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Wikileaks' Julian Assange court appeal makes Twitter history

Wikileaks' Julian Assange court appeal makes Twitter history

The court appeal of Julian Assange in London has made history today as the first time ever tweeting has been allowed in a UK courtroom. Usu...

10 mistakes every programmer makes

<img src="http://cdn.mos.techradar.com//Review%20images/PC%20Plus/PCP%20300/PCP300.theory.pc_tower-200-200.jpg"> When you start programming, you get disillusioned quickly. No longer is the computer the allinfallible perfect machine – "do as I mean, not as I say" becomes a frequent cry. At night, when the blasted hobgoblins finally go to bed, you lie there and ruminate on the errors you made that day, and they're worse than any horror movie. So when the editor of <a href="http://pcplus.techradar.com/">PC Plus</A> asked me to write this article, I reacted with both fear and knowing obedience. I was confident that I could dash this off in a couple of hours and nip down to the pub without the usual resultant night terrors. The problem with such a request is, well, which language are we talking about? I can't just trot out the top 10 mistakes you could make in C#, Delphi, JavaScript or whatever – somehow my top ten list has to encompass every language. Suddenly, the task seemed more difficult. The hobgoblins started cackling in my head. Nevertheless, here goes… 1. Writing for the compiler, not for people When they use a compiler to create their applications, people tend to forget that the verbose grammar and syntax required to make programming easier is tossed aside in the process of converting prose to machine code. A compiler doesn't care if you use a single-letter identifier or a more human-readable one. The compiler doesn't care if you write optimised expressions or whether you envelop sub-expressions with parentheses. It takes your human-readable code, parses it into abstract syntax trees and converts those trees into machine code, or some kind of intermediate language. Your names are by then history. So why not use more readable or semantically significant identifiers than just i, j or x? These days, the extra time you would spend waiting for the compiler to complete translating longer identifiers is minuscule. However, the much-reduced time it takes you or another programmer to read your source code when the code is expressly written to be self-explanatory, to be more easily understandable, is quite remarkable. Another similar point: you may have memorised the operator precedence to such a level that you can omit needless parentheses in your expressions, but consider the next programmer to look at your code. Does he? Will he know the precedence of operators in some other language better than this one and thereby misread your code and make invalid assumptions about how it works? Personally, I assume that everyone knows that multiplication (or division) is done before addition and subtraction, but that's about it. Anything else in an expression and I throw in parentheses to make sure that I'm writing what I intend to write, and that other people will read what I intended to say. The compiler just doesn't care. Studies have shown that the proportion of some code's lifecycle spent being maintained is easily five times more than was spent initially writing it. It makes sense to write your code for someone else to read and understand. 2. Writing big routines Back when I was starting out, there was a rule of thumb where I worked that routines should never be longer than one printed page of fan-fold paper – and that included the comment box at the top that was fashionable back then. Since then, and especially in the past few years, methods tend to be much smaller – merely a few lines of code. In essence, just enough code that you can grasp its significance and understand it in a short time. Long methods are frowned upon and tend to be broken up. The reason is extremely simple: long methods are hard to understand and therefore hard to maintain. They're also hard to test properly. If you consider that testing is a function of the number of possible paths through a method, the longer the method, the more tests you'll have to write and the more involved those tests will have to be. There's actually a pretty good measurement you can make of your code that indicates how complex it is, and therefore how probable it is to have bugs – the cyclomatic complexity. Developed by Thomas J. McCabe Sr in 1976, cyclomatic complexity has a big equation linked to it if you're going to run through it properly, but there's an easy, basic method you can use on the fly. Just count the number of 'if' statements and loops in your code. Add 1 and this is the CC value of the method. It's a rough count of the number of execution paths through the code. If your method has a value greater than 10, I'd recommend you rewrite it. 3. Premature optimisation This one's simple. When we write code, sometimes we have a niggling devil on our shoulder pointing out that this clever code would be a bit faster than the code you just wrote. Ignore the fact that the clever code is harder to read or harder to comprehend; you're shaving off milliseconds from this loop. This is known as premature optimisation. The famous computer scientist Donald Knuth said, "We should forget about small efficiencies, say about 97 per cent of the time: premature optimisation is the root of all evil." In other words: write your code clearly and cleanly, then profile to find out where the real bottlenecks are and optimise them. Don't try to guess beforehand. 