Installing Nvidia driver in Wheezy...Can someone explain this code?

I'm setting up a Mythtv box at home using Debian Wheezy and I wanted the Nvidia drivers for VDPAU. In the past, I have installed Nvidia drivers manually downloaded from the Nvidia web site. This time, I found the following line of code from the Debian wiki:

aptitude -r install linux-headers-$(uname -r|sed 's,[^-]*-[^-]*-,,') nvidia-kernel-dkms

To my surprise, this worked in one step. Upon reboot, the Nouveau driver was blacklisted and the Nvidia driver was installed and working.

I'm posting this with the hope that I can learn something, because I don't understand what the code above is doing. It seems I will never progress from being a newbie. I understand that the command is to install linux-headers for the currently installed kernel. What I don't understand is what the sed command is doing? Can someone break it down?

If you'd type in

uname -r

you get the version of your kernel, the sed command filters out the type...

And example

uname -r gives 3.2.0-48-generic

the line

uname -r|sed 's,[^-]*-[^-]*-,,'

returns "generic" - the type of kernel I use here...

Sed has a lot more to offer as some tutorials indicate...

Thor

what uname -r returns and how useful it is really depends on the distro. With most Debian kernels, this would have worked just as well:

# aptitude -r install linux-headers-$(uname -r) nvidia-kernel-dkms

Or even

# aptitude -r install linux-headers-`uname -r` nvidia-kernel-dkms

Originally Posted by cynwulf what uname -r returns and how useful it is really depends on the distro. With most Debian kernels, this would have worked just as well: # aptitude -r install linux-headers-$(uname -r) nvidia-kernel-dkms Or even # aptitude -r install linux-headers-`uname -r` nvidia-kernel-dkms

Might the method suggested by the wiki be advantageous because it installs the metapackage rather than the package for the specific kernel installed at that point in time? I have to say I don't want to go through the hassle of testing it but I wondered whether installing the package specific to the installed kernel may mean it is not updated when the kernel is?

Originally Posted by 273 Might the method suggested by the wiki be advantageous because it installs the metapackage rather than the package for the specific kernel installed at that point in time? I have to say I don't want to go through the hassle of testing it but I wondered whether installing the package specific to the installed kernel may mean it is not updated when the kernel is?

You're absolutely right. I keep forgetting about the meta packages as I always run off my own kernels.

$ uname -r|sed 's,[^-]*-[^-]*-,,'
smp

$ uname -r
3.9.8-686-smp