by b-gen-jack-o-neill

  Hi, me again :) I am very curious in messing up with HW. But my top level "messing" so far was linked or inline assembler in C program. If my understanding of CPU and ring mode is right, I cannot directly from user mode app access some low level CPU features, like disabling interrupts, or changing protected mode segments, so I must use system calls to do everything I want. But, if I am right, drivers can run in ring mode 0. I actually don´t know much about drivers, but this is what I ask for. I just want to know, is learning how to write your own drivers and than call them the way I should go, to do what I wrote? I know I could write whole new OS (at least to some point), but what I exactly want to do is acessing some low level features of HW from standart windows application. So, is driver the way to go?

  Read the article

• JPA and aggregate functions. How do I use the result of the query?

  - by Bogdan

  Hey guys, I'm new to ORM stuff and I need some help understanding something. Let's assume I have the following standard SQL query: SELECT *, COUNT(test.testId) AS noTests FROM inspection LEFT JOIN test ON inspection.inspId = test.inspId GROUP BY inspection.inspId which I want to use in JPA. I have an Inspection entity with a one-to-many relationship to a Test entity. (an inspection has many tests) I tried writing this in JPQL: Query query = em.createQuery("SELECT insp, COUNT(???what???) FROM Inspection insp LEFT JOIN insp.testList " + "GROUP BY insp.inspId"); 1) How do I write the COUNT clause? I'd have to apply count to elements from the test table but testList is a collection, so I can't do smth like COUNT(insp.testList.testId) 2) Assuming 1 is resolved, what type of object will be returned. It will definitely not be an Inspection object... How do I use the result?

  Read the article

• Copy of Access mdb database being updated by live database

  - by James

  I'm trying to compute statistics for data held in an Access .mdb database. In order to avoid interfering with the live database, I'm working from a copy which I made by simply using copy-paste in Windows Explorer. The copy resides in the same directory, but with a different name. I'm using R and RODBC to connect to the copy of the file. The strange thing is that new data that is being updated on the original live database is appearing in my queries. This is despite the file timestamps of the copy not changing at all. It is also causing some slowdown in the live database. My understanding is that the .mdb files are standalone, or is this not the case? Should I have copied the database in a different way?

  Read the article

• Undefined behaviour with non-virtual destructors - is it a real-world issue?

  - by Roddy

  Consider the following code: class A { public: A() {} ~A() {} }; class B: public A { B() {} ~B() {} }; A* b = new B; delete b; // undefined behaviour My understanding is that the C++ standard says that deleting b is undefined behaviour - ie, anything could happen. But, in the real world, my experience is that ~A() is always invoked, and the memory is correctly freed. if B introduces any class members with their own destructors, they won't get invoked, but I'm only interested in the simple kind of case above, where inheritance is used maybe to fix a bug in one class method for which source code is unavailable. Obviously this isn't going to be what you want in non-trivial cases, but it is at least consistent. Are you aware of any C++ implementation where the above does NOT happen, for the code shown?

  Read the article

• How do I prevent a pair of XMLEvent[Reader|Writer] from splitting empty tags into start+end tags?

  - by java.is.for.desktop

  Hello, everyone! I have an understanding problem of how the following code works: XMLInputFactory xif = XMLInputFactory.newFactory(); XMLOutputFactory xof = XMLOutputFactory.newFactory(); XMLEventReader reader = xif.createXMLEventReader(/* ... */); XMLEventWriter writer = xof.createXMLEventWriter(/* ... */); writer.add(reader); The method writer.add([some reader]) reads all events from reader and writes them consequently. Sadly, following happens: The input <root><c/></root> gets transformed to <root><c><c/></root> I know, from XML point of view, these are equal trees, but not for a human ;) What can I do to get the same output? FYI: I need a XMLEvent[Reader|Writer] pair later to filter "XML events".

  Read the article

• .NET platform independant sync framework

  - by Quandary

  Question: I need to synchronize a few ActionScript files from my computer to a network share (backup). I saw a quick fix would be using Microsoft Sync Framework for this, and write a windows service. My problem is I also use Linux, and before I start with MS vendor lockin, is there any sync framework/library/whatever I could use that works accross platform? Or does the MS sync framework work on Linux, too? It is my understanding that it is a wrapper around some com objects, thus it wouldn't work. All I need is synchronizing files. So never mind the database part, although it would be nice to have it, too.

  Read the article

• AJAX XMLHttpRequest POST X-Domain

  - by Tom

  Hi Guys, I am sending an AJAX request using POST over X-Domain for a widget we are producing for our website. The problem we are facing is that this is getting blocked. My question is - for "modern browsers" [Chrome, Safari, FF, IE8] - it is my understanding that setting "Access-Control" headers Access-Control-Allow-Origin: http://www.test.com Access-Control-Allow-Methods: POST, GET, OPTIONS Access-Control-Allow-Headers: * Access-Control-Max-Age: 1728000 Will allow these "POST" requests to work ? But for IE7 we need to implement some "custom" JSONP solution? Am I correct in this ?

