Search Results

Search found 18926 results on 758 pages for 'systems programming'.

Page 583/758 | < Previous Page | 579 580 581 582 583 584 585 586 587 588 589 590  | Next Page >

• What are the Ruby Gotchas a newbie should be warned about?

  - by MiniQuark

  I have recently learned the Ruby programming language, and all in all it is a good language. But I was quite surprised to see that it was not as simple as I had expected. More precisely, the "rule of least-surprise" did not seem very respected to me (of course this is quite subjective). For example: x = true and false puts x # displays true! and the famous: puts "zero is true!" if 0 # zero is true! What are the other "Gotchas" you would warn a Ruby newbie about?

  Read the article

• Locking a file to verify a single execution of a service. How reliable?

  - by Camilo Díaz

  Hello, I am deploying a little service to an UNIX(AIX) system. I want to check if there is no active instance of that service running when starting it. How reliable is to implement that check like this? Try to acquire a lock on a file (w/ FileChannel) If succeeds, keep lock and continue execution If fails, exit and refuse to run the main body I am aware of software like the Tanuki wrapper, however, I'm longing for a simpler(maybe not portable) solution. Regarding PIDFILE(s): I want to avoid using them if possible, as I don't have administrative rights on the machine, neither knowledge in AIX's shell programming.

  Read the article

• Teaching a mainframe COBOL programmer Java?

  - by Jared

  I’m trying to help someone learn Java who’s only programming experience is COBOL on the mainframe. I was wondering if anyone knew any good resources for object oriented concepts. I learned how to program with C++ so just understand the theory behind basic OOP. I’m more concerned about a way to get the basic concepts across, such as encapsulation and inheritance rather then Java syntax. I think it’d be better to teach the concepts of OOP then a language rather then trying to cram both a new language and paradigm in at the same time. Does anyone have any resources or ideas that could help this person learn OOP followed by Java?

  Read the article

• Expert system for writing programs?

  - by aaa

  I am brainstorming an idea of developing a high level software to manipulate matrix algebra equations, tensor manipulations to be exact, to produce optimized C++ code using several criteria such as sizes of dimensions, available memory on the system, etc. Something which is similar in spirit to tensor contraction engine, TCE, but specifically oriented towards producing optimized rather than general code. The end result desired is software which is expert in producing parallel program in my domain. Does this sort of development fall on the category of expert systems? What other projects out there work in the same area of producing code given the constraints?

  Read the article

• Why "do...while" does not exist in F#

  - by Kev

  I cannot find "do...while..." I have to code like this: let bubbleSort a= let n = Array.length a let mutable swapped = true let mutable i = 0 while swapped do swapped <- false for j = 0 to n-i-2 do if a.[j] > a.[j+1] then let t = a.[j] a.[j] <- a.[j+1] a.[j+1] <- t swapped <- true i <- i+1 The code is bad without "do...while". Sadly, "break/continue" are also not available. Is F# not suitable for non-functional-programming?

  Read the article

• Calculating terrain height in 3d-space

  - by Jonas B

  Hi I'm diving into 3d programming a bit and am currently learning by writing a procedural terrain generator that generates terrain based on a heightmap. I would also want to implement some physics and my first attempt at terrain collision was by simply checking the current position vs the heightmap. This however wont work well against small objects as you'd have to calculate the height by taking the heightdifference of the nearest vertices of the object and doing this every colision check is pretty slow. Beleive me I tried googling for it but there's simply so much crap and millions of blogs posting ripped-of newbie tutorials everywhere with basically no real information on the subject, I can't find anything that explains it or even names any generally used techniques. I'm not asking for code or a complete solution, but if anyone knows a particular technique good for calculating a high-res heightmap out of the already generated and smoothed terrain I would be very happy as I could look into it further when I know what I'm looking for. Thanks

  Read the article

• Beginning VSTO development

  - by idazuwaika

  Hi, I'm quite confused with what are the necessary tools for VSTO develpment. Specifically I want to manipulate Excel 2003/2007 documents programmatically. I did quite a lot of VBA before, if you want to relate any answer to that. Few questions I have about VSTO: Can I use Visual Studio 2008 Express Edition C#/C++ for this? Do I need to have .NET framework installed? Does the resulting VSTO program need to have a copy of Office installed in the same system to run? Direct links to the relevant tools/plugins/IDE will be appreciated. Note: I'm totally new to VSTO and .NET but an Office power user. Have experience with COM programming. Thanks.

