You can find the original book at this amazon page.

Note: This blog article is still under construction.

Introduction

Names can talk for themselves

• If a variable, class or method name needs a separate comment to identify itself, the name probably needs to change.
• Names should not include misinformation. For example, a grouped set of subscribers should not be identified as ‘subscriber_list’ if it’s not a list.
• Names should not look similar at the first sight, as people who are reading code often don’t read the full name.
• Avoid using l and O in small variable names as it could be easily misread for 1 and 0 ( one and zero).
• Do not use misspelling as a tool to create new names (ex: listenToAdapter, listenToAdaptor).
• Use pronounceable names as possible, which could be easy when at the code reviews.
• Remove obvious redundant words from the names like the, a , an, class, var.
• Names should be unique enough to easily search, if needed. This is strictly needed if the scope is high.
• No need to shorten names as we have more advanced languages and GUI tools now days.
• Use nouns (or nouns which can be used as verbs) for class names and verbs for method names.
• Any name should be generally understood by any programmer of any demographics.
• Use one word for a similar concept throughout the code base.

All the new posts will be posted to the new blog address above; so it is recommended to visit the above site.

Possibility to redirect  lmpeiris.wordpress.com to linux.lmpeiris.com by automatic redirection is under consideration, but it comes at a financial charge. At the mean time, you may need to click the above hyperlink to visit the new site.

Cheers

Malshan Peiris (lmpeiris)

Music on Console (MOC or MOCP) (homepage)

MOC 2.44 running on my fedora 14 (64 bit)

The MOC has a decent UI for a CLI program. Consists of two panes, one displaying the music files in the current directory and the other showing the current playlist. Play stats and tag info are displayed in the bottom, with the progress bar. Navigation within playlist and song can be done using keyboard. It’s updated support for pulse, OSS and alsa output.

Installation

for debian based sytems use, sudo apt-get install moc

for rpm based systems, it is unlikely that moc would be on the repository. Try yum install moc and see. If that’s the case, we need to compile from source which can be downloaded from this link. You would need following packages

for mp3 support: yum install libmad-devel libid3tag-devel

for wma,mp4,aac,ra support: yum install ffmpeg-devel (This caused a compile error due to ffmpeg-devel relocating its .h files .. so please don’t do this if you know how to use linking). To activate support for other codecs, see README.

then decompress the file, go to the folder and type usual

./configure && make && install as root to compile and install. See my article on compiling from source for more information.

After installation to run, type

mocp <filename>

press q and type mocp -x to end program. Otherwise the server will still be running

Mplayer

Mplayer running on console

This doesn’t need much introduction; which is as my perception is the best multimedia player ever, which can play videos too. Apart from the gmplayer (or mplayer-gui), the mplayer command can be used to play music on command line, with showing in depth info. Mplayer can play any audio file, it’s heavily stable and takes less resources. You can see my previous post on mplayer.

to install,

sudo apt-get install gmplayer (for debian based systems)

yum install mplayer-gui (for rpm based systems)

My hacked terminal startup using cowsay and figlet

Now you know what they use in Linux Mint to make a cow “talk” when the terminal starts :). I’m going to tell you how to do it in a much more awesome way. The programs they use are cowsay and fortune-mode. Cowsay can show any string, a text output of a command,program to appear as a dialog generated by an ascii art (including cow).

You can install program by

sudo apt-get install cowsay (in debian-based systems)

yum install cowsay (rpm based sytems)

Now try these in the terminal

cowsay “$USER is my boyfriend” ($ shows string value of environmental variable USER)

ls | cowsay (output of ls is piped to cowsay)

There are options to decide the appearance of the cow and its eyes. For example the switch -d will cause the cow to appear dead. But the most important hack can be done by -f which forces to use a files called cowsay files, so that we can get anything other than cow. Type

cowsay -l

to find the path of these files. Try each file with following syntax

cowsay -f <cowfile name, without extension> <string to display>

ex: cowsay -f tux $USER

The cowfiles can be edited to appear as we want. Only edit the stuff rounded by the circle. Do not edit anything else, and save by giving a different file name. Or we can simply download an ascii art from internet and replace the stuff in rounded area.

