Monthly Archives: March 2013

De ce linux se dezvolta mai repede ca windows

Chuck Norris vs. Linus Torvalds

I’m sure everybody remembers facts on Chuck Norris, and here are Linus Torvalds facts!

Look at the picture, do you see any differences, don’t you? :) ;) :)

chuck_linus

 

Linus Torvalds once found a segmentation fault in the universe.

Linus Torvalds can run kill -9 and kill Chuck Norris.

Linus Torvalds doesn’t die, he simply returns zero.

Linus Torvalds first written program had artificial intelligence.

Linus can divide by zero.

Linus Torvalds runs Linux on his wristwatch and toster.

Linus Torvalds doesn’t receive error messages.

There is no theory of probability, just a list of events that Linus Torvalds allows to occur.

Linus Torvalds does not sleep. He hacks.

Linus surfs the web using nothing but netcat.

Linus Torvalds can play 3D games in his head by interpreting the source code in real-time.

Linus made the red pill.

Linus Torvalds didn’t learn from the University of Helsinki, the University of Helsinki learned from Linus Torvalds.

Linus Torvalds once developed a programming language so good that it makes python look like punch cards.

Linus Torvalds doesn’t need to boot.

Linus is real, unless declared Integer.

Linus doesn’t push the flush toilet button. He simply says “make clean”.

Linus Torvalds has no dependencies.

Linus Torvalds takes one look at your desktop and knows which porn sites you visited. In the last ten years.

Linus Torvalds sleeps with nunchucks.

Linus can enrich himself simply by chowning your bank account. He does not do this because there is no challenge in it.

There are no man pages for Linus Torvalds, only god pages.

Linus Torvalds can do an infinite loop in five seconds… in his head.

Linus Torvalds doesn’t wear glasses anymore not because he had laser eye surgery, but because he finally got his xorg.conf properly configured in his head.

Linus Torvalds can use a nice level lower than -20.

Linus Torvalds doesn’t need to mount his drives.

Linus Torvalds doesn’t debug. His programs are always perfect.

Linus Torvalds can install Linux on a dead badger.

Linus Torvalds doesn’t need backups. He just uploads his files and lets the world mirror them.

Linus Torvalds is taking over the world. Microsoft is just a diversion so that no one would suspect a mild mannered Finnish programmer.

Linus Torvalds already has Linux 3.0. He is just keeping it to himself to build suspense.

Linus Torvalds didn’t design Linux to run on the 386. Intel designed the 386 to run Linux.

People pray to Jesus, but Jesus prays to Linus Torvalds.

Linus need not worry about Microsoft patent crap, he simply do `sudo mv /tmp/ms /dev/null`.

Linus Torvalds is more powerful than root.

If you could read Linus Torvald’s mind, you’d find that his stream of conciousness is entirely in binary.

Linus scared A and B away, so they had to make C.

Linus only has 2 buttons on his keyboard ’1′ and ’0′

Linus’s kernel never panics.

Linus does not use the GCC, he _writes_ binaries.

Virusi Care Afecteaza Sistemele Linux

all linux

Securitatea Sistemelor Linux

Exista o credinta cum ca Linux ar fi ferit de infectarile cu virusi, de aceea pentru cei mai multi utilizatori ar fi o surpriza sa afle ca virusii destinati distributiilor Linux chiar exista. Totusi nu va alarmati foarte tare pentru ca numarul acestora este mult mai mic (pot fi numarati pe degetele de la o mana) fata de celelalte Sisteme de Operare (SO). In acest articol este o introducere in cunoasterea catorva dintre cei mai raspanditi virusi si cateca imbunatatiri ale securitatii sistemelor Linux.

Credinta generala despre distributiile Linux este cu nu se infecteaza niciodata cu virusi. Intr-adevar Linux este un sistem foarte securizat, dar a crede despre acesta ca nu exista virusi care sa-l infecteze este o gandire naiva. Acestia pot altera codurile, redirectiona paginile web accesate etc.

Scurta lista a virusilor Linux

Alaeda (Virus.Linux.Alaeda)

Anul aparitiei: 2003
Nivel de risc: scazut
Platforma: Linux

Alaeda injecteaza un cod malitios in fisierele cu o sectiune .text transferand controlul acestuia codului injectat.

Badbunny (Perl.Badbunny)

Anul apoaritiei: 2007
Nivel de risc: scazut
Platforma: Linux, Windows

Badbunny este un virus afecteaza pachetul OpenOfficeprin afisarea unei imagini pornografice. Modalitatea de prevenire este evitarea manipularii fisiereleor OpenOffice din surse nesigure.

OSF.8759

Anul aparitiei: 2002
Nivel de risc: scazut
Platforma: Unix
Virusul Linux.OSF.8759 este executabil, iar odata rulat infecteaza toate fisierele din directorul curent. Rulat dintr-un cont de administrator va incerca sa infecteze fisierele din directorul “/bin”.

Vit virus (Virus.Linux.Vit.4096)

Anul Aparitiei:1999
Nivel de risc: scazut pentru utilizatorii Linux
Platforme: Unix, Linux, Windows and MSD0S

Virusul Vit infecteaza fisierele executabile din linux. Pentru un utilizator mediu, fara acces la contul de administrator, acest virus are un impact minim.

