Xiong's Journal

Changing Agora Forum using Joomla users' name rather username

2010-02-07T06:14:00.000-08:00

Agora Forum is an excellent extension for Joomla as an Forum. Rather using bridge to phpBB which causes the system overhead (since it runs 2 system: Joomla & phpBB), we only run one system.

Anyway, the problem that I encounter is I don't want Agora using my Joomla username, but I prefer it to use Joomla name. But I've never found any settings or configurations about this. So the only way is to hack it a little. It is kinda hard to find where the code to change it, since I am not so familiar with its code anyway. But at least today, I've successfully change it to using name :D

I am not sure whether this setting is already sufficient or not. So there might be a additional hack in the future.

First of all I must create a function that change all the username in #__agora_users to name of #__users. For me, I create a component called com_tar_setforum in administrator, and put the code like this.

class Tar_setforumController{
...
function setUsername(){
$model = & $this->getModel('forum');

foreach($model->listIdUsers() as $value){
$model->updateUsername($value);
}
$link = JRoute::_('index.php?option=com_tar_setforum');
$this->setRedirect($link,'Nama berhasil di-set');
$this->redirect();
}
....
}

And put a model with function like this :

class Tar_setforumModelForum extends JModel{
function updateUsername($jos_id){
$query = "UPDATE #__agora_users SET username=(SELECT name FROM #__users WHERE id='$jos_id')
WHERE jos_id='$jos_id'";
$this->_db->Execute($query);
}
.....

But only update the name in the #__agora_users doesn't solve the problem. Somehow everytime users access the forum, the table is updated to old value. That's why we need to hack the Agora code.
Here what I change the code :

/components/com_agora/model/user.php

function loadCurrent(){
....
// Update loaded user to not load it again
foreach ($data as $param=>$value) {
$user[$param] = $value;
}

//Here my additional code
$user['username'] = $my->name;
$data['username'] = $my->name;

$this->edit($user['id'],$data);
....
}

and one more
/components/com_agora/model/online.php

function getOnline()
{
....
/*$query = 'SELECT a.id, a.username' .
' FROM #__session AS s INNER JOIN ##__users AS a ON s.userid=a.jos_id' .
' WHERE client_id = 0 AND s.guest=0';
*///commented. This is the old one. Replace with below codes
$query = 'SELECT a.id, u.name
FROM #__session AS s INNER JOIN ##__users AS a ON s.userid=a.jos_id
INNER JOIN #__users AS u ON u.id=s.userid
WHERE client_id = 0 AND s.guest=0';
....
if (count($sessions)) {
foreach ($sessions as $session) {
//$user_array[] = array('id' => $session->id, 'name' =>$session->username); //commented by Xiong
$user_array[] = array('id'=> $session->id, 'name'=>$session->name);
}
}
....
}

After changing this, it should can preserve the username in #__agora_users

FireGesture causes TinyMCE's context menu disabled

2010-01-28T20:18:00.000-08:00

If you enable the context menu on TinyMCE, then whenever you right click on the TinyMCE textarea it supposed to pop up a menus. But somehow my Firefox doesn't show anything. It seems like the right click doesn't show anything!

So the first thing come to my mind is must be one of my Firefox's add-ons causes this. Later by disabling all the add-ons, and restart the Firefox, the context menu is working!! :)
Then I just enable one by one add-ons until I enable the FireGesture, the context menu is not working again. Aha! I've found the culprit. :D

FireGesture is an add-on enables user to use mouse gesture (just like mouse gesture in Opera or Maxthon) to operate Firefox. Since FireGesture use right click, I think it somehow conflicts with TinyMCE context menu javascript. I haven't found the solution though except disabling this add-ons.

Update:
Later, I uninstalled FireGesture, and install All-In-One Gesture. It's doesn't conflict with TinyMCE. So this is my solution, but I hope one day I found the solution for FireGesture.

Upload to FTP using PHP script

2009-05-12T22:52:00.000-07:00

For some reasons maybe you need to upload files to ftp. In my case, I need to upload the image files to ftp account because the capacity of the hosting is limited. So in order to upload the image to ftp account we using cURL. Here is the code

// FTP access parameters:
$host = 'www.ftp.com';
$usr = 'username';
$pwd = 'passw0rd';

// file to upload:
$local_file = 'test.png';
$ftp_path = 'test.png';

// connect to FTP server (port 21)
$conn_id = ftp_connect($host, 21) or die ("Cannot connect to host");

// send access parameters
ftp_login($conn_id, $usr, $pwd) or die("Cannot login");

// turn on passive mode transfers (some servers need this)
// ftp_pasv ($conn_id, true);

// perform file upload
$upload = ftp_put($conn_id, $ftp_path, $local_file, FTP_ASCII);

// check upload status:
print (!$upload)? 'Cannot upload' : 'Upload complete';
print "\n";

/*
** Chmod the file (just as example)
*/

// If you are using PHP4 then you need to use this code:
// (because the "ftp_chmod" command is just available in PHP5+)
if (!function_exists('ftp_chmod')) {
function ftp_chmod($ftp_stream, $mode, $filename){
return ftp_site($ftp_stream, sprintf('CHMOD %o %s', $mode, $filename));
}
}

// try to chmod the new file to 666 (writeable)
if (ftp_chmod($conn_id, 0666, $ftp_path) !== false) {
print $ftp_path . " chmoded successfully to 666\n";
} else {
print "could not chmod $file\n";
}

// close the FTP stream
ftp_close($conn_id);

?>

Reason why mother want you to use Linux

2009-05-11T08:11:00.000-07:00

Today I found a funny article at here about the reasons why your mother would want you to use Linux. Seems like because yesterday is Mother's Day (Happy mother's day!!), the author create this funny articles.

Here I copy the article to here:

1. Since Linux is free, you have no more reason to ask her for money every time you install, upgrade, and get new software applications. Now instead of buying you a Windows Vista Ultimate Edition, she now has extra money to spare for a spa.

2. Because she loves you so much, she wants you and your computer to be free from virus always. In addition, most mothers want the house to be always clean, and just hearing the words like bacteria, fungi, and virus make them angry.

3. She wants you to learn new things and gain deeper knowledge on how computers work instead of playing Xbox all day. Linux will greatly enhance your computer skills since you are free to explore its inner workings.

4. You don't have to ask her for money to buy new computer hardware to cope up with the latest software since there are lightweight and resource-efficient Linux distros that could make your old computer fly. So another money saved and another spa for your mother.

5. She wants you stop using bad words after a BSOD. Linux rarely crashes so she should be happy hearing you say "Wow" instead of "F*@k!" or "S#%t!" :-)

Connect guest with host in virtualbox

2009-01-04T05:56:00.000-08:00

Now is the fifth semester in my study at university. My friends who take Networking must do a Network Programming project. So, you must create a application which can play game from different computer with some constraint. The server must on Linux, while the client application must in other system operation. Since, most of the student using Windows, no need to mention all of them using Windows. There still another constraint on client. The application must be graphical user interface (GUI). They are free to use any developing program to make. But most of them choose to use Visual Basic or Java.

Ok, since there are 2 friends of mine (Aping and Awui) is having this project, I help a little. First thing first, I suggest them to install Virtualbox in their computer. Why? Because we must run server and client on different system operation, I don't think there is other way except using Virtual Machine. Because their computer only installed Windows, then the guest OS on virtualbox is Linux. I install Ubuntu to Aping's Virtualbox and Kubuntu to Awui's. Why I installed different OS, you might wonder. I just want to do it, no any special reason. :p

Ok. After installing it now is the time for testing whether the guest computer (linux) can connect to the host (Windows). Actually they can access our boarding host LAN network and browsing Internet. But, guest computer can't ping to host computer and vice versa. Ok now is time for investigation.