Editing a cowfile - only edit stuff on the red area

You can download ascii arts from sites like http://www.chris.com/ascii/ or simply you can build your own using these programs http://www.ascii-art.de/tools/. I’m not going to mention about them here. But the program Jave5 is a good one with a easy to use GUI, and runs on linux.

http://www.jave.de/download/download.html

Linux mint uses an additional program called fortune-mod to get’s stuff. Other than the command cowsay, cowthink can be used to appear like the cow is thinking, not speaking.

Fortune-mod (The classic fortune cookie program)

Fortune-mod is so far the funniest FOSS program i have come across with. It generates a random text string of a joke, a saying by a great person, something useful etc… Can’t be saying it all just try it by yourself. I haven’t seen the same thing twice after using it for some time.

Sudo apt-get install fortune-mod (for debian based systems)

yum install fortune-mod (for rpm based systems)

to use type fortune in the command line.

This can piped to above cowsay easily

ex: fortune | cowsay

a fortune | cowsay piped output

for other options of fortune, refer man pages.

Making the cow talk

To make this show on terminal startup (or run any program) you can put the above command in your bashrc file.

gedit ~/.bashrc

and add above commands, as you wish in it. You can add figlet command too. Open a new terminal to see the change.

So, mine produced something like the first picture in this post by these commands

cd ~/Desktop/figlet222/

./figlet -c -f script “lmpeiris rocks”

fortune | cowsay -f love

cd ~

Figlet – print a text as a logo http://www.figlet.org

Happy new year on figlet version 2.22

How to install – figlet is not provided with most of the Linux distributions, and it’s not included in their package hosting servers. Hence using yum or apt-get simply may not work. If that’s the case, we need to compile it from the source. You can download the source from here. Decompress it and change in to it’s directory in the terminal and type;

make

to compile figlet. For further information on compiling from source, see my article. Unfortunately, there’s no make install here so we need to change in to figlet directory always to use the command (you can copy the binaries and man pages in to correct directories but this is complex).

cd <path to figlet folder>/figlet222/

./figlet <the text you want to show as a logo>

figlet features

I’ ll be mentioning only the important ones here.

Change style/font : A sub directory called fonts holds some .flf files which contains style info.

./figlet -f <fontfile_name> text

ex: ./figlet -f script Happy new year will produce something like above picture.

change alignment : To center -c , -l for left and -r for right

change right to left: -R

layout: -t will fit the text to terminal width, -P paragraph mode

figlet using some tweaks above

There’s a lot more; see figlet man page for more details. http://www.figlet.org/figlet-man.html

Part 2 of the post is about using cowsay and fortune-mod. Will be followed soon.

Heretic running on DENG - extracted from dengine.net

Made by the ID software inc. these games became so immensely popular with the then younger generation, because they were the first, 3D first-person shooting games (like call of duty) ever to be on the market requiring just only a few hardware requirements, and first ones to exploit the power of creative sound-blaster sound cards. And the gaming experiences, still thrilling. The gaming innovation and logic behind doom and heretic keeps players playing it after 17 years.

Of course, I played these within MS-DOS at those times, but many people who are now using Linux likes to play the game. They can do so by choosing the dosbox emulator, and play the original game as in those times.

But many people thought of hacking (to improve) the game and came up with an open source emulator called doomsday engine (DENG) which uses the original id3 core files (.wad files); only to get the games strategic data (how the game goes, maps). The coolest thing is that every texture, unit, player, effect, weapon can be loaded from different ones from the original. Simply, people got together and re-designed textures etc.. to give superb 3D performance like in a new game! So you’ll be playing the same games (doom,heretic,hexen), with superb graphics! (and hacks) . Visit there homepage, for more information.

Doom running on DENG - extracted from dengine.net

Installation

Installation is some what tricky. I heavily recommend compiling from source. You can download from here.

Tar -xvf deng-1.9****tar.gz ‘unpacking the tar file

cd <source directory> ‘ go inside the source directory , from here on i will use deng-1.9*** for the source folder.

cd doomsday

mkdir mybuild ‘create this directory if doesn’t exist

cmake .

If dependency problems found, install them. See installing from source (in my blog) for more info.

make

make install ‘(for debian systems, sudo make install)

We still need some stuff. This is the downloading part. These are called resource packs which includes open-source textures,units for the games. Download below things and copy each to deng-1.9***/snowberry/addons folder, after unzipping them. (you can go and have a look at the addons folder, it includes examples how unzipped things should be there).

http://files.dengine.net/jdrp-packaged-20070404.zip

http://files.dengine.net/jhrp-20090703.zip

this is enough for now. When you start to get things correctly, go to http://files.dengine.net/index.php and download other stuff you want. Go to http://www.doomsdayhq.com/ if you don’t know what to download.