Staog

Anul Aparitiei:1996
Nivel de risc: low
Platforma: Linux
Virusul Staog este primul care a fost scris special pentru sistemele care ruleaza Linux. Acesta foloseste se foloseste de vulnerabilitatile  din kernel ceea ce-i permite se stea cantonat in memorie infectand fisierele bin.

Acestia sunt cativa dintre cei mai importanti virusi care afecteaza sistemele Linux. Pentru o lista mai ampla vizitati acesta adresa. Pentru a fi siguri ca sistemul vostru Linux este curat si securizat folositi un antivirus si activati firewall-ul.

Compilare kernel – Debian way

kernel-debian

 

Kernelul poate fi compilat cu metode diferite. De obicei fiecare distributie are o metoda care poate fi aplicate mai usor si fara probleme.

Compilare Kernel in Debian Linux

1: Prima data downlodam pachetele care sunt necesare pt. versiunile kernel 2.6 in Debian Linux
apt-get install kernel-package ncurses-dev fakeroot  wget bzip2
2: Intram in directorul /usr/srccd /usr/src
3: Downlodam versiunea cea mai noua a kernelului de la situl kernel.org/pub/linux/kernel/v2.6/….(ulitma versiune)wget kernel.org/pub/linux/kernel/v2.6/…
4: Despachetam kernelul cu programul gunzip sau bunzip2 – depinde ce varianta am downlodatde ex: gunzip kernel2.6.21.tar.gziptar -xvf kernel2.6.21.tarcd linux2.6 etc

5: Configuram kernelul – Daca avem deja un fisier de configurare pe care am facut noi putem folosi pe acesta pentru a duce la capat mai rapid configurareaex:executam comanda:make menuconfig- selectam obtiunea : Load from external file (si acolo definim ruta catre fisierul vechi)dupa ce am terminat, ne uitam la inbunatatirile kernelului nou, si alegem sau lasam afara noile obtiuni.Daca avem un kernel instalat default, e bine sa ne uitam la toate obtiunile ale kernelului si sa alegem numai obtiunile pe care chiar vrem sa folosim.
Obtiunile disponibile in kernel, pot fi alese ca built in * ( in cazul acesta vor fi compilate in kernel – sau putem alege varianta ( load as module M ) ceea ce inseamna ca modulul respectiv va fi lodat de catre RAMDisk care trebuie creat dupa compilare.
Dupa ce am konfigurat Kernelul executam comenzile:

6: make-kpkg clean7: fakeroot make-kpkg –revision=custom.1.0 kernel_image- comanda respectiva creeaza un pachet de format deb a kernelului si care va arata de ex: kernel-image-2.6.21.2_custom.1.0_i386.deb

8: Instalam programe care sunt necesare pentru crearea initRAMDiskului, de care vom avea nevoie in caz daca nu am compilat kernelul in asa fel incat toate modulele sa fie ( built in )apt-get install module-init-tools initrd-tools procps

9: Instalam kernelul nou:dpkg -i kernel-image-2.6.21.2_custom.1.0_i386.deb

10: Daca avem nevoie de initramdisk(daca folosim module M – atunci avem)executam comanda in directorul /boot/mkinitrd -o /boot/initrd.img-2.6.21.2 2.6.21.2

11: ultimul lucru care trebuie facut – sa ne asiguram ca loaderul pe care folosim stie despre noul kernel instalat ( GRUB, LILO )
– de obicei GRUB face un update automat dupa instalarea noului kernel, in caz daca folosim lilo – > editam fisierul de configurare /etc/lilo.conf si facem schimbarile necesareex:default=Linux
image=/vmlinuz           label=Linux ( kernel nou )           read-only           initrd=/boot/initrd.img-2.6.21.2

Mult succes! – La boot daca kernelul nou nu a fost bine configurat s-ar puta sa aveti un kernel panic  .  In aces caz porniti kernelul vechi si reconfigurati kernelul.

Google open sources very slow compression algorithm

gmartisor

Google has open sourced a new compression algorithm called Zopfli that it says is a slower-but-stronger data squasher than the likes of zlib.

The product of Googler Lode Vandevenne’s 20 per cent time, the day a week Google allows its staff to work on side projects, Zopfli is said to reduce files to sizes 3.7–8.3 per cent smaller than its rivals (PDF). The catch is that it takes one hundred times longer to do so.

Google’s ‘fessed up to that delay, noting that Zopfli requires two to three times the CPU power of its rivals and is therefore “best suited for applications where data is compressed once and sent over a network many times, for example, static content for the web.”

Over the years many have claimed to have created compression systems that cram data into wonderfully tiny bundles. Several have been revealed as scammers. So while Google has made only modest compression gains and has done so without time savings, eight per cent is still nothing to be sneezed at in applications like content delivery to mobile devices, where any reduction in the amount of time radios work means better battery life and lower bills for data consumption. And while Zopfli takes ages to pack data, it uses existing tools to unpack it at the same speed as rival algorithms, meaning no processing penalty on the device.

Open sourcing the algorithm therefore makes a lot of sense, given Google (and world+dog) is keen on getting more content into more mobile devices more often in more places, and that most everyone who owns a mobile device wishes it would do things faster.

And let’s not forget the looming spectrum crunch predicted to send mobile data costs rising to unpleasant levels, a phenomenon a little more compression could ease.

Zopfli’s code is available here. ®