Search Results

Search found 30347 results on 1214 pages for 'jamie read'.

Page 102/1214 | < Previous Page | 98 99 100 101 102 103 104 105 106 107 108 109  | Next Page >

  • eBooks on iPad vs. Kindle: More Debate than Smackdown

    - by andrewbrust
    When the iPad was presented at its San Francisco launch event on January 28th, Steve Jobs spent a significant amount of time explaining how well the device would serve as an eBook reader. He showed the iBooks reader application and iBookstore and laid down the gauntlet before Amazon and its beloved Kindle device. Almost immediately afterwards, criticism came rushing forth that the iPad could never beat the Kindle for book reading. The curious part of that criticism is that virtually no one offering it had actually used the iPad yet. A few weeks later, on April 3rd, the iPad was released for sale in the United States. I bought one on that day and in the few additional weeks that have elapsed, I’ve given quite a workout to most of its capabilities, including its eBook features. I’ve also spent some time with the Kindle, albeit a first-generation model, to see how it actually compares to the iPad. I had some expectations going in, but I came away with conclusions about each device that were more scenario-based than absolute. I present my findings to you here.   Vital Statistics Let’s start with an inventory of each device’s underlying technology. The iPad has a color, backlit LCD screen and an on-screen keyboard. It has a battery which, on a full charge, lasts anywhere from 6-10 hours. The Kindle offers a monochrome, reflective E Ink display, a physical keyboard and a battery that on my first gen loaner unit can go up to a week between charges (Amazon claims the battery on the Kindle 2 can last up to 2 weeks on a single charge). The Kindle connects to Amazon’s Kindle Store using a 3G modem (the technology and network vary depending on the model) that incurs no airtime service charges whatsoever. The iPad units that are on-sale today work over WiFi only. 3G-equipped models will be on sale shortly and will command a $130 premium over their WiFi-only counterparts. 3G service on the iPad, in the U.S. from AT&T, will be fee-based, with a 250MB plan at $14.99 per month and an unlimited plan at $29.99. No contract is required for 3G service. All these tech specs aside, I think a more useful observation is that the iPad is a multi-purpose Internet-connected entertainment device, while the Kindle is a dedicated reading device. The question is whether those differences in design and intended use create a clear-cut winner for reading electronic publications. Let’s take a look at each device, in isolation, now.   Kindle To me, what’s most innovative about the Kindle is its E Ink display. E Ink really looks like ink on a sheet of paper. It requires no backlight, it’s fully visible in direct sunlight and it causes almost none of the eyestrain that LCD-based computer display technology (like that used on the iPad) does. It’s really versatile in an all-around way. Forgive me if this sounds precious, but reading on it is really a joy. In fact, it’s a genuinely relaxing experience. Through the Kindle Store, Amazon allows users to download books (including audio books), magazines, newspapers and blog feeds. Books and magazines can be purchased either on a single-issue basis or as an annual subscription. Books, of course, are purchased singly. Oddly, blogs are not free, but instead carry a monthly subscription fee, typically $1.99. To me this is ludicrous, but I suppose the free 3G service is partially to blame. Books and magazine issues download quickly. Magazine and blog subscriptions cause new issues or posts to be pushed to your device on an automated basis. Available blogs include 9000-odd feeds that Amazon offers on the Kindle Store; unless I missed something, arbitrary RSS feeds are not supported (though there are third party workarounds to this limitation). The shopping experience is integrated well, has an huge selection, and offers certain graphical perks. For example, magazine and newspaper logos are displayed in menus, and book cover thumbnails appear as well. A simple search mechanism is provided and text entry through the physical keyboard is relatively painless. It’s very easy and straightforward to enter the store, find something you like and start reading it quickly. If you know what you’re looking for, it’s even faster. Given Kindle’s high portability, very reliable battery, instant-on capability and highly integrated content acquisition, it makes reading on whim, and in random spurts of downtime, very attractive. The Kindle’s home screen lists all of your publications, and easily lets you select one, then start reading it. Once opened, publications display in crisp, attractive text that is adjustable in size. “Turning” pages is achieved through buttons dedicated to the task. Notes can be recorded, bookmarks can be saved and pages can be saved as clippings. I am not an avid book reader, and yet I found the Kindle made it really fun, convenient and soothing to read. There’s something about the easy access to the material and the simplicity of the display that makes the Kindle seduce you into chilling out and reading page after page. On the other hand, the Kindle has an awkward navigation interface. While menus are displayed clearly on the screen, the method of selecting menu items is tricky: alongside the right-hand edge of the main display is a thin column that acts as a second display. It has a white background, and a scrollable silver cursor that is moved up or down through the use of the device’s scrollwheel. Picking a menu item on the main display involves scrolling the silver cursor to a position parallel to that menu item and pushing the scrollwheel in. This navigation technique creates a disconnect, literally. You don’t really click on a selection so much as you gesture toward it. I got used to this technique quickly, but I didn’t love it. It definitely created a kind of anxiety in me, making me feel the need to speed through menus and get to my destination document quickly. Once there, I could calm down and relax. Books are great on the Kindle. Magazines and newspapers much less so. I found the rendering of photographs, and even illustrations, to be unacceptably crude. For this reason, I expect that reading textbooks on the Kindle may leave students wanting. I found that the original flow and layout of any publication was sacrificed on the Kindle. In effect, browsing a magazine or newspaper was almost impossible. Reading the text of individual articles was enjoyable, but having to read this way made the whole experience much more “a la carte” than cohesive and thematic between articles. I imagine that for academic journals this is ideal, but for consumer publications it imposes a stripped-down, low-fidelity experience that evokes a sense of deprivation. In general, the Kindle is great for reading text. For just about anything else, especially activity that involves exploratory browsing, meandering and short-attention-span reading, it presents a real barrier to entry and adoption. Avid book readers will enjoy the Kindle (if they’re not already). It’s a great device for losing oneself in a book over long sittings. Multitaskers who are more interested in periodicals, be they online or off, will like it much less, as they will find compromise, and even sacrifice, to be palpable.   