  Read the article

• How to get Value of dropdown to other page populated using ajax?

  - by Chintan

  Hello Programming Experts, To Nik, I am facing same problem.I am generating two dropdown using ajax. But I can't access value of those dropdowns to another page. i cannot understand this code..what should i do to get value from those dropdowns....Where should i put this function? Plz reply me at [email protected] php page is like this $result = mysql_query($sql); echo''; while($row = mysql_fetch_array($result)) { echo ''.$row['lname'].' '; } echo''; Thanks Chintan

  Read the article

• Converting a constantly changing scalar value to a changing interval or frequency

  - by eco_bach

  Although I'm coding in Objective C, this is more of a general programming question. What is the best way to convert a constantly changing scalar value to a changing interval or frequency? Right now every time the scalar value changes I am destroying the NSInterval ie [self.myTimer invalidate]; self.myTimer = nil; and creating a new one, but this seems like a VERY expensive way to achieve my goal, since the changing scalar value in my case represents the horizontal velocity of a swipe. For a rough analogy, think of the speed of a swipe being reflected in a visual metronome, the faster you swipe, the higher(shorter interval) the frequency of the metronome.

  Read the article

• Ideas for building vulnerabilities into your site?

  - by Jaco Pretorius

  I'm trying to create a programming challenge that would require developers to hack into the MVC site I create. The idea is obviously to teach them about preventing these types of attacks. The current idea I have is to build multiple vulnerabilities into the site - but the second vulnerability would require the first to be completed, etc. So I was thinking the first could be a sql injection attack, the second would require a modified GET request, etc. Exploiting the final vulnerability would reveal a specific piece of information which is proof that you have completed the entire challenge. This will not be deployed on a public site - it's simply a learning tool for developers at my company. I'm not looking for MVC-specific vulnerabilities - I'm simply using MVC because it allows me to work with the 'raw' HTML. Any ideas on the different vulnerabilities I can use?

  Read the article

• How to create Web services and link it to Smart device Application?

  - by Crimsonland

  I am a fresh graduate and hired to develop Smart Device Application.They use Data logic Memoir with windows CE 5.0. Even though i have novice skills in programming in vb.net,I just finish my project and applications for Data logic memoir wherein the data has been save to text file or SQL compact server database in the Handheld Device and use Active Sync Connection to pass Data into H/PC to Desktop P.C and Vice Versa.I just shift now to C#.net and start learning it and i just successfully transpose my Smart Device Project from VB to C#. But now i want to Start Projects linking The device to server using Web services but i don't have any idea how to begin?

  Read the article

• Android: Change activity state when receiving a phone call

  - by thetrompf

  Hi. A problem came up in my latest android programming project. The problem is I would like to change Activity that launches when the phone receives a call. Is it possible to add some text after the contact name when a call is received. I have search the web for something that could do that, and been looking in the API for hours and I cannot find anything, is it possible with reflection of something like that? I have made a class that listens to when the phone_state is receiving a call, and I can get the incomming number, but I would like to change the appearance on the screen. // Thanks in advance

  Read the article

• Java Program Design Layout Recommendations?

  - by Leebuntu

  I've learned enough to begin writing programs from scratch, but I'm running into the problem of not knowing how to design the layout and implementation of a program. To be more precise, I'm having difficulty finding a good way to come up with an action plan before I dive in to the programming part. I really want to know what classes, methods, and objects I would need beforehand instead of just adding them along the way. My intuition is leading me to using some kind of charting software that gives a hierarchal view of all the classes and methods. I've been using OmniGraffle Pro and while it does seem to work somewhat, I'm still having trouble planning out the program in its entirety. How should I approach this problem? What softwares out there are available to help with this problem? Any good reads out there on this issue? Thanks so much! Edit: Oh yeah, I'm using Eclipse and I code mainly in Java right now.