  Read the article

• Multiple things at once (Threads?)

  - by Jonathan

  All, What is a really simple way of having a program do more than one thing at once, even if the computer does not necessarily have multiple 'cores'. Can I do this by creating more than one Thread? My goal is to be able to have two computers networked (through Sockets) to respond to each-other's requests, while my program will at the same time be able to be managing a UI. I want the server to potentially handle more than one client at the same time as well. My understanding is that the communication is done with BufferedReader.readLine() and PrintWriter.println(). My problem is that I want the server to be waiting on multiple readLine() requests, and also be doing other things. How do I handle this? Many thanks, Jonathan

  Read the article

• Why is volatile not considered useful in multithreaded C or C++ programming?

  - by Michael E

  As demonstrated in this answer I recently posted, I seem to be confused about the utility (or lack thereof) of volatile in multi-threaded programming contexts. My understanding is this: any time a variable may be changed outside the flow of control of a piece of code accessing it, that variable should be declared to be volatile. Signal handlers, I/O registers, and variables modified by another thread all constitute such situations. So, if you have a global int foo, and foo is read by one thread and set atomically by another thread (probably using an appropriate machine instruction), the reading thread sees this situation in the same way it sees a variable tweaked by a signal handler or modified by an external hardware condition and thus foo should be declared volatile (or, for multithreaded situations, accessed with memory-fenced load, which is probably a better a solution). How and where am I wrong?

  Read the article

• How can CopyOnWriteArrayList be thread-safe?

  - by Shooshpanchick

  I've taken a look into OpenJDK's sources of CopyOnWriteArrayList and it seems that all write operations are protected by the same lock and read operations are not protected at all. As I understand, under JMM all accesses to a variable (both read and write) should be protected by lock or reordering effects may occur. For example, set(int, E) method contains these lines (under lock): /* 1 */ int len = elements.length; /* 2 */ Object[] newElements = Arrays.copyOf(elements, len); /* 3 */ newElements[index] = element; /* 4 */ setArray(newElements); The get(int) method, on the other hand, only does return get(getArray(), index);. In my understanding of JMM, this means that get may observe the array in an inconsistent state if statements 1-4 are reordered like 1-2(new)-4-2(copyOf)-3. Do I understand JMM incorrectly or is there any other explanations on why CopyOnWriteArrayList is thread-safe?

  Read the article

• javasrcipt asyncronous function

  - by Ben

  Hi there, i have a problem understanding how this could/should be solved. I have two functions. In the first function ( I call it loadData() ) I'm doing an asyncronous request to the server to load some data. In the second function ( saveData() ) I'm also doing an asyn request to the server to write some data. In the callback of this request I'm callin loadData() to refresh the data. Now the problem: In the saveData() function I want to wait for loadData() to be finished bevore I show a dialog (like alert('Data saved')) I guess this is a common problem, but I couldn't find the solution for it (if there is one..) A solution would be to make the requests syncronous, but the framework I'm using doesn't offer that and I hope there's a better solution.. Thanks to all!

  Read the article

• C99 strict aliasing rules in C++ (GCC)

  - by Checkers

  As far as I understand, GCC supports all of its C99 features in C++. But how is C99 strict aliasing handled in C++ code? I know that casting with C casts between unrelated types is not strict-aliasing-safe and may generate incorrect code, but what about C++? Since strict aliasing is not part of C++ standard (is that correct?), GCC must be specifying the semantics itself. I figure const_cast and static_cast cast between related types, hence they are safe, while reinterpret_cast can break strict aliasing rules. Is this a correct understanding?

  Read the article

• How to stop an activity with GL view. Application not responding

  - by David

  I have an activity that I want to programmatically stop after some elapsed time. I have a GL view running. My understanding is that the GLSurfaceView.renderer is running in its own thread, so I created a handler instantiated from the activity. In the GLSurfaceView I post a message. The handler then attempts to stop the activity with the following: onStop(); finish(); The activity seems to close. However, if I try to restart the application, I get a blank screen, the phone is practically locked up and eventually I get a message that the activity in the application is not responding. I'm also getting geting a wake lock, ie PowerManager.newWakeLock(...). When I try to release it, I get an exception. Not sure if its the GL view of the wake lock which is causing me troubles. Any ideas appreciated.

  Read the article

• How to write a simple usb driver?