iPad The iPad is a very different device from the Kindle. While the Kindle is oriented to pages of text, the iPad orbits around applications and their interfaces. Be it the pinch and zoom experience in the browser, the rich media features that augment content on news and weather sites, or the ability to interact with social networking services like Twitter, the iPad is versatile. While it shares a slate-like form factor with the Kindle, it’s effectively an elegant personal computer. One of its many features is the iBook application and integration of the iBookstore. But it’s a multi-purpose device. That turns out to be good and bad, depending on what you’re reading. The iBookstore is great for browsing. It’s color, rich animation-laden user interface make it possible to shop for books, rather than merely search and acquire them. Unfortunately, its selection is rather sparse at the moment. If you’re looking for a New York Times bestseller, or other popular titles, you should be OK. If you want to read something more specialized, it’s much harder. Unlike the awkward navigation interface of the Kindle, the iPad offers a nearly flawless touch-screen interface that seduces the user into tinkering and kibitzing every bit as much as the Kindle lulls you into a deep, concentrated read. It’s a dynamic and interactive device, whereas the Kindle is static and passive. The iBook reader is slick and fun. Use the iPad in landscape mode and you can read the book in 2-up (left/right 2-page) display; use it in portrait mode and you can read one page at a time. Rather than clicking a hardware button to turn pages, you simply drag and wipe from right-to-left to flip the single or right-hand page. The page actually travels through an animated path as it would in a physical book. The intuitiveness of the interface is uncanny. The reader also accommodates saving of bookmarks, searching of the text, and the ability to highlight a word and look it up in a dictionary. Pages display brightly and clearly. They’re easy to read. But the backlight and the glare made me less comfortable than I was with the Kindle. The knowledge that completely different applications (including the Web and email and Twitter) were just a few taps away made me antsy and very tempted to task-switch. The knowledge that battery life is an issue created subtle discomfort. If the Kindle makes you feel like you’re in a library reading room, then the iPad makes you feel, at best, like you’re under fluorescent lights at a Barnes and Noble or Borders store. If you’re lucky, you’d be on a couch or at a reading table in the store, but you might also be standing up, in the aisles. Clearly, I didn’t find this conducive to focused and sustained reading. But that may have more to do with my own tendency to read periodicals far more than books, and my neurotic . And, truth be known, the book reading experience, when not explicitly compared to Kindle’s, was still pleasant. It is also important to point out that Kindle Store-sourced books can be read on the iPad through a Kindle reader application, from Amazon, specific to the device. This offered a less rich experience than the iBooks reader, but it was completely adequate. Despite the Kindle brand of the reader, however, it offered little in terms of simulating the reading experience on its namesake device. When it comes to periodicals, the iPad wins hands down. Magazines, even if merely scanned images of their print editions, read on the iPad in a way that felt similar to reading hard copy. The full color display, touch navigation and even the ability to render advertisements in their full glory makes the iPad a great way to read through any piece of work that is measured in pages, rather than chapters. There are many ways to get magazines and newspapers onto the iPad, including the Zinio reader, and publication-specific applications like the Wall Street Journal’s and Popular Science’s. The New York Times’ free Editors’ Choice application offers a Times Reader-like interface to a subset of the Gray Lady’s daily content. The completely Web-based but iPad-optimized Times Skimmer site (at www.nytimes.com/timesskimmer) works well too. Even conventional Web sites themselves can be read much like magazines, given the iPad’s ability to zoom in on the text and crop out advertisements on the margins. While the Kindle does have an experimental Web browser, it reminded me a lot of early mobile phone browsers, only in a larger size. For text-heavy sites with simple layout, it works fine. For just about anything else, it becomes more trouble than it’s worth. And given the way magazine articles make me think of things I want to look up online, I think that’s a real liability for the Kindle.   Summing Up What I came to realize is that the Kindle isn’t so much a computer or even an Internet device as it is a printer. While it doesn’t use physical paper, it still renders its content a page at a time, just like a laser printer does, and its output appears strikingly similar. You can read the rendered text, but you can’t interact with it in any way. That’s why the navigation requires a separate cursor display area. And because of the page-oriented rendering behavior, turning pages causes a flash on the display and requires a sometimes long pause before the next page is rendered. The good side of this is that once the page is generated, no battery power is required to display it. That makes for great battery life, optimal viewing under most lighting conditions (as long as there is some light) and low-eyestrain text-centric display of content. The Kindle is highly portable, has an excellent selection in its store and is refreshingly distraction-free. All of this is ideal for reading books. And iPad doesn’t offer any of it. What iPad does offer is versatility, variety, richness and luxury. It’s flush with accoutrements even if it’s low on focused, sustained text display. That makes it inferior to the Kindle for book reading. But that also makes it better than the Kindle for almost everything else. As such, and given that its book reading experience is still decent (even if not superior), I think the iPad will give Kindle a run for its money. True book lovers, and people on a budget, will want the Kindle. People with a robust amount of discretionary income may want both devices. Everyone else who is interested in a slate form factor e-reading device, especially if they also wish to have leisure-friendly Internet access, will likely choose the iPad exclusively. One thing is for sure: iPad has reduced Kindle’s market, and may have shifted its mass market potential to a mere niche play. If Amazon is smart, it will improve its iPad-based Kindle reader app significantly. It can then leverage the iPad channel as a significant market for the Kindle Store. After all, selling the eBooks themselves is what Amazon should care most about.

