RuiOnWriting
Trying to learn something new every day!
Qt/PyQt 4 initialization failed when installing hplip
1If you found this error running hp-setup or diagnosed when running hp-check, just install python2-qt package. Run this on your terminal:
# pacman -S python2-qt
hp-check will give you all the diagnostic you’ll need to install your printer/scanner, in my case HP Officejet 4500, on your Arch installation.
VMWare Player modules update fails after kernel update linux-3.1.0-4-ARCH
0Again some issues with kernel updates when build wmware modules:
In action...
MySQL rand() benchmark, don’t use rand()
0568 days
The need to get a certain amount of data randomly to present on a website so that your audience can view that your website is alive and, in the most cases, to be aware of the variety of products you have to present. It’s very common as also the performance side effect.
There are so many approaches for rand() replacements: ‘rand() mixed soup variations’, using join’s, etc but I found that with queries over very large tables none of them actually ease you from the pain of having a lot of heavy queries over your database.
Rand is not efficient and if you need to retrieve random rows having several columns on the where clause it’s even worst.
Bye Gnome 3, hello Xfce
0After 2 months using Gnome 3 I’ve reached my patient limits (Linus did the same) with all the desktop limitations, buggy shell extensions, etc. It looks nice, isn’t slow as some talk about, but it’s not practical for users that like having full control over the desktop.
In my case the most annoying ‘un-features’ is the fact that we don’t have control over the notification area and also multi-monitor is so bad, you cannot get control over the notification area that goes always to the 2nd screen.
VMWare Player 3.1.14 fails to start/build on kernel 3.0
0Yesterday I’ve made the big change updating to kernel 3.0 on my arch installation. One side effect, the only so far, was the fact that my VMWare Player was not loading. On all kernel updates VMWare loader detects kernel version changes, updates/recompile all it’s binaries and than loads without any problems, but this time it didn’t and was returning the error ‘Unable to initialize kernel module configuration’.
Fortunately, as always, the Arch community found the cause and the solution very fast. The problem relies on VMWare module builder not handling correctly the new version layout. In Order to fix an easy solution is to patch two binaries:
# sed 's/\x83\xe8\x03\x83\xf8\x01\x0f\x96\xc0/\x83\xe8\x02\x83\xf8\x01\x0f\x96\xc0/' -i /usr/lib/vmware/lib/libvmware-modconfig-console.so/libvmware-modconfig-console.so # sed 's/\x83\xe8\x03\x83\xf8\x01\x0f\x96\xc0/\x83\xe8\x02\x83\xf8\x01\x0f\x96\xc0/' -i /usr/lib/vmware/lib/libvmware-modconfig.so/libvmware-modconfig.so
Here you can find the solution posted on Arch Wiki.
Cannot move dialog windows on Gnome 3
1There are those who hate, other who love and others that really don’t care why dialog windows have strange borders and don’t allow you to move them grabbing the title bar, oh wait 
, where is the title bar?
The solution is simple: gconf-editor to the rescue. Just open gconf-editor and untick /desktop/gnome/shell/windows/attach_modal_dialogs. Press Alt + F2, type r and press Enter (reloads gnome shell). Now you have the normal behavior back.
In case of using Arch, my home distro in this case, you need to install gconf-editor. Very easy with pacman:
$ sudo pacman -S gconf-editor
or
# pacman -S gconf-editor
MySQL: Easily delete all data and reseed all tables
0The need for a fresh start during the development stage is very frequent. This script allows to delete data from all tables and also to reseed all tables that have identity columns. I’ts clean and simple.
This is my version for MySQL (see previous article for MS SQL).
/* disable all constraints */
CALL usp_mysql_foreachtable('ALTER TABLE ? DISABLE KEYS');
SET FOREIGN_KEY_CHECKS=0;
/* delete data in all tables */
CALL usp_mysql_foreachtable('DELETE FROM ? WHERE Id > 0');
/* enable all constraints */
SET FOREIGN_KEY_CHECKS=1;
CALL usp_mysql_foreachtable('ALTER TABLE ? ENABLE KEYS');
/* reset auto-increment columns */
CALL usp_mysql_foreachtable('ALTER TABLE ? AUTO_INCREMENT = 1');
Boost your Linux with preload
0preload is an adaptive readahead daemon. It monitors applications that users run, and by analyzing this data, predicts what applications users might run, and fetches those binaries and their dependencies into memory for faster startup times.
Install (for debian based distros) easily running this simple command in terminal:
sudo apt-get install preload
After installed the service will start without requiring additional actions. Several options are available. Using help switch (- – help or -h) to get help.
I’ve test on Ubuntu Natty 11.04 x64 and on Mint Julia 10 x64. On Mint, I must say, application launch improved a lot.
‘Error authenticating some packages’ updating from Maverick to Natty
0If you run into this situation and everything else fails I have found the solution here. This takes you to make an release update using terminal commands.
In my case the packages were tzdata and tzdata-java.