4. Using global variables Back when I started, lots of languages had no concept of local variables at all and so I was forced to use global variables. Subroutines were available and encouraged but you couldn't declare a variable just for use within that routine – you had to use one that was visible from all your code. Still, they're so enticing, you almost feel as if you're being green and environmentally conscious by using them. You only declare them once, and use them all over the place, so it seems you're saving all that precious memory. But it's that "using all over the place" that trips you up. The great thing about global variables is that they're visible everywhere. This is also the worst thing about global variables: you have no way of controlling who changes it or when the variable is accessed. Assume a global has a particular value before a call to a routine and it may be different after you get control back and you don't notice. Of course, once people had worked out that globals were bad, something came along with a different name that was really a global variable in a different guise. This was the singleton, an object that's supposed to represent something of which there can only be one in a given program. A classic example, perhaps, is an object that contains information about your program's window, its position on the screen, its size, its caption and the like. The main problem with the singleton object is testability. Because they are global objects, they're created when first used, and destroyed only when the program itself terminates. This persistence makes them extremely difficult to test. Later tests will be written implicitly assuming that previous tests have been run, which set up the internal state of the singleton. Another problem is that a singleton is a complex global object, a reference to which is passed around your program's code. Your code is now dependent on some other class. Worse than that, it's coupled to that singleton. In testing, you would have to use that singleton. Your tests would then become dependent on its state, much as the problem you had in testing the singleton in the first place. So, don't use globals and avoid singletons. 5. Not making estimates You're just about to write an application. You're so excited about it that you just go ahead and start designing and writing it. You release and suddenly you're beset with performance issues, or out-of-memory problems. Further investigations show that, although your design works well with small number of users, or records, or items, it does not scale – think of the early days of Twitter for a good example. Or it works great on your super-duper developer 3GHz PC with 8GB of RAM and an SSD, but on a run-of-the-mill PC, it's slower than a Greenland glacier in January. Part of your design process should have been some estimates, some back-back-of- the-envelope calculations. How many simultaneous users are you going to cater for? How many records? What response time are you targeting? Try to provide estimates to these types of questions and you'll be able to make further decisions about techniques you can build into your application, such as different algorithms or caching. Don't run pell-mell into development – take some time to estimate your goals. 6. Off by one This mistake is made by everyone, regularly, all the time. It's writing a loop with an index in such a way that the index incremented once too often or once too little. Consequently, the loop is traversed an incorrect number of times. If the code in the loop is visiting elements of an array one by one, a non-existent element of the array may be accessed – or, worse, written to – or an element may be missed altogether. One reason why you might get an off-by one error is forgetting whether indexes for array elements are zero-based or one-based. Some languages even have cases where some object is zero-based and others where the assumption is one-based. There are so many variants of this kind of error that modern languages or their runtimes have features such as 'foreach loops' to avoid the need to count through elements of an array or list. Others use functional programming techniques called map, reduce and filter to avoid the need to iterate over collections. Use modern 'functional' loops rather than iterative loops. 7. Suppressing exceptions Modern languages use an exception system as an error-reporting technique, rather than the old traditional passing and checking of error numbers. The language incorporates new keywords to dispatch and trap exceptions, using names such as throw, try, finally and catch. The remarkable thing about exceptions is their ability to unwind the stack, automatically returning from nested routines until the exception is trapped and dealt with. No longer do you have to check for error conditions, making your code into a morass of error tests. All in all, exceptions make for more robust software, providing that they're used properly. Catch is the interesting one: it allows you to trap an exception that was thrown and perform some kind of action based upon the type of the exception. The biggest mistakes programmers make with exceptions are twofold. The first is that the programmer is not specific enough in the type of exception they catch. Catching too general an exception type means that they may be inadvertently dealing with particular exceptions that would be best left to other code, higher up the call chain. Those exceptions would, in effect, be suppressed and possibly lost. The second mistake is more pernicious: the programmer doesn't want any exceptions leaving their code and so catches them all and ignores them. This is known as the empty catch block. They may think, for example, that only certain types of exceptions might be thrown in his code; ones that they could justifiably ignore. In reality, other deadly runtime exceptions could happen – things such as out-of-memory exceptions, invalid code exceptions and the like, for which the program shouldn't continue running at all. Tune your exception catch blocks to be as specific as possible. 8. Storing secrets in plain text A long time ago, I worked in a bank. We purchased a new computer system for the back office to manage some kind of workflow dealing with bond settlements. Part of my job was to check this system to see whether it worked as described and whether it was foolproof. After all, it dealt with millions of pounds daily and then, as now, a company is more likely to be defrauded by an employee than an outsider. After 15 minutes with a rudimentary hex editor, I'd found the administrator's password stored in plain text. Data security is one of those topics that deserves more coverage than I can justifiably provide here, but you should never, ever store passwords in plain text. The standard for passwords is to store the salted hash of the original password, and then do the same salting and hashing of an entered password to see if they match. Here's a handy hint: if a website promises to email you your original password should you forget it, walk away from the site. This is a huge security issue. One day that site will be hacked. You'll read about how many logins were compromised, and you'll swallow hard and feel the panic rising. Don't be one of the people whose information has been compromised and, equally, don't store passwords or other 'secrets' in plain text in your apps. 9. Not validating user input In the good old days, our programs were run by individuals, one at a time. We grew complacent about user input: after all, if the program crashed, only one person would be inconvenienced – the one user of the program at that time. Our input validation was limited to number validation, or date checking, or other kinds of verification of input. Text input tended not to be validated particularly. Then came the web. Suddenly your program is being used all over the world and you've lost that connection with the user. Malicious users could be entering data into your program with the express intent of trying to take over your application or your servers. A whole crop of devious new attacks were devised that took advantage of the lack of checking of user input. The most famous one is SQL injection, although unsanitised user input could precipitate an XSS attack (crosssite scripting) through markup injection. Both types rely on the user providing, as part of normal form input, some text that contains either SQL or HTML fragments. If the application does not validate the user input, it may just use it as is and either cause some hacked SQl to execute, or some hacked HTML/JavaScript to be produced. This in turn could crash the app or allow it to be taken over by the hacker. So, always assume the user is a hacker trying to crash or take over your application and validate or sanitise user input. 10. Not being up to date All of the previous mistakes have been covered in depth online and in various books. I haven't discovered anything new – they and others have been known for years. These days you have to work pretty hard to avoid coming into contact with various modern design and programming techniques. I'd say that not spending enough time becoming knowledgeable about programming – and maintaining that expertise – is in fact the biggest mistake that programmers make. They should be learning about techniques such as TDD or BDD, about what SLAP or SOLID means, about various agile techniques. These skills are of equal or greater importance than understanding how a loop is written in your language of choice. So don't be like them: read McConnell and Beck and Martin and Jeffries and the Gang of Four and Fowler and Hunt & Thomas and so on. Make sure you stay up to date with the art and practice of programming. And that concludes my top 10 list of mistakes programmers make, no matter what their language stripe. There are others, to be sure, perhaps more disastrous than mine, but I would say that their degree of dread is proportional to the consequences of making them. All of the above were pretty dire for me the last time I made them. If you have further suggestions or calamities of your own, don't hesitate to contact me and let me know.

