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One of the commercial AT&T-Unix heirs has announced the end sales of it’s operating system. In a press release today SGI announced the end of general availability of its IRIX operating system with December 29, 2006.
The company will continue support this product until December 2013 though. The full press release can be found here.

IRIX has won fame as the Unix for graphical applications such as rendering or finite element modeling and simulations. The end of sales of IRIX now again hardens the prejudice that Unixes are generally graphic averse operating systems.

And note the extreme long support IRIX gets from SGI. But for ‘hard iron’ manufacturers such long support periods are totally normal. This is a commercial product after all and the customers pay (heavily) for getting care as long as they run their machines.

As far as FreeBSD is concerned, the level of maturity it has compared to Linux is nothing compared to such products as IRIX. So I wonder why SGI decided to switch to Linux and didn’t follow Apple by starting over with a (i386-)BSD OS.

Again a post about a well spread but unknown command pair on the terminal. It’s the pushd / popd pair to control the directory stack of the shell.

The pushd command adds the directory given as argument to the directory stack and changes the working directory to that location.
The popd restores the current directory to the first entry of the directory stack and removes this entry.
The dirs command lists the content of the directory stack.

But what does this mean? Consider the following example:
%dirs
~
%pushd /usr/local/etc/
/usr/local/etc ~
%pwd
/usr/local/etc
%pushd /etc
/etc /usr/local/etc ~
%pwd
/etc
%pushd /var/named/etc/
/var/named/etc /etc /usr/local/etc ~
%pwd
/var/named/etc
%popd
/etc /usr/local/etc ~
%pwd
/etc
%popd
/usr/local/etc ~
%pwd
/usr/local/etc
%popd
~
%pwd
~

This comes extreme handy for shell scripts if you have to visit a bunch of directories, do some work there and revisit them in reversed order again.
For the daily use I can’t come up with any real world example, but this doesn’t mean there is none!

I just came across the following four stances of securing an appliance (that is, a combination of a specific application and a machine capable of running it):

• Most existing systems are too complex to guarantee that they are bug free and the service(s) they provide are inpenetrable. Hence one has always has to suspect them being compromised. There is no way in finding and fixing all bugs. Be it out of lack of funding or time.
• Even if an exising system has known flaws, one can hardly replace the system due to economic restrictions or the simple truth that the application just won’t run on any other system or the lack of alternatives.
• Developing secure software is extremely tedious and costly. It doesn’t pay for most situations.
• The best security measure is powerless against malign insiders who misuse their privileges.

Especially the first two points are, though well known, not always esteemed:
Usually, software vendors don’t like the first point. They prefer to view their products as secure without taking into account that without secure hardware running a secure operating system there is no such thing as a secure application.
The second point is disliked by software evangelists since it undermines the fact that their propagated software can’t meet all requirements in all scenarios.

So the next time you hear someone preaching about security, judge him on those four principles.