  Read the article

• What are the major differences between Windows CE and Windows Mobile for a programmer?

  - by Brad Bruce

  What are the major differences between Windows CE and Windows Mobile for a programmer? I'd love to find a feature table, but haven't been able to find one on the Microsoft web site. I'm starting to work on a project involving industrial handheld terminals. I'm early into the design phase and need to find a comparison of Windows CE and Windows Mobile. Many of the people I'll be talking to jump on the first option that sounds "good enough". I want my first suggestion to be the best based on their needs. We're talking heavy duty hardware with a heavy duty price. I've got to get the programming questions out of the way early. We're currently a MFC6 and .Net 2.0 shop

  Read the article

• What combination of project-management software will meet my just-started project's needs?

  - by taz

  Hello all, I have a got couple of software projects that I want to run with my friends(max 10 persons) privately(at least for now). But I'm kind of lost between software management systems. I am not even sure about the definitions of my needs. Dear all, what is the definition/name of the system/software that meets my needs listed below? Continuous Integration? And please suggest me a good ALL-IN-ONE instance of it: project roadmap/planning project resource(people) allocation project issue&bug tracking project mailing list project forum project wiki source control server source control client repository change notifier client build system(like scons) nightly build automation IDE integration(VS) Note: I tried Redmine and liked it, but found it kind of slow. All-in-one kind ones will be the most appreciated but if your suggestion includes more than 3 softwares, please suggest me the ones that work together painlessly. thanks in advance..

  Read the article

• Are there any easy ways to generate OpenGL code for drawing shapes from a GUI?

  - by Sam152

  I have enjoyed learning to use OpenGL under the context of games programming, and I have experimented with creating small shapes. I'm wondering if there are any resources or apps that will generate code similar to the following with a simple paint-like interface. glColor3f(1.0, 0.0, 0.0); glBegin(GL_LINE_STRIP); glVertex2f(1, 0); glVertex2f(2, 3); glVertex2f(4, 5); glEnd(); I'm having trouble thinking of the correct dimensions to generate shapes and coming up with the correct co-ordinates.

  Read the article

• Succinct code over verbose?

  - by WeNeedAnswers

  With C# becoming more and more declarative and becoming the new Swiss army knife of Programming. Is it better to be succinct thus reducing the actual code base, or long winded but verbose. Is there a performance issue with succinct or does being succinct improve performance because your putting more of your code in the hands of the compiler. (LINQ being an example when used correctly). I know that verbosity should override succinct where code would become less readable, but is this a good idea when your style could affect the performance.

  Read the article

• Is it secure to use malloc?

  - by Felix Guerrero

  Somebody told me that allocating with malloc is not secure anymore, I'm not a C/C++ guru but I've made some stuff with malloc and C/C++. Does anyone know about what risks I'm into? Quoting him: [..] But indeed the weak point of C/C++ it is the security, and the Achilles' heel is indeed malloc and the abuse of pointers. C/C++ it is a well known insecure language. [..] There would be few apps in what I would not recommend to continue programming with C++."

  Read the article

• Linux based MS Office thumbnail generation

  - by El Yobo

  I've been taken on board to work on a PHP based web application. One part of the application generates thumbnail images for MS Office documents on demand, and it uses MS Office + the VeryPDF docprint utility to do this. Because of this one requirement, the system is running on Windows Server 2003 + IIS. I would prefer to have the system running on a Linux server, rather than MS, as I have far more experience in administering Linux systems than Windows and we have no other in-house technical staff. Does anyone know a way to handle the document conversion using native Linux software? I would love something PHP native, but am willing to look outside that if necessary. Thanks for your suggestions.

