Wednesday, March 24, 2010

Remove image tags from an html page

On my company's wiki site, there is an internal phone book . I wanted to be able to use it offline, so I saved it to my local computer. The web paged saved with a folder and attached images (normal behavior). But I wanted to remove the images.

I used Scite's replace function with regular expressions, I first removed all line breaks, then I used the simple regular expression
 <img[^>]*>
to match for all images and replace them with no text.

Wednesday, March 17, 2010

Installing Ubuntu server on KVM virtual machine

In the previous post, I tested the usage of Xubuntu on a virtual machine.

Today I installed Ubuntu server edition on a virtual machine. The 64 bit edition won't install on the virtual machine. By dowloading the 32 bit version , I could install a server on the virtual machine. Command:
kvm -m 750 -cdrom ../Downloads/ubuntu-9.10-server-i386.iso -boot d ubuntu-server.img
It installed fine, and I added the 2 options to install a LAMP server and a Postgreesql database.
After installation, I restarted the new system with the command:
kvm -no-acpi -m 700 ubuntu-server.img
[edit] The -no-acpi flag is to disable acpi. I used the command from a how-to done by a guy who wanted to avoid a kernel panic on an Ubuntu 7.10, but in ubuntu 9.10 acpi works well. So I can start the server with:
kvm -m 700 ubuntu-server.img

Starting Ubuntu-Server on KVM Virtual Machine

Next step would be to access the http server from outside the virtual machine. For this I probably need to set a public bridge.

Tuesday, March 16, 2010

Virtual Machine

I installed KVM on my Ubuntu computer.
Following this instruction, I created a raw drive image with the command:
qemu-img create xubuntu.img -f qcow2 2G
I used the option -m 750 to start the virtual machine (VM) with 750 Mb of RAM. Then I used the option -cdrom to use a file as a cdrom image and the option -boot d to say that the VM shall boot on a cdrom drive. The command:
kvm -m 750 -cdrom ../xubuntu-9.10-desktop-i386.iso -boot d xubuntu.img
...starts the installation of Xubuntu on the virtual machine.

Screenshot of the starting page of Xubuntu on the virtual machine.

The virtual Machine runing Xubuntu

Now I'm going to install Ubuntu server and try to install a LAMP on it.

Thursday, March 04, 2010

From DOS to Windows NT

In 1981 IBM relesead the Personal Computer with Microsoft's MS DOS as operating system.CP/M-86:
When IBM contacted other companies to obtain components for the IBM PC, the as-yet unreleased CP/M-86 was its first choice for an operating system because CP/M had the most applications at the time. Negotiations between Digital Research and IBM quickly deteriorated over IBM's non-disclosure agreement and its insistence on a one-time fee rather than DRI's usual royalty licensing plan.[1] After discussions with Microsoft, IBM decided to use 86-DOS (QDOS), a CP/M-like operating system that a Seattle area computer company had made for its own hardware. Microsoft adapted 86-DOS for the PC hardware and IBM shipped it as PC-DOS.

After learning about the deal, Digital Research founder Gary Kildall threatened to sue IBM for infringing DRI's intellectual property, and IBM agreed to offer CP/M-86 on the PC to settle the claim. CP/M-86 was released a few months after the PC and was one of three operating systems a customer could buy from IBM. At $240 per copy it sold poorly compared to the $40 PC-DOS. Kildall would later accuse IBM of setting the prices to marginalize him, but the accounts of Microsoft, IBM, and other DRI executives indicate that Kildall had demanded a substantial royalty for CP/M-86 while Microsoft had accepted a fixed sum. Customers rapidly adopted the PC platform with PC-DOS as the new industry standard, and opportunities for DRI to license CP/M-86 to other customers dwindled.


Windows NT:
Microsoft decided to create a portable operating system, compatible with OS/2 and POSIX support and with multiprocessing in October 1988.[10] When development started in November 1989, Windows NT was to be known as OS/2 3.0,[11] the third version of the operating system developed jointly by Microsoft and IBM. In addition to working on three versions of OS/2, Microsoft continued parallel development of the DOS-based and less resource-demanding Windows environment. When Windows 3.0 was released in May 1990, it was eventually so successful that Microsoft decided to change the primary application programming interface for the still unreleased NT OS/2 (as it was then known) from an extended OS/2 API to an extended Windows API. This decision caused tension between Microsoft and IBM and the collaboration ultimately fell apart. IBM continued OS/2 development alone while Microsoft continued work on the newly renamed Windows NT. Though neither operating system would immediately be as popular as Microsoft's MS-DOS or Windows products, Windows NT would eventually be far more successful than OS/2.