  - by ScReYm0

  I make this treat because you are closing my other before i get my answer. Here is my answer clear and exactly what i want to do! I wanna create a usb driver, so my own C application be able to get into my flash drive and take information from the imported flash drive. OS: Windows Please don't close it again I still cant find my answer... more details I start my app/which contains my USB driver/ i plug-in my flash and its shows in Explorer that this drive is plugged and it is accessible, while that's happening, my app is checking that file data.txt EXIST if that file exist, program run next function, if not program, my program runs down/exit/! I hope that this helps understanding my idea...

  Read the article

• How to use cbreak mode in Ruby terminal application?

  - by Thomas

  In a small Ruby application, I'd like user input to be accepted without having to wait for a carriage return. My understanding is that cbreak mode needs to be enabled in order for the terminal to feed user input directly into the script. I tried simply running x%[cbreak()] at the top of my script but that didn't work. I've also seen that it's possible to use (n)curses to achieve the same results, although that seems like overkill. Does anybody have a suggestion on how to implement this? Thanks

  Read the article

• How to manage different form contexts of same form element in single DOM tree

  - by nimp

  Hi, As my question title could be bit unclear to you (I tried best), following is what I'm exactly trying to do. I'm having a form element (say a user_info form), where such form elements will be generated for different users by java script and displayed in different js tabs (example: dojo tabs). once form elements are generated, later I need to react on user actions performed on different html elements defined inside user_info form. In this case I need to identify what is the context (in which user_info form element) in which user is working on. The simplest example would be how to retrieve form id of the form in which user actions are being performed. According to my understanding, I can not simply retrieve from by form id, because now DOM tree contains duplicate form instances of the same from element. So, IS there anyway, I could identify form context based on the user actions on its input elements. Thank You.

  Read the article

• using time() to measure how long a function takes

  - by hap497

  Hi, I am trying to use time() to measure various points of my program. http://www.cplusplus.com/reference/clibrary/ctime/time/ What I don't understand is why the values in the before and after are Different? I understanding this is not the best way to profile my program, I just want to see how long does something take. printf ("**MyProgram::before time= %ld\n", time(NULL)); doSomthing(); doSomthingLong(); printf ("**MyProgram::after time= %ld\n", time(NULL)); Thank you.

  Read the article

• Why should "miter" joints be slower than others?

  - by Hanno Fietz

  I'm having a graphics problem on drawing lines in Flash Player, where two lines drawn on top of each other with different thickness don't align properly if I use any other JointStyle than MITER. For pictures of the effect, and for the graphics oriented part of the question, see my post over on doctype. However, there's also a second angle on this problem, which is: why should drawing the "mitered" joints be so much slower than others? This seems to be a problem since at least FP 8, but I couldn't find any detailed info on what the problem might be. Is this just an ordinary bug that didn't get fixed yet, or is there something inherently slower about drawing these joints? For example, they seem to have something to do with square roots, but I seriously lack understanding of what this joint style thing is all about, technically. It just looks like some minor detail a graphic designer might worry about. I'm asking because I'm wondering if I can do something to mitergate, er, mitigate, the problem.

  Read the article

• Passing input to Ant's <exec> task

  - by mikek

  I have an Ant script running a standard -task after taking in an inputed password: <input message="Password:" addproperty="password"> <handler classname="org.apache.tools.ant.input.SecureInputHandler" /> </input> <exec executable="/bin/sh" input="${password}" failonerror="true"> <arg line='-c "myScript.sh"' /> </exec> The script myScript.sh prompts the user for a password, and, it was my understanding that from the Ant documentation that input is supposed relay input into whatever the <exec> task is executing, but instead I get (for entering the password foobar) [exec] Failed to open /usr/local/foobar which is followed by a stack trace from my script complaining about an incorrect password...so obviously I've understood the documentation wrong. Does anybody know how to handle prompted input from external scripts in Ant?

  Read the article

• I'm having a hard time wrapping my head around handling the Activity Lifecycle...

  - by kefs

  So it seems i've created a fatal flaw and coded an app before understanding/handling rotation/lifecycle events.. Currently, all of my code is in onCreate of each activity. I've read a lot of lifecycle tutorials online, including the official dev guide info, but i'm still having an almost unbelievably hard time trying to wrap my head around the rotation/lifecycle events/methods and when to use them correctly. For example, my app currently has an activity that opens the db, inserts a record, then closes the db.. if i rotate my screen on this activity, the data is re-entered into the db. Using the available lifecycle events (onPause(), onResume(), etc..), how would I prevent this db call from happening again? Would I have to pass a variable through the state saying that the db call has been done, and not to do it again? Thanks in advance..

  Read the article

< Previous Page | 116 117 118 119 120 121 122 123 124 125 126 127  | Next Page >