Got a Linux on my ASUS N75S

Finally I managed to get a Linux distro running on my ASUS N75S. It wasn’t easy, but after lots of tries and failures Ubuntu 12.04 alpha managed to install itself regardless of the pickiness of the nvidia Optimus. My basic problem was that I wanted to use all the 1920×1080 pixels on the 17″ screen, but no Linux distro was able to use the nouveau nor the nvidia proprietary drivers due to the Optimus technology which incorporates two video cards and depending on the need uses this or that.

Ubuntu 12.04 alpha 2 didn’t go easily up either, since the installer crashes at the custom hard disk partitioning step, so I had to choose install along Windows 7, and lose the flexibility of a custom partitioning but for now this is only a test ride, ie. an alpha version, so hopefully this will be fixed in the final release coming in April, this year.

The installer did not finish the first run, it crashed somewhere at the end (and opened a bug for me, which it identified as a duplicate quickly), but after a restart I chose the Upgrade existing Linux distro, and finally this worked.

I have a full HD ubuntu, for now I forgive the un-user-friendliness of Unity, but looking forward to a final release of Ubuntu 12.04, hoepfully it will contain something else too.

And here is a list of Linuxes I have tried, together wit the result:

Ubuntu 11.10 – the boot disk crashes with the familiar nouveau driver error
CentOS 6 – the installer reaches to the point where it is supposed to start the installation and the bails out due to some python error
Fedora 13 – same as CentOS 6, but it does not tell me the error source
Fedora 15 – same as above
Fedora 16 – actually I have installed this in basic video mode, but bumblebee was not working regardless that I followed the steps found here.
ArchLinux – did not find my network card (nor the wireless, nor the wired)
Debian 6 – same as ArchLinux
NetBSD – totally freaked out when it saw my hard secondary disk
FreeBSD – totally freaked out when I installed X

That’s all folks.

Thing you should never do

As a programmer you inevitably get in a situation when you apply for a job, pass the interview, the occasional testings, pay a visit to the company site, get to know them, and decide that yes, I’d like to work for these guys. And then comes the almighty phrase: “We are really happy with your interview results, we think you would be a valuable member to our community, but before we make the next step, we would like to ask you for some references who can give recommendations regarding your work and experience”. And bang, here comes your big dilemma: whom should I give as a reference. Giving your current manager would be a kind of career suicide at your current company, if the new company is not accepting you (or you don’t accept their offer) in the end. Actually giving anyone from your current company will create a really awkward situation, so never do this. Why?

Let’s suppose you are an excellent programmer, and you give your colleague as a reference. You already convinced the other company that you are good at what you do. Now, your colleague is in the following strange situation: If he tells the other company, that you are a great programmer, he effectively paves your road into the new company. But your current company will not do any better without you, because they’ve just lost a great programmer, and in the end, he will also have to suffer the lack of you. Also, this makes him feel like a traitor, knowing that he is doing harm to the current company. So there’s a chance that he will tell the new company that you’re a lousy programmer, and they should not consider hiring you. With this he just told a big fat lie, and put you in a strange situations, since you’ve felt that you already have your foot inside the door at the new company.

Now, if you are a lousy programmer and give your colleague as a reference, he will be extraordinarily happy to tell the new company, that yes, he is a great guy, an excellent programmer, knowing that he can get rid of you and maybe get a new and better developer. It won’t hurt them. But now the people at the new company are confused… They might have already formed an opinion about you and they just wanted an assurance that their opinion is the right one. And then you get this excellent review from a reference.

So, as a basic rule, always try to give someone from a previous company as reference. It is much better for you, and for the people working at your current company.

Actually there is one exception to the rule. When they are closing down the offices, you are free to give any reference from your current company. Since all of you are in the same situation.

Does Open Source experience Help in Today’s Job Market?

The title is taken from the linux-mag article (http://www.linux-mag.com/id/7250) but obviously I had to comment on this too … My experience is that depends on the company you are applying to. If you’re applying to one of those mega companies, who get the Windows license in bulks, packed together with Office and by default they have an NTLM authentication enabled web server connecting you to the outside world, then the managers there simply don’t care if you have any experience in the Open Source world. For them Open source does not exist, and regardless that you’re trying to convince them, that there’s a world outside of windows, you’ll lack the success. They won’t hear.