  Read the article

• Noob Droid Question regarding random number

  - by Pete Herbert Penito

  Brand new to droid programming, but would love to learn as much as possible, so I finally got my emulator working correctly, I even got a hello world button to work, I'm attempting to make this button display a random number, I've googled this and came up with this code: Random generator = new Random(); int n = generator.nextInt(n); I fixed the Random function by including some Random java utility. I'm assuming this code above goes in the .java file of the project, so my button code looks as follows (tested and works): PopUpText.makeText(v.getContext(), "Hello World", PopUpText.LENGTH_LONG).show(); I figured I could replace "Hello World" with n to display the number in the box, however the following error is stopping the compile: The local variable n may not have been initialized Any ideas why this is happening? Any advice would be hugely appreciated.

  Read the article

• If you were developing shareware softwares for windows, would you target the .Net Framework or use n

  - by bohoo

  For the sake of the question, by 'shareware' I mean a software which is relatively small in size (up to few dozens of mb) and available for download and evaluation through a web site. I'm asking this question, because I don't understand something regarding the current state of windows commercial desktop development. It seems to me that: There is no reliable statistic regarding the extent of windows systems with .Net Framework installed. It makes no sense to force the end user to install the 20-60mb .Net for an application which may be smaller. Applications conforms to the term 'shareware' above have a big share on the win os market. Much of them don't need the capabilities of low level languages like c++, and therefore ideally they should be developed with a RAD enviroment. So, One would suppose there will be a blossom of RAD enviroments for native win code. But I know about only one - Delphi, and Delphi is so unpopular. How is that?

  Read the article

• How can i determine the version of the Windows SDK installed on my computer?

  - by NuclearCheese781

  Hello everyone :) I've very recently decided to teach myself c++ and win32 programming after learning vb.net, and i've got a very simple question: How can I determine what version of the Windows SDK is installed on my computer? I'm asking so I can install the latest version if it isn't installed allready, before i start playing around with c++. I'm using Microsoft Visual Studio 2008 SP1 as my IDE. (I spent 10 minutes using Google to search for an answer, but I couldn't find one) If anyone could help me, it would be very much appreciated. Matt.

  Read the article

• Mathematics for AI/Machine learning ?

  - by Ankur Gupta

  I intend to build a simple recommendation systems for fun. I read a little on the net and figured being good at math would enable on to build a good recommendation system. My math skills are not good. I am willing to put considerable efforts and time in learning maths. Can you please tell me what mathematics topics should I cover? Also if any of you folks can point me to some online material to learn from it would be great. I am aware of MIT OCW, book like collective intelligence. Math Topics to cover and from where to read would really help.

  Read the article

• How Do I Remove The First 4 Characters From A String If It Matches A Pattern In Ruby

  - by James

  I have the following string: "h3. My Title Goes Here" I basically want to remove the first 4 characters from the string so that I just get back: "My Title Goes Here". The thing is I am iterating over an array of strings and not all have the h3. part in front so I can't just ditch the first 4 characters blindly. I have checked the docs and the closest think I could find was chomp, but that only works for the end of a string. Right now I am doing this: "h3. My Title Goes Here".reverse.chomp(" .3h").reverse This gives me my desired output, but there has to be a better way right? I mean I don't want to reverse a string twice for no reason. I am new to programming so I might have missed something obvious, but I didn't see the opposite of chomp anywhere in the docs. Is there another method that will work? Thanks!

  Read the article

• Straight Java/Groovy versus ETL tool (Talend/etc) - what libraries would you use?

  - by Alex R

  Assume you have a small project which on the surface looks like a good match for an ETL tool like Talend. But assume further, that you have never used Talend and furthermore, you do not trust "visual programming" tools in general and would rather code everything the old fashioned way (text on a nice IDE!) with the help of an appropriate language & support libraries. What are some language patterns & support libraries that could help you stay away from the ETL tool temptation/trap?

  Read the article

< Previous Page | 579 580 581 582 583 584 585 586 587 588 589 590  | Next Page >