I try using my own Virtualbox. I boot to my Windows XP, fire up my Virtualbox with CentOS 5.2 as guest. And try to ping. The result is same. So I try to browse in Internet to see, whether there is any information regarding this. I found out that by default the Virtualbox is using NAT as network on its guest. And because by using NAT, it make the guest computer appear to be connected directly to the network. This explain why I can browse internet or browse the LAN network but can't ping the host computer.
I try to find out, but most of forum suggest to read the manual. Nothing can be done, I download the manual then.

After read a while, at last I found the point in the manual. Actually its very simple indeed. I just need to set the NAT connection become Host Interface and select the host's network interface to connect with. Geez~ it's so simple. Ok then, so I close my CentOS (host) and change the setting in Setting->Networks. And run my CentOS once again. But this time is strange, the CentOS unable to ping the gateway causing it doesn't connect to anywhere, causing its eth0 is not set. Feeling strange, I try to googling. There, I found somebody claim that Redhat 5.2 cannot connect using Host Interface. As you know, CentOS is almost same with Redhat, except the name and the logo. Knowing this, I try my other guest computer. I run my Kubuntu 8.04 using Host Interface. Aha! This time, its eth0 is not empty. In fact the IP address is different with before. Usually if you using NAT to connect, the IP address will always 10.0.2.15. Now it change to other IP Address(I forgot what is it). Try to ping it from Windows command prompt. Bingo! It replies. So actually it is simple. You just need to change it to Host Interface. But as you can see CentOS 5.2 and Redhat 5.2 is somehow cannot detected the connection.

Adding username and password for Proxy authentication

2008-12-19T09:25:00.000-08:00

Not long ago, because of some reasons, my ISP add user authentication on the proxy. Which means we must enter username and password everytime want to connect to Internet (HTTP protocol, other protocol such as YM and MSN don't need to set proxy). Last time to set proxy in terminal, we can use

export http_proxy="http://proxy:port"

Now since it need to authentication user, we must add a little. So, just add the username and password at here:

export http_proxy="http://username@password:proxy:port"

That's all.

Fix the ugly font in Firefox

2008-12-10T07:56:00.000-08:00

After a long time, I finally have bought the 320 GB. And I have installed Kubuntu Intrepid Ibex (8.10), using KDE4 is quite awesome. But still I need to adept the new way. This time when I open my Firefox, the first thing I've notice is the font is too ugly :p

So I googling and found somebody also has a same opinion with me and also the solution to fix this. He give a first solution, but later I realize that actually I just need to do the second one.

http://ubuntusite.com/fix-get-best-firefox-font-linux/

What we need is to download :
http://www.fileden.com/files/2008/2/9/1749988/segoe_ui.zip
extract and put it in
~/.font

If you haven't have .font directory, just create it. Then I set the font in System Settings->Appearance->Fonts
Set all the fonts to become Segoe UI, click Apply

And that's it now my Firefox font is more decent.

Case : Fedora 9 on KDE4 black screen

2008-11-24T15:39:00.000-08:00

One of my friend, Ping, is taking Networking. Because it need Linux to learn network programming, I choose Fedora 9 with KDE4 for him. Everything working fine (except a little glitch on KDE4, still acceptable). Because we want this computer can be play Windows game, so we try to install the proprietary driver. Before installing the driver, he can open those games through Wine but it is too slow. He is using Geforce 6600 series. There is no problem in installing the driver. Everything working fine, till entering the KDE4 until suddenly it goes black. In a glance, we can see actually it successfully goes to desktop. But something has cause it become black.

After doing googling, later it is found the causer. It is the KDE4 compositing cause this. So what we need only do a little change on ~/.kde/share/config/kwinrc
in the file find [compositing] section. In there change the
enable = true
to
enable = false

After doing the changes then restart X (just log out the computer). The screen won't goes black anymore! And now he can open Warcraft III and other games with no noticeable slow down.

The problem with Vi and VIM

2008-11-22T08:47:00.000-08:00

If you are using Vi or Vim in Kubuntu version 7.10 till 8.04 you might notice some unusual things. Lets talk about vi first. When I use vi, you might see how the vi seems doesn't respond with the arrow key or somehow doesn't recognize the i button(for insert). That's why I always use Vim instead Vi.

The second is about the Vim. There is one feature provided by Vim called syntax highlight. To enable it we just need to type
:syntax enable or :syntax on
But somehow it can't. It said like this
E319: Sorry, the command is not available in this version: syntax on

Later, after some googling I got the answer for the latter problem. The problem is I never installed Vim on my Kubuntu! So the Vim I use until that day is from vim-common. So using synaptic package manager, I installed the vim package. It begin to download files, one is vim, the other vim-runtime. After the installation complete, now I can use my Vim to highlighting the syntax. Beside that the vi strange behaviour seems disappear. So well... one stone kill two birds, isn't it? :D

Remote to my Kubuntu

2008-11-17T09:59:00.000-08:00

Today, I have successfully remote to my computer from other computer. I am using VNC (Virtual Network Computing). It is a graphical desktop sharing using RFB Protocol. If only want to remote in terminal ssh is the best (as far as I know, most of people recommended it).

So I install vnc4server on my Kubuntu Hardy Heron. As usual I can found it on my Synaptic package manager, just check it, click apply and it does the rest. After installing it, now we can try it. First you must decide on which user account will be used when someone remote to this computer. Because I am the only the user, so I don't need to change user name. If you want to change user just type

su user_name

To start the vnc4server just type :

vncserver -geometry 1024x768 -depth 24

I haven't mastered all the syntax parameter, but these parameters, I think everyone will understand it. So it means, if someone remote to this computer, it will got a 1024x768 pixels view with color depth 24 bits. It will prompt to fill the password. This typing password only once, the next time you run the server, it won't ask the password anymore. After this, it will create some files to you(which is located on your home directory, folder .vnc )

Now I try to remote myself, but before doing it, I use one of my remote computer program which come with other KDE applications, called Krdc
This program is simple to use. I successfully log in, it only show the grey screen with a "X" cursor. At first I don't understand what happened. But the thing become clearer after doing some googling. I must add something on the files!

As you know, when the first time we run the server, it will create some files located on your ~/.vnc/ One of this file is called xstartup. Seems like this file is execute when the someone successfully remote to this computer. So I must add:

startkde &

at the bottom of the file. So it looks like this :

#!/bin/sh

# Uncomment the following two lines for normal desktop:
# unset SESSION_MANAGER
# exec /etc/X11/xinit/xinitrc

[ -x /etc/vnc/xstartup ] && exec /etc/vnc/xstartup
[ -r $HOME/.Xresources ] && xrdb $HOME/.Xresources
xsetroot -solid grey
vncconfig -iconic &
xterm -geometry 80x24+10+10 -ls -title "$VNCDESKTOP Desktop" &
twm &
startkde &

After changing this file, I stop the server by typing this :

vncserver -kill :1

That's mean I stop the first running server. As far as I know, if you only run one server then you only need to know to type that.