    Read the article

  • Why does fprintf start printing out of order or not at all?

    - by Steve Melvin
    This code should take an integer, create pipes, spawn two children, wait until they are dead, and start all over again. However, around the third time around the loop I lose my prompt to enter a number and it no longer prints the number I've entered. Any ideas? #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <errno.h> #define WRITE 1 #define READ 0 int main (int argc, const char * argv[]) { //Pipe file-descriptor array unsigned int isChildA = 0; int pipeA[2]; int pipeB[2]; int num = 0; while(1){ fprintf(stderr,"Enter an integer: "); scanf("%i", &num); if(num == 0){ fprintf(stderr,"You entered zero, exiting...\n"); exit(0); } //Open Pipes if(pipe(pipeA) < 0){ fprintf(stderr,"Could not create pipe A.\n"); exit(1); } if(pipe(pipeB) < 0){ fprintf(stderr,"Could not create pipe B.\n"); exit(1); } fprintf(stderr,"Value read: %i \n", num); fprintf(stderr,"Parent PID: %i\n", getpid()); pid_t procID = fork(); switch (procID) { case -1: fprintf(stderr,"Fork error, quitting...\n"); exit(1); break; case 0: isChildA = 1; break; default: procID = fork(); if (procID<0) { fprintf(stderr,"Fork error, quitting...\n"); exit(1); } else if(procID == 0){ isChildA = 0; } else { write(pipeA[WRITE], &num, sizeof(int)); close(pipeA[WRITE]); close(pipeA[READ]); close(pipeB[WRITE]); close(pipeB[READ]); pid_t pid; while (pid = waitpid(-1, NULL, 0)) { if (errno == ECHILD) { break; } } } break; } if (procID == 0) { //We're a child, do kid-stuff. ssize_t bytesRead = 0; int response; while (1) { while (bytesRead == 0) { bytesRead = read((isChildA?pipeA[READ]:pipeB[READ]), &response, sizeof(int)); } if (response < 2) { //Kill other child and self fprintf(stderr, "Terminating PROCID: %i\n", getpid()); write((isChildA?pipeB[WRITE]:pipeA[WRITE]), &response, sizeof(int)); close(pipeA[WRITE]); close(pipeA[READ]); close(pipeB[WRITE]); close(pipeB[READ]); return 0; } else if(!(response%2)){ //Even response/=2; fprintf(stderr,"PROCID: %i, VALUE: %i\n", getpid(), response); write((isChildA?pipeB[WRITE]:pipeA[WRITE]), &response, sizeof(int)); bytesRead = 0; } else { //Odd response*=3; response++; fprintf(stderr,"PROCID: %i, VALUE: %i\n", getpid(), response); write((isChildA?pipeB[WRITE]:pipeA[WRITE]), &response, sizeof(int)); bytesRead = 0; } } } } return 0; } This is the output I am getting... bash-3.00$ ./proj2 Enter an integer: 101 Value read: 101 Parent PID: 9379 PROCID: 9380, VALUE: 304 PROCID: 9381, VALUE: 152 PROCID: 9380, VALUE: 76 PROCID: 9381, VALUE: 38 PROCID: 9380, VALUE: 19 PROCID: 9381, VALUE: 58 PROCID: 9380, VALUE: 29 PROCID: 9381, VALUE: 88 PROCID: 9380, VALUE: 44 PROCID: 9381, VALUE: 22 PROCID: 9380, VALUE: 11 PROCID: 9381, VALUE: 34 PROCID: 9380, VALUE: 17 PROCID: 9381, VALUE: 52 PROCID: 9380, VALUE: 26 PROCID: 9381, VALUE: 13 PROCID: 9380, VALUE: 40 PROCID: 9381, VALUE: 20 PROCID: 9380, VALUE: 10 PROCID: 9381, VALUE: 5 PROCID: 9380, VALUE: 16 PROCID: 9381, VALUE: 8 PROCID: 9380, VALUE: 4 PROCID: 9381, VALUE: 2 PROCID: 9380, VALUE: 1 Terminating PROCID: 9381 Terminating PROCID: 9380 Enter an integer: 102 Value read: 102 Parent PID: 9379 PROCID: 9386, VALUE: 51 PROCID: 9387, VALUE: 154 PROCID: 9386, VALUE: 77 PROCID: 9387, VALUE: 232 PROCID: 9386, VALUE: 116 PROCID: 9387, VALUE: 58 PROCID: 9386, VALUE: 29 PROCID: 9387, VALUE: 88 PROCID: 9386, VALUE: 44 PROCID: 9387, VALUE: 22 PROCID: 9386, VALUE: 11 PROCID: 9387, VALUE: 34 PROCID: 9386, VALUE: 17 PROCID: 9387, VALUE: 52 PROCID: 9386, VALUE: 26 PROCID: 9387, VALUE: 13 PROCID: 9386, VALUE: 40 PROCID: 9387, VALUE: 20 PROCID: 9386, VALUE: 10 PROCID: 9387, VALUE: 5 PROCID: 9386, VALUE: 16 PROCID: 9387, VALUE: 8 PROCID: 9386, VALUE: 4 PROCID: 9387, VALUE: 2 PROCID: 9386, VALUE: 1 Terminating PROCID: 9387 Terminating PROCID: 9386 Enter an integer: 104 Value read: 104 Parent PID: 9379 Enter an integer: PROCID: 9388, VALUE: 52 PROCID: 9389, VALUE: 26 PROCID: 9388, VALUE: 13 PROCID: 9389, VALUE: 40 PROCID: 9388, VALUE: 20 PROCID: 9389, VALUE: 10 PROCID: 9388, VALUE: 5 PROCID: 9389, VALUE: 16 PROCID: 9388, VALUE: 8 PROCID: 9389, VALUE: 4 PROCID: 9388, VALUE: 2 PROCID: 9389, VALUE: 1 Terminating PROCID: 9388 Terminating PROCID: 9389 105 Value read: 105 Parent PID: 9379 Enter an integer: PROCID: 9395, VALUE: 316 PROCID: 9396, VALUE: 158 PROCID: 9395, VALUE: 79 PROCID: 9396, VALUE: 238 PROCID: 9395, VALUE: 119 PROCID: 9396, VALUE: 358 PROCID: 9395, VALUE: 179 PROCID: 9396, VALUE: 538 PROCID: 9395, VALUE: 269 PROCID: 9396, VALUE: 808 PROCID: 9395, VALUE: 404 PROCID: 9396, VALUE: 202 PROCID: 9395, VALUE: 101 PROCID: 9396, VALUE: 304 PROCID: 9395, VALUE: 152 PROCID: 9396, VALUE: 76 PROCID: 9395, VALUE: 38 PROCID: 9396, VALUE: 19 PROCID: 9395, VALUE: 58 PROCID: 9396, VALUE: 29 PROCID: 9395, VALUE: 88 PROCID: 9396, VALUE: 44 PROCID: 9395, VALUE: 22 PROCID: 9396, VALUE: 11 PROCID: 9395, VALUE: 34 PROCID: 9396, VALUE: 17 PROCID: 9395, VALUE: 52 PROCID: 9396, VALUE: 26 PROCID: 9395, VALUE: 13 PROCID: 9396, VALUE: 40 PROCID: 9395, VALUE: 20 PROCID: 9396, VALUE: 10 PROCID: 9395, VALUE: 5 PROCID: 9396, VALUE: 16 PROCID: 9395, VALUE: 8 PROCID: 9396, VALUE: 4 PROCID: 9395, VALUE: 2 PROCID: 9396, VALUE: 1 Terminating PROCID: 9395 Terminating PROCID: 9396 105 Value read: 105 Parent PID: 9379 Enter an integer: PROCID: 9397, VALUE: 316 PROCID: 9398, VALUE: 158 PROCID: 9397, VALUE: 79 PROCID: 9398, VALUE: 238 PROCID: 9397, VALUE: 119 PROCID: 9398, VALUE: 358 PROCID: 9397, VALUE: 179 PROCID: 9398, VALUE: 538 PROCID: 9397, VALUE: 269 PROCID: 9398, VALUE: 808 PROCID: 9397, VALUE: 404 PROCID: 9398, VALUE: 202 PROCID: 9397, VALUE: 101 PROCID: 9398, VALUE: 304 PROCID: 9397, VALUE: 152 PROCID: 9398, VALUE: 76 PROCID: 9397, VALUE: 38 PROCID: 9398, VALUE: 19 PROCID: 9397, VALUE: 58 PROCID: 9398, VALUE: 29 PROCID: 9397, VALUE: 88 PROCID: 9398, VALUE: 44 PROCID: 9397, VALUE: 22 PROCID: 9398, VALUE: 11 PROCID: 9397, VALUE: 34 PROCID: 9398, VALUE: 17 PROCID: 9397, VALUE: 52 PROCID: 9398, VALUE: 26 PROCID: 9397, VALUE: 13 PROCID: 9398, VALUE: 40 PROCID: 9397, VALUE: 20 PROCID: 9398, VALUE: 10 PROCID: 9397, VALUE: 5 PROCID: 9398, VALUE: 16 PROCID: 9397, VALUE: 8 PROCID: 9398, VALUE: 4 PROCID: 9397, VALUE: 2 PROCID: 9398, VALUE: 1 Terminating PROCID: 9397 Terminating PROCID: 9398 106 Value read: 106 Parent PID: 9379 Enter an integer: PROCID: 9399, VALUE: 53 PROCID: 9400, VALUE: 160 PROCID: 9399, VALUE: 80 PROCID: 9400, VALUE: 40 PROCID: 9399, VALUE: 20 PROCID: 9400, VALUE: 10 PROCID: 9399, VALUE: 5 PROCID: 9400, VALUE: 16 PROCID: 9399, VALUE: 8 PROCID: 9400, VALUE: 4 PROCID: 9399, VALUE: 2 PROCID: 9400, VALUE: 1 Terminating PROCID: 9399 Terminating PROCID: 9400 ^C Another thing that's strange, when ran from within XCode it behaves normally. However, when ran from bash on Solaris or OSX it acts up.

    Read the article

  • Matrix in python

    - by Werner
    Hi, I am very new to Python, I need to read numbers from a file and store them in a matrix like I would do it in fortran or C; for i for j data[i][j][0]=read(0) data[i][j][1]=read(1) data[i][j][2]=read(2) ... ... How can I do the same in Python? I read a bit but got confused with tuples and similar things If you could point me to a similar example it would be great thanks