To my biggest surprise, while working at a company like this for several years, the major key in small meetings and large meetings always was TCO reduction (yes, TCO means: Total cost of Ownership) for customers and even for inside the company. At almost every meeting someone (with an open mind … not me) suggested, what about trying out other alternatives, for example providing a Linux version of our application for smaller customers who did not had the need nor the money to pay several thousands of dollars for a genuine *x machine, or to simply uninstall a commercial version of one of the most used applications from a well known company and install the Open version of it. At all the meetings someone from high management suggested that due to strategic partnerships, this is out of question. Such a real example of closed mindedness always succeeded to make me question what on earth do they want to reduce, if not this and not that.

On the other end, at small companies you have a much bigger freedom of choosing what applications you want to use (of course, this also depends on the company profile, management, etc…) and
But this thread has gone already too far from the original question So, back to the original scope. Does it really matter for an average secretary application if you know how to use OpenOffice and Thunderbird instead of the commercial variants? Maybe not. So, I’m sure it won’t help at all, since again, for not Tech jobs (NOT programmers, sys admins, etc…) there is not too much to choose from, so non-tech employees better stuck to the standard applications, since there is a much better chance that they’ll find a better job by knowing applications that you can find in (almost) every office.

With the tech-related areas, however the situation is different. Regardless that you’re a programmer, or a graphic designer it’s, sysadmin, etc… it can be useful that you know some “freeer” variants of commercial applications. But whether you’ll use these skills or not, depends a lot on the actual environment you will be working in.

As a programmer it is not mandatory to have programming experience in Linux and be an emacs guru or vi master, however it does not hurt, because the more you are experienced in the more opportunities you have to find a job you will like to stuck to for a longer time. In my experience companies which use open source software on a daily basis, regardless if they are developing for them, or just use, have a much more open and relaxed attitude towards their employees giving a much larger freedom and possibilities to choose from.

So, un-dust your old computer and go grab some Linux distro and up with it.

New programming languages

Some interesting new programming languages came out lately, I picked three of them and gave them a quick overview. Don’t expect something deep here, just a short presentation of the language itself.

Go

On of these new languages is “Go” (coming from Google). According to their web site ” Go is expressive, concise, clean, and efficient.” … A very short application down here written in the Go language shows not only the power of the language but also some interesting constructs that either can make your code more readable or a little bit confusing:

package main
import "fmt"
var y, u, t = "A text", 12, false;
func main() {
    fmt.Println(y,u,t)
}

with the output:

A text 12 false

I’ve said a little bit confusing, since at first look I’d be confused at how three variables of three different types are being initialized in one line, however you can consider this also a nice feature. It’s up to you. Applications written in the Go language can return more than one value. This comes especially handy in some cases, you can forget some ugly constructs where you had to define a new structure to hold your two variables you had to return from one function. I specially like this feature and also the syntax is very nice. See how it looks in reality:

func swap(x, y string) (string, string) {
    return y, x
}

In the Go language the for has lost the parentheses … that’s fine with me, so a simplified Go for looks like:

sum := 0
for i := 0; i < 10; i++ {
    sum += i
}

However, not that the curly braces are mandatory. Yes, that makes sense, not only to enforce some basic readability but also to make the life of the parser easier Also, a very funny thing: there is no while keyword in Go. The while for Go is for:

sum := 1
for sum < 1000 {
    sum += sum
}

… so the infinite loops look like: for{} that’s pretty short.

Shortly… the Go language looks like an interesting alternative for those who look to do some C style programming, without all the messy pointers and the overly complicated C++ class handling since Go has a funny way of dealing with classes… they are not there (however there are alternatives too, don’t get scared). Just go and read the doc.

Rust

Another promising language called Rust is coming from Mozilla. Again, this is also a C like syntax with all the curly braces but not only. They took over some Pascal like syntax in the variable definition, just like:

const repeat: uint = 5u;

and the function definitions have a funny feeling. You define a function like:

fn is_four(x: int) -> bool { x == 4 }

ie. this defines (with the keyword fn) a function called is_four, which takes an int and returns a bool. Now everyone decides for themselves if they like more this arrow like thing for return or the way that Go language handles the return syntax. Personally I prefer the Rust way… However I did not find a way to return more than one value from a function. So this is a big go, for the Go…

Rust has some feelings that the developers were influenced by Pascal, Basic, C, C++ … it is a nice mixture of those languages. I plan to spend some time with this language so maybe more posts will be here about it.

Ceylon

Beside of being a tea making small island Ceylon also is a new programming language backed up by RedHat. Ceylon has it roots in Java, clearly an object oriented language itself, with a few useful additions and a very java-ish syntax. Ceylon promises to get rid of the null value, with the following constructs:

void hello(String? name) {
    if (exists name) {
        print("Hello, " name "!");
    }
    else {
        print("Hello, world!");
    }
}

So, as you can see, the String type ends with a question mark, this means, this might be a null value, and in this case it is mandatory to check its existence wit ht exists keyword otherwise the compiler will yell on you. The quick introduction to Ceylon page gives a good overview of all the new features, it’s a good read for those interested in the future and coming direction of  the java programming language.