After stop the server and start the server again. Now I can remote my computer. Later I try to remote from my friend's computer(his name is Cloud as I ever mention on other post). Because he is using Windows XP, I have downloaded the Real VNC Viewer which is freeware and portable. The result, of course is successfully to remote to my Kubuntu desktop. :D

Installing CentOS (III)

2008-11-04T23:00:00.000-08:00

Ok I figure out now. Yum need proxy to get connection of Internet. Even you are using CentOS on the Virtualbox. Initially, I thought that since I got internet connection from my host computer, so it doesn't need the proxy. I believe this hypothesis since I can wget without any problem. But later I realized Yum need it. Since like the way they got package is different.

Ok so I export http_proxy and export ftp_proxy to the computer. And yup my computer can install package. Now is the time to install the X Window System and GNOME Desktop Environment. I type :

yum groupinstall "X Window System" "GNOME Desktop Environment"

The process itself is quite long, so I let the computer on while I go to work. After back from work, I found the packages have been installed. Now I type startx
and yohoo the GNOME is starting, now I got the GUI in my CentOS...

Installing CentOS (II)

2008-10-22T17:45:00.000-07:00

Wew.. I just realize one thing. The reason I can't ping outside is because I am using static IP, while in VirtualBox it got connection through DHCP. This is realised after I look the ifcfg-eth0 file in livecd. It is DHCP....

So I change the interface to DHCP. Also I undo the last time move(ifconfig, route add) Now I also realize there are rpms file in the bin cd. So I install a few package for my new computer, man, wget, tree and the others..

To prove that using DHCP is the right one. I try to download file in one of my internet file hosting using wget. And yes.. I successfully download the file. Now it seems the problem is in the yum itself. Need to figure out.

Installing CentOS (I)

2008-10-21T09:43:00.000-07:00

After a year trying Kubuntu, now I am trying to use CentOS. For information, CentOS is derivative from Redhat Enterprise. Now I am still waiting a perfect time to buy a new harddisk 320 GB. My old one only 80 GB is already about to full.

Before to install to my harddisk, I tried CentOS to Virtualbox. This is the first time I found that the livecd is can't be used to install to harddisk. So I download another iso which is bin. There are 6 bin files. And of course to full install you must download 6 files, which each burn to each disk. So we need 6 cds. Geez. Because I don't want to download to many iso just for this. I found there is a way to minimal install. Just need the first cd to install.

The first attempt failed. Coz even I have deselected all the package. It still require 3 cds. The second time it only require one cd. Strange huh? May be because the second time I have put the IP and mirror of CentOS before proceed. That's why it get from Internet? Dunno. The point is I have successfully install CentOS 5.2 :D

This CentOS only terminal, since I do minimal install. Just unbelievable, a cd only terminal, no man (yes! man ), no a lot of thing. I just wonder why it require one cd. Ok, not problem. Now try to install GNOME Window Manager....... ups.
It cannot connect to Internet. How could it be? I can connect perfectly in Livecd, why I can't at here. No problem I try googling. And thank goodness I found the answer at here :
http://www.linuxquestions.org/questions/linux-networking-3/network-is-unreachable-81728/

So now I have successfully ping to DNS, which is used to be result : connect : Network is unreachable

Ok the first problem has solved. But still..... I can't install..
this time it show :
Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=5&arch=i386&repo=os error was [Errno 4] IOError:
Error : Cannot retrieve repository metadata (repomd.xml) for repository: base. Please verify its path and try again.

Hm... what the heck is this? Dunno. So I will continue to investigate tomorrow...

The craziest problem after one year using Kubuntu

2008-10-13T09:12:00.000-07:00

I still remember about one year ago, when I first use Kubuntu. It was Feisty Fawn, 7.04. I installed from my friend's disc. Everything work fine except that it didn't recognize my LAN card. And that thing almost made me to dump the Linux. Luckily, I with my friend (a.k.a Cloud) later figured out the problem. The Feisty Fawn was not detected my LAN Card, that couldn't be help. I upgraded to Ubuntu Gutsy Gibbon, 7.10.
I have used almost it half year without any major problem. And then do a upgrade to Hardy Heron 8.04. And of course without any problem too, except I need to install some packages, because they are not compatible with the new Kubuntu, and automatically delete them.
And today, I meet the most weird problem that ever exist after using Kubuntu one year.
If I move, copy or delete file (any file) at desktop, it will hang. I mean the KDesktop will hang. Other process still normal. But if I wait for a little longer, I will got my Kicker hang. And not long to see the inputbox will "locked", cannot been input. Any inputbox, Firefox search input box, aMsn's typing message box, any inputbox!! And then I cannot move the window. Seems like the window manager is die too. What happened actually? It still a mystery. And I forgot what have I done, to make it become like this. Nobody know.....

Maybe I just shall wait a few days and get ready to upgrade to 8.10

Setting terminal high resolution

2008-09-15T05:44:00.000-07:00

Yesterday, I found one interesting blog about how to set Ubuntu terminal into high resolution.

You see, everytime Kubuntu startup there is terminal explaining what are the kernel doing. For some people, including me, prefer to look those things rather than watch the splash(showing bouncing bar and then the bar getting full). But some of these people don't like the size of the terminal. The characters just too big. The solution of these is to make the higher resolution.
Here is the blog, that I mentioned : http://joeamined.wordpress.com/2008/02/25/enabling-high-resolution-console-in-ubuntu/

Here, I quoted it:

sudo gedit /etc/modprobe.d/blacklist-framebuffer

then comment the line : blacklist vesafb

Save the modifications and close the text editor. Now, still in a gnome terminal, type :

sudo gedit /etc/initramfs-tools/modules

At the end of the file, add these two separate lines :

fbcon
vesafb

Close the edited file and type :

sudo update-initramfs -u

Finally, open your menu.lst file :

sudo gedit /boot/grub/menu.lst

In the kernel line for ubuntu delete ’splash’ (so you no longer have the usplash displayed) and add vga=791 (to have a 1024*768 resolution)

That’s it ! One last tip, to have more messages displayed you can change ‘quiet’ to ’services’ or to ‘verbose’ in the kernel line.

A little partition disaster

2008-09-13T10:21:00.000-07:00

Today I decide to delete one of my 3 GB partition. (Initially I want this partition merged back to my Linux partition. It is impossible though). I remove all the files and directories at there. And lastly I delete the partition and re-format to ext3. And install Fedora 9 just for fun. ^^. Beside this, I also merge 2 swap partitions into one partition. Here comes a little disaster.

Because I delete the partition and re-create it. It seems like the name of partition has been shifted. My Linux partition is used to be sda7, becomes sda6. The Fedora 9 becomes in sda7 partition. And my swap become sda8. The problem is, the Master Boot Record used to be find grub file at sda7. I don't want it, because I never intend to use it in long term. But I can't change it to find partition sda6. Later, I found one way to solve it. It is easy though.

So what I need just open terminal or Konsole. Type the following words, step by step.
sudo grub
root (hd0,5)
setup (hd0)
quit

Here, root (hd0,5), why do I use '5'?? That's because the number of partition at grub begin from zero. So need to remember that, the number in grub is begin from zero. In real life the naming of partition is begin from one. After that I restart the computer and... yups! The grub found menu.lst at sda6.

Beside changing grub, I have found out that why the swap uuid can be changed. See the achieves at April 2008 for more information. That's because I change the partition of swap. That's why the Linux didn't know that the partition of disk has changed. That's why the /etc/fstab file never been changed. We must change it manually. Maybe there is better way, but that is all what I can do.

No soundcard detected?

2008-09-03T19:37:00.002-07:00

After upgrading the kernel linux to 2.6.24.20 my computer encounter two problems. First one is the driver for Geforce 6200 LE(same problem that occured last time) and the second is rather special.
I never encountered this before, after entering the desktop the Kmix report "Mixer cannot be found", Amarok report "xine cannot found sound driver".