    Read the article

  • Query performs poorly unless a temp table is used

    - by Paul McLoughlin
    The following query takes about 1 minute to run, and has the following IO statistics: SELECT T.RGN, T.CD, T.FUND_CD, T.TRDT, SUM(T2.UNITS) AS TotalUnits FROM dbo.TRANS AS T JOIN dbo.TRANS AS T2 ON T2.RGN=T.RGN AND T2.CD=T.CD AND T2.FUND_CD=T.FUND_CD AND T2.TRDT<=T.TRDT JOIN TASK_REQUESTS AS T3 ON T3.CD=T.CD AND T3.RGN=T.RGN AND T3.TASK = 'UPDATE_MEM_BAL' GROUP BY T.RGN, T.CD, T.FUND_CD, T.TRDT (4447 row(s) affected) Table 'TRANSACTIONS'. Scan count 5977, logical reads 7527408, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0. Table 'TASK_REQUESTS'. Scan count 1, logical reads 11, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0. SQL Server Execution Times: CPU time = 58157 ms, elapsed time = 61437 ms. If I instead introduce a temporary table then the query returns quickly and performs less logical reads: CREATE TABLE #MyTable(RGN VARCHAR(20) NOT NULL, CD VARCHAR(20) NOT NULL, PRIMARY KEY([RGN],[CD])); INSERT INTO #MyTable(RGN, CD) SELECT RGN, CD FROM TASK_REQUESTS WHERE TASK='UPDATE_MEM_BAL'; SELECT T.RGN, T.CD, T.FUND_CD, T.TRDT, SUM(T2.UNITS) AS TotalUnits FROM dbo.TRANS AS T JOIN dbo.TRANS AS T2 ON T2.RGN=T.RGN AND T2.CD=T.CD AND T2.FUND_CD=T.FUND_CD AND T2.TRDT<=T.TRDT JOIN #MyTable AS T3 ON T3.CD=T.CD AND T3.RGN=T.RGN GROUP BY T.RGN, T.CD, T.FUND_CD, T.TRDT (4447 row(s) affected) Table 'Worktable'. Scan count 5974, logical reads 382339, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0. Table 'TRANSACTIONS'. Scan count 4, logical reads 4547, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0. Table '#MyTable________________________________________________________________000000000013'. Scan count 1, logical reads 2, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0. SQL Server Execution Times: CPU time = 1420 ms, elapsed time = 1515 ms. The interesting thing for me is that the TASK_REQUEST table is a small table (3 rows at present) and statistics are up to date on the table. Any idea why such different execution plans and execution times would be occuring? And ideally how to change things so that I don't need to use the temp table to get decent performance? The only real difference in the execution plans is that the temp table version introduces an index spool (eager spool) operation.

    Read the article

  • What does it mean when a ByteInputStream keeps returning 0?

    - by Zombies
    I have a ByteInputStream, created from a Socket in Java. The connection is to a simple web server that uses chunked transfer encoding. The web server does in fact work in normal browser. But in my program, I am attempting to read, I read the first first bytes (some 5kb of data). But each read after that returns 0 bytes read. Isn't it supposed to block until it can read?

    Read the article

  • Do I suffer from encapsulation overuse?

    - by Florenc
    I have noticed something in my code in various projects that seems like code smell to me and something bad to do, but I can't deal with it. While trying to write "clean code" I tend to over-use private methods in order to make my code easier to read. The problem is that the code is indeed cleaner but it's also more difficult to test (yeah I know I can test private methods...) and in general it seems a bad habit to me. Here's an example of a class that reads some data from a .csv file and returns a group of customers (another object with various fields and attributes). public class GroupOfCustomersImporter { //... Call fields .... public GroupOfCustomersImporter(String filePath) { this.filePath = filePath; customers = new HashSet<Customer>(); createCSVReader(); read(); constructTTRP_Instance(); } private void createCSVReader() { //.... } private void read() { //.... Reades the file and initializes the class attributes } private void readFirstLine(String[] inputLine) { //.... Method used by the read() method } private void readSecondLine(String[] inputLine) { //.... Method used by the read() method } private void readCustomerLine(String[] inputLine) { //.... Method used by the read() method } private void constructGroupOfCustomers() { //this.groupOfCustomers = new GroupOfCustomers(**attributes of the class**); } public GroupOfCustomers getConstructedGroupOfCustomers() { return this.GroupOfCustomers; } } As you can see the class has only a constructor which calls some private methods to get the job done, I know that's not a good practice not a good practice in general but I prefer to encapsulate all the functionality in the class instead of making the methods public in which case a client should work this way: GroupOfCustomersImporter importer = new GroupOfCustomersImporter(filepath) importer.createCSVReader(); read(); GroupOfCustomer group = constructGoupOfCustomerInstance(); I prefer this because I don't want to put useless lines of code in the client's side code bothering the client class with implementation details. So, Is this actually a bad habit? If yes, how can I avoid it? Please note that the above is just a simple example. Imagine the same situation happening in something a little bit more complex.

    Read the article

  • Increasing deadlocks with NoLock

    - by Dave Ballantyne
    One on my personnel pet issues is with inappropriate use of the NOLOCK hint (and read uncommitted) .  Dont get me wrong, I have used it in exceptional circumstances , but as a general statement it is a bad thing.  Mostly , when NOLOCK, is used the discussion is around a single statement,  “it runs faster with nolock for XYZ reason”,  however ,IMO, this is quite a shorted sighted view.  What about the Transaction ? What about other concurrent users ?  What is good for one statement in isolation , does not mean that it is good for the system as a whole.  I have seen on a number of occasions deadlocks happen, when tasks that would of(and should of) be blocked continue to execute, only for a deadlock to occur at a later data writing (INSERT,UPDATE,DELETE) statement.  Writers will block writers regardless of isolation level. By Way of (fairly contrived ) example , lets generate some dummy tables and populate with some data drop table a go drop table b go Create Table a ( col1 integer ) go insert into a values(1) insert into a values(2) go Create Table b ( col1 integer ) go insert into b values(1) insert into b values(2) go   Now make two connections. In connection one execute set transaction isolation level read committed BEGIN TRAN Select * from a Select * from b delete from a In connection two execute set transaction isolation level read committed BEGIN TRAN Select * from a Select * from b delete from b Right now the ‘select from a’ in connection two is being blocked by the ‘delete from a’ in connection one.  This is ,IMO, quite a healthy and natural thing to be happening , some see this as a ‘slow down’, a drop in performance.  So, lets reach for our ‘NOLOCK’ magic pill.  Cancel the blocked query and ROLLBACK both transactions, then in connection one execute set transaction isolation level read uncommitted BEGIN TRAN Select * from a Select * from b delete from b and then in connection two execute set transaction isolation level read uncommitted BEGIN TRAN Select * from a Select * from b delete from a We have now solved out performance problem , no more blocking.  Lets finish the work required by the transaction, in connection one , execute delete from a Oh, ‘ performance problem’ again , its now being blocked. Still, lets complete the work in connection two…. delete from b DEADLOCK!!  It is important to be clear about the role of the select statements.  They do not participate within the deadlock, but are preventing code executing that would of.   Additionally, without the select readers to block, a deadlock would occur on the deletes with READ COMMITTED. Naturally, other isolation levels will exhibit different behaviour as to where and when they will and wont block,  and I would encourage you to read BOL and satisfy yourself that you really do NEED to NOLOCK.

    Read the article

  • Python: How can I read in the characters from a line in a file and convert them to floats and strs, depending on if they are numbers or letters?

    - by user1467577
    I have a file that looks like: 1 1 C C 1.9873 2.347 3.88776 1 2 C Si 4.887 9.009 1.21 I would like to read in the contents of the file, line-by-line. When I only had numbers on the lines I used: for line in readlines(file): data = map(float, line.split) But this only works when all the elements of line.split are numbers. How can I make it store the letters as strings and the numbers as floats?