Now you need some .wad files from the original games. Download those from this torrent. http://torrents.thepiratebay.org/3555137/Doom_Heretic_Hexen_WADs.3555137.TPB.torrent Unzip and put those in somewhere you can find. (if the above link doesn’t work, try searching for “doom heretic hexen wads” in torrentz.Com.

Configuration

cd deng-1.9****/snowberry ‘Goto deng-1.9***/snowberry .

Snowberry is the graphical configuring tool for deng, which makes our life easy. Type,

python snowberry.py

If you have WxPython and pyGTK (i actually cannot remember) installed correctly, it will show a gui like below.

Snowberry graphical deng configure running on my FC11

Configuring doom2

From the mini bar click profile and select new. A dialog box will appear, give it a name which you can identify, and select jdoom from the combo-box. You should see it on the left panel under shared settings.

Now it’s time to change some settings. Select the jdoom from panel, and click on the settings tab. Something like below should appear. For the game data file, browse the doom2.wad from the torrent download folder. Click on display and adjust resolution, and full screen view. Click on the addons tab and check jdoom-resource pack if it’s not checked.

Configuring doom1 and heretic

For the jheretic, choose heretic.wad and jheretic resource pack. (use your brain).

For doom1, choose doom.wad or ultimate.wad(something similar) and do as above.

The Playing part ….!

Just tell me whether you understand the stuff above and got it running …. then i will start telling you something about the games itself. Enjoy!

When I was little, I always happened to wonder about the millions of stars which light up the night sky. I needed to be a astronomer some day, and I wanted to buy a telescope. Anyway, I couldn’t have enough time to do it. Anyways, for the people who are armature astronomers, the skychart is an excellent program.

Skychart 3 alpha running on my fedora 11

It renders sky of any time of the day, at any location of earth (or anywhere), at any angle using the supplied data with the program. As you can see in the screen shot above, you can rotate, select,zoom any star object in the map to gain information about it. The Field of Vision (FOV) can be changed, deciding the angle you want to look at (the pane to the right). The standard markers like equatorial coordinates, galactic coordinates etc… are on the left pane. Did I tell you that this program can show sky from 3000BC to 3000AD?

As you know, the galaxies contain huge amount of star objects so it’s not possible to render everything in the data files. Program settings allow to change what you want to see… it could be galaxies, nebula or even asteroids. Powerful search functions enable to find desired object in seconds. The core of the program is built with freepascal and the GUI is built with lazarus.

The professional approach

Without just looking at the map, skychart has the ability to edit them, label objects and build a map from the scratch. It can conect with SQL databases and standard astronomy catalogue sites like CDS or ADC. It uses catgen to convert these to a format which is readable by skychart. You can add a telescope (manual or automatic) to the program, and process the data directly from it. (These data can be sent to SQL databases too).

Additionally, program can predict a whole astronomical calendar.. eclipses, twilight, sun-rise, comets etc…

A fascinating feature is the night vision mode. This is heavily required when you looking at the stars from naked eye. (You loose sensitivity in dark if you see a bright light for some seconds). You can visit their homepage for more details from this link.

Skychart running on night vision mode

Installing

Binaries

For Fedora,suse, mandriva people type in terminal as root

yum install skychart

For ubuntu,mint,debian use

sudo apt-get skychart

Or you can go to sourforge download page to download what is best for you.

source

Anyways, the Version 3 was released late, so you may get beta versions with above method. The source code for the latest version can be downloaded from this link.

]]> https://lmpeiris.wordpress.com/2009/07/08/skychart-cartes-du-ciel-%e2%80%93-explore-and-map-the-skies/feed/ 0 malshanpeiris skychart1 skychart3 https://lmpeiris.wordpress.com/2009/07/03/fedora-11-%e2%80%93-the-buggiest-fedora-ever/ https://lmpeiris.wordpress.com/2009/07/03/fedora-11-%e2%80%93-the-buggiest-fedora-ever/#comments Fri, 03 Jul 2009 09:28:04 +0000 http://lmpeiris.wordpress.com/?p=103

Fedora 11 is the buggiest of the Fedora clan but it doesn’t mean it’s bad. As my opinion it’s the best Linux Distro… Most of these bugs were due to the fact that I have out-dated hardware!

My fedora 11 Gnome desktop ... Nothing new fron FC9

I have mentioned why I decided to upgrade from fedora 9 to 11 in my previous blog article. So here I’m almost after a week ……. wonder what happened? I was fighting the bugs which were found to be ultimate challenge and test of stamina after I started using Linux. For 3 days, I was hopeless as I was unable to see even the desktop! But problems did not end there for me… There are still some unsolved mysteries even with after upgrading bug-fixes. You should understand that I’m kind of addicted to Fedora, so whatever happens I would be using her just hoping that bug-fixes will arrive in time, and the next Fedora 12 would be somthing brilliant like Fedora 9. (Still, i think Fedora is the best as it comes with cutting-edge tech which is why actually these bugs come)

On last Saturday, after writing my previous blog, I first decided to upgrade from version 9 to 11. I saw the warnings on others who tried it, but as I have upgraded 7,8 to 9 it didn’t come new to me. So I upgraded which took 4 hours, and when restarted it shows GRUB all over the screen where GRUB should be loading. Like this:

GRUB GRUB GRUB GRUB GRUB GRUB GRUB

So I boot Fedora11 with rescue mode and typed

chroot /mnt/sysimage ‘changing root path to FC11 root

and i opened grub.conf file in /etc and it appeared good, it shows that it had identified the windows OS, and had pointed to correct paths. No problem.

The /boot/grub/device.map file was correct, which says which hard drive is sda and sdb. The file looks like this:

(hd0) /dev/sda

(hd1) /dev/sdb

Hence, (hd0,0) refers to 1^st partition on 1^st hard drive (ex: sda1) on the grub.conf file, (hd1,1) refers to 2^nd partition on the 2^nd (ex: sdb2).

So i reinstalled grub with grub-install sdb (as my linux installation was in 2^nd hard drive) but didn’t work, but doing

grub-install -–force-lba sdb

did work. Error found to be something to do with the AWARD bios and grub.

So I came to the fedora 11, but upgrade has been buggy. So buggy that it crashes every time. With no choice, I decided to back-up my data and do a fresh install.

So I did the fresh-install using “use entire drive” option, and without changing any details as a beginner would do. When installation was complete, I saw “Error 22” instead of grub upon rebooting. It means that system cannot find the bootloader, which is GRUB. I looked at the files and it seemed like system has detected the drives in wrong #’s. So I did grub-install again, with –recheck and -–force-lba which didn’t work.

So I decide to install again, this time using custom settings for partitions. I used Ext3 for / partition where Ext4 was the default. This did work, finally. Finally I was able to run fedora11. The problem was that the GRUB still cannot identify Ext4 file system, and it gives errors in some systems.

So here I see the desktop, but wrong resolution. So i typed system-config-display on the terminal… but there was no such command! You do have a “Display” applet on System>Prefrences but it couldn’t even get my monitor type. So I installed system-config-display by,

yum install system-config-display

I was soon to find out that i’m becoming a yum addict. This is because programs which used to compile well on FC9, ends up on errors (C syntax errors – you can’t solve those) particularly due to version incompitabilty of GCC and Cmake etc… So a person who haven’t used yum before (me) started doing everything by it!

Upon installing mplayer – my favourite player, I found out that it crashes everytime I open a video! Damn— It did superbly on FC9! Unable to figure out why, I was shocked that even the vlc played buggy and totem too did the same! By this time I knew something was wrong with multimedia drivers — but later found out that it’s a bug of PulseAudio — and again updating didn’t help. Changing to ALSA and OSS didn’t help as they seem “deactivated” although everything I could find on these have been installed.

Anyway, I could get mplayer to run by changing the video output driver from Xvideo to opengl. But it doesn’t give the previous quality. But still up to now, i can’t hear any sound at lmms,hydrogen, audacity and record-sound.

Finally trying to print by IT degree notes I plugged in my HP P1005 laserjet. I saw an improvement than in FC9, it automatically installed driver and software for the printer! But when I sent a document to print… nothing happened.. It says “your printer may not be connected” … what the HELL? I checked the installed drivers and they were 100% correct. I guess this is a bug in new hplip 3 or cups. Still not solved. Printer did well in FC9 where I manually installed hplip 2.8.

]]> https://lmpeiris.wordpress.com/2009/07/03/fedora-11-%e2%80%93-the-buggiest-fedora-ever/feed/ 7 malshanpeiris desktopfc11 https://lmpeiris.wordpress.com/2009/06/27/goodbye-fedora-9/ https://lmpeiris.wordpress.com/2009/06/27/goodbye-fedora-9/#comments Sat, 27 Jun 2009 12:06:42 +0000 http://lmpeiris.wordpress.com/?p=101 I upgraded to the Fedora Core 9 Alias Sulphur distribution, more than a year ago. The one I had at that time (werewolf), was so buggy that I told some one to download the FC9, within the first week of it’s release. Everything you see in this blog, and many other up to 200 programs which were not the standard distribution of the DVD were tested on Fedora 9.

Bye Bye Sulphur

So it’s like loosing an old faithful friend to me. I learned FOSS up to this level from Fedora 9, Although I was using FC8 and FC7 before, they somewhat did not give me the feeling to experiment. And talking about fedora, it’s the best distro to experiment… bit harder than ubuntu, I know.. but that’s what pure Linux is.

Other than trying to be new, there’s some major improvements in utility programs I expect from FC11. As almost a year has passed by now, the new versions of the programs and compleately fresh programs came this year, seemed too mush to be handled by old FC9.

1. Qt 4.3 to 4.5 – This has caused me to stop installing about 20 programs. People these days need Qt for GUI as they need coke
2. Mono 1.9 – 2.x – C# happy people tends to right code in newest way possible to them. So until now, I was unable to install mono 2.0 !
3. Boost libraries – Try installing some stastics programs without old versions. It gives hell.
4. Gnome 2.26 – Always easy to do things when you have new GUI !
5. Xulrunner – FC9 came with a beta, and it did give hell.

Other reasons are bugs:

• Sleeping problem – FC9 system couldn’t sleep, it shuts down !
• The authentic driver for 945GZ failed. So I used an experimental one.
• GDM had a bug, so I can’t logout and loggin with another user, using GUI.
• So many more

Anyway, of those 200 programs, many of them were compiled from source. So the RPM does not know about them and if the FC11 has the .rpm for those, it will overwrite the files, and this could cause problems. And above programs were compiled for kernel year ago, so I expect many programs to fail at the new OS. So I have listed all the manually installed programs, current list of RPM’s , bins and includes. This is hoe I did it.

rpm -qa >> filename ‘saves all RPM to a file

ls /usr/bin >> filename ‘saves list of binaries

ls /usr/include >> filename ‘saves list of source files

In case neede to search for something,

cat filename | grep <search string>

Ok i’m going to start it now. I hope current won’t go off.

Special thanks for Isuru Udana for providing me the FC9 DVD.

It’s a simple program written using Swing, mostly like 3D studio max to design and animate 3D objects. A grid is there as usual with space vectors x,y,z. 3D view and xy,yz,xz plane views are shown simultaneously. A timeline is visible when you hit create animation button. Additionally, python scripts can be used to program the animation.  You can select one of many basic shapes under create object pane, and modify it from the modify menu bar. So my first drawing looked like this. (I’m not good at graphics). Anyway, you can have some fun with this program, whatever you know.

3D graphics I created - version 0.2.0 running on JRE 1.6 (@ FC9)

According to their homepage , these are the features of version 0.2.2

• Modelling – Unique history-based approach ,Support for non-manifold meshes, including polygons with arbitrary vertex counts ,3D manipulators ,Object instancing ,Fully editable object history at any time
• Materials, Lighting and Rendering-Fully integrated Sunflow, a renderer with support for modern lighting features like ambient occlusions, global illumination and caustics ,Omnidirectional, spherical and spot light sources ,HDR image output ,GLSL support including GLSL shader editor
• Animation-Multiple animations of scenes ,Virtually all parameters in the construction history are animateable separately,Rendering of animations
• Other-Flexible user interface that can be adapted to the user’s needs ,Flexible and extensible plugin based architecture ,Full Python scripting capability,Headless batch mode ,Integrated script editor

The operator graph of moonlight 0.2.0

Installing
You can download the binary files version 0.2.2 for Linux from this link (14MB). Just make sure you have latest Java Runtime installed to run the program. Untar the downloaded file and double-click on moonlight.sh or at the terminal type,
./moonlight.sh
Moonlight Application Framework
Is the package for programming moonlight components, specially it’s plugins. My knowledge is limited on this subject, anyway you can download the source code from here.