Later I found out that the modules for kernel 2.6.24.20 haven't installed. The solution is simple. Use Adept or Synaptic to install linux-ubuntu-modules-xx.xx.xx.xxx

xx.xx.xx.xxx is your kernel version. You can find out by typing
uname -r
For mine it will be linux-ubuntu-modules-2.6.24.20

After restart my computer, the sound modules loaded successfully.

QSyntaxHighlighter little code

2008-09-01T20:17:00.000-07:00

In process to create a editor that can highlight words in QT. I have try to do a little research. Here is my code. This code is written on form1.ui.h . While in form1.ui there is one textEdit which names textEdit1.

#include <qsyntaxhighlighter.h>

class Highlight : public QSyntaxHighlighter
{
public:
Highlight(QTextEdit * textEdit);
int highlightParagraph ( const QString & text, int endStateOfLastPara ) ;
virtual ~Highlight(){}
};

Highlight :: Highlight(QTextEdit * textEdit) : QSyntaxHighlighter(textEdit)
{
}

int Highlight::highlightParagraph ( const QString & text, int endStateOfLastPara )
{
setFormat(1,20,Qt::blue);
}

void Form1::init()
{
Highlight *newHighlight;
newHighlight = new Highlight(textEdit1);
}

After compile it generate a strange error:
.obj/moc_form1.o:(.gnu.linkonce.r._ZTV5Form1[vtable for Form1]+0x1cc): undefined reference to `Form1::highlightParagraph(QString const&, int)'

After doing some search in Qt forums, I found the reason behind this. The forum I have read is here : http://www.qtforum.org/article/1381/2/qsyntax-highlighter.html

The conclusion is, somehow, Qt Designer has created highlightParagraph in Form1. That's why compiler couldn't find the function.

Scheduling the task

2008-09-01T10:37:00.000-07:00

In Linux, there is a program for manage scheduled task. The program itself is cron. While to put the list of schedules we use crontab. Usually we won't do anything with cron. What we only need to do is put the description of time and task.

Firstly we need to create a file. Later this file will be put into the crontab. One thing, the file extension should be .cron, for examples foo.cron. Here is an explanation with examples, taken from http://www.scrounge.org/linux/cron.html

Here is the format of a cron job file:

[min] [hour] [day of month] [month] [day of week] [program to be run]

where each field is defined as
[min] Minutes that program should be executed on. 0-59. Do not set as * or the program will be run once a minute.
[hour] Hour that program should be executed on. 0-23. * for every hour.
[day of month] Day of the month that process should be executed on. 1-31. * for every day.
[month] Month that program whould be executed on. 1-12 * for every month.
[day of week] Day of the week. 0-6 where Sunday = 0, Monday = 1, ...., Saturday = 6. * for every day of the week.
[program] Program to be executed. Include full path information.

Here are some examples:

0,15,30,45 * * * * /usr/bin/foo

Will run /usr/bin/foo every 15 minutes on every hour, day-of-month, month, and day-of-week. In other words, it will run every 15 minutes for as long as the machine it running.

10 3 * * * /usr/bin/foo

Will run /usr/bin/foo at 3:10am on every day.

10 * 1 * * /usr/bin/foo

Will run /usr/bin/foo at 12:10am on the first day of the month.

10 * * 1 * /usr/bin/foo

Will run /usr/bin/foo at 12:10am on the first month of the year.

10 14 * * 1 /usr/bin/foo

Will run /usr/bin/foo at 2:10pm on every Monday.

After created the file, we put the task, descripted in the file to the crontab. By doing this, the crontab will load the cron jobs to the cron. For example, you want to load foo.cron to crontab :
crontab foo.cron

Check to see if it was loaded by typing
crontab -l

PS:Before adding the cron jobs, it's better to see whether there are any cron jobs running (type: crontab -l). If there is no cron jobs loaded currently, then it is safe to add it.

Linux 072 ver 1.0 has been created on 11-7-2008

2008-07-11T10:00:00.000-07:00

At last...... the livecd which I remaster has come to its first version. The name is Linux 072. Why 072? That's because I am software laboratory assistant in Binus university, the 2007 generation second semester. Thanks to Virtualbox, without this program, I don't know how many cdroms wasted.
Also many thanks to this link,
http://www.linux.com/feature/137524
without it I don't what can I do....

I successfully install the most important part of this project. That is Qt3 Designer. This application is quite important so my trainees can try this program at home. But the size of this application is big, kinda afraid that the spaces of disc is not enough. In reality it is really not enough (if I don't remove some packages). So I remove some language support packages, burner packages (forgot the name), photo editor packages (F-Spot). Then I install g++, and it dependencies. After installing and removing, at last the disk spaces left 1% from 3 GB.
The next step is change the wallpaper of Ubuntu. I use one of my scenery picture (wet grasses in morning with "Linux 072" on the top left corner) to replace the default wallpaper from Ubuntu. I prefer fresh and colourful picture rather than Ubuntu's rather-dark wallpaper of heron. :p

Note the above step is not done only once. But many times, since I need to install/remove and see the changes. Keep doing those steps until every packages that I want is installed all.

When creating livecd I encountered a few minor problems. The first problem is, I uninstall all of Evolution packages. I thought surely the trainees don't need this software. Evolution is a mail client. Little do I know that one of evolution package must not be removed. It is evolution-data-server-common is one of gnome-panel dependency. Delete this package also cause gnome-panel be removed. Gnome-panel it self is Gnome taskbar. No panel means no access program. Even Alt+F2 can't do a thing(the run window won't open). That's why I install back gnome-panel with evolution-data-server-common and other gnome-panel dependencies. But the other evolution packages, I still didn't install them.

The second problem is when I enter the GUI, suddenly show 3 windows. One of them said "The panel encountered a problem while loading "OAFIID:GNOME_MixerApplet" ". The other 2 almost the same with different name "OAFIID:GNOME_FastUserSwitchApplet" and "OAFIID:GNOME_TrashApplet". After looking at Ubuntu forum, it is gnome-applets. Seems like because gnome-panel been removed also cause gnome-applets been removed. But when I install gnome-panel, gnome-applets didn't be installed. Because gnome-panel itself doesn't depend on gnome-applets. So I install it. And try again with Virtualbox. Now it only pop one window said that "The panel encountered a problem while loading "OAFIID:GNOME_FastUserSwitchApplet"". So there is still one package need to be installed. this is fast-user-switch-applet. After install this last package, at last.......
the Linux 072 ver 1.0 is out.

Still remember last year, when I am still a trainee, I saw my trainer's livecd named Lidya Linux. I just wonder, could I next year create my own livecd, when I become trainer. I never used Linux before. So that's was my first time to use Linux. Seems impossible to me then. How could a merely beginner who know nothing about Linux, can create own livecd. But hehe.. thanks to my interest in Linux and abundance of guides in internet about how to create livecd, A livecd which last year, my little dream, fulfilled. :)

Actually before using Ubuntu to remastered, I already had remastered Knoppix 5.1, which I called it Linux 072 version 0.1. Later, after some thoughts, I change to Ubuntu. Because Knoppix can't detect my ethernet card, Realtek(actually Kubuntu Feisty Fawn also fail to detect this card until Gutsy Gibbon out). Without link to internet it is impossible for me to install package to the livecd. That's all folk, today shall be a little achievement from me. Kinda happy... :)
If you think, nothing can be proud from this, never mind. Because I am still just a newbie. :)

Qemu cannot run Ubuntu 8.04 livecd

2008-07-07T04:23:00.001-07:00

Still continue the last time to try make a livecd. After following every step, at last it produce an iso file. Yeah.. It's time to try it. then I try to run this iso file with Qemu with like this :
qemu -cdrom ubuntu-8.04-desktop-i386.iso -boot d
It can run until when it's gonna enter GUI. It is said, the xserver hasn't been configured.