    Read the article

  • UPOS RFIDScanner data format

    - by Robert Snyder
    A lot of work that I do currently is based in the OPOS/UPOS world. My company has a device that can read 13.56Mhz tags (RFID), Smart Cards, and Mag Stripe cards. Up until somewhat recently I have only been working with RFID for a very specific scenario. That was to read UltraLight C and Desfire cards. These cards were all setup very specifically so that I could take the data read from those cards and force it into a MSR track2 format. The past couple of weeks, however, I have been working on reading RFID credit cards (since I have a Visa card I've been using mine), and Smart Card credit cards. (The visa card I have has both) In learning how to communicate with SmartCard and reading ISO7816 and EMVCO documents I became a little more familiar with how info is stored. But now I have a question regarding UPOS. The RFID data on my Visa is stored (and read) very similar to how the data is stored and read from the Smart Card on my Visa. Cool. Well in the UPOS spec for SmartCardRW the ReadData method returns a byte array. That's cool, I can just return all that data and then parse it as my heart desires. The RFID though has a LinkedList of Tags. Well this makes sense in terms of my Visa card (reminds me of a question I have in regards to SmartCard, but that is for another question) but what about ULC and Desfire, or for that matter any Mifare card. Pages, Files, Purses don't exactly fit the Tag profile. For instance lets just say I read pages 4-12 on my ULC card. Each page I read is 4 bytes long. Does this mean I have 9 tags in my LinkedList? Is my Tag id the page number? Or then how does that translate to Desfire? I open application 123456 and read file 1 and file 2, Do I have 2 tags? and if so what is my tag id? At least with my Visa I think that I have to use the Tag id (ex 5F24 for my expiration date) and value of {0x15, 0x10, 0x31} Part of me says yes..that makes sense. Another part of me says, "well if that is the case then why doesn't SmartCardRW have Tags?" So that is my question. How do I format my data from those different types of media? or is that the job of my Control Object (the application)? Is so how does it know? The only protocols I have are: // Summary: // Enumerates the available predefined RFID tag protocols the device supports. [Flags] public enum RFIDProtocols { EpcClass0 = 1, RFIDSdt0Plus = 2, EpcClass1 = 4, EpcClass1Gen2 = 8, EpcClass2 = 16, Iso14443A = 4096, Iso14443B = 8192, Iso15693 = 12288, Iso180006B = 16384, Other = 16777216, All = 1073741824, } If I use that well all of my cards that I have are all Iso14443A. I use the ATQA and the SAK to know what type of card I really have. There is no RFID property that lets me specify that. So I'm lost.

    Read the article

  • I am not able to delete a corrupt NTFS partition on my pen drive. How can I force its deletion?

    - by yesuraj
    I formatted my 16GB pen drive with the NTFS file system in windows vista. After that I started copying some files. However, only a few files were copied to the pen drive before the copy operation hung. So I cancelled the copy operation. Now I am unable to use the pen drive. I DON'T REALLY NEED ANY FILES THAT I COPIED TO THE PENDRIVE. I JUST WANT TO USE THE PENDRIVE AGAIN. I have tried using Ubuntu to format the pen drive. But when i use fdisk to delete the partition, it looks like it is working fine but in fact it does not delete the partition. Also I am unable to format it with any other file system. When I tried to use gparted, it throws the following error: Error mounting: mount exited with exit code 14: The disk contains an unclean file system(0,0). The file system wasn't safely closed on window. Fixing ntfs_attr_pread_i:ntfs_pread failed: Input/output error Failed to read NTFS$Bitmap:Input/output error NTFS is either inconsistent, or there is a hardware fault, or it's a softRAID/FakeRAID hardware. In the first case run chkdsk /f on Windows then reboot into windows twice. The usage of the /f parameter is very important!. If the device is a SoftRAID/FakeRAID then first activate it and mount a different device under the /dev/mapper directory, (e.g. /dev/mapper/nvidia_eahaabcc1). Please see the dmraid documentation for more details When I searched the Internet I found help on how to recover. But I don’t want to recover, I want to format it again. When I pressed w after deleting the partition, it took more time than previously. After that i removed the pen drive and re-inserted, but the partition I had deleted was still present. If I simply type the command fdisk /dev/sdb without removing the pen drive after the partition is deleted, then it returns the error message Unable to open /dev/sdb. Here are the steps that I followed: root@yesuraj-ubuntu:~# fdisk /dev/sdb Command (m for help): d Selected partition 1 Command (m for help): w The partition table has been altered! Calling ioctl() to re-read partition table. Syncing disks THE DEMESG PRINTS ARE AS FOLLOWS, [ 6139.774753] usb 2-1.3: reset high speed USB device number 4 using ehci_hcd [ 6154.816941] usb 2-1.3: device descriptor read/64, error -110 [ 6169.968908] usb 2-1.3: device descriptor read/64, error -110 [ 6170.158427] usb 2-1.3: reset high speed USB device number 4 using ehci_hcd [ 6185.200638] usb 2-1.3: device descriptor read/64, error -110 [ 6200.352572] usb 2-1.3: device descriptor read/64, error -110 [ 6200.542093] usb 2-1.3: reset high speed USB device number 4 using ehci_hcd [ 6205.559460] usb 2-1.3: device descriptor read/8, error -110 I used the dd command and it erased the partition table. But now when I connect the pen drive, dmesg contains this error message: [88143.437001] sdb: unknown partition table. I am not able to create a partion using fdisk /dev/sdb. The error message says that it is unable to find the node. Other messages from dmesg follow below. [87100.531596] usb 2-1.3: new high speed USB device number 39 using ehci_hcd [87130.915257] usb 2-1.3: new high speed USB device number 40 using ehci_hcd [87135.932647] usb 2-1.3: device descriptor read/8, error -110

    Read the article

  • XML Validation in ASP.NET MVC during load

    - by Jamie Nordmeyer
    I'm writing an ASP.NET MVC 2 application where one of the backing stores I plan to support is XML. I have a POCO that represents the settings for the site, along with an XML file to contain these settings. My question is what is the best way to validate this data as it is read from disk in to the POCO? I know I can use an XSD, or maybe use the Data Annotations library to mark up the POCO, and use reflection to validate the data, but is there another way, perhaps in .NET 3.5 or MVC to do this? I've spent some time Googling this issue, and want to be sure I'm doing it in the best manner. Thanks in advance!

    Read the article

  • Problem with assembly loading in .NET

    - by Jamie
    Hi guys, I have got two projects in my solution: Silverlight and standard one. The standard one references System.Xml assembly (version 4.0.0.0), however the Silverlight one references System.Xml assembly (v. 2.0.5.0). I want to make an instance of XmlWriter in my Silverlight project. Here comes the problem - the exception is thrown (file not found for System.Xml assembly). I believe it is a matter of different assembly versions. Do you have any idea how to resolve this issue? Ive read something about the binding redirection - is it the key to the solution? If so, how to do this? Thank you in advance for the reply! Cheers.

    Read the article

  • Java: Reading images and displaying as an ImageIcon

    - by 11helen
    I'm writing an application which reads and displays images as ImageIcons (within a JLabel), the application needs to be able to support jpegs and bitmaps. For jpegs I find that passing the filename directly to the ImageIcon constructor works fine (even for displaying two large jpegs), however if I use ImageIO.read to get the image and then pass the image to the ImageIcon constructor, I get an OutOfMemoryError( Java Heap Space ) when the second image is read (using the same images as before). For bitmaps, if I try to read by passing the filename to ImageIcon, nothing is displayed, however by reading the image with ImageIO.read and then using this image in the ImageIcon constructor works fine. I understand from reading other forum posts that the reason that the two methods don't work the same for the different formats is down to java's compatability issues with bitmaps, however is there a way around my problem so that I can use the same method for both bitmaps and jpegs without an OutOfMemoryError? (I would like to avoid having to increase the heap size if possible!) The OutOfMemoryError is triggered by this line: img = getFileContentsAsImage(file); and the method definition is: public static BufferedImage getFileContentsAsImage(File file) throws FileNotFoundException { BufferedImage img = null; try { ImageIO.setUseCache(false); img = ImageIO.read(file); img.flush(); } catch (IOException ex) { //log error } return img; } The stack trace is: Exception in thread "AWT-EventQueue-0" java.lang.OutOfMemoryError: Java heap space at java.awt.image.DataBufferByte.<init>(DataBufferByte.java:58) at java.awt.image.ComponentSampleModel.createDataBuffer(ComponentSampleModel.java:397) at java.awt.image.Raster.createWritableRaster(Raster.java:938) at javax.imageio.ImageTypeSpecifier.createBufferedImage(ImageTypeSpecifier.java:1056) at javax.imageio.ImageReader.getDestination(ImageReader.java:2879) at com.sun.imageio.plugins.jpeg.JPEGImageReader.readInternal(JPEGImageReader.java:925) at com.sun.imageio.plugins.jpeg.JPEGImageReader.read(JPEGImageReader.java:897) at javax.imageio.ImageIO.read(ImageIO.java:1422) at javax.imageio.ImageIO.read(ImageIO.java:1282) at framework.FileUtils.getFileContentsAsImage(FileUtils.java:33)

    Read the article

  • Why do the outputs differ when I run this code using Netbeans 6.8 and Eclipse?

