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  • The fundamentals of Hash tables?

    - by kylex
    I'm quite confused about the basic concepts of a Hash table. If I were to code a hash how would I even begin? What is the difference between a Hash table and just a normal array? Basically if someone answered this question I think all my questions would be answered: If I had 100 randomly generated numbers (as keys), how would I implement a hash table and why would that be advantageous over an array? Psuedo-code or Java would be appreciated as a learning tool...

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  • What is wrong with the performance ?

    - by Innovative
    I created an application ( Creating up to 1,00,000 files in a folder ) with 2 different languages ( C#.Net & JAva ) with file concepts and its best methods. The Application that I created with .NET takes just 3 seconds to create all the files. At the same time, with Java, it takes 15 seconds. Why is it so ?

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  • examples of good concurrent programs meant to scale

    - by vishr
    I am looking for seminal and excellent examples of libraries and projects that emulate the good practices of the Java Concurrency in Practice book. The book is marvelous. However, I think supplementing this book reading with code reviews of projects and libraries that make use of the concurrency APIs effectively is necessary to drive the concepts into the brain. One good example of what I am looking for is https://code.google.com/p/concurrentlinkedhashmap/ Can folks help me with finding exemplary, well written code that use the concurrency api well?

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  • What areas of computer science are particularly relevant to mobile development?

    - by MalcomTucker
    This isn't a platform specific question - rather I'm interested in the general platform independent areas of computer science that are particularly relevant to mobile applications development. For example, things like compression techniques, distributed synchronisation algorithims etc.. what theoretical concepts have you found relevant, useful or enabling when building mobile apps?

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  • Do Java or C++ lack any OO features?

    - by tsv
    I am interested in understanding object-oriented programming in a more academic and abstract way than I currently do, and want to know if there are any object-oriented concepts Java and C++ fail to implement. I realise neither of the languages are "pure" OO, but I am interested in what (if anything) they lack, not what they have extra.

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  • Functional Programming Equivalent of Design Patterns Book?

    - by JasonFruit
    Is there a functional-programming equivalent to the Gang of Four Design Patterns book? That is, is there a book that explains and gives examples of how commonly-needed code structures are implemented functionally? I think seeing that would give me a better idea of how to go about using in practice the functional concepts whose theory I understand.

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  • Best book / content for .NET 3.5

    - by Ram
    Hi, I want to study new .NET 3.5 concepts like WPF, WCF for work as well as for interviews. I am aware of .NET 2 but do not have any detailed knowledge of .NET 3.5 and newly added features in .NET 3.5 and C#. is there any good book/ online resource which would help me?

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  • Project to learn J2EE technologies.

    - by Chandra
    Attended a 2 week j2EE course and learnt the concepts. Want to try in a simple project and wanted ideas on what that could be? PetStore or Small Business App are so boring... Anything interesting that can be done to learn the breadth but at the same time it not being a full fledged project?

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  • Book with C programs that have real programming examples.

    - by Siamore
    This is my first question on Stack Overflow, I would like to know about any c programming books that have real programs to introduce real problems as opposed to standard books with examples aimed to teach the language it should be sort of like a challenge with solutions so that concepts like recursion can be used i know that i should find solutions to existing problems to learn the language but this is my first attempt and i find it hard to understand some simple problems so i was hoping for a book with solutions.

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  • Favorite C/C++ questions for an interview [closed]

    - by Nullw0rm
    What are your favorite C/C++ interview questions? It may be question or contain question of concepts, some subjects are: Logic, multithreading, algorithms (and performance), STL, templates, inheritence, pointers. This is a useful tool for me, to look at what would be tested on a career-like application.

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  • Project manager programming background

    - by Henryk Konsek
    Do you think that project manager should have programming background? Do you consider this role as a natural way of evolution for the skilled/leader programmers (as an alternative for architect role)? Or maybe you believe that PM should be just a good manager with a basic understanding of the programming concepts and a fundamental knowledge about the technology you use. What is your experience with working with both kinds of managers (ex-programmers or just managers).

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  • If you knew then what you know now, what language(s) will you start learning first?

    - by John
    I will probably start with C and then Lisp. Although I started programming in C, I did not program in it as much as I want. It's fun working with the low level stuff. Learning C helped me a lot when I started working. I've only started learning Lisp now and I found it amazing that the concepts it supported from the very start are still very relevant today. Well I think it's better late than never.

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  • Red Gate Coder interviews: Alex Davies

    - by Michael Williamson
    Alex Davies has been a software engineer at Red Gate since graduating from university, and is currently busy working on .NET Demon. We talked about tackling parallel programming with his actors framework, a scientific approach to debugging, and how JavaScript is going to affect the programming languages we use in years to come. So, if we start at the start, how did you get started in programming? When I was seven or eight, I was given a BBC Micro for Christmas. I had asked for a Game Boy, but my dad thought it would be better to give me a proper computer. For a year or so, I only played games on it, but then I found the user guide for writing programs in it. I gradually started doing more stuff on it and found it fun. I liked creating. As I went into senior school I continued to write stuff on there, trying to write games that weren’t very good. I got a real computer when I was fourteen and found ways to write BASIC on it. Visual Basic to start with, and then something more interesting than that. How did you learn to program? Was there someone helping you out? Absolutely not! I learnt out of a book, or by experimenting. I remember the first time I found a loop, I was like “Oh my God! I don’t have to write out the same line over and over and over again any more. It’s amazing!” When did you think this might be something that you actually wanted to do as a career? For a long time, I thought it wasn’t something that you would do as a career, because it was too much fun to be a career. I thought I’d do chemistry at university and some kind of career based on chemical engineering. And then I went to a careers fair at school when I was seventeen or eighteen, and it just didn’t interest me whatsoever. I thought “I could be a programmer, and there’s loads of money there, and I’m good at it, and it’s fun”, but also that I shouldn’t spoil my hobby. Now I don’t really program in my spare time any more, which is a bit of a shame, but I program all the rest of the time, so I can live with it. Do you think you learnt much about programming at university? Yes, definitely! I went into university knowing how to make computers do anything I wanted them to do. However, I didn’t have the language to talk about algorithms, so the algorithms course in my first year was massively important. Learning other language paradigms like functional programming was really good for breadth of understanding. Functional programming influences normal programming through design rather than actually using it all the time. I draw inspiration from it to write imperative programs which I think is actually becoming really fashionable now, but I’ve been doing it for ages. I did it first! There were also some courses on really odd programming languages, a bit of Prolog, a little bit of C. Having a little bit of each of those is something that I would have never done on my own, so it was important. And then there are knowledge-based courses which are about not programming itself but things that have been programmed like TCP. Those are really important for examples for how to approach things. Did you do any internships while you were at university? Yeah, I spent both of my summers at the same company. I thought I could code well before I went there. Looking back at the crap that I produced, it was only surpassed in its crappiness by all of the other code already in that company. I’m so much better at writing nice code now than I used to be back then. Was there just not a culture of looking after your code? There was, they just didn’t hire people for their abilities in that area. They hired people for raw IQ. The first indicator of it going wrong was that they didn’t have any computer scientists, which is a bit odd in a programming company. But even beyond that they didn’t have people who learnt architecture from anyone else. Most of them had started straight out of university, so never really had experience or mentors to learn from. There wasn’t the experience to draw from to teach each other. In the second half of my second internship, I was being given tasks like looking at new technologies and teaching people stuff. Interns shouldn’t be teaching people how to do their jobs! All interns are going to have little nuggets of things that you don’t know about, but they shouldn’t consistently be the ones who know the most. It’s not a good environment to learn. I was going to ask how you found working with people who were more experienced than you… When I reached Red Gate, I found some people who were more experienced programmers than me, and that was difficult. I’ve been coding since I was tiny. At university there were people who were cleverer than me, but there weren’t very many who were more experienced programmers than me. During my internship, I didn’t find anyone who I classed as being a noticeably more experienced programmer than me. So, it was a shock to the system to have valid criticisms rather than just formatting criticisms. However, Red Gate’s not so big on the actual code review, at least it wasn’t when I started. We did an entire product release and then somebody looked over all of the UI of that product which I’d written and say what they didn’t like. By that point, it was way too late and I’d disagree with them. Do you think the lack of code reviews was a bad thing? I think if there’s going to be any oversight of new people, then it should be continuous rather than chunky. For me I don’t mind too much, I could go out and get oversight if I wanted it, and in those situations I felt comfortable without it. If I was managing the new person, then maybe I’d be keener on oversight and then the right way to do it is continuously and in very, very small chunks. Have you had any significant projects you’ve worked on outside of a job? When I was a teenager I wrote all sorts of stuff. I used to write games, I derived how to do isomorphic projections myself once. I didn’t know what the word was so I couldn’t Google for it, so I worked it out myself. It was horrifically complicated. But it sort of tailed off when I started at university, and is now basically zero. If I do side-projects now, they tend to be work-related side projects like my actors framework, NAct, which I started in a down tools week. Could you explain a little more about NAct? It is a little C# framework for writing parallel code more easily. Parallel programming is difficult when you need to write to shared data. Sometimes parallel programming is easy because you don’t need to write to shared data. When you do need to access shared data, you could just have your threads pile in and do their work, but then you would screw up the data because the threads would trample on each other’s toes. You could lock, but locks are really dangerous if you’re using more than one of them. You get interactions like deadlocks, and that’s just nasty. Actors instead allows you to say this piece of data belongs to this thread of execution, and nobody else can read it. If you want to read it, then ask that thread of execution for a piece of it by sending a message, and it will send the data back by a message. And that avoids deadlocks as long as you follow some obvious rules about not making your actors sit around waiting for other actors to do something. There are lots of ways to write actors, NAct allows you to do it as if it was method calls on other objects, which means you get all the strong type-safety that C# programmers like. Do you think that this is suitable for the majority of parallel programming, or do you think it’s only suitable for specific cases? It’s suitable for most difficult parallel programming. If you’ve just got a hundred web requests which are all independent of each other, then I wouldn’t bother because it’s easier to just spin them up in separate threads and they can proceed independently of each other. But where you’ve got difficult parallel programming, where you’ve got multiple threads accessing multiple bits of data in multiple ways at different times, then actors is at least as good as all other ways, and is, I reckon, easier to think about. When you’re using actors, you presumably still have to write your code in a different way from you would otherwise using single-threaded code. You can’t use actors with any methods that have return types, because you’re not allowed to call into another actor and wait for it. If you want to get a piece of data out of another actor, then you’ve got to use tasks so that you can use “async” and “await” to await asynchronously for it. But other than that, you can still stick things in classes so it’s not too different really. Rather than having thousands of objects with mutable state, you can use component-orientated design, where there are only a few mutable classes which each have a small number of instances. Then there can be thousands of immutable objects. If you tend to do that anyway, then actors isn’t much of a jump. If I’ve already built my system without any parallelism, how hard is it to add actors to exploit all eight cores on my desktop? Usually pretty easy. If you can identify even one boundary where things look like messages and you have components where some objects live on one side and these other objects live on the other side, then you can have a granddaddy object on one side be an actor and it will parallelise as it goes across that boundary. Not too difficult. If we do get 1000-core desktop PCs, do you think actors will scale up? It’s hard. There are always in the order of twenty to fifty actors in my whole program because I tend to write each component as actors, and I tend to have one instance of each component. So this won’t scale to a thousand cores. What you can do is write data structures out of actors. I use dictionaries all over the place, and if you need a dictionary that is going to be accessed concurrently, then you could build one of those out of actors in no time. You can use queuing to marshal requests between different slices of the dictionary which are living on different threads. So it’s like a distributed hash table but all of the chunks of it are on the same machine. That means that each of these thousand processors has cached one small piece of the dictionary. I reckon it wouldn’t be too big a leap to start doing proper parallelism. Do you think it helps if actors get baked into the language, similarly to Erlang? Erlang is excellent in that it has thread-local garbage collection. C# doesn’t, so there’s a limit to how well C# actors can possibly scale because there’s a single garbage collected heap shared between all of them. When you do a global garbage collection, you’ve got to stop all of the actors, which is seriously expensive, whereas in Erlang garbage collections happen per-actor, so they’re insanely cheap. However, Erlang deviated from all the sensible language design that people have used recently and has just come up with crazy stuff. You can definitely retrofit thread-local garbage collection to .NET, and then it’s quite well-suited to support actors, even if it’s not baked into the language. Speaking of language design, do you have a favourite programming language? I’ll choose a language which I’ve never written before. I like the idea of Scala. It sounds like C#, only with some of the niggles gone. I enjoy writing static types. It means you don’t have to writing tests so much. When you say it doesn’t have some of the niggles? C# doesn’t allow the use of a property as a method group. It doesn’t have Scala case classes, or sum types, where you can do a switch statement and the compiler checks that you’ve checked all the cases, which is really useful in functional-style programming. Pattern-matching, in other words. That’s actually the major niggle. C# is pretty good, and I’m quite happy with C#. And what about going even further with the type system to remove the need for tests to something like Haskell? Or is that a step too far? I’m quite a pragmatist, I don’t think I could deal with trying to write big systems in languages with too few other users, especially when learning how to structure things. I just don’t know anyone who can teach me, and the Internet won’t teach me. That’s the main reason I wouldn’t use it. If I turned up at a company that writes big systems in Haskell, I would have no objection to that, but I wouldn’t instigate it. What about things in C#? For instance, there’s contracts in C#, so you can try to statically verify a bit more about your code. Do you think that’s useful, or just not worthwhile? I’ve not really tried it. My hunch is that it needs to be built into the language and be quite mathematical for it to work in real life, and that doesn’t seem to have ended up true for C# contracts. I don’t think anyone who’s tried them thinks they’re any good. I might be wrong. On a slightly different note, how do you like to debug code? I think I’m quite an odd debugger. I use guesswork extremely rarely, especially if something seems quite difficult to debug. I’ve been bitten spending hours and hours on guesswork and not being scientific about debugging in the past, so now I’m scientific to a fault. What I want is to see the bug happening in the debugger, to step through the bug happening. To watch the program going from a valid state to an invalid state. When there’s a bug and I can’t work out why it’s happening, I try to find some piece of evidence which places the bug in one section of the code. From that experiment, I binary chop on the possible causes of the bug. I suppose that means binary chopping on places in the code, or binary chopping on a stage through a processing cycle. Basically, I’m very stupid about how I debug. I won’t make any guesses, I won’t use any intuition, I will only identify the experiment that’s going to binary chop most effectively and repeat rather than trying to guess anything. I suppose it’s quite top-down. Is most of the time then spent in the debugger? Absolutely, if at all possible I will never debug using print statements or logs. I don’t really hold much stock in outputting logs. If there’s any bug which can be reproduced locally, I’d rather do it in the debugger than outputting logs. And with SmartAssembly error reporting, there’s not a lot that can’t be either observed in an error report and just fixed, or reproduced locally. And in those other situations, maybe I’ll use logs. But I hate using logs. You stare at the log, trying to guess what’s going on, and that’s exactly what I don’t like doing. You have to just look at it and see does this look right or wrong. We’ve covered how you get to grip with bugs. How do you get to grips with an entire codebase? I watch it in the debugger. I find little bugs and then try to fix them, and mostly do it by watching them in the debugger and gradually getting an understanding of how the code works using my process of binary chopping. I have to do a lot of reading and watching code to choose where my slicing-in-half experiment is going to be. The last time I did it was SmartAssembly. The old code was a complete mess, but at least it did things top to bottom. There wasn’t too much of some of the big abstractions where flow of control goes all over the place, into a base class and back again. Code’s really hard to understand when that happens. So I like to choose a little bug and try to fix it, and choose a bigger bug and try to fix it. Definitely learn by doing. I want to always have an aim so that I get a little achievement after every few hours of debugging. Once I’ve learnt the codebase I might be able to fix all the bugs in an hour, but I’d rather be using them as an aim while I’m learning the codebase. If I was a maintainer of a codebase, what should I do to make it as easy as possible for you to understand? Keep distinct concepts in different places. And name your stuff so that it’s obvious which concepts live there. You shouldn’t have some variable that gets set miles up the top of somewhere, and then is read miles down to choose some later behaviour. I’m talking from a very much SmartAssembly point of view because the old SmartAssembly codebase had tons and tons of these things, where it would read some property of the code and then deal with it later. Just thousands of variables in scope. Loads of things to think about. If you can keep concepts separate, then it aids me in my process of fixing bugs one at a time, because each bug is going to more or less be understandable in the one place where it is. And what about tests? Do you think they help at all? I’ve never had the opportunity to learn a codebase which has had tests, I don’t know what it’s like! What about when you’re actually developing? How useful do you find tests in finding bugs or regressions? Finding regressions, absolutely. Running bits of code that would be quite hard to run otherwise, definitely. It doesn’t happen very often that a test finds a bug in the first place. I don’t really buy nebulous promises like tests being a good way to think about the spec of the code. My thinking goes something like “This code works at the moment, great, ship it! Ah, there’s a way that this code doesn’t work. Okay, write a test, demonstrate that it doesn’t work, fix it, use the test to demonstrate that it’s now fixed, and keep the test for future regressions.” The most valuable tests are for bugs that have actually happened at some point, because bugs that have actually happened at some point, despite the fact that you think you’ve fixed them, are way more likely to appear again than new bugs are. Does that mean that when you write your code the first time, there are no tests? Often. The chance of there being a bug in a new feature is relatively unaffected by whether I’ve written a test for that new feature because I’m not good enough at writing tests to think of bugs that I would have written into the code. So not writing regression tests for all of your code hasn’t affected you too badly? There are different kinds of features. Some of them just always work, and are just not flaky, they just continue working whatever you throw at them. Maybe because the type-checker is particularly effective around them. Writing tests for those features which just tend to always work is a waste of time. And because it’s a waste of time I’ll tend to wait until a feature has demonstrated its flakiness by having bugs in it before I start trying to test it. You can get a feel for whether it’s going to be flaky code as you’re writing it. I try to write it to make it not flaky, but there are some things that are just inherently flaky. And very occasionally, I’ll think “this is going to be flaky” as I’m writing, and then maybe do a test, but not most of the time. How do you think your programming style has changed over time? I’ve got clearer about what the right way of doing things is. I used to flip-flop a lot between different ideas. Five years ago I came up with some really good ideas and some really terrible ideas. All of them seemed great when I thought of them, but they were quite diverse ideas, whereas now I have a smaller set of reliable ideas that are actually good for structuring code. So my code is probably more similar to itself than it used to be back in the day, when I was trying stuff out. I’ve got more disciplined about encapsulation, I think. There are operational things like I use actors more now than I used to, and that forces me to use immutability more than I used to. The first code that I wrote in Red Gate was the memory profiler UI, and that was an actor, I just didn’t know the name of it at the time. I don’t really use object-orientation. By object-orientation, I mean having n objects of the same type which are mutable. I want a constant number of objects that are mutable, and they should be different types. I stick stuff in dictionaries and then have one thing that owns the dictionary and puts stuff in and out of it. That’s definitely a pattern that I’ve seen recently. I think maybe I’m doing functional programming. Possibly. It’s plausible. If you had to summarise the essence of programming in a pithy sentence, how would you do it? Programming is the form of art that, without losing any of the beauty of architecture or fine art, allows you to produce things that people love and you make money from. So you think it’s an art rather than a science? It’s a little bit of engineering, a smidgeon of maths, but it’s not science. Like architecture, programming is on that boundary between art and engineering. If you want to do it really nicely, it’s mostly art. You can get away with doing architecture and programming entirely by having a good engineering mind, but you’re not going to produce anything nice. You’re not going to have joy doing it if you’re an engineering mind. Architects who are just engineering minds are not going to enjoy their job. I suppose engineering is the foundation on which you build the art. Exactly. How do you think programming is going to change over the next ten years? There will be an unfortunate shift towards dynamically-typed languages, because of JavaScript. JavaScript has an unfair advantage. JavaScript’s unfair advantage will cause more people to be exposed to dynamically-typed languages, which means other dynamically-typed languages crop up and the best features go into dynamically-typed languages. Then people conflate the good features with the fact that it’s dynamically-typed, and more investment goes into dynamically-typed languages. They end up better, so people use them. What about the idea of compiling other languages, possibly statically-typed, to JavaScript? It’s a reasonable idea. I would like to do it, but I don’t think enough people in the world are going to do it to make it pick up. The hordes of beginners are the lifeblood of a language community. They are what makes there be good tools and what makes there be vibrant community websites. And any particular thing which is the same as JavaScript only with extra stuff added to it, although it might be technically great, is not going to have the hordes of beginners. JavaScript is always to be quickest and easiest way for a beginner to start programming in the browser. And dynamically-typed languages are great for beginners. Compilers are pretty scary and beginners don’t write big code. And having your errors come up in the same place, whether they’re statically checkable errors or not, is quite nice for a beginner. If someone asked me to teach them some programming, I’d teach them JavaScript. If dynamically-typed languages are great for beginners, when do you think the benefits of static typing start to kick in? The value of having a statically typed program is in the tools that rely on the static types to produce a smooth IDE experience rather than actually telling me my compile errors. And only once you’re experienced enough a programmer that having a really smooth IDE experience makes a blind bit of difference, does static typing make a blind bit of difference. So it’s not really about size of codebase. If I go and write up a tiny program, I’m still going to get value out of writing it in C# using ReSharper because I’m experienced with C# and ReSharper enough to be able to write code five times faster if I have that help. Any other visions of the future? Nobody’s going to use actors. Because everyone’s going to be running on single-core VMs connected over network-ready protocols like JSON over HTTP. So, parallelism within one operating system is going to die. But until then, you should use actors. More Red Gater Coder interviews

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  • How do I add xen kernel boot parameters in grub2?

    - by Matt
    I know that I can add command line parameters to the grub2 command line by editing /etc/default/grub according to this answer How do I add a boot parameter to grub2 in Ubuntu 10.10? However, that would apply to ALL kernels would it not? How do I apply the command line parameters to specific kernels? i.e. only xen. I'm wanting to append something like: xen-pciback.hide=(06:00.0) I'm guessing I need to add it somewhere in the file: /etc/grub.d/20_linux_xen Which contains: #! /bin/sh set -e # grub-mkconfig helper script. # Copyright (C) 2006,2007,2008,2009,2010 Free Software Foundation, Inc. # # GRUB is free software: you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation, either version 3 of the License, or # (at your option) any later version. # # GRUB is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with GRUB. If not, see <http://www.gnu.org/licenses/>. prefix=/usr exec_prefix=${prefix} bindir=${exec_prefix}/bin libdir=${exec_prefix}/lib . ${libdir}/grub/grub-mkconfig_lib export TEXTDOMAIN=grub export TEXTDOMAINDIR=${prefix}/share/locale CLASS="--class gnu-linux --class gnu --class os --class xen" if [ "x${GRUB_DISTRIBUTOR}" = "x" ] ; then OS=GNU/Linux else OS="${GRUB_DISTRIBUTOR} GNU/Linux" CLASS="--class $(echo ${GRUB_DISTRIBUTOR} | tr '[A-Z]' '[a-z]' | cut -d' ' -f1) ${CLASS}" fi # loop-AES arranges things so that /dev/loop/X can be our root device, but # the initrds that Linux uses don't like that. case ${GRUB_DEVICE} in /dev/loop/*|/dev/loop[0-9]) GRUB_DEVICE=`losetup ${GRUB_DEVICE} | sed -e "s/^[^(]*(\([^)]\+\)).*/\1/"` # We can't cope with devices loop-mounted from files here. case ${GRUB_DEVICE} in /dev/*) ;; *) exit 0 ;; esac ;; esac if [ "x${GRUB_DEVICE_UUID}" = "x" ] || [ "x${GRUB_DISABLE_LINUX_UUID}" = "xtrue" ] \ || ! test -e "/dev/disk/by-uuid/${GRUB_DEVICE_UUID}" \ || uses_abstraction "${GRUB_DEVICE}" lvm; then LINUX_ROOT_DEVICE=${GRUB_DEVICE} else LINUX_ROOT_DEVICE=UUID=${GRUB_DEVICE_UUID} fi linux_entry () { os="$1" version="$2" xen_version="$3" recovery="$4" args="$5" xen_args="$6" if ${recovery} ; then title="$(gettext_quoted "%s, with Xen %s and Linux %s (recovery mode)")" else title="$(gettext_quoted "%s, with Xen %s and Linux %s")" fi printf "menuentry '${title}' ${CLASS} {\n" "${os}" "${xen_version}" "${version}" if ! ${recovery} ; then save_default_entry | sed -e "s/^/\t/" fi if [ -z "${prepare_boot_cache}" ]; then prepare_boot_cache="$(prepare_grub_to_access_device ${GRUB_DEVICE_BOOT} | sed -e "s/^/\t/")" fi printf '%s\n' "${prepare_boot_cache}" xmessage="$(gettext_printf "Loading Xen %s ..." ${xen_version})" lmessage="$(gettext_printf "Loading Linux %s ..." ${version})" cat << EOF echo '$xmessage' multiboot ${rel_xen_dirname}/${xen_basename} placeholder ${xen_args} echo '$lmessage' module ${rel_dirname}/${basename} placeholder root=${linux_root_device_thisversion} ro ${args} EOF if test -n "${initrd}" ; then message="$(gettext_printf "Loading initial ramdisk ...")" cat << EOF echo '$message' module ${rel_dirname}/${initrd} EOF fi cat << EOF } EOF } linux_list=`for i in /boot/vmlinu[xz]-* /vmlinu[xz]-* ; do basename=$(basename $i) version=$(echo $basename | sed -e "s,^[^0-9]*-,,g") if grub_file_is_not_garbage "$i" && grep -qx "CONFIG_XEN_DOM0=y" /boot/config-${version} 2> /dev/null ; then echo -n "$i " ; fi done` xen_list=`for i in /boot/xen*; do if grub_file_is_not_garbage "$i" ; then echo -n "$i " ; fi done` prepare_boot_cache= while [ "x${xen_list}" != "x" ] ; do list="${linux_list}" current_xen=`version_find_latest $xen_list` xen_basename=`basename ${current_xen}` xen_dirname=`dirname ${current_xen}` rel_xen_dirname=`make_system_path_relative_to_its_root $xen_dirname` xen_version=`echo $xen_basename | sed -e "s,.gz$,,g;s,^xen-,,g"` echo "submenu \"Xen ${xen_version}\" {" while [ "x$list" != "x" ] ; do linux=`version_find_latest $list` echo "Found linux image: $linux" >&2 basename=`basename $linux` dirname=`dirname $linux` rel_dirname=`make_system_path_relative_to_its_root $dirname` version=`echo $basename | sed -e "s,^[^0-9]*-,,g"` alt_version=`echo $version | sed -e "s,\.old$,,g"` linux_root_device_thisversion="${LINUX_ROOT_DEVICE}" initrd= for i in "initrd.img-${version}" "initrd-${version}.img" \ "initrd-${version}" "initrd.img-${alt_version}" \ "initrd-${alt_version}.img" "initrd-${alt_version}"; do if test -e "${dirname}/${i}" ; then initrd="$i" break fi done if test -n "${initrd}" ; then echo "Found initrd image: ${dirname}/${initrd}" >&2 else # "UUID=" magic is parsed by initrds. Since there's no initrd, it can't work here. linux_root_device_thisversion=${GRUB_DEVICE} fi linux_entry "${OS}" "${version}" "${xen_version}" false \ "${GRUB_CMDLINE_LINUX} ${GRUB_CMDLINE_LINUX_DEFAULT}" "${GRUB_CMDLINE_XEN} ${GRUB_CMDLINE_XEN_DEFAULT}" if [ "x${GRUB_DISABLE_RECOVERY}" != "xtrue" ]; then linux_entry "${OS}" "${version}" "${xen_version}" true \ "single ${GRUB_CMDLINE_LINUX}" "${GRUB_CMDLINE_XEN}" fi list=`echo $list | tr ' ' '\n' | grep -vx $linux | tr '\n' ' '` done echo "}" xen_list=`echo $xen_list | tr ' ' '\n' | grep -vx $current_xen | tr '\n' ' '` done

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  • How to open a server port outside of an OpenVPN tunnel with a pf firewall on OSX (BSD)

    - by Timbo
    I have a Mac mini that I use as a media server running XBMC and serves media from my NAS to my stereo and TV (which has been color calibrated with a Spyder3Express, happy). The Mac runs OSX 10.8.2 and the internet connection is tunneled for general privacy over OpenVPN through Tunnelblick. I believe my anonymous VPN provider pushes "redirect_gateway" to OpenVPN/Tunnelblick because when on it effectively tunnels all non-LAN traffic in- and outbound. As an unwanted side effect that also opens the boxes server ports unprotected to the outside world and bypasses my firewall-router (Netgear SRX5308). I have run nmap from outside the LAN on the VPN IP and the server ports on the mini are clearly visible and connectable. The mini has the following ports open: ssh/22, ARD/5900 and 8080+9090 for the XBMC iOS client Constellation. I also have Synology NAS which apart from LAN file serving over AFP and WebDAV only serves up an OpenVPN/1194 and a PPTP/1732 server. When outside of the LAN I connect to this from my laptop over OpenVPN and over PPTP from my iPhone. I only want to connect through AFP/548 from the mini to the NAS. The border firewall (SRX5308) just works excellently, stable and with a very high throughput when streaming from various VOD services. My connection is a 100/10 with a close to theoretical max throughput. The ruleset is as follows Inbound: PPTP/1723 Allow always to 10.0.0.40 (NAS/VPN server) from a restricted IP range >corresponding to possible cell provider range OpenVPN/1194 Allow always to 10.0.0.40 (NAS/VPN server) from any Outbound: Default outbound policy: Allow Always OpenVPN/1194 TCP Allow always from 10.0.0.40 (NAS) to a.b.8.1-a.b.8.254 (VPN provider) OpenVPN/1194 UDP Allow always to 10.0.0.40 (NAS) to a.b.8.1-a.b.8.254 (VPN provider) Block always from NAS to any On the Mini I have disabled the OSX Application Level Firewall because it throws popups which don't remember my choices from one time to another and that's annoying on a media server. Instead I run Little Snitch which controls outgoing connections nicely on an application level. I have configured the excellent OSX builtin firewall pf (from BSD) as follows pf.conf (Apple App firewall tie-ins removed) (# replaced with % to avoid formatting errors) ### macro name for external interface. eth_if = "en0" vpn_if = "tap0" ### wifi_if = "en1" ### %usb_if = "en3" ext_if = $eth_if LAN="{10.0.0.0/24}" ### General housekeeping rules ### ### Drop all blocked packets silently set block-policy drop ### all incoming traffic on external interface is normalized and fragmented ### packets are reassembled. scrub in on $ext_if all fragment reassemble scrub in on $vpn_if all fragment reassemble scrub out all ### exercise antispoofing on the external interface, but add the local ### loopback interface as an exception, to prevent services utilizing the ### local loop from being blocked accidentally. ### set skip on lo0 antispoof for $ext_if inet antispoof for $vpn_if inet ### spoofing protection for all interfaces block in quick from urpf-failed ############################# block all ### Access to the mini server over ssh/22 and remote desktop/5900 from LAN/en0 only pass in on $eth_if proto tcp from $LAN to any port {22, 5900, 8080, 9090} ### Allow all udp and icmp also, necessary for Constellation. Could be tightened. pass on $eth_if proto {udp, icmp} from $LAN to any ### Allow AFP to 10.0.0.40 (NAS) pass out on $eth_if proto tcp from any to 10.0.0.40 port 548 ### Allow OpenVPN tunnel setup over unprotected link (en0) only to VPN provider IPs ### and port ranges pass on $eth_if proto tcp from any to a.b.8.0/24 port 1194:1201 ### OpenVPN Tunnel rules. All traffic allowed out, only in to ports 4100-4110 ### Outgoing pings ok pass in on $vpn_if proto {tcp, udp} from any to any port 4100:4110 pass out on $vpn_if proto {tcp, udp, icmp} from any to any So what are my goals and what does the above setup achieve? (until you tell me otherwise :) 1) Full LAN access to the above ports on the mini/media server (including through my own VPN server) 2) All internet traffic from the mini/media server is anonymized and tunneled over VPN 3) If OpenVPN/Tunnelblick on the mini drops the connection, nothing is leaked both because of pf and the router outgoing ruleset. It can't even do a DNS lookup through the router. So what do I have to hide with all this? Nothing much really, I just got carried away trying to stop port scans through the VPN tunnel :) In any case this setup works perfectly and it is very stable. The Problem at last! I want to run a minecraft server and I installed that on a separate user account on the mini server (user=mc) to keep things partitioned. I don't want this server accessible through the anonymized VPN tunnel because there are lots more port scans and hacking attempts through that than over my regular IP and I don't trust java in general. So I added the following pf rule on the mini: ### Allow Minecraft public through user mc pass in on $eth_if proto {tcp,udp} from any to any port 24983 user mc pass out on $eth_if proto {tcp, udp} from any to any user mc And these additions on the border firewall: Inbound: Allow always TCP/UDP from any to 10.0.0.40 (NAS) Outbound: Allow always TCP port 80 from 10.0.0.40 to any (needed for online account checkups) This works fine but only when the OpenVPN/Tunnelblick tunnel is down. When up no connection is possbile to the minecraft server from outside of LAN. inside LAN is always OK. Everything else functions as intended. I believe the redirect_gateway push is close to the root of the problem, but I want to keep that specific VPN provider because of the fantastic throughput, price and service. The Solution? How can I open up the minecraft server port outside of the tunnel so it's only available over en0 not the VPN tunnel? Should I a static route? But I don't know which IPs will be connecting...stumbles How secure would to estimate this setup to be and do you have other improvements to share? I've searched extensively in the last few days to no avail...If you've read this far I bet you know the answer :)

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  • Generate JFreeChart in servlet

    - by San4o
    I'm trying to generate graphs using JFreeChart. I added record in web.xml, installed jfreechart library. Compiled servlet. Below code of servlet has shown: import java.io.IOException; import java.io.OutputStream; import java.io.File; import javax.servlet.*; import javax.servlet.http.*; import java.awt.Color; import org.jfree.chart.ChartFactory; import org.jfree.chart.ChartUtilities; import org.jfree.chart.JFreeChart; import org.jfree.data.general.DefaultPieDataset; public class diagram extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doTestPieChart(request,response); } protected void doTestPieChart(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException { OutputStream out = response.getOutputStream(); try { DefaultPieDataset dataset = new DefaultPieDataset(); dataset.setValue("Graphic Novels", 192); dataset.setValue("History", 125); dataset.setValue("Military Fiction", 236); dataset.setValue("Mystery", 547); dataset.setValue("Performing Arts", 210); dataset.setValue("Science, Non-Fiction", 70); dataset.setValue("Science Fiction", 989); JFreeChart chart = ChartFactory.createPieChart( "Books by Type", dataset, true, false, false ); chart.setBackgroundPaint(Color.white); response.setContentType("image/png"); ChartUtilities.writeChartAsPNG(out, chart, 400, 300); /* ServletContext sc = getServletContext(); String filename = sc.getRealPath("pie.png"); File file = new File(filename); ChartUtilities.saveChartAsPNG(file,chart,400,300); */ } catch (Exception e) { System.out.println(e.toString()); } finally { out.close(); } } } When i launch the servlet, mistake has shown : HTTP Status 500 - type Exception report message description The server encountered an internal error () that prevented it from fulfilling this request. exception javax.servlet.ServletException: Error instantiating servlet class diagram org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298) org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:852) org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588) org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489) java.lang.Thread.run(Thread.java:619) root cause java.lang.NoClassDefFoundError: org/jfree/data/general/PieDataset java.lang.Class.getDeclaredConstructors0(Native Method) java.lang.Class.privateGetDeclaredConstructors(Class.java:2389) java.lang.Class.getConstructor0(Class.java:2699) java.lang.Class.newInstance0(Class.java:326) java.lang.Class.newInstance(Class.java:308) org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298) org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:852) org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588) org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489) java.lang.Thread.run(Thread.java:619) root cause java.lang.ClassNotFoundException: org.jfree.data.general.PieDataset org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1484) org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1329) java.lang.ClassLoader.loadClassInternal(ClassLoader.java:316) java.lang.Class.getDeclaredConstructors0(Native Method) java.lang.Class.privateGetDeclaredConstructors(Class.java:2389) java.lang.Class.getConstructor0(Class.java:2699) java.lang.Class.newInstance0(Class.java:326) java.lang.Class.newInstance(Class.java:308) org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298) org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:852) org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588) org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489) java.lang.Thread.run(Thread.java:619) note The full stack trace of the root cause is available in the Apache Tomcat/6.0.24 logs. Help me to solve a problem. and where is problem?

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  • Merge XML files with configurable rules (context: Maven POMs, Java)

    - by Patrick Bergner
    Hi, I'm currently writing some kind of a Maven POM preprocessor that assembles a POM for a project from multiple input files (basically a template and a module specific file). The files are hierarchically ordered (template = most general, module specific = least general). The problem is now to merge these files into a single POM file. Long story short or if you're not familiar with Maven: a POM looks like this (shortened): <project> <modelVersion>4.0.0</modelVersion> <dependencies> <dependency> <groupId>org.apache.maven</groupId> <artifactId>maven-core</artifactId> </dependency> </dependencies> </project> Basically the merger shall replace all values of the more general file with the values of the more specific file (i.e. singletons, e.g. the <modelVersion> above) but there are certain elements where the merger shall add the more certain element to a parent (i.e. collections, e.g. <dependency> elements shall always be added to the <dependencies> element and no <dependency> element shall be replaced by another). A more detailed example with definition of desired output: File A: <project> <modelVersion>A</modelVersion> <dependencies> <dependency> <groupId>groupIdA</groupId> <artifactId>artifactIdA</artifactId> </dependency> </dependencies> </project> File B: <project> <modelVersion>B</modelVersion> <dependencies> <dependency> <groupId>groupIdB</groupId> <artifactId>artifactIdB</artifactId> </dependency> </dependencies> </project> Desired output: <project> <modelVersion>B</modelVersion> <dependencies> <dependency> <groupId>groupIdA</groupId> <artifactId>artifactIdA</artifactId> </dependency> <dependency> <groupId>groupIdB</groupId> <artifactId>artifactIdB</artifactId> </dependency> </dependencies> </project> The set of collection type elements are known and should be configurable (preferably via a set of XPath expressions). A Java based solution is appreciated. What looked most promising so far was the tool mentioned here but the MERGE action produces something like <dependency> <groupId>groupIdAgroupIdB</groupId> <artifactId>artifactIdAartifactIdB</artifactId> </dependency> when merging, which is not what I need. Any ideas? Thanks for your help!

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  • mine phrases (up to 3 words) from a given text

    - by DS_web_developer
    I asked before for a simple solution to my problem (using sphinx search service) but I got nowhere... someone has kindly provided me with this code <?php /** * $Project: GeoGraph $ * $Id$ * * GeoGraph geographic photo archive project * This file copyright (C) 2005 Barry Hunter ([email protected]) * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ /** * Provides the methods for updating the worknet tables * * @package Geograph * @author Barry Hunter <[email protected]> * @version $Revision$ */ function addTwoLetterPhrase($phrase) { global $w2; $w2[$phrase] = (isset($w2[$phrase]))?($w2[$phrase]+1):1; } function addThreeLetterPhrase($phrase) { global $w3; $w3[$phrase] = (isset($w3[$phrase]))?($w3[$phrase]+1):1; } function updateWordnet(&$db,$text,$field,$id) { global $w1,$w2,$w3; $alltext = strtolower(preg_replace('/\W+/',' ',str_replace("'",'',$text))); if (strlen($text)< 1) return; $words = preg_split('/ /',$alltext); $w1 = array(); $w2 = array(); $w3 = array(); //build a list of one word phrases foreach ($words as $word) { $w1[$word] = (isset($w1[$word]))?($w1[$word]+1):1; } //build a list of two word phrases $text = $alltext; $text = preg_replace('/(\w+) (\w+)/e','addTwoLetterPhrase("$1 $2")',$text); $text = $alltext; $text = preg_replace('/(\w+)/','',$text,1); $text = preg_replace('/(\w+) (\w+)/e','addTwoLetterPhrase("$1 $2")',$text); //build a list of three word phrases $text = $alltext; $text = preg_replace('/(\w+) (\w+) (\w+)/e','addThreeLetterPhrase("$1 $2 $3")',$text); $text = $alltext; $text = preg_replace('/(\w+)/','',$text,1); $text = preg_replace('/(\w+) (\w+) (\w+)/e','addThreeLetterPhrase("$1 $2 $3")',$text); $text = $alltext; $text = preg_replace('/(\w+) (\w+)/','',$text,1); $text = preg_replace('/(\w+) (\w+) (\w+)/e','addThreeLetterPhrase("$1 $2 $3")',$text); foreach ($w1 as $word=>$count) { $db->Execute("insert into wordnet1 set gid = $id,words = '$word',$field = $count");// ON DUPLICATE KEY UPDATE $field=$field+$count"); } foreach ($w2 as $word=>$count) { $db->Execute("insert into wordnet2 set gid = $id,words = '$word',$field = $count"); } foreach ($w3 as $word=>$count) { $db->Execute("insert into wordnet3 set gid = $id,words = '$word',$field = $count"); } } ?> It works fine and does almost exactly what I need....... except.... it is not utf8 friendly... I mean... it splits whole words into parts (on special chars) where it shouldn't! so my guess is I should use multibyte functions instead of regular preg_replace... I tried to replace preg_replace with mb_ereg_replace but it is not working as it should... at least not for 2 and 3 words phrases any ideas?

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  • SQL SERVER – Developer Training Resources and Summary Roundup

    - by pinaldave
    It is always pleasure for any author when other renowned authors in the industry write about you. Earlier I wrote a five part blog series on Developer Training and I have received a phenomenal response to the series. I have received plenty of comments, questions and feedback. I thought it would be nice to sum up the whole series as well answer a few of the questions received. Quick Recap Developer Training - Importance and Significance - Part 1 In this part we discussed the importance of training in the real world. The most important and valuable resource any company is its employee. Employees who have been well-trained will be better at their jobs and produce a better product.  An employee who is well trained obviously knows more about their job and all the technical aspects. I have a very high opinion about training employees and it is the most important task. Developer Training – Employee Morals and Ethics – Part 2 In this part we discussed the most crucial components of training. Often employees are expecting the company to pay for their training and the company expresses no interest in training the employee. Quite often training expenses are the real issue for both the employee and employer. There are companies that pay for 100% of the expenses and there are employees who opt for training on their own expense during their personal time. Training is often looked at as vacation by employee and employers and we need to change this mind-set. One of the ways is to report back the learning to your manager and implement newly learned knowledge in day-to-day work. Developer Training – Difficult Questions and Alternative Perspective - Part 3 This part was the most difficult to write as I tried to address a few difficult questions and answers. Training is such a sensitive issue that many developers when not receiving chance for training think about leaving the organization. The manager often feels pressure to accommodate every single employee for training even though his training budget is limited. It is indeed the responsibility of the developer to get maximum advantage from the training. Training immediately helps organizations but stays as a part of an employee’s knowledge forever. Developer Training – Various Options for Developer Training – Part 4 In this part I tried to explore a few methods and options for training. The generic feedback I received on this blog post was short and I should have explored each of the subject of the training in details. I believe there are two big buckets of training 1) Instructor Lead Training and 2) Self Lead Training. The common element between both the methods is “learning material”. Learning material can be of any format – videos, books, paper notes or just a plain black board. Instructor-led training is a very effective mode but not possible every single time. During the course of the developer’s career, one has to learn lots of new technology and it is almost impossible to have a quality trainer available on that subject at that time. Books are most effective and proven methods, however, it always helps if someone explains the concepts of the book with a demonstration. In recent times I have started to believe in online trainings which leads to a hybrid experience. Online trainings take the best part of the books and the best part of the instructor-led training and gives effective training in a matter of hours. Developer Training – A Conclusive Summary- Part 5 In this part, I shared what I was continuously thinking about developer training. There is no better teacher than oneself. There is no better motivation than a personal desire to learn new technology. Honestly there is nothing more personal learning. That “change is the only constant” and “adapt & overcome” are the essential lessons of life. One cannot stop the learning and resist the change. In the IT industry “ego of knowing all” and the “resistance to change” are the most challenging issues. Once someone overcomes them, life is much easier. I believe that proper and appropriate high quality training can help to address the burning issues. Opinion of Friends I invited a few of my friends to express their opinion about developer training and here are their opinions. I am listing them here in the order of the blog post publishing date. Nakul Vachhrajani - Developer Trainings-Importance, Benefits, Tips and follow-up Nakul’s sums of many of the concepts which are complementary to my blog posts. Nakul addresses the burning question of developer training with different angles. I am personally very impressed by his following statement - “Being skilled does not mean having just a stack of certifications, but it also means having an understanding about the internals of the products that you are working on – and using that knowledge to improve the efficiency & productivity at the workplace in turn resulting in better products, better consulting abilities and a happier self.” Nakul also suggests the online training options of Pluralsight. Vinod Kumar - Training–a necessity or bonus Vinod Kumar comes up with excellent follow up on developer training. Vinod is known for his inspirational writing about SQL Server. Vinod starts with a story of a student who is extremely eager to learn the wisdom of life from a monk but the monk does not accept him as a disciple for a long time. The conversation between student and monk is indeed an essence of all learning. We all want to learn quickly and be successful but the most important thing in life is to have the right attitude towards learning and more so towards life. The blog post end with a very important thought about how to avoid the famous excuse – “I don’t have enough time.” Ritesh Shah - Training – useful or useless? Ritesh brings up very important concept related to training. Ritesh in his meticulous style explains why training is an important and lifelong process. Training must not stop at any age but should continue forever. The moment training stops, progress stops along with. Paras Doshi - Professional Development Resource Paras is known for his to–the-point writing, and has summarized the five part series very precisely. He read the five part series and created a digest summary of the blog post. If you are in a rush and have no time to read my five series – I suggest you read his blog post. Training Resources I am often asked what the best resources for learning new technology are. This is the most difficult question EVER. There are plenty of good training resources available. When it is about training our needs are different, our preference of learning is different and we all have an opinion. Additionally, we all are located in different geographic locations worldwide and there is no way one solution will fit all. However, let me list a few of the training resources which I have built so far and you can consume them if you find it relevant to your need. SQL Server Books SQL Server Interview Questions and Answers SQL Wait Stats SQL Programming Joes 2 Pros SQL Server Video Tutorials SQL Server Questions and Answers SQL Server Performance: Indexing Basics SQL Server Performance: Introduction to Query Tuning SQL in Sixty Seconds Series of Sixty Seconds Learning Video on YouTube Trust me worldwide web is very big and there are plenty of high quality learning materials available worldwide – trainer-led as well online. I suggest you explore various options and make the best choice for yourself. Remember, training is your personal journey and it should never stop. Are you ready? Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Developer Training, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • Need help with PHP web app bootstrapping error potentially related to Zend [migrated]

    - by Matt Shepherd
    I am trying to get a program called OpenFISMA running on an Ubuntu AMI in AWS. The app is not really coded on the Ubuntu platform, but I am in my comfort zone there, and have tried both CentOS and OpenSUSE (both are sort of "native" for the app) for getting it working with the same or worse results. So, why not just get it working on Ubuntu? Anyway, the app is found here: www.openfisma.org and an install guide is found here: https://openfisma.atlassian.net/wiki/display/030100/Installation+Guide The install guide kind of sucks. It doesn't list dependencies in any coherent way or provide much of any detail (does not even mention Zend once on the entire page) so I've done a lot of work to divine the information I do have. This page provided some dependency inf (though again, Zend is not mentioned once): https://openfisma.atlassian.net/wiki/display/PUBLIC/RPM+Management#RPMManagement-BasicOverviewofRPMPackages Anyway, I got all the way through the install (so far as I could reconstruct it). I am going to the login page for the first time, and there should be some sort of bootstrapping occurring when I load the page. (I am not a programmer so I have no idea what it is doing there.) Anyway, I get a message on the web page that says: "An exception occurred while bootstrapping the application." So, then I go look in /var/www/data/logs/php.log and find this message: [22-Oct-2013 17:29:18 UTC] PHP Fatal error: Uncaught exception 'Zend_Exception' with message 'No entry is registered for key 'Zend_Log'' in /var/www/library/Zend/Registry.php:147 Stack trace: #0 /var/www/public/index.php(188): Zend_Registry::get('Zend_Log') #1 {main} thrown in /var/www/library/Zend/Registry.php on line 147 This occurs every time I load the page. I gather there is an issue related to registering the Zend_Log variable in the Zend registry, but other than that I really have no idea what to do about it. Am I missing a package that it needs, or is this app not coded to register the variables properly? I have no clue. Any help is greatly appreciated. The application file referenced in the log message (index.php) is included below. <?php /** * Copyright (c) 2008 Endeavor Systems, Inc. * * This file is part of OpenFISMA. * * OpenFISMA is free software: you can redistribute it and/or modify it under the terms of the GNU General Public * License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later * version. * * OpenFISMA is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more * details. * * You should have received a copy of the GNU General Public License along with OpenFISMA. If not, see * {@link http://www.gnu.org/licenses/}. */ try { defined('APPLICATION_PATH') || define( 'APPLICATION_PATH', realpath(dirname(__FILE__) . '/../application') ); // Define application environment defined('APPLICATION_ENV') || define( 'APPLICATION_ENV', (getenv('APPLICATION_ENV') ? getenv('APPLICATION_ENV') : 'production') ); set_include_path( APPLICATION_PATH . '/../library/Symfony/Components' . PATH_SEPARATOR . APPLICATION_PATH . '/../library' . PATH_SEPARATOR . get_include_path() ); require_once 'Fisma.php'; require_once 'Zend/Application.php'; $application = new Zend_Application( APPLICATION_ENV, APPLICATION_PATH . '/config/application.ini' ); Fisma::setAppConfig($application->getOptions()); Fisma::initialize(Fisma::RUN_MODE_WEB_APP); $application->bootstrap()->run(); } catch (Zend_Config_Exception $zce) { // A zend config exception indicates that the application may not be installed properly echo '<h1>The application is not installed correctly</h1>'; $zceMsg = $zce->getMessage(); if (stristr($zceMsg, 'parse_ini_file') !== false) { if (stristr($zceMsg, 'application.ini') !== false) { if (stristr($zceMsg, 'No such file or directory') !== false) { echo 'The ' . APPLICATION_PATH . '/config/application.ini file is missing.'; } elseif (stristr($zceMsg, 'Permission denied') !== false) { echo 'The ' . APPLICATION_PATH . '/config/application.ini file does not have the ' . 'appropriate permissions set for the application to read it.'; } else { echo 'An ini-parsing error has occured in ' . APPLICATION_PATH . '/config/application.ini ' . '<br/>Please check this file and make sure everything is setup correctly.'; } } else if (stristr($zceMsg, 'database.ini') !== false) { if (stristr($zceMsg, 'No such file or directory') !== false) { echo 'The ' . APPLICATION_PATH . '/config/database.ini file is missing.<br/>'; echo 'If you find a database.ini.template file in the config directory, edit this file ' . 'appropriately and rename it to database.ini'; } elseif (stristr($zceMsg, 'Permission denied') !== false) { echo 'The ' . APPLICATION_PATH . '/config/database.ini file does not have the appropriate ' . 'permissions set for the application to read it.'; } else { echo 'An ini-parsing error has occured in ' . APPLICATION_PATH . '/config/database.ini ' . '<br/>Please check this file and make sure everything is setup correctly.'; } } else { echo 'An ini-parsing error has occured. <br/>Please check all configuration files and make sure ' . 'everything is setup correctly'; } } elseif (stristr($zceMsg, 'syntax error') !== false) { if (stristr($zceMsg, 'application.ini') !== false) { echo 'There is a syntax error in ' . APPLICATION_PATH . '/config/application.ini ' . '<br/>Please check this file and make sure everything is setup correctly.'; } elseif (stristr($zceMsg, 'database.ini') !== false) { echo 'There is a syntax error in ' . APPLICATION_PATH . '/config/database.ini ' . '<br/>Please check this file and make sure everything is setup correctly.'; } else { echo 'A syntax error has been reached. <br/>Please check all configuration files and make sure ' . 'everything is setup correctly.'; } } else { // Then the exception message says nothing about parse_ini_file nor 'syntax error' echo 'Please check all configuration files, and ensure all settings are valid.'; } echo '<br/>For more information and help on installing OpenFISMA, please refer to the ' . '<a target="_blank" href="http://manual.openfisma.org/display/ADMIN/Installation">' . 'Installation Guide</a>'; } catch (Doctrine_Manager_Exception $dme) { echo '<h1>An exception occurred while bootstrapping the application.</h1>'; // Does database.ini have valid settings? Or is it the same content as database.ini.template? $databaseIniFail = false; $iniData = file(APPLICATION_PATH . '/config/database.ini'); $iniData = str_replace(chr(10), '', $iniData); if (in_array('db.adapter = ##DB_ADAPTER##', $iniData)) { $databaseIniFail = true; } if (in_array('db.host = ##DB_HOST##', $iniData)) { $databaseIniFail = true; } if (in_array('db.port = ##DB_PORT##', $iniData)) { $databaseIniFail = true; } if (in_array('db.username = ##DB_USER##', $iniData)) { $databaseIniFail = true; } if (in_array('db.password = ##DB_PASS##', $iniData)) { $databaseIniFail = true; } if (in_array('db.schema = ##DB_NAME##', $iniData)) { $databaseIniFail = true; } if ($databaseIniFail) { echo 'You have not applied the settings in ' . APPLICATION_PATH . '/config/database.ini appropriately. ' . 'Please review the contents of this file and try again.'; } else { if (Fisma::debug()) { echo '<p>' . get_class($dme) . '</p><p>' . $dme->getMessage() . '</p><p>' . "<p><pre>Stack Trace:\n" . $dme->getTraceAsString() . '</pre></p>'; } else { $logString = get_class($dme) . "\n" . $dme->getMessage() . "\nStack Trace:\n" . $dme->getTraceAsString() . "\n"; Zend_Registry::get('Zend_Log')->err($logString); } } } catch (Exception $exception) { // If a bootstrap exception occurs, that indicates a serious problem, such as a syntax error. // We won't be able to do anything except display an error. echo '<h1>An exception occurred while bootstrapping the application.</h1>'; if (Fisma::debug()) { echo '<p>' . get_class($exception) . '</p><p>' . $exception->getMessage() . '</p><p>' . "<p><pre>Stack Trace:\n" . $exception->getTraceAsString() . '</pre></p>'; } else { $logString = get_class($exception) . "\n" . $exception->getMessage() . "\nStack Trace:\n" . $exception->getTraceAsString() . "\n"; Zend_Registry::get('Zend_Log')->err($logString); } }

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