So I swith to use virtualbox and it runs the livecd of Ubuntu 8.04 successfully from start to the end flawlessly.

Only one loop device file

2008-07-04T05:50:00.000-07:00

I am trying to remaster Ubuntu Hardy Heron, by following steps provided in this link
http://www.linux.com/feature/137524

Everything is normal, till this step
sudo mount -t squashfs -o loop mnt/casper/filesystem.squashfs squashfs

When I try this it is said that, something like not enough loop device, or maybe device is busy. Sorry I've forgotten what did it say exactly. The problem become clear after I checked at /dev/ , there is only one loop device file : loop0

Normally, Ubuntu should have 8 loop device files, loop0, loop1, loop2, .., loop7. I don't understand why, but after doing some googling, it is easy to fix this. Just edit /etc/modules
There just add "loop" (without quotes) at the last line, then restart your pc. After restart, the amount of loop device files increase to 8.

Nvidia.ko not found after upgrade kernel

2008-07-03T10:57:00.000-07:00

Few days ago, I upgrade my kernel version from 2.6.24-17 to 2.6.24-19. The installation is successful, nothing special. I didn't restart immediately. The next day when I started the computer, the problem occurred. It failed to enter KDM mode.

I tried to startx from terminal, and it said
/lib/modules/2.6.24-19-generic/volatile/nvidia.ko not found

Luckily there is nvidia.ko at my /lib/modules/2.6.24-17-generic/kernel/drivers/video directory. So I copied the file to there and startx one more time. This time it success to enter KDM.
Note : Others install the nvidia-glx-driver to fix it.

But that not solved the problem. Because when I restarted the computer, it happened again. The file that I copied was disappeared. And this happened everytime I boot the PC. (The problem happened to the one install nvidia-glx-driver).

Then someone said that the graphic card driver might be not match with my current kernel version. I often upgrade kernel, but not for graphic card driver. So I download the newest graphic card driver and install. It replaces automatically my old nvidia driver. When I boot again, the problem didn't show up anymore. So the conclusion I can get is, sometimes the newer kernel version might not match with older version of other device driver, so make sure to upgrade driver frequently too.

Firefox Always Start With Work Offline

2008-06-26T06:12:00.000-07:00

After upgrade Firefox 2 to Firefox 3 in Kubuntu Hardy Heron, the browser always begin with work offline. After finding in forum, at last I found the solution.
Here is the link : http://ubuntuforums.org/showthread.php?t=800179

Well, it is said the cause of the problem is the Firefox try to communicate with NetworkManager. And because Network Manager doesn't recognize there is internet connection, it tells Firefox that this computer has no internet connection. This is a bug from Network Manager not Firefox. To fix it:
you must edit a file. Type :
kdesu kate /etc/dbus-1/system.d/NetworkManager.conf

find 3
<allow send_interface="org.freedesktop.NetworkManager"/>
and change it to
<deny send_interface="org.freedesktop.NetworkManager"/>

It is said, it will prevent Firefox (or Pidgin) to communicate with Network Manager, so it will always in online state.

临时抱佛脚

2008-06-04T09:10:00.001-07:00

The time of project deadline is getting nearer. Most of the student are getting worried about their task. As lab software assistant, I am quite happy. At least, they care their grade don't they. But I just wonder, why don't they begin from the first. They have almost half year to do project. Most of the cases usually 2 weeks before the deadline, they become more active to asking about project to me(I assume on that time, they just begin). Including my ex-student. T_T. She only left a few days, and yet nothing is made yet!!! This case, no hope to get full mark for project. (A still possible :) )
Some come to my boarding house to ask about the project. Some make appointment with me to ask about their project.
In Chinese we called that "临时抱佛脚" Litteraly means immediatly "Hug Buddha's feet n one's hour of need". Meaning they only find me (as assistant) when the project is getting nearer. Haih.... You see, I have a lot of tasks to do too. But I just can't ignore them. So yeah, never mind. Let's hope all of their project score a good mark. :)
Good luck everyone!!

The Nvidia 6200 LE and Hardy Heron

2008-06-01T08:21:00.000-07:00

When I upgrade my Kubuntu from Gutsy Gibbon to Hardy Heron, it is quite easy. Everything goes well, except some program is lost, such as apache2, mysql, phpmyadmin, Smart Common Input Method(SCIM) for Chinese. Hm.. although one of my reason why I don't want to clean install is to preserve those programs, but Ok, maybe the old package is not suitable for Hardy Heron.
The main problem is my graphic card. It used to be easy to install Nvidia driver. I still remember, when I am using Gutsy, how I downloaded the driver and just a few step, I can use my graphic card perfectly). But now, it is not so easy.

After the installation, I downloaded the driver from Nvidia website. The driver for Linux-32 bit is NVIDIA-Linux-x86-169.12-pkg1.run (I still remember it was when Hardy Heron was been launched not so long before). I try to install it. At first, it said I cannot install, cause I still at X Server. Ok, I kill the kdm with

sudo /etc/init.d/kdm stop

After that, it installed to my computer. But after the restart, I can't enter to GUI. The problem is simple though. I just need to get the xorg.conf where the line wrote:

modules "nvidia"

change to

modules "nv"

That's mean I can't use the driver from Nvidia. I must use the restricted kernel from Linux which called NV44 (for 6200). Using this driver, I can't activate my compiz fusion and can't open glxgears.

At last a few days ago, after using NV44 for about a month, I upgrade my Linux kernel from 2.6.24-16-generic to 2.6.24-17-generic. After that, I also check whether there any new driver from Nvidia. And yes, there is! It was NVIDIA-Linux-x86-173.14.05-pkg1.run

At last I tried to install. Still the same, it asked me to not install with the X Server open. I killed the kdm. And then it asked me whether want to find the precompiled kernel. I didn't know what was that. But the driver was failed to connect to Nvidia website. It asked something after saying it was failed. I just pressed OK. ANd yes it installed succesfully. After a restart, I could saw there is Nvidia logo again...! :)

After that, I also tried to open glxgears and compiz fusion. And it worked too. So, I guest the reason why my computer couldn't run properly if install nvidia driver is lay on the kernel version of Nvidia driver with the linux version. The older driver of Nvidia, seems like not support the Hardy yet(I guest).

Problem in activating swap partition

2008-04-10T08:29:00.000-07:00

One day, I found my computer often hang everytime if the program is too busy. Later it was revealed that the swap is not on. So I check a few thing.
I look the swappiness with "cat /proc/sys/vm/swappiness " and it show 60. Meanings Linux has tendency to use swap rather than ram.
So the problem is not swappiness.