    - by Vimal Basdeo
    When I am running the following codes using Eclipse and Netbeans 6.8. I want to see the available COM ports on my computer. When running in Eclipse it is returning me all available COm ports but when running t in Netbeans, it does not seem to find any ports .. public static void test(){ Enumeration lists=CommPortIdentifier.getPortIdentifiers(); System.out.println(lists.hasMoreElements()); while (lists.hasMoreElements()){ CommPortIdentifier cn=(CommPortIdentifier)lists.nextElement(); if ((CommPortIdentifier.PORT_SERIAL==cn.getPortType())){ System.out.println("Name is serail portzzzz "+cn.getName()+" Owned status "+cn.isCurrentlyOwned()); try{ SerialPort port1=(SerialPort)cn.open("ComControl",800000); port1.setSerialPortParams(9600, SerialPort.DATABITS_8, SerialPort.STOPBITS_1, SerialPort.PARITY_NONE); System.out.println("Before get stream"); OutputStream out=port1.getOutputStream(); InputStream input=port1.getInputStream(); System.out.println("Before write"); out.write("AT".getBytes()); System.out.println("After write"); int sample=0; //while((( sample=input.read())!=-1)){ System.out.println("Before read"); //System.out.println(input.read() + "TEsting "); //} System.out.println("After read"); System.out.println("Receive timeout is "+port1.getReceiveTimeout()); }catch(Exception e){ System.err.println(e.getMessage()); } } else{ System.out.println("Name is parallel portzzzz "+cn.getName()+" Owned status "+cn.isCurrentlyOwned()+cn.getPortType()+" "); } } } Output with Netbeans false Output using Eclipse true Name is serail portzzzz COM1 Owned status false Before get stream Before write After write Before read After read Receive timeout is -1 Name is serail portzzzz COM2 Owned status false Before get stream Before write After write Before read After read Receive timeout is -1 Name is parallel portzzzz LPT1 Owned status false2 Name is parallel portzzzz LPT2 Owned status false2

    Read the article

  • x86 Assembly: Before Making a System Call on Linux Should You Save All Registers?

    - by mudge
    I have the below code that opens up a file, reads it into a buffer and then closes the file. The close file system call requires that the file descriptor number be in the ebx register. The ebx register gets the file descriptor number before the read system call is made. My question is should I save the ebx register on the stack or somewhere before I make the read system call, (could int 80h trash the ebx register?). And then restore the ebx register for the close system call? Or is the code I have below fine and safe? I have run the below code and it works, I'm just not sure if it is generally considered good assembly practice or not because I don't save the ebx register before the int 80h read call. ;; open up the input file mov eax,5 ; open file system call number mov ebx,[esp+8] ; null terminated string file name, first command line parameter mov ecx,0o ; access type: O_RDONLY int 80h ; file handle or negative error number put in eax test eax,eax js Error ; test sign flag (SF) for negative number which signals error ;; read in the full input file mov ebx,eax ; assign input file descripter mov eax,3 ; read system call number mov ecx,InputBuff ; buffer to read into mov edx,INPUT_BUFF_LEN ; total bytes to read int 80h test eax,eax js Error ; if eax is negative then error jz Error ; if no bytes were read then error add eax,InputBuff ; add size of input to the begining of InputBuff location mov [InputEnd],eax ; assign address of end of input ;; close the input file ;; file descripter is already in ebx mov eax,6 ; close file system call number int 80h

    Read the article

  • Subversion all or nothing access to repo tree

    - by Glader
    I'm having some problems setting up access to my Subversion repositories on a Linux server. The problem is that I can only seem to get an all-or-nothing structure going. Either everyone gets read access to everything or noone gets read or write access to anything. The setup: SVN repos are located in /www/svn/repoA,repoB,repoC... Repositories are served by Apache, with Locations defined in etc/httpd/conf.d/subversion.conf as: <Location /svn/repoA> DAV svn SVNPath /var/www/svn/repoA AuthType Basic AuthName "svn repo" AuthUserFile /var/www/svn/svn-auth.conf AuthzSVNAccessFile /var/www/svn/svn-access.conf Require valid-user </Location> <Location /svn/repoB> DAV svn SVNPath /var/www/svn/repoB AuthType Basic AuthName "svn repo" AuthUserFile /var/www/svn/svn-auth.conf AuthzSVNAccessFile /var/www/svn/svn-access.conf Require valid-user </Location> ... svn-access.conf is set up as: [/] * = [/repoA] * = userA = rw [/repoB] * = userB = rw But checking out URL/svn/repoA as userA results in Access Forbidded. Changing it to [/] * = userA = r [/repoA] * = userA = rw [/repoB] * = userB = rw gives userA read access to ALL repositories (including repoB) but only read access to repoA! so in order for userA to get read-write access to repoB i need to add [/] userA = rw which is mental. I also tried changing Require valid-user to Require user userA for repoA in subversion.conf, but that only gave me read access to it. I need a way to default deny everyone access to every repository, giving read/write access only when explicitly defined. Can anyone tell me what I'm doing wrong here? I have spent a couple of hours testing and googling but come up empty, so now I'm doing the post of shame.

    Read the article

  • ExpressCache not working after Windows 8 reinstall on Samsung Series 7 Gamer

    - by Morven
    I have a Samsung Series 7 Gamer laptop which came with Windows 8. After doing a reinstall of Windows, the ExpressCache software is no longer caching. Running "eccmd -info" shows me that the software is present and it has the MSATA drive partition configured. However, it's not actually caching anything. These are the results after having the system booted for days: C:\windows\system32eccmd -info ExpressCache Command Version 1.0.94.0 Copyright¬ 2010-2012 Condusiv Technologies. Date Time: 11/3/2013 12:26:20:263 (JAMETHIEL #36) EC Cache Info ================================================== Mounted : Yes Partition Size : 7.46 GB Reserved Size : 3.00 MB Volume Size : 7.46 GB Total Used Size : 86.50 MB Total Free Space : 7.38 GB Used Data Size : 16.63 MB Used Data Size on Disk : 84.38 MB Tiered Cache Stats ================================================== Memory in use : 32.00 MB Blocks in use : 136 Read Percent : 0.02% Cache Stats ================================================== Cache Volume Drive Number : 1 Total Read Count : 97242 Total Read Size : 4.13 GB Total Cache Read Count : 0 Total Cache Read Size : 595.50 KB Total Write Count : 161546 Total Write Size : 5.89 GB Total Cache Write Count : 0 Total Cache Write Size : 0 Bytes Cache Read Percent : 0.01% Cache Write Percent : 0.00% As you can see on the last two lines, cache read and write percent is nigh on zero. Anyone know where to look next? The only guides I can find deal with ExpressCache not being present or not having a configured drive.