10 mistakes every programmer makes

When you start programming, you get disillusioned quickly. No longer is the computer the allinfallible perfect machine – "do as I mean...

Are You Interested to Know What Makes a Computer Freeze?

If you know how to treat these kind of issues, then it will only takes a little of your time to diagnose what the solution is. However, for someone who is still a newbie with computers, they might already be going berserk and still can't figure out what is happening.Computers keep on freezing up is one of the "everyday" issues most of the computer users encounter. Whether you're a newbie or an expert with it. To know exactly what does this, here are some of the basic things you will need to do to stop your computer from freezing up:o Too many devices attached to your computer. You have this new video downloaded from the net and you want to transfer it to your iPod. So, you attached your iPod to your computer. And another thing, you remember you had a date with your friends last night and they are begging you to upload all the pictures to Twitter or Facebook. You have to attach the digital camera again to your PC to be able to do so. Technology has come a long way and we are too excited to use them all at the same time. However, this may crunch up your computer's RAM. These things attached to your computer, you might need some and the other's not, but do remember, overloading your computer's capability might result to fatal crash or freezing up. Unplug any devices that you are not using to make room for other devices that you will be using to avoid any inconveniences.o New hardware. You found a new gaming software and you want it to install right away to your computer but you will need to buy this new video card. And you did. Your friend said that he just have this marvelous motherboard he bought at a very low price and it runs perfectly with his PC. And you did buy it, too, hoping it will make your computer runs faster. After a week of doing so, you started to notice, your pc starts to slow down, it will reboot itself, viewing of pictures are so blurry and videos are slowly moving. Not all hardware, the ones that best promise to make your PC lifestyle easier, is compatible with your computer. Check out with your computer manufacturer, a local technician you know, or go to forums that tackles the performance / reviews of the product before buying it.o Faulty hardware devices. This could be the driver that needs updating or a device that needs to be replaced. Each operating systems, whether Windows or Mac or any other OS, has a built in system checker for this. Try running it for your PC's sake.o Obsolete program versions. You had the new antivirus software installed but the old version was not deleted. This will only eat up your memory. Try removing these kind of programs in your pc.o Startup programs. These programs were there, either because your computer manufacturer configured it or when you installed that program, it was set to start up immediately once your computer boots up. Figure out which programs needs to be in start up and which are not.o Icons almost covering your desktop. You can no longer see your wallpaper because of the many icons displayed. Try reducing the number of icons displayed Figure out which of those you need and not. For those you don't really need, try moving these icons / files to their appropriate locations.o Too many unnecessary files stored in your memory. Did you know that when surfing the net, it will automatically saved files to your system? It will simply tell you the activities you've done while surfing that particular website. Well, you don't really need this. It will just be a reason for hackers to hack into your system. Better delete this. The backup files of your original files, which are not really invisible to most users, are also stored in your computer's RAM. Delete this one as well. You can use the disk cleanup tools of your operating system to delete any of these.o Too many programs running in the background. Go to your task manager and check which programs are running. If you can only see one program running, check out the msconfig utility. There you will find a lot of programs running in which some of those are not supposed to be enabled. Disable them but make sure that they should not really be running in the background or else it will cause a lot more issues than freezing up.o Duplicate files / programs. There can be two antivirus software installed in your computer, you forgot that you already downloaded this video and now there's two in your PC - these things happened. Once in a while, check your pc for these so you can free up some memory space in your computer.o System errors. Don't ignore those most of all if the message is coming from your pc and not from a site that you are just surfing. This system error comes with an information why your computer generated such error. Do the fixes suggested.o Software Suggested Updates. Once in a while, a message will pop up on your computer screen suggesting an update on your PC. After thorough reading, better to download it for your computer's sake. But beware! Make sure that the updates are genuine and not just coming from a third-party site. You might be installing viruses / spywares / malwares in your computer.o Spywares / Malwares / Viruses. In order to prevent this, just make sure that your anti-virus software is up-to-date. If your antivirus software does not have spywares / malwares detector, look for a software that can do this and download it. Any of these three are enough to bring chaos to your computer. Additionally, make sure to scan your system at least thrice a week to make sure there is no presence of these three in your computer.Now you know what makes your computer freeze up. You already have the knowledge on how you can stop your pc from this inconvenience. If none of these help, it is time for you to bring your computer to local technician or to your computer manufacturer for advanced troubleshooting.	 	 		 			 				 					 						Do you often ask yourself " <a href="http://www.bestregistrycleanerguides.com/" target="_new">what makes a computer freeze</a>?" You can definitely know the answer to it with the best registry cleaner software! Don't wait any longer! We're expecting you. Take this important first step to know "why does my computer keep freezing" and fix your computer registry problems at <a href="http://www.bestregistrycleanerguides.com" target="_new">http://www.bestregistrycleanerguides.com</a>

Are You Interested to Know What Makes a Computer Freeze?

If you know how to treat these kind of issues, then it will only takes a little of your time to diagnose what the solution is. However, f...

What Makes Hackers Ecstatic?

Hackers have taken a different face. Previously, most hackers were just on for the thrill of the game. Nowadays, however, they are not just in for the game because they love what they do, but because they are making huge profits out of it.Despite the many security measures that are being advertised, not one can claim that their product can provide a hundred percent protection from hackers. These people abound, and their numbers are growing each minute of the day. With the newest advancemenet in technology, they even proliferate even more as technological advancements makes everything easier for them.But what makes hackers ecstatic? Here are some:People Making Online PurchasesWhen you make an online purchase, you cannot use cash for your payments. You have to use your credit or debit card for any financial transaction. Before you do, most online retailers often require that you become a member of the site by registering with your chosen username and passwords. Everything that you use to make your purchase can be accessed by hackers. They can hack into the retailer's database and steal the personal information of every client recorded. These identities are sold to people who commit identity theft and they can be sold for a huge amount of money. Wi-Fi hot spots and wireless home networksThese are also favorite playgrounds of hackers as they can also access a lot of personal information when they tap in to these hot spots. People use the internet for a lot of transactions and since hot spots are typically public zones, they can connect to the network, hack it and use their knowledge and skills to commit identity theft or do other illegal activities. Wi-Fi hot spots do not typically have passwords that is why they are easier to access and there are always a lot of people who are using them which makes hackers more ecstatic because they can access more information.The InternetThe World Wide Web has provided a lot of channels for hackers to perpetuate their crimes-identity theft, illegally accessing corporate systems and financial institutions, etc. The internet connects millions of computer worldwide into one big network. This then makes it easier for hackers to commit, for instance, identity theft even when they are at the comfort of their own homes because as long as you are online-wirelessly or not-you are connected to the entire internet network. Surely you have passwords, firewalls, anti-virus programs, everything to keep you protected but you cannot really assure that you will be.Hackers now come in all shapes and sizes. They can be professionals who make their living out of hacking, college students hired by identity theft syndicates to steal personal information to be used in varied identity theft crimes, or even teenagers who happened to have excellent computer skills that allowe them to access various network ports. No matter who they are and what they can do, every individual who uses the computer should be vigilant enough and take necessary defensive measures to make themselves less attractive to hackers and identity theft criminals online.	 	 		 			 				 					 						Tina L. Douglas is a skilled writer from California. With numerous experiences in the field of writing for several financial institutions, she is greatly qualified across a variety of economic issues. Her notable pieces of writing involve <a href="http://5identitytheftprotection.com/" rel="nofollow" target="_new">identity theft</a>.

What Makes Hackers Ecstatic?

Hackers have taken a different face. Previously, most hackers were just on for the thrill of the game. Nowadays, however, they are not ju...

iPhone Flash app makes $1 million in a weekend

<img src="http://cdn.mos.techradar.com//classifications/images/skyfire-200-200.jpg"> SkyFire, the app that lets iPhone users view Flash video on their phones, has managed to generate a cool $1 million in its first weekend on sale. The SkyFire app for iPhone costs $2.99 in the US and yet is still not officially available on the UK iTunes Store. How to make a quick million bucks However, reports from the jailbreak scene indicate that there are plenty of British users with jailbroken iPhones already happily using the Flash app. SkyFire is available for free on all other smartphone platforms, but that is clearly because those platforms already offer Flash video support, unlike Apple's iPhone. The company told MobileCrunch that its download numbers for their first weekend on the US iTunes store were 2well over 300,000." After Apple takes its 30 per cent cut, this means that SkyFire walked about with somewhere between $600,000 to $700,000. Not bad for a weekend's work! The iPhone app has suffered a few teething troubles in its first few weeks on sale, with SkyFire putting this down to the huge demand for Flash on iPhone from its customers.

iPhone Flash app makes $1 million in a weekend

SkyFire, the app that lets iPhone users view Flash video on their phones, has managed to generate a cool $1 million in its first weekend on ...