After some googling, to activate swap partition we can use "swapon". So I type "sudo swapon -a /dev/hda6" (my swap partition is hda6). It said that there is something wrong in /dev/disk/by-uuid/
So I check at there using "ls-l"
This is the result:
total 0
lrwxrwxrwx 1 root root 10 2008-04-11 03:51 21d592f8-c644-4605-85a4-781e216cddb0 -> ../../hda6
lrwxrwxrwx 1 root root 10 2008-04-11 03:51 48AC1356AC133E3E -> ../../hda5
lrwxrwxrwx 1 root root 10 2008-04-11 03:51 5245c180-9a8b-4465-a8f8-d92902fc329a -> ../../hda7
lrwxrwxrwx 1 root root 10 2008-04-11 03:51 68FB-5937 -> ../../hda1
lrwxrwxrwx 1 root root 10 2008-04-11 03:51 8748fcad-6e66-4339-b046-14f1395765e3 -> ../../hda8
lrwxrwxrwx 1 root root 10 2008-04-11 03:51 af63a094-ec51-11dc-8244-d1cfae280f6f -> ../../hda9

And then I see the fstab to compare the swap. And what I found is ......

...
# /dev/hda6
UUID=9cc2b9d5-0b39-4724-82de-01e80ba5e6ed none swap sw 0 0
# /dev/hda8
UUID=dc9dcecf-bde9-487a-ae54-f7c204d6fefe none swap sw 0 0
....

The UUID variable is not same!!!. So I replace the value in fstab with the value from /dev/disk/by-uuid .And after I save the file, and open KSysGuard (shortcut : Ctrl+Esc), it detected swap is working.

Although I manage to activate the swap, but the reason why UUID value changed is a real mystery.

The second step I look the /etc/fstab file . And

Input Chinese Characters

2008-01-23T17:17:00.000-08:00

Here is a link to the how-to :

http://foolip.org/blog/2006/09/12/chinese-fonts-and-input-in-ubuntu/

To put it simple, you just need to type a few lines of command.

$ sudo aptitude install language-support-zh

This command to install the Chinese languange.

$ im-switch -s zh_CN

This creates a link in ~/.xinput.d/ for your current locale.

After a restart, you should be able to use chinese character input

Superkaramba and Compiz problem

2008-01-22T18:57:00.000-08:00

If you enable Compiz and run Superkaramba, you might encounter some problems. For example, the superkaramba themes only show in one Desktop (even you have choose "All Desktop"). When you "Show Desktop", all the themes will disappear. Or when you restart or log off and then return to session, the themes won't show, even when you see at Superkaramba it is "running". To fix it :
1. Activate Regex Matching! Otherwise Window Rules have no effect.
2. Go to Window Rules in Utility
Input these labels to its text field:
Below
class=Superkaramba & type=dock
Sticky
class=Superkaramba & type=dock
Non Minimizable Windows
class=Superkaramba & type=dock

The Below is to prevents superkaramba to be on top of other app. Sticky to let Superkaramba in all desktops. Non Minimizable Windows won't let your superkaramba disappear when you hit the show desktop button. But somehow it still disappear. But it is better, because it can be restored when you click show desktop button again.

Adept Installer Always Error

2008-01-20T19:09:00.001-08:00

Some users may encounter the problem when installing packages with Adept Installer. They always encounter message like this :

"There was an error commiting changes. Possibly there was a problem downloading some packages or the commit would break packages."

One of solution is, type :

sudo dpkg --configure -a
sudo apt-get install -f

Meaning of these steps:
sudo dpkg --configure -a

Reconfigure all (because we give -a) unpacked packages but unfigured packages are configured.
Configuring consists of the following steps:
1. Unpack the configuration files, and at the same time back up the old configuration files, so that they can be restored if something goes wrong.
2. Run postinst script, if provided by the package.

sudo apt-get install -f
Fix; attempt to correct a system with broken dependencies in place.
This option, when used with install/remove, can omit any packages to
permit APT to deduce a likely soltion. Any Package that are specified must
completly correct the problem.

Gameboy Advance Emulator

2008-01-09T07:26:00.000-08:00

To play gameboy advance games... you can use emulator. You may want to try visualboyadvance (vba). Once you have installed, you can run the gameboy games by type:
vba filename

the filename should be ROM files, like *.gba .

vba doesn't have GUI. But if you want GUI you can install vba express. This is GUI design for vba. And it is more easy for use. But for power user, you might found not all options included in vba express. One of them is there is no option for setting flash size(some games need to be set 128k to run). To see all options just type
vba

If you want to save the games, you may hold Shift + F1 , Shift + F2 until Shift + F10.
To load just press F1 or F2 or etc (until F10).
So there are 10 slots for you to save.
The default path for save game is at your home directory , in .vba directory(it is hidden)

Setting 2 IP in one NIC

2007-12-26T07:20:00.000-08:00

I have to set 2 IPs for my computer. The reason is simple one is for internet and another is for LAN. (I don't understand either why must 2 IPs). So there is no way I can set 2 IP in System Settings. I must manual edit the interfaces files in /etc/newtork/ .
I just have one ethernet card, so the file only have eth0. So in order to add the other IP, I use eth0:0 here is my interfaces file

auto lo
iface lo inet loopback
address 127.0.0.1
netmask 255.0.0.0

iface eth0 inet static
address xx.xx.xxx.xxx
netmask 255.255.255.252
gateway 27.227.27.254

auto eth0

auto eth0:0
iface eth0:0 inet static
address yy.yyy.yy.yyy
netmask 255.255.0.0

So the xx.xx.xxx.xx is my IP for internet, while yy.yyy.yy.yyy is for LAN. After edit it I restart using
/etc/init.d/networking restart
and I can access my network now (using samba)....

Autostart the Application

2007-12-25T07:57:00.000-08:00

In order to add application to start up, there are a few ways.
1. There are application shortcuts(*.desktop) in /usr/share/autostart/ . To edit, add or remove these shortcuts, you need root access.
2. There are also application shortcuts in your home directory ~/.kde/Autostart/ . This one you don't need root access to use it.
3. Install kde autostart package( name kcontrol-autostart in repository manager)

For me, it is better to configure autostart at /.kde/autostart because everything without root access is always safer.
If you have installed kcontrol-autostart package, then you can manage startup at kcontrol(labeled control center). I can't find the kcontrol at KDE menu, so I run application (Alt+F2) and type "kcontrol" (without quote). In Control Center go to KDE Components. And choose Autostart. We can add or remove any application at here.

Add Startup

2007-12-24T22:58:00.000-08:00

In order to add application to start up, there are a few ways.
1. There are application shortcuts(*.desktop) in /usr/share/autostart/ . To edit, add or remove these shortcuts, you need root access.
2. There are also application shortcuts in your home directory ~/.kde/Autostart/ . This one you don't need root access to use it.
3. Install kde autostart package( name kcontrol-autostart in repository manager)

I never use kcontrol-autostart. But I think it should be same as we add in the autostart directory. For me, it is better to configure autostart at /.kde/autostart because it only effect you.

Make OpenOffice Start Faster

2007-12-18T07:03:00.000-08:00

OpenOffice is quite slow when starting. Everybody knows it. Me too. So how to make it faster? Here some tips :
1. Go to Tools->Options->Memory
2. Reduce Numbers of step Undo. Mine is 20.
3. Graphics Cache , set Use for OpenOffice.org to 128 MB(if you have at least 512 mb)
4. Check OpenOffice.org Quickstarter (be sure to install the Quickstarter package names oooqs )
5. Uncheck Use a Java runtime environment in Tools->Options->Java

No Sound in Pidgin and aMSN

2007-12-15T23:27:00.000-08:00

I am using pidgin and aMSN for chatting. Pidgin is fine. But there is one thing I dislike until yesterday. My pidgin never sounds. So I try a few ways to force this application sounds.