    Read the article

  • From Binary to Data Structures

    - by Cédric Menzi
    Table of Contents Introduction PE file format and COFF header COFF file header BaseCoffReader Byte4ByteCoffReader UnsafeCoffReader ManagedCoffReader Conclusion History This article is also available on CodeProject Introduction Sometimes, you want to parse well-formed binary data and bring it into your objects to do some dirty stuff with it. In the Windows world most data structures are stored in special binary format. Either we call a WinApi function or we want to read from special files like images, spool files, executables or may be the previously announced Outlook Personal Folders File. Most specifications for these files can be found on the MSDN Libarary: Open Specification In my example, we are going to get the COFF (Common Object File Format) file header from a PE (Portable Executable). The exact specification can be found here: PECOFF PE file format and COFF header Before we start we need to know how this file is formatted. The following figure shows an overview of the Microsoft PE executable format. Source: Microsoft Our goal is to get the PE header. As we can see, the image starts with a MS-DOS 2.0 header with is not important for us. From the documentation we can read "...After the MS DOS stub, at the file offset specified at offset 0x3c, is a 4-byte...". With this information we know our reader has to jump to location 0x3c and read the offset to the signature. The signature is always 4 bytes that ensures that the image is a PE file. The signature is: PE\0\0. To prove this we first seek to the offset 0x3c, read if the file consist the signature. So we need to declare some constants, because we do not want magic numbers.   private const int PeSignatureOffsetLocation = 0x3c; private const int PeSignatureSize = 4; private const string PeSignatureContent = "PE";   Then a method for moving the reader to the correct location to read the offset of signature. With this method we always move the underlining Stream of the BinaryReader to the start location of the PE signature.   private void SeekToPeSignature(BinaryReader br) { // seek to the offset for the PE signagure br.BaseStream.Seek(PeSignatureOffsetLocation, SeekOrigin.Begin); // read the offset int offsetToPeSig = br.ReadInt32(); // seek to the start of the PE signature br.BaseStream.Seek(offsetToPeSig, SeekOrigin.Begin); }   Now, we can check if it is a valid PE image by reading of the next 4 byte contains the content PE.   private bool IsValidPeSignature(BinaryReader br) { // read 4 bytes to get the PE signature byte[] peSigBytes = br.ReadBytes(PeSignatureSize); // convert it to a string and trim \0 at the end of the content string peContent = Encoding.Default.GetString(peSigBytes).TrimEnd('\0'); // check if PE is in the content return peContent.Equals(PeSignatureContent); }   With this basic functionality we have a good base reader class to try the different methods of parsing the COFF file header. COFF file header The COFF header has the following structure: Offset Size Field 0 2 Machine 2 2 NumberOfSections 4 4 TimeDateStamp 8 4 PointerToSymbolTable 12 4 NumberOfSymbols 16 2 SizeOfOptionalHeader 18 2 Characteristics If we translate this table to code, we get something like this:   [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)] public struct CoffHeader { public MachineType Machine; public ushort NumberOfSections; public uint TimeDateStamp; public uint PointerToSymbolTable; public uint NumberOfSymbols; public ushort SizeOfOptionalHeader; public Characteristic Characteristics; } BaseCoffReader All readers do the same thing, so we go to the patterns library in our head and see that Strategy pattern or Template method pattern is sticked out in the bookshelf. I have decided to take the template method pattern in this case, because the Parse() should handle the IO for all implementations and the concrete parsing should done in its derived classes.   public CoffHeader Parse() { using (var br = new BinaryReader(File.Open(_fileName, FileMode.Open, FileAccess.Read, FileShare.Read))) { SeekToPeSignature(br); if (!IsValidPeSignature(br)) { throw new BadImageFormatException(); } return ParseInternal(br); } } protected abstract CoffHeader ParseInternal(BinaryReader br);   First we open the BinaryReader, seek to the PE signature then we check if it contains a valid PE signature and rest is done by the derived implementations. Byte4ByteCoffReader The first solution is using the BinaryReader. It is the general way to get the data. We only need to know which order, which data-type and its size. If we read byte for byte we could comment out the first line in the CoffHeader structure, because we have control about the order of the member assignment.   protected override CoffHeader ParseInternal(BinaryReader br) { CoffHeader coff = new CoffHeader(); coff.Machine = (MachineType)br.ReadInt16(); coff.NumberOfSections = (ushort)br.ReadInt16(); coff.TimeDateStamp = br.ReadUInt32(); coff.PointerToSymbolTable = br.ReadUInt32(); coff.NumberOfSymbols = br.ReadUInt32(); coff.SizeOfOptionalHeader = (ushort)br.ReadInt16(); coff.Characteristics = (Characteristic)br.ReadInt16(); return coff; }   If the structure is as short as the COFF header here and the specification will never changed, there is probably no reason to change the strategy. But if a data-type will be changed, a new member will be added or ordering of member will be changed the maintenance costs of this method are very high. UnsafeCoffReader Another way to bring the data into this structure is using a "magically" unsafe trick. As above, we know the layout and order of the data structure. Now, we need the StructLayout attribute, because we have to ensure that the .NET Runtime allocates the structure in the same order as it is specified in the source code. We also need to enable "Allow unsafe code (/unsafe)" in the project's build properties. Then we need to add the following constructor to the CoffHeader structure.   [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)] public struct CoffHeader { public CoffHeader(byte[] data) { unsafe { fixed (byte* packet = &data[0]) { this = *(CoffHeader*)packet; } } } }   The "magic" trick is in the statement: this = *(CoffHeader*)packet;. What happens here? We have a fixed size of data somewhere in the memory and because a struct in C# is a value-type, the assignment operator = copies the whole data of the structure and not only the reference. To fill the structure with data, we need to pass the data as bytes into the CoffHeader structure. This can be achieved by reading the exact size of the structure from the PE file.   protected override CoffHeader ParseInternal(BinaryReader br) { return new CoffHeader(br.ReadBytes(Marshal.SizeOf(typeof(CoffHeader)))); }   This solution is the fastest way to parse the data and bring it into the structure, but it is unsafe and it could introduce some security and stability risks. ManagedCoffReader In this solution we are using the same approach of the structure assignment as above. But we need to replace the unsafe part in the constructor with the following managed part:   [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)] public struct CoffHeader { public CoffHeader(byte[] data) { IntPtr coffPtr = IntPtr.Zero; try { int size = Marshal.SizeOf(typeof(CoffHeader)); coffPtr = Marshal.AllocHGlobal(size); Marshal.Copy(data, 0, coffPtr, size); this = (CoffHeader)Marshal.PtrToStructure(coffPtr, typeof(CoffHeader)); } finally { Marshal.FreeHGlobal(coffPtr); } } }     Conclusion We saw that we can parse well-formed binary data to our data structures using different approaches. The first is probably the clearest way, because we know each member and its size and ordering and we have control about the reading the data for each member. But if add member or the structure is going change by some reason, we need to change the reader. The two other solutions use the approach of the structure assignment. In the unsafe implementation we need to compile the project with the /unsafe option. We increase the performance, but we get some security risks.

    Read the article

  • What does the BIOS setting XHCI Pre-Boot Mode do?

    - by Jamie Kitson
    I have a BIOS setting called XHCI Pre-Boot Mode. If I have this enabled USB devices which aren't plugged in at boot are never recognised, if I set it to Disabled then USB devices work normally. The brief BIOS description says "Enable this option if you need USB3.0 support in DOS." Which I don't, but it also says "Please note that XHCI controller will be disabled if you set this item as Disabled." So does that mean that USB3 is disabled with this option? Here's a picture of the screen: http://www.flickr.com/photos/jamiekitson/8017563004/

    Read the article

  • Dovecot install: what does this error mean?