Verdict

There is no verdict. Go, take a look on them, decide which is best for thou.

I’m really annoyed

I am trying to install Linux on my brand new ASUS N75S and all the major distros fail due to an error in the nouveau driver. This means, that the live CD doesn’t even start … No Ubuntu, No Fedora, No Mint… I think I’ll just go back to good old Arch … But now really, distro compilers, nouveau developers… that GeForce GT555 is out there for some time.

Libraries and librarians – 1.

It’s been some time that I really try to find what library to use for completing my plain daily C and C++ programming tasks, but to be honest, did not find any of them that 100% satisfies my needs. And for god’s sake, these tasks are not so complicated, just some simple string handling, some sockets, and threads, so as you can see, nothing extraordinarily complex. I thought, I’d give a shoot to

boost

since everyone is speaking very gladly about this pretty powerful library. It has indeed nice features, shared pointers and arrays, support for sockets, and a lot of other nice features, that all come handy. Obviously (because this is not an article praising boost) I have found things I don’t like about it. Firstly, I have an issue reading the code written with boost. The more advanced the feature you want to create, the more awkward the code becomes. Long template instantiations, then hidden objects, that are being created and silently destroyed, this is not for me. Secondly the compile times are massively increased after including a few boost header files, due to the heavy template utilisation in the libraries. Thirdly, if it compiles on your computer, does not mean, it will compile on the colleagues computer too, if there’s a different version of boost installed. But till now, still this is my favourite library till I find something else. I use boost combined with

stl

because it has already the string handling implemented, it’s C++ and thanks god, it’s standard. The lacks of stl (no threading, no sockets, others…) are being nicely complemented with the features offered by boost, and using these two together you can come up with a very powerful C++ solution, which will take humongous time to compile. Also, the combination of these two offers a solution, which can be ported with more or less effort very easily to a different platform and operating system. Now, I was just curious about some other alternatives, that have facilities I need. One of them was

Qt

which is open sourced by Nokia, and has almost everything an application developer needs. And, it’s also multi-platform. The only issue with Qt is that once you want to deploy your solution, you will need to ship the entire Qt fleet with it, the libraries having support for everything from string handling to network protocols and xml dealing, but also you can choose to statically link your application with Qt libraries, resulting in a pretty big executable. Qt is good, but do not try to mix applications written in Qt with some other C++ libraries unless you really really have to. Qt has a very authoritarian build system and you might end up getting results you are not expecting. Also, the extension to C++ (slots, signals, etc…) might drive off developers who seek a more standard way of solving things.  The next step from this was obviously

MFC

which is available for Windows. It’s really C++, and has all the required functionality I want … but it also comes with some strange AFX things … and since it’s defaulted to Windows, I had to drop it, since I develop a multi-platform application.

In the next chapter I’ll explore more libraries.

Perils of strdup

Let’s take two nice RPM based distros: Fedora12 and CentOS5.5. And the following piece of code:

char *s = strdup(something);

This works on Fedora. All the time. This works on CentOS too … most of the time. So, pale C programmer, be aware that using strdup on CentOS is evil, evil, evil. Instead do this:

int l = strlen(something);
char *s = (char*)calloc(l + 1, sizeof(char));
if(!s) return;
memcpy(s, something, l);

This works all the time… Some people say, that strdup is not standard C. Fine with me. But it still should work once it compiles.

Pitfalls of Apache mod programming

I think apache needs no introduction to anyone having some knowledge in Linux, web servers, internet or other digital-era inventions … Also, if you’re a little bit more tech-savvy, you might know, that you can write apache modules, which can do various other things beside of the standard “give me the file” feature already existing in apache. A very good tutorial can be found at: http://threebit.net/tutorials/apache2_modules/tut1/tutorial1.html this will introduce you to the basics of how to write an apache module, starting from almost zero, and if you are more interested you also can read some of the chapters from the great book of Doug MacEachern and Lincoln Stein: “Writing Apache modules with Perl and C”.

On the other end writing apache modules is a pretty cumbersome task, so there are not too many resources available. I will try to share a few of my “Lessons Learned” throughout this blog with you, in case it will help someone.

Lesson 1. – Creating a web server inside an apache mod.