Later I use command since all fail. So, here step by step:
1. Open your pidgin ( :P )
2. go to Tools -> Preferences -> Sounds
3. at Sound Methods choose : Command
4. on Sound Command type this :
aplay %s
5. Click close

Same with aMSN too. Mine never sounds since installed. So I try to change its command.
1. Preferences->Others->Sound Server
2. Check the "Use a different program"
3. then type :
aplay $sound
4. Click Save
5. Make sure "Sound Alarm" is checked. (Go to "Configure/Add/Remove Global Alarm"). Click "Ok"

That should fix the problem.

No stdio.h in Kubuntu?

2007-12-12T03:01:00.000-08:00

One day I just try learn C language and try to compile my just-made hello world program. And guests what? The gcc said I don't have stdio.h. So I think, I must install something. And what should I install. The answer is simple build-essential. Yes that's it.
Just type :
sudo apt-get install build-essential

Before installing it may ask you to insert Kubuntu installation disc. Just insert it.
After installing you can use most of standard library now.

If you want to install the man pages for development syntax. For example how to use shmget(share memory function), semget( semaphore function), printf( stdio function) and the others. You need to install a package names manpages-dev

You may try to install it via Adept Manager. Just find a package name manpages-dev

NOTE: for somebody who don't know what is gcc and stdio.h, let me explain a little.
GCC formerly is known as Gnu C Compiler. Later it changes become Gnu Compiler Collection. The reason is now GCC not only can compile C, but it also can compile other languanges.
GCC is a compiler that can compile a lot of languages. One of them is C Language( my favourite language after Mandarin ;) ) Stdio.h (stands for standard input and output) is one of standar library that a C Compiler must have( according to ANSI standard and ISO). Without stdio.h your program can't print anything to screen. That's why almost every C language code includes stdio.h (as far as I know).

No GCC in Kubuntu!?

2007-12-12T03:00:00.000-08:00

When first time after installing Kubuntu, I tried to compile my hello world program to test whether Kubuntu has compiler or not. Later I found that Kubuntu indeed has gcc (stands for Gnu Compiler Collection). But it stated "stdio.h not found". stdio(stands for Standard Input Output) is a very important header file for basic input output at C. Impossible there is no stdio.h file. So, it must be hasn't installed in my box.

After search for a while, I found what I want. I just need to install a package which contains the library. So I just need to type

apt-get install build-essential

Before installing it may ask you to insert Kubuntu installation disc. Just insert it.
After installing you can use most of standard library now.

If you want to install the man pages for development syntax. For example how to use shmget(share memory function), semget( semaphore function), printf( stdio function) and the others. You need to install a package names manpages-dev

You may try to install it via Adept Manager. Just find a package name manpages-dev

GCC formerly is known as Gnu C Compiler. Later it changes become Gnu Compiler Collection. The reason is now GCC not only can compile C, but it also can compile other languanges.

Be an Admin! (Part 2)

2007-12-11T20:28:00.001-08:00

Last time I wrote about System Administrator, now I will write about Network Administrator.

The position of network administrator is sometimes advertised as systems administrator, LAN administrator, network operations analyst, network technician or information systems administrator, but no matter what the exact job title, this IT professional is responsible for the day to day operations of the network infrastructure of the organization. Depending on the organization, this network infrastructure will consist of such elements as individual desktop PCs, specially designed thin clients or workstations, file servers, mail servers, application servers, backup servers and more. Network administrators are basically the network equivalent of system administrators: they maintain the hardware and software that comprises the network.

The Duty
So the tasks of network admin are troubleshooting day to day problems and unusual issues with networked equipment, and evaluating the need for upgrades or replacements of current computer hardware and software solutions beside installing and configuring new equipment (including desktop PCs and servers).

The Career Path
Career paths for network administrators can include moves into positions of greater responsibility, including management roles and other leadership positions.

The Salary
While salaries for such positions varies, experienced network administrators often earn $50,000 per year or more. While in www.itjobswatch states £33,359.

Requirements
Extensive knowledge of computer terms, microcomputer concepts, capabilities and hardware/software components, including operating systems, application software such as word processing, spreadsheets, databases, and graphics, servers, and connections for networks, modems, printers, and scanners, i.e., microcomputer associated components.
Basic knowledge in operating systems programs, maintenance, systems administration, and network systems
Beside, you might want to have certificate too. There are a lot of certification such as:
Microsoft Certifications(MCSA, MCSE), Linux Certifications(Linux+, LPIC level 1, LPIC level 2, RHCE, SCNA), Cisco Certification (CCNA) , Citrix Certification (CCA), Novel Certification (NetWare CNA), TruSecure Certification (TICSA), and many more..... ;)

Well those all about network administrator...

Be an Admin!

2007-12-10T19:00:00.000-08:00

Now I am interesting about the administrator. But, only little do I know what are admin doing, how to become an admin and what is good to become admin. So I try to search in internet and gather some information. Here are as far I got it.

There are several types of administrator according they job. There are network administrator, system administrator, database administrator and server administrator.

First: System Admin.
System Administrators are responsible for maintaining the computer systems of a company. Server management is a primary responsibility, and a System Administrator would be responsible for installing, maintaining and upgrading servers. They are also responsible for ensuring the servers are backed up, and that the server data is secure from unauthorized access. System administrators will also often perform light programming (usually scripting, which involves writing programs to automate tasks). They are member of an information technology department.

To be come a sysadmin require some skills, at least we must have computer skill, have knowledge of an operating systems and applications, as well as software and hardware troubleshooting. Just you know, many System Administrators do not have a formal education, they are self taught. But some of they may have a 4 year degree in Computer Science or Management Information Systems (MIS). Knowledge of business functions is also important, as is the ability to communicate with other employees in the company in both technical and non-technical roles. To progress to more senior roles, a system administrator should have some knowledge of project management.

What are the job descriptions of System Administrators?

A system administrator's responsibilities might include:

Performing routine audits of systems and software.
Performing backups.
Applying operating system updates, patches, and configuration changes.
Installing and configuring new hardware and software
Adding, removing, or updating user accounting information, resetting passwords, etc.
Answering technical queries.
Responsibility for security.
Responsibility for documenting the configuration of the system.
Troubleshooting any reported problems.
System performance tuning.
Insuring that the network infrastructure is up and running.

The Career Path of Sysadmin

System Administrators often promote to a more senior administrator role and then into a project management role. Strategic roles involving long term planning and company technology strategy, such MIS Manager or CIO (Chief Information Officer), may be a fit for those with the appropriate education and experience. Some System Administrators specialize in a certain area, such as security, and become experts in that particular area.

So who might hire system administrators

Some companies in IT field surely need them. Such as :
Microsoft Corporation
Sun Microsystems
Cisco Systems
Oracle Corporation
Apple Computers
Google
Yahoo

The Salary
Well, the salary is about £36,354 as average salary(taking from www.itjobswatch.co.uk) . While the minimum salary is £34,067

Well that's it about the system administrator. ;)

Case : Problem in SoundBlaster 5.1 soundcard

2007-12-09T17:36:00.000-08:00

My friend, Zai a.k.a Cloud just installed Kubuntu 7.10 few days ago. But strangely when we run live-cd, his speaker began to produce some noisy sound. (You know the sound when your tv or radio can't get signal). It started to sound in load screen.
We thought, it should be fine after install Kubuntu. Ow... ok...it was I thought.... So we installed it. But later it was revealed that I was wrong. The sound still persists. I began suspected that his pick-from-trash soundcard is out of order. (He insisted that the ex-owner put at there, not throwed at there and the soundcard is not rubbish!!)
Later, he found the solution. In KMix, he went to "Switches" tab. At there, he disabled "SB Live Analog/Digital Output jack". And immedeatly the noisy sound is vanished. We still unable to figure out the main cause of this problem. It still remain mystery...

Case closed.

Update :
Later I did googling, I found a few solutions that might be work. (I never test it, since my speaker is fine). Here is it..
- mute "AC97" in "Playback" tab.
- check "IEC95B Optical Raw" in "Switches" tab.
- uncheck "SB Live Analog/Digital Output jack" in "Switches" tab.
- turn off audio recording from "Capture" in "Recording" tab.

Install from compressed file (.tgz or .tar.gz)

2007-12-09T17:25:00.000-08:00

When we want to install program, we usually will use Adept Manager. Or maybe using syntax "apt-get install package_name.deb". If you got a installer in .tar , .tar.gz , or .tgz what will you do?

Here is the step:
$ untar xfvz nama.tgz #if the installer in .tgz form.

Enter to the directory. If the installer at Games directory, then type "cd Games"

$ ./configure
$ make
$ make install

What happend actually? Here, I quoted tutorial at internet.
Generally you would get Linux software in the tarball format (.tgz) This file has to be uncompressed into any directory using tar command. In case you download a new tarball by the name game.tgz, then you would have to type the following command

$ tar xfvz game.tgz

This would create a directory within the current directory and unzip all the files within that new directory. Once this is complete the installation instructions ask you to execute the 3 (now famous) commands : configure, make & make install. Most of the users do this and successfully install their softwares. But most of the newbies have no idea what this really does. The rest of the article shall explain the meaning of these 3 commands

Each software comes with a few files which are solely for the purpose of installation sake. One of them is the configure script. The user has to run the following command at the prompt

$ ./configure

The above command makes the shell run the script named ' configure ' which exists in the current directory. The configure script basically consists of many lines which are used to check some details about the machine on which the software is going to be installed. This script checks for lots of dependencies on your system. For the particular software to work properly, it may be requiring a lot of things to be existing on your machine already. When you run the configure script you would see a lot of output on the screen , each being some sort of question and a respective yes/no as the reply. If any of the major requirements are missing on your system, the configure script would exit and you cannot proceed with the installation, until you get those required things.

The main job of the configure script is to create a ' Makefile ' . This is a very important file for the installation process. Depending on the results of the tests (checks) that the configure script performed it would write down the various steps that need to be taken (while compiling the software) in the file named Makefile.

If you get no errors and the configure script runs successfully (if there is any error the last few lines of the output would glaringly be stating the error) then you can proceed with the next command which is

$ make

' make ' is actually a utility which exists on almost all Unix systems. For make utility to work it requires a file named Makefile in the same directory in which you run make. As we have seen the configure script's main job was to create a file named Makefile to be used with make utility. (Sometimes the Makefile is named as makefile also)

make would use the directions present in the Makefile and proceed with the installation. The Makefile indicates the sequence, that Linux must follow to build various components / sub-programs of your software. The sequence depends on the way the software is designed as well as many other factors.

The Makefile actually has a lot of labels (sort of names for different sections). Hence depending on what needs to be done the control would be passed to the different sections within the Makefile Or it is possible that at the end of one of the section there is a command to go to some next section.

Basically the make utility compiles all your program code and creates the executables. For particular section of the program to complete might require some other part of the code already ready, this is what the Makefile does. It sets the sequence for the events so that your program does not complain about missing dependencies.

One of the labels present in the Makefile happens to be named ' install ' .

If make ran successfully then you are almost done with the installation. Only the last step remains which is

$ make install

As indicated before make uses the file named Makefile in the same directory. When you run make without any parameters, the instruction in the Makefile begin executing from the start and as per the rules defined within the Makefile (particular sections of the code may execute after one another..thats why labels are used..to jump from one section to another). But when you run make with install as the parameter, the make utility searches for a label named install within the Makefile, and executes only that section of the Makefile.

The install section happens to be only a part where the executables and other required files created during the last step (i.e. make) are copied into the required final directories on your machine. E.g. the executable that the user runs may be copied to the /usr/local/bin so that all users are able to run the software. Similarly all the other files are also copied to the standard directories in Linux. Remember that when you ran make, all the executables were created in the temporary directory where you had unzipped your original tarball. So when you run make install, these executables are copied to the final directories.

Compiz and the problems

2007-12-09T16:31:00.000-08:00

In order to make your Kubuntu 3D effect, (such as Cube effect, 3d Switch tab, etc) without slowing down your computer, you can install Compiz fusion.

Compiz fusion, a "fusion" of Beryl and Compiz, is collection of plugins and a configuration system for the Compiz compositing window manager for the X Window System.

When the first time I try its effect, it is kinda amazing.... But later, I found something very wrong. Here are they :

-Shutdown & Restart button missing

You might also found your shutdown/restart button in log off is missing. And there was only log off. I found a lot of people experience this. In order to shutdown, they click log off and shutdown at there(there is menu shutdown and restart in logoff).
Later it was revealed, that the xserver-xgl who caused the shutdown and restart button missing. So you just need to uninstall this package. Just choose xserver-xgl at Adept Manager and uninstall it. Now you computer should back to normal. (Note : Even if you uninstall the Compiz, the button will not back to normal. You definetly must uninstall this package). Until now, my computer is still fine without that package. So I think it is safe.

-OpenOffice ruin everything!!
When you open OpenOffice, you might see your OpenOffice don't have frame. It is because of "Legacy Fullscreen Support" from Compiz that I think still imperfect. Just non-activate this option in setting(Utility->Workarounds). And when you open OpenOffice next time, it won't happend again.

-Suddenly Kwin crash.
I am not sure, is my Kwin crash or what. The crash handler dialog told me so. I am still cannot figure out, what cause this. But in the newest version (which is 0.6.0), I never encounter this problem anymore.
If you ever encountered, you might notice all the window frame was missing. Meaning there wasn't titlebar and you are unable to move to the window, close the window(with clicking the 'x' button at there) etc. When this happend to you, you need to reload the compiz, or you want it back to normal, open Run Application(Alt+F2) then type :
compiz --replace
--->for reload your compiz

kwin --replace
--->for reload the KDE desktop manager, this will switch back your Kubuntu back to normal.

Play Windows Games in Linux

2007-12-06T17:56:00.000-08:00

Since I am still newbie, I am not sure which is better for play game. There are some suggestions such as using Wine, Cedega or Vmware player. I personally only have used Wine.

Wine Is Not Emulator. Think of wine is a compability layer for running Windows program. So you can put some Windows dll files(library files) to your Wine in order to run some program. Well, not every programs can run well with Wine. For example Yahoo Messenger 8.x and Msn 8.x cannot sign in(although we can run the programs). But Warcraft III : Frozen Throne and Counter Strike can run perfectly on my Kubuntu box. At first the game run rather slow. Later it was solved by installing the driver.

Cedega (formerly known as WineX) is TransGaming Technologies' proprietary fork of Wine (from when the license of Wine wasn't the LGPL but the X11 license), which is designed specifically for running games written for Microsoft Windows under Linux.(quoted from Wikipedia). So I think it should be suitable for games. But since I never used it, so unable to confirm, is it better than Wine in playing games.

The last, is VmWare Player. I think I should search what is this exactly first. But I think it is Virtual PC.

Kubuntu 7.10

2007-12-06T03:13:00.000-08:00

Currently I am using Kubuntu Gutsy Gibbon. I am a newbie in Linux, but I will collect and research what I get about Kubuntu to post at here as my notes. Maybe some of them might be useful too.