    - by jamie
    I have postfix and dovecot installed on CentOS 6 (linode) along with MySQL. The table and user is already set up, postfix installed fine, but dovecot gives me this error in the mail log: Warning: Killed with signal 15 (by pid=9415 uid=0 code=kill) The next few lines say this: Apr 7 16:13:35 dovecot: master: Dovecot v2.0.9 starting up (core dumps disabled) Apr 7 16:13:35 dovecot: config: Warning: NOTE: You can get a new clean config file with: doveconf -n > dovecot-new.conf Apr 7 16:13:35 dovecot: config: Warning: Obsolete setting in /etc/dovecot/dovecot.conf:1: protocols=pop3s is no longer supported. to disable non-ssl pop3, use service pop3-login { inet_listener pop3 { p$ Apr 7 16:13:35 dovecot: config: Warning: Obsolete setting in /etc/dovecot/dovecot.conf:5: ssl_cert_file has been replaced by ssl_cert = <file Apr 7 16:13:35 dovecot: config: Warning: Obsolete setting in /etc/dovecot/dovecot.conf:6: ssl_key_file has been replaced by ssl_key = <file Apr 7 16:13:35 dovecot: config: Warning: Obsolete setting in /etc/dovecot/dovecot.conf:8: namespace private {} has been replaced by namespace { type=private } Apr 7 16:13:35 dovecot: config: Warning: Obsolete setting in /etc/dovecot/dovecot.conf:24: add auth_ prefix to all settings inside auth {} and remove the auth {} section completely Apr 7 16:13:35 dovecot: config: Warning: Obsolete setting in /etc/dovecot/dovecot.conf:25: auth_user has been replaced by service auth { user } I am following directions for the install on CentOS 5 with changes in the dovecot.conf file from different sources specific to CentOS 6. So the dovecot.conf file might not be correct, but there is no good source I have found yet for making dovecot install correctly. Can anyone tell me what the error above means? The terminal does not give any message as to start OK or FAIL. When I issue the service dovecot start command, it says: Starting Dovecot Imap: and nothing more.

    Read the article

  • Apple Airport Express, Extreme and Time Capsules, BT Home Hub, Wireless Extenders confusion

    - by Jamie Hartnoll
    I post quite frequently in Stack Overflow, but use Superuser less frequently. Mainly as I don't change hardware often and rarely have software issues! I live in a small stone cottage, and have an office in a separate building across a yard. I have a BT Homehub which is located in the cottage and a series of Ethernet cables running across the yard to the office. This is fine for my wired stuff. My main office computers are PCs running Windows 7 Ultimate, and one on Win7 Home, all working fine. I also have an old laptop on Win XP which works fine wirelessly in the house for those evenings in front of the TV catching up on a bit of work. I also have an iPhone and an iPad. Recently, I have been trying to get WiFi in the office so I can use Adobe Shadow (or whatever it now is!) to improve mobile web development efficiency using my iPhone and iPad, so I bought this: http://www.ebuyer.com/393462-zyxel-wre2205-500mbps-powerline-wireless-n300-range-extender-wre2205-gb0101f Thinking that would be lovely just plugged into the socket by the door in the office, extending the perimeter of the WiFi from my Homehub. I can't get it to work properly! If I plug a laptop into its ethernet port I can get it to connect to the Homehub and give me a kinda of wired, wireless extender. If, however, I plug the ethernet port into my home hub, it then seems to extend the network, but only my iOs devices work, and all my wired stuff stops working, and seems to create an infinite loop where windows connects to my homehob, and then rather to the internet, it then connects back to the extender thing. Anyway... in the meantime, I took a fatal trip to the Apple Store, where I purchased an Airport Express... solely for the purpose of hooking my iOs devices up as wireless music players in the house. I knew it had WiFi, but didn't want to use that part as an extender, I didn't think it would work on a Homehub anyway. It doesn't work on a Homehub! I now have a new wireless network in the house, which, when anything connects to it cannot connect to the Internet, so it works ONLY as a wireless music player. I then borrowed some Powerline Adaptors from someone and realised that this whole thing was getting totally out of control! It seems all the technology is out there but it's so complicated to get the right series of devices. To further add to the confusion, I wouldn't mind a network hard drive. I bought one that broke and lost everything, so now we're on to looking at the Apple Time Capsules. So my question is... IF... I buy an Apple Time Capsule, can I: Hook that up to my Homehub, leaving the homehub connected to the Internet so my Hub phones still work, then disable wireless on the homehub Link up my Airport Express to the Time Capsule PROPERLY so it will connect to the Internet Do the above with an Apple TV box should I buy one in future Use the Time Capsule as a network hard drive to store video and music that can be viewed/listened to via my iOS devices/Apple TV/Aiport Express anywhere even with my main PC off (this currently stores all this data) Hope that the IOS devices like the WiFi from the TimeCapsule better than the Homehub and work without extension, or buy another Airport Express to get WiFI in the office. Or... should I buy an Airport Extreme and use a USB hard drive for the network drive?

    Read the article

  • Unable to see External HDD in Windows Explorer

    - by Jamie Keeling
    I have bought a 320GB External HDD which I want to use with my Playstation3. I know it will only work with a Fat32 file system so using some free HP software it formatted it, unbeknown to me it will only work up to 32GB. After seeing this I panicked, downloaded Partition Wizard Home Edition and deleted the partition. As I was about to create a new partition to put it back to NTFS (I'd just wanted to be able to use it in the first place at this point) I accidently knocked the cable out of my computer for the HDD and after replacing it the External HDD is no longer recognised by the My Computer option, Disk Management asks me to initialise the disc using MBR but it fails saying "Copy protected". Even the partitioning software I previously mentioned can't do anything about it, all it says is "Bad Condition" and I can't perform any operations on it. Would anybody be able to guide me in getting this sorted? I'm terrified i've wasted a perfectly good 320GB HDD.

    Read the article

  • Decoding PAM configuration files ...

    - by Jamie
    Could someone point me to some (recent) documentation that would help me with decoding PAM configuration file lines like this: auth [success=2 default=ignore] pam_unix.so nullok_secure auth [success=1 default=ignore] pam_winbind.so krb5_auth krb5_ccache_type=FILE cached_login try_first_pass I'm trying to get my Ubuntu box (testing 10.04 Server Beta 2) to use Active Directory, and the last step is to get PAM on the unix box to work, but I'm wary about making changes (and locking myself out) without understanding how to merge what I'm reading here with what ubuntu has implemented.

    Read the article

  • Suggest methods for testing changes to "pam.d/common-*" files

    - by Jamie
    How do I test the changes to the pam.d configuration files: Do I need to restart the PAM service to test the changes? Should I go through every service listed in the /etc/pam.d/ directory? I'm about to make changes to the pam.d/common-* files in an effort to put an Ubuntu box into an active directory controlled network. I'm just learning what to do, so I'm preparing the configuration in a VM, which I plan to deploy in metal in the coming week. It is a clean install of Ubuntu 10.04 Beta 2 server, so other than SSH daemon, all other services are stock.

    Read the article

  • Can snort output an alert for a portscan (sfPortscan) to syslog?

    - by Jamie McNaught
    I've been working on this for too long now. I'm sure the answer should be obvious, but... Snort manual: http://www.snort.org/assets/125/snort_manual-2_8_5_1.pdf lists two logging outputs on pg 39 (pg 40 according to Acrobat Reader) as: "Unified Output" and "Log File Output" which I am guessing the former refers to the "unified" output mode... which makes me think the answer is "No, snort cannot output alerts for detected portscans to syslog." Config file I've been using is: alert tcp any 80 -> any any (msg:"TestTestTest"; content: "testtesttest"; sid:123) preprocessor sfportscan: proto { all } \ memcap { 10000000 } \ scan_type { all } \ sense_level { high } \ logfile { pscan.log } (yes, very basic I know). A simple nmap triggers output to the pscan.log Can anyone confirm this? Or point out how I do this?

    Read the article

< Previous Page | 98 99 100 101 102 103 104 105 106 107 108 109  | Next Page >