Additional classes in Informatics

Again my blog is a little unmaintained. That’s not because I’m lazy. In fact It’s completely different. Anyway I have some voluntary work right now. I teach C++ and algorithms in my high school.

Here is the script for first lesson. It covers basic C++ skills.

Flash no fonts problem – SOLVED

After last re-installation of gentoo I noticed that in some Adobe Flash programs fonts doesn’t render. It was especially visible in Google Analytics. I check if I have all necessary fonts (like corefonts from Microsoft), but that wasn’t a problem.
At first googling didn’t give any interesting results. I tried to see where flash plugin search for fonts so I run opera, determine it pid and attach strace. Surprisingly, it didn’t search for fonts at all. So, as I quess, it must be X‘s tasks. I googled for a while and found that I need to add FontPath into xorg.conf. After restarting X‘s everything work correctly.

Detail description of using strace:

1. Launch opera
2. “ps -aux | grep opera”, to see opera pid
3. “strace -fp 12345 &> opera_log”, log sys calls
4. Go to that flash, where no text was displayed
5. Kill strace (CTRL+C is enough)
6. “less opera_log”, look for open or read in folders /usr/share/fonts/*

Solution:

1. “emerge –noreplace corefonts”
2. edit “/etc/X11/xorg.conf”, in section “Files” add: FontPath “/usr/share/fonts/corefonts”
3. save and restart X‘s (CTRL+ALT+BACKSPACE)

Installing kydpdict

Installing 3rd part software that isn’t in official repository/tree in linux distributions is often problematic. Here is the guide how to install dictionary frontend – Kydpdict in gentoo:

1. Log as root (su)
2. Create directory /usr/local/overlays/mysiar (*or other in /usr/local)
3. Download http://www.synowiec.org/mysiar-portage.sh (wget http://www.synowiec.org/mysiar-portage.sh)
4. Give it right to run and run it (chmod o+x mysiar-portage.sh && ./mysiar-portage.sh)
5. Add line PORTDIR_OVERLAY=”/usr/local/overlays/mysiar” to /etc/make.conf
6. Sync portage tree (emerge –sync)
7. Try emerge kydpdict
8. If it fail saying that Manifest point file that doesn’t exist, remove that entry from Manifest and try to emerge again
9. Copy dictionary files from your windows version and rename them to lowercast characters

I hope that this guide was helpful.

UPDATE:
Added step 5. (2006-09-16)

Gentoo installation

Last Saturday I finished installation and configuration of Gentoo distribution. My previous major operating system was also Linux flavour. It was OpenSUSE. Despite it worked well, there were several areas to improve:

• support of Geforce2 MX400 nvidia graphic card and HP 710C printer was problematic, it was definitely downgrade in compare to older releases of SUSE,
• package repositories miss a lot of applications that I use daily,
• installation of programs that are outside of repositories is weird,
• in general, doing things like downloading KDE 4 sources and building them require too much IMO manual work; Yast isn’t helpful in that case,

So why I choose to try Gentoo (not Debian for e.g.):

• it’s different; almost all Linux distributions are build around packaging, of course they have different formats or dependencies system, but the philosophy is the same: “pack it”; while Gentoo provide recipes how to build it,
• it has well-written documentation,
• I’m on a holiday so compile time doesn’t really matter;
• it is the most popular OS among finalists of Polish Olympics in Informatics,

Thoughts after installation

I’m satisfied with gentoo distribution. Portage (gentoo “package” system) works well. It extremely easy to install an older version of a program or an unstable one. Moreover, the configuration took as much time as in SUSE. SUSE GUIs are nice, but they don’t speed up your work.

Hassles:

• during the installation you’re encouraged to use tool mirrorselect; It use “space” to select and enter to “end” program. However It doesn’t metion anything about using “space” and doesn’t prompt if you doesn’t select anything. A typical user (not *NIX) might be confused.
• two hassles with portage, while I try install nvidia-driver opengl was required to one of the packet and installation stop; another was audacity which require wxGTK 2.4.x but not 2.6.x which is default, error messages was unhelpful;
• searching packages information takes too much time(“emerge -s” and “emerge –searchdesc”), it should use suffix trees as indexes;
• There is no one package in portage tree that I use frequently – kydpdict.