Let’s suppose you have the weird situation, that you need a module which needs to act as a server (yes, don’t forget, you are already integrating in an existing solution) so that clients can connect to it, and exchange information. This might freak out a security expert, but let’s hope there’s not even one around to see this requirement. The first thing you need to take into consideration, is that apache doesno’t really like the standard BSD socket functions. They work, but in my experience they are totally unreliable, since their resources might not be manageable by the apache runtime… (yes, apache is managing its resources in so called pools, meaning, you don’t need to take care of memory management if you decide to use these… and I highly recommend using these apache pools. They’ll save you a lot of time). To get your hand on the apache portable runtime’s socket management functions please consult the following link: http://dev.ariel-networks.com/apr/apr-tutorial/html/apr-tutorial-13.html

This is the best that is out there right now, so just read it and understand it. But your problems are far from being over. Remember the following: by default, apache is allocating a process to a request, because on the posix flavored world of X-es, spawning a process was much easier than spawning a thread. So, apache gets the request from the remote browser, spawns your process, your process loads the requested modules, your process gets the request, does some work on it and the result is sent back to the client, the process dies. Let’s see what is happening for your module: when apache spawns the new process there are some callbacks executed, usually these register some so called hooks, that are executed in various phases of the request processing. More details can be found out at: http://httpd.apache.org/docs/2.0/developer/modules.html

Usually you would like to create the web server in the initialization phase of the module and would like to keep it there till the apache is up and running. But with the default configuration, a web server is created for each of the processes, and with some network programming background you easily spot the bug: there can be only one web server on one port. Period. The solution is that you configure apache to run in a multi threaded, one process setup, this way you can create a shared web server between the various apache threads as a global, static variable.

Now you’re happy. You deploy your code, works flawlessly… for 3 or 4 hours. Then suddenly crashes. Lots of debugging don’t bring you closer to the solution. You read, and read through the code. Put in lots of debug messages… re-deploy. Great, works for 7-8 hours, then it crashes again. Yup… multi threading, sharing a global object is usually a bad idea. You deploy some cleverly placed mutexes. Finally, your code works as it’s supposed to. Don’t forget to use apache’s own mutex locking mechanism

How to write C++ applications under Windows – Chapter 1

How to compile C++ applications under Windows

A friend of mine has asked me how to compile C applications under Windows. He just started walking the pathways of C programming, so obviously some questions might come up during the rocky road of C development. To help him I’ve compiled this short list. I want to stuck to sources which are freely available on the internet, and are easy to start up with.

Here is the first application I want to compile


#include
int main(int argc, char** argv)
{
printf("%s was called with %d arguments\n", argv[0], argc);
}


So, here are my methods of compiling a C program under windows.

Visual Studio Express 2010

The fastest way to start C development under Windows is to download the freely available Microsoft Visual Studio Express: http://www.microsoft.com/express/Downloads/#2010-Visual-CPP . After the download has finished, run it, it will download more stuff, but after the mandatory restart you will end up with a fully functional IDE, which will be pretty easy to use.

When it’s set up just start it, and go to File -> New -> Project (or just press Ctrl + Shift + N) and select Win32 Console application, down below fill in the required fields and press Ok. The screenshot looks like:

Now, on the next screen do the following: Click on the Application settings, and check the empty project.

Screenshot:

Press Finish.

Now you have an empty project. I personally prefer creating empty projects, since you have a much better control over file creation.

The next step is to create a C++ source file and add it to the project, so: right click the project icon select Add -> New Item…

Screenshot:

in the new dialog box select select C++ file.

Screenshot:

And click Add…

type in the program above, Save and press Ctrl + F5 to run it. The result should look like.

Now, this should do it.

The advantages of the Visual Studio approach are that you will get a very good IDE, and you will have the chance to familiarize yourself with it, later it might come handy. This is an industry standard application, if you will get a job later in the Windows application development area, the chances that you will use Visual Studio are almost 100% otherwise do not work for that company.

The disadvantages Visual Studio are, that you will get used to it … and later when you will not have the chance to work with it you will really miss all its great features. Beside of this, no disadvantage was identified.

The next chapter will present how to write applications using different IDE’s

blackmagic in linux

So, I have this wonderful blackmagic SDI card, insert the card in its PCI-E slot, compile the drivers, insmod and then my machine freezes… Restart, insmod, freeze. Restart, install official driver from their site. Restart. Not even starting, kernel panic in the first screen… some googling, and then back to the provider site. They tell me is I want to use pcie_aspm=off in the bootloader. Good… card remove, edit /boot/grub/menu.lst append stuff at the end, card back, start machine and it works. Wonderful…