Windows NT was intended to complement consumer versions of Windows that were based on MS-DOS. NT was the first fully 32-bit version of Windows, whereas its consumer-oriented counterparts, Windows 3.1x and Windows 9x, were 16-bit/32-bit hybrids. Windows 2000, Windows XP, Windows Server 2003, Windows Vista, Windows Home Server, Windows Server 2008 and Windows 7 are based on Windows NT, although they are not branded as Windows NT.

Wednesday, March 03, 2010

Linus: Software evolves over time

Linus (after having been asked about cooperation in writing software): "I never actually though about how the kind of community works at all. Until people started asking me about it later on, like journalists started - how can this ever work? - (in a very doubting way, by the way). [...] these people who asked the questions, they were not exactly convinced that it could work at all. So I kind of had to rationalise, why the Linux kind of development does work. And I don't know if this answers your question, but I actually came to my private conclusion which is that it really is all about evolution. And what you find, whether you like it or not is that [...] you don't design software, you don't even know what it is the user wants. Most cases the user himself doesn't know what he wants [...] If you designing things and you don't know what you're designing for, the design simply cannot work [...] and it turns out that this is a problem that humanity has had forever"

In this video (around 0:36:00) :



Interactive linux kernel map.

Tuesday, March 02, 2010

Richard Stallman comparing proprietary software companies with colonial powers

Richard Stallman speaking at a conference on development. He compares proprietary software companies to the colonial powers of the past: Another feature you might remember from the colonial system was that the colonial power would recruit a local elite, a few local people who would - like maybe the nobles or whoever, or one tribe against another or they would create tribes if they weren't tribes (so they can massacre each other decades later) - and so the local elite, they would get certain privileges and in return they would help keep everybody else down. Well you can see that today, some proprietary software companies actively recruit local elites, they set up a software development centre in your country and the people who work there are part of the local elite or they do some favour either for politicians secretly or for the government openly. But it doesn't make any difference which one, either way they're buying influence in the government, converting that governement - from a sovereign state - into their local overseer, of their empire, who's job is to make sure everybody else becomes dependent on the same non-free software. They say the schools: "we will help you by giving you these gratis copies of our non-free software, so that you can turn your students into addicts of our software. Why do I use the term addicts? Because they develop a dependency, on this software. And then after they graduate, you can be sure they're not going to be offered these gratis copies any more. Because it's only the first dose that's gratis. Once you're addicted, then you're supposed to pay. And then, also of course the companies that these graduates work for,... those companies are not going to be offered gratis copies, so what essentially these companies - these software developers - are doing is: they're recruiting the schools into agents to lead people into permanent life-long dependency. These are things that the open-source movement usually doesn't talk about, that's why I don't support open-source. Open source is a way of promoting software that usually is free, but without mentioning these ideals. These are issues of freedom, they're left in the background, open source people usually talk only about practical values, you know, how do you get powerful convenient software and how much will it cost. Well free software probably allows you to save money too if you're not being forced to pay for permission to use it, you can probably save money. But I think that's a secondary issue, even in poor countries freedom is important. We should never start saying: "Oh they're so poor, freedom for them doesn't matter. All they need is some bread and circuses". Which they had here once upon a time. and then they shouldn't even think about being free. I think freedom is important in every country, in every society, whether its rich or poor. Nonetheless, people who support open-source often contribute to extending the free software community. Many of them develop free software, those are useful contributions. I'm not saying that what they do is bad, I'm saying that by itself it is not enough. Because it's weak, you see. When you say: "the goal is to have powerful, reliable, convenient software and get it cheap", then it becomes possible for the representatives of proprietary software to say: "well we claim that we'll deliver you more powerful reliable software, we claim that our total cost of ownership will be cheaper". And I think it's usually bullshit. When Microsoft says this, it's based on distorted facts, but it's weak, but when we say the goal is to live in freedom and to be allowed to cooperate with other people in a community, they can't say they're going to offer us more of that cheaper. Because they don't offer that at all, they're not even competing with us. They're out of the running! Once you decide you want to live in freedom, they're out of the running. So we are trying to help you reach freedom, in a community, they are trying to subjugate you, but they say that they'll get you there faster! And maybe they would.



Monday, March 01, 2010

Wikibook linuxguide

Linuxguide: "The easiest way to begin using a Linux system may be to use an already running system. For example, some systems may be available in various educational or work environments. In this case you only need to contact the appropriate administrator and obtain a user ID and password. You will only be able to explore the system to a certain extent, but the first steps can be taken without having go through the installation process. Another trouble-free way of obtaining a Linux system is to buy a computer with Linux pre-installed. The number of vendors selling such systems is constantly increasing."