Bambang P notes...

Disabling middle click paste and close in ubuntu 18.04 by enabling /etc/rc.local

2018-12-27T17:32:00.000-08:00

How to disable middle click button in ubuntu 18.04 by enabling /etc/rc.local

Create or edit/etc/rc.local file

#!/bin/bash xinput set-button-map 11 1 0 3 exit 0
Make sure it is executable
$sudo chmod 755 /etc/rc.local
Edit rc-local.service file
sudo vim /etc/systemd/system/rc-local.service
Add this section
[Install] WantedBy=multi-user.target
Enable the service
sudo systemctl enable rc-local

Postgresql 9.6 and Pgadmin3 trouble

2017-04-09T22:46:00.000-07:00

Yesterday, I updated my PostgreSQL to the latest version 9.6 from version 9.5.

The upgrade process went successfully, unfortunately pgadmin choked a little bit dealing with PostgreSQL 9.6, everytime we want to define primary key an error is thrown:

ERROR: column "amgettuple" does not exist
LINE 1: ...am WHERE EXISTS (SELECT 1 FROM pg_proc WHERE oid=amgettuple...

we can ignore this error and the primary key creation will succeed, however it is annoying.

My pgadmin was the latest version: pgadmin3 v 1.22.2

Visiting https://pgadmin.org/download/source.php reveals that this version is the final version and won't be supported anymore. We are encouraged to use pgadmin4 instead.

I then downloaded and installed pgadmin4, installation was a pain in ass but I succeeded got it installed. However, pgadmin4 was terribly very slow. It also got a problem with the function debugger. After function parameters entry, the debugger is showed, unfortunately it only shows a blank page. However, invoking the debugger via Setting Breakpoint menu runs well (...but slow). I would say pgadmin4 is not ready yet.

Fortunately, google search told that there is someone who forked the pgadmin3 project and continue to maintain it. In his website https://www.bigsql.org/pgadmin3/ only the Windows version are available. If you use linux like me, you have to compile your self.

Here is the steps I took to compile pgadmin3. I use ubuntu 12.04, if you use other distro please adjust accordingly.

Install the required packages:

$sudo apt-get install build-essential git libwxgtk2.8-dev libwxgtk2.8 libxml2 libxslt-dev python-sphinx
Create directory and git clone the source code

$git clone https://github.com/dimv36/pgadmin3.git
Make

$cd pgadmin3
$make
After make you can proceed installing with sudo make install, but as I had already have pgadmin3 package installed, I just copied the resulted binary overwriting the old one:

$sudo cp pgadmin/pgadmin3 `which pgadmin3`
Finished. Big thanks to Dmitri Voronin ( https://github.com/dimv36 ) for maintaining pgadmin3.

Install Sketchup 2017 64 bits on Linux Ubuntu 16.04 64 bits

2017-03-10T23:58:00.000-08:00

Install Sketchup 2017 64 bits on Linux Ubuntu 16.04 64 bits:

1.Enable 32 bit architecture:

$sudo dpkg --add-architecture i386

2. Set wine PPA

$sudo add-apt-repository ppa:wine/wine-builds

Update repository

$sudo apt-get update

3. Install wine newest staging branch version

$sudo apt-get install --install-recommends winehq-staging

4. Ensure we get a 64bits wine, edit file ~/.profile and locate for text:

export WINEARCH=

If the value is win64 you are good, if the value is win32 change it to win64. Save the file.

Ensure the environment variable also set to win64 by typing command:

$export WINEARCH=win64

5. Download winetricks:

$wget https://raw.githubusercontent.com/Winetricks/winetricks/master/src/winetricks

Don't forget to set the attribute so it is executable

$chmod +x winetricks

6. Run winetricks

$./winetricks

Inside winetricks:

Choose Select the default wineprefix, click OK

Choose Install a Windows DLL or component, click OK

Choose vcrun2015, click OK

...after vcrun2015 installation complete

Choose winecfg, click OK

Choose tab Applications, set Windows version to Windows 8.1

Choose tab Libraries, Add New override for library: mfc140u.dll

Click OK

Click Cancel to quit winetricks

7. Download Sketchup 2017 Make 64 bit from https://www.sketchup.com/download/all

8. From nautilus, locate file SketchUpMake-en-x64.exe, highlight the file, right click, Open with Archive Manager and then extract file SketchUp2017-x64.msi

If Archive Manager says "An error occured while loading the archive", you need to install 7z first.

$sudo apt-get install p7zip-full

9. From terminal run:

$wine explorer

10. Locate file SketchUp2017-x64.msi and double click to install.

11. In Destination folder change the installation folder to

C:\Program Files\SketchUp\SketchUp 2017\

Click Next and then Install.

12. If you want to use the Professional you need to install Microsoft .Net Framework 4.5.2 (Offline installer), download from here:

https://www.microsoft.com/en-us/download/details.aspx?id=42642

After download install the file NDP452-KB2901907-x86-x64-AllOS-ENU.exe

13. Enjoy Sketchup in linux.

POSTGRESQL: Dealing with 'current transaction is aborted, commands ignored until end of transaction block' in Lazarus/Delphi

2016-10-22T23:45:00.000-07:00

Scenario:

Programming Environment: Lazarus/Delphi

Database: PostgreSQL

DB Component: Zeos

Problem:

You have a form displaying a table content in a grid. It is a typical data form where user can insert, update or delete record.

When user inserting record which fails going through Table integriry constraints (foreign key, unique constraint, check constraints etc), postgresql will throw exception: current transaction is aborted, commands ignored until end of transaction block. After this, all operation is not possible except closing the form and losing all modification you might have done.

Solution:

Define events of the query component, FDBConnection is db the connection component.

BeforePost and BeforeDelete events:

Self.FDBConnection.ExecuteDirect( 'SAVEPOINT mysavepoint');

AfterPost and AfterDelete events:

Self.FDBConnection.ExecuteDirect( 'RELEASE SAVEPOINT mysavepoint');

OnPostError and OnDeleteError events:

Self.FDBConnection.ExecuteDirect( 'ROLLBACK TO SAVEPOINT mysavepoint');

Note: you can change mysavepoint with any valid identifier name.

NOTEPAD++ SOURCECOOKIFIER SETTING FOR CLIPPER LANGUAGE

2015-02-22T18:26:00.002-08:00

Notepad++ is a very excellent programmer editor for Windows. It has plugin system which enhances it's functionality. Sourcecookifier is a plugin I like very much, it is a simple plugin which shows the outline of your source code.

The screenshot below shows a pascal (delphi) source code. We can easily see the structure of the source code, and we can go to a particular method/function just by one click.

Sourcecookifier recognizes several programming languages, but it does not support Clipper language. Fortunately, it is very easy to add Clipper configure. Follow this step:

Click setting icon (the yellow gear icon) on the sourcecookiefier window.
Click Language Settings
On the setting form, type Clipper on the language box and click add.
Set the file extension setting, add .prg to the extenson box
On Tag Type choose any letter you like. Here I add “f” for “function” (any letter will be fine)
On Appearance box, you can write the description, choose Icon etc. It is not too important, I just put [function] in description and leave the other fields as it is.
Set the regular expression, fill the input and output as follow
Input: (^(FUNC.*)[ \t]*)(([a-zA-Z0-9_]+))
Output: \1
Clear the case sensitive box and click Add
Repeat step 5 to step 7 to define additional keyword regexes for static function, procedure, static procedure, create class and method. Here are the regexes:

static function: Input = (^(STAT.*)(FUNC.*)[ \t]*)(([a-zA-Z0-9_]+))
Output = \1
procedure: Input = (^(PROC.*)[ \t]*)(([a-zA-Z0-9_]+))
Output = \1
static procedure: Input = (^(STAT.*)(PROC.*)[ \t]*)(([a-zA-Z0-9_]+))
Output = \1
create class: Input = (^(CREA.*)(CLAS.*)[ \t]*)(([a-zA-Z0-9_]+))
Output = \1
method: Input = (^(METH.*)[ \t]*)(([a-zA-Z0-9_]+))
Output = \1
The result is like this.

It is not perfect yet, in the example above “METHOD Init(...” scanned as “METHOD Ini”, I still don't know how to resolve.

Install PCI Parallel card murah meriah di Linux.

2013-09-21T05:40:00.000-07:00

Baru-baru ini, parallel port onboard di salah satu komputer klienku rusak. Lalu dibelikan Parallel card PCI made in China yang murah meriah. Card ini tidak ada merknya cuma ada tulisannya PCI60806A dan cuma terdiri dari 1 IC :)

Tapi setelah dipasang ternyata parallel card ini tidak dikenali di ubuntu, sehingga kemarin terpaksa komputernya di bawa ke rumahku untuk opname. Anehnya, output dari perintah lspci -v mengatakan bahwa card ini adalah serial port:

03:00.0 Serial controller: Device 4651:7073 (rev 10) (prog-if 02 [16550])

Subsystem: Device 4651:7073

Flags: medium devsel, IRQ 20

I/O ports at df00 [size=8]

I/O ports at de00 [size=8]

Kernel driver in use: serial

Dari hasil googling ternyata ini memang kasus umum pada pci parallel card murah meriah, card-card ini sebenarnya mempunyai 2 fungsi interface, serial interface dan parallel interface. I/O port pertama (df00) adalah port untuk Serial Port sedangkan port kedua (de00) adalah untuk Parallel port.

Sekarang kita coba gunakan driver parallel port linux (partport_pc) untuk mengakses port 0xde00 di atas.

Unload terlebih dahulu driver lp dan parport_pc
# rmmod lp
# rmmod parport_pc
Reload parport_pc dengan io address de00
# cd /lib/modules/`uname -r`/kernel/drivers/parport
# insmod parport_pc.ko io=0xde00
Reload driver lp
# cd /lib/modules/`uname -r`/kernel/drivers/char
# insmod lp.ko
Check dengan dmesg
# dmesg | grep parport
dan ini outputnya:
[ 10.650355] parport0: PC-style at 0xde00, irq -227213512 [PCSPP,TRISTATE]
[ 10.650362] parport0: irq -227213512 in use, resorting to polled operation
[ 10.736222] lp0: using parport0 (polling).

Masalahnya, setting ini tidak permanen, artinya jika direboot akan kembali ke kondisi semula. Untuk itu kita bisa membuat initialization script yang bisa diletakkan di /etc/init.d/

Tetapi solusi yang lebih baik adalah dengan membuat konfigurasi di directory /etc/modprobe.d, buat sebuah file dengan sembarang nama tapi extensionnya .conf di directory tersebut. Isi file tsb. adalah:

options parport_pc io=0xde00

Maka setiap kali komputer booting, driver parallel port akan diload dengan option di atas.

Install Windows Printer Fuji Xerox DocuPrint P205 b di Ubuntu

2013-09-02T21:26:00.000-07:00

Kemarin ada yang baik hati memberikan aku printer laser Fuji Xerox type DocPrint P205b. Masalahnya, printing system di Ubuntu (CUPS) tidak ada driver untuk printer ini. Situs Fuji Xerox pun (http://www.fujixeroxprinters.com.au/en/Downloads.aspx?product=9933) tidak menyediakan printer driver untuk linux, karena ternyata printer ini adalah GDI printer.

GDI printer biasanya merupakan printer murah meriah, karena dia tidak mempunyai 'otak' untuk memproses image (rasterize). Pemrosesan image diserahkan ke operating system. Oleh karena itu printer-printer semacam ini biasanya hanya bisa dipakai di Windows saja.

Namun, dunia linux benar-benar menakjubkan – hampir tidak ada yang mustahil di linux. Setelah searching di internet, akhirnya aku menemukan sebuah situs yang menyediakan driver untuk printer ini, namun untuk menginstallnya tidak sekedar mengcopy file drivernya (.ppd) saja. Silahkan cek http://foo2hbpl.rkkda.com/ .

Di bawah ini adalah langkah-langkah untuk menginstallnya di Ubuntu. Untuk distro-distro lain silahkan ikuti petunjuk di situs tsb:

Download source dari package foo2zjs dari http://foo2zjs.rkkda.com/foo2zjs.tar.gz. Di ubuntu, sebenarnya package ini sudah terinstall, namun kita tidak dapat memakainya.
Extract:
$tar zxf foo2zjs.tar.gz
Uninstall package foo2zjs bawaan ubuntu:
$cd foo2zjs
$make uninstall
Uninstall package system-config-printer-udev:
$sudo apt-get remove system-config-printer-udev
Install dependencies yang dibutuhkan dan compile:
$sudo apt-get install build-essential tix foomatic-filters groff dc
$make
Install package foo2zjs-nya:
$sudo make install install-hotplug cups
Setelah langkah ini kita bisa menginstall driver printernya. Di komputer penulis, install tidak bisa dijalankan lewat menu Install printer seperti biasa, namun harus lewat web interface.
Hubungkan kabel USB printer ke komputer dan nyalakan printer.
Buka browser anda dan buka web interface dari CUPS: https://127.0.0.1:631
Klik Menu Administration, lalu klik Add Printer. Pilih printernya lalu ikuti sampai langkah di mana kita diminta memilih drivernya. Pada langkah ini, klik “Provide a PPD file” dan arahkan filenya ke /usr/share/cups/model/Fuji_Xerox-DocuPrint_P205.ppd.gz
Selesai, printer bisa digunakan.

UPDATE: ubuntu 14.04 bisa mengenali printer ini out of box dengan baik tanpa harus menjalankan langkah-langkah di atas

Creating custom build wine deb package

2012-01-28T12:12:00.000-08:00

In one of my projects, I need to install custom build of wine to several computers running ubuntu.
Hence, I had to get the sources, apply the patch files and then compile the source. Doing this for 1 computer is okay, however repeating this to several computers is a huge waste of time.

The solution is compiling once and then build a debian package (*.deb), so for the other computers we just install the debian package file. Fortunately, making a debian package is very-very easy. Here is what I did:

Install wine recommended packages:
$ wget http://winezeug.googlecode.com/svn/trunk/install-wine-deps.sh $ chmod 755 install-wine-deps.sh $ sudo ./install-wine-deps.sh
Install checkinstall:
$ sudo apt-get install checkinstall
Get the wine source:
$ wget http://ibiblio.org/pub/linux/system/emulators/wine/wine-1.3.38.tar.bz2 $ tar -xf wine-1.3.38.tar.bz2
Patch the wine sources
Configure and compile:
$ cd wine-1.4-rc1
$ ./configure
Create the deb file with checkinstall:
In this step, instead of run sudo make install, we run checkinstall to make the .deb file:
$ sudo checkinstall
checkinstall will present some parameter. Modify the parameters as you like and then press ENTER to continue. At the end of the process, wine will be installed in your system and as a bonus you will have a .deb file which can be installed on other computers without the tedious process of compiling.

Merge several pdfs in ubuntu

2012-01-14T10:23:00.000-08:00

Some times we need to merge several pdf files into 1 pdf file. Fortunately, it is very easy to do it in ubuntu. For instance, I have 2 pdf files: proposal_rpi.pdf and program_qc.pdf.

Here is how I merge these 2 files into 1 pdf file: proposal_jan_15_2012.pdf:


bambang@bambang-notebook:~$ gs -dNOPAUSE -sDEVICE=pdfwrite -sOUTPUTFILE=proposal_jan_15_2012.pdf -dBATCH proposal_rpi.pdf program_qc.pdf

Tip: Recompiling PHP under linux

2012-01-11T19:23:00.000-08:00

There is a problem if we install PHP from source, i.e: when we need to recompile due to a new version we should reapply the old configure parameter. Forgetting to enable some features often means break our web application which depends to the feature, however it is also hard memorizing what parameters we passed to the configure command as we do not often compiling the PHP. Fortunately, there is an easy way. Here it goes:

Download the newest php source, here is the newest version (5.3.9) as I wrote this blog:
http://www.php.net/get/php-5.3.9.tar.bz2/from/a/mirror

Extract the php source:
bambang@bambang-notebook:~/Downloads/php$ tar -xf php-5.3.9.tar.gz bambang@bambang-notebook:~/Downloads/php$ cd php-5.3.9 bambang@bambang-notebook:~/Downloads/php/php-5.3.9$

Write a phpinfo.php to your web server document folder. The content of the script:
<html> <head> </head> <body> <?php echo phpinfo(); ?> </body> </html>
Open the phpinfo.php above in your browser:

Notice the configure command on the third row, block and copy the configure command

Go back to your terminal in the step 2, and paste the command and press enter:
bambang@bambang-notebook:~/Downloads/php/php-5.3.9$ './configure' '--with-apxs2=/usr/bin/apxs2' '--with-interbase=/opt/firebird' '--enable-sockets' '--with-pear' '--with-gd' '--with-mysql=/usr/bin/mysql_config' '--with-mysqli=mysqlnd' '--with-pdo-mysql=mysqlnd' '--enable-soap' '--enable-libxml' '--enable-calendar' '--with-pdo-firebird=/opt/firebird'
After this step, you simply run make and sudo make install to upgrade your php.

HTML <textarea> maxlength problem

2011-12-07T23:33:00.001-08:00

We can limit the maximum characters in <input> with <maxlength> attribute. However it is not possible to do the same thing with <textarea>. This will be a problem if value of the <textarea> will be stored into database table and the length of the user input exceeds the field's length, either the value will be truncated or your database will throw an error to you.

Fortunately, a little jquery script can help here:

<html>
<head>

</head>

<body>

<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript">
$(document).ready
(
 function()
 {
  $("textarea[maxlength]").keypress
  (
   function()
   {
    var maxlength = $(this).attr("maxlength");
    if ( this.value.length > maxlength )
    {
     this.value = this.value.substring(0,maxlength-1);
    }    
   }
  )
 }
)
</script>

<form>
This text box is limited to 5 chars <textarea maxlength="5"></textarea><br>
This text box is not limited <textarea></textarea>
</form>

</body>

</html>

Debugging php application with xdebug, netbeans and Google Chrome

2011-12-06T22:45:00.001-08:00

Debugging PHP application is a pain. When we get problems, we often to use var_dump() or die() in various location to inspect the variables and then clean them again once the problem is solved. Fortunately, there is a piece of software called xdebug which can tremendously help us debugging php code. This article is about using xdebug in linux environment.

What we need:
- A working apache2 web server with PHP
- Netbeans: an excellent IDE for writing PHP application
- xdebug
I assume you already have the first two.

Install xdebug, open linux terminal, change to root and install xdebug with command (pecl install debug). See below

bambang@bambang-notebook:~$ sudo su
[sudo] password for bambang: 
root@bambang-notebook:/home/bambang#pecl install xdebug
downloading xdebug-2.1.2.tar ...
Starting to download xdebug-2.1.2.tar (Unknown size)
.................................done: 1,340,416 bytes
66 source files, building
running: phpize
Configuring for:
PHP Api Version:         20090626
Zend Module Api No:      20090626
Zend Extension Api No:   220090626
.....
..... 
......
Build process completed successfully
Installing '/usr/local/lib/php/extensions/no-debug-non-zts-20090626/xdebug.so'
install ok: channel://pecl.php.net/xdebug-2.1.2
configuration option "php_ini" is not set to php.ini location
You should add "extension=xdebug.so" to php.ini

Note where the xdebug.so is installed in the line Installing '/usr/local/lib/php/extensions/no-debug-non-zts-20090626/xdebug.so'

Add these lines to your php.ini. In my case /usr/local/lib/php.ini.

zend_extension="/usr/local/lib/php/extensions/no-debug-non-zts-20090626/xdebug.so"
xdebug.remote_enable=on
xdebug.remote_log="/var/log/xdebug.log"
xdebug.remote_host=localhost
xdebug.remote_handler=dbgp
xdebug.remote_port=9000

Restart apache

root@bambang-notebook:/home/bambang# /etc/init.d/apache2 restart
 * Restarting web server apache2                                                 ... waiting                                                             [ OK ]
root@bambang-notebook:/home/bambang#

Write a phpinfo.php page in your web directory like this:

<html>
<head>
</head>
<body>
<?php echo phpinfo(); ?>
</body>
</html>

Open the phpinfo.php in your browser and check whether the xdebug is successfully installed.
Now go to Netbeans and navigate through menu Tools->Option->PHP and make sure the Debugger port is the same with what we set in the php.ini above. I clear Stop at First Line check mark, but it is okay if you let it checked. If it is checked, the debugger will stop at first php statement. But I only want it stops on break point.

Open your chrome, goto https://chrome.google.com/webstore/detail/eadndfjplgieldjbigjakmdgkmoaaaoc and install the xdebug helper.
Now we are ready to debug, in this example I'll debug my CodeIgniter application. First I open one of my controller: daftar_negara.php and place a breakpoint in line 11 by clicking the line number or press ctrl-f8.
Still inside Netbeans run the debugger by clicking menu Debug->Debug Project or clicking the debug icon in the netbeans taskbar like (see the image below):

The debugger will launch our project in chrome. Now we need to activate chrome xdebug helper, click the xhelper debug icon in right end of the address bar until it turns to green.
Now press F5 (refresh), xdebug will stop the execution on our breakpoint and switch to our neatbeans:

Now, we can step over, step info etc. via netbeans debugger tool bar, of course you can also use the shortcut key (F8,F7 etc):

We can also inspect the variable values in the window below the code window:

From here, I am sure you can figure the rest yourself. Happy bug hunting!

Web app: move to next field with enter ala dos application

2011-12-06T09:08:00.001-08:00

This is a little experiment on how to use enter as a mean to move to the next input field in web application ala dos application. We need jquery here. Here we simply trap the enter key with keypress event.

Inside the event, we check the control tabIndex. Actually, the html elements have tabIndex property, unfortunately (at least in my case with google chrome) the value always 0, so we need a helper funtion myTabPosition which simply scan the parent's child node until it find itself name.
After we have the tab index, we simply focus to the next sibling.

Here is my solution:

<html>
<head>

</head>

<body>

<script type="text/javascript" src="jquery.js"></script>

<script type="text/javascript">
$(document).ready
(
 function()
 {
  $(".ala_desktop").keypress
  (
   function(event)
   {
    if (event.which==13)
    {
     i = myTabPosition(this) + 1;
     nxt=this.form.elements[i];
     nxt.focus();
     nxt.select();
     return false;
    }
    return true;   
   }
  )
 }
)

function myTabPosition( o )
{
 var MyName = o.name;
 var MyParent = o.form;
 var i;
 var retval = -1;
 for (i = 0 ; i < MyParent.elements.length - 1 ; i++ )
 {
  if ( MyParent.elements[i].name == MyName )
  {
   retval = i;
   break;
  }
 }
 return retval;
}
</script>

<form name="coba">
Name : <input type="text" name="Name" id="Name" class="ala_desktop"><br>
Address : <input type="text" name="Address" id="Address" class="ala_desktop"><br>
City : <input type="text" name="City" id="City" class="ala_desktop">

</form>

</body>

</html>

HTML <input> tips - 01

2011-12-04T00:56:00.001-08:00

Beberapa tips yang berguna untuk penggunaan <input> pada html.

Membatasi jumlah character maksimal yang boleh diinput.
Gunakan attribute maxlength. Contoh:

<html>
<head>
</head>

<body>
Input ini hanya dibatasi 5 character saja <input type="text" maxlength="5">
</body>

</html>

Memaksa semua input ke huruf besar atau huruf kecil.
Untuk hal ini kita harus menggunakan CSS property text-transform. Untuk memaksa semua input ke huruf besar gunakan text-transform:uppercase, untuk ke huruf kecil gunakan text-transform:lowercase. Namun harus diperhatikan bahwa CSS hanya merubah tampilan saja, tetapi value dari text box itu sendiri tetap. Semisal kita mengketik kata 'semarang' dalam huruf kecil, dengan text-transform:uppercase yang ditampilkan adalah 'SEMARANG', tetapi value dari <input> tetap 'semarang' dalam huruf kecil. Untuk memaksa value juga berubah ke huruf besar, kita harus mengkombinasikan css dengan jquery script yang mentrap event blur. Dalam hal ini kita memerlukan jquery, jika di komputer anda belum terinstall download terlebih dahulu jquery versi terbaru di http://docs.jquery.com/Downloading_jQuery.
Nama file hasil download jQuery mengandung version number dan jenis script yang kita download (minified atau compressed). Copykan file tsb. ke web directory kita dan rename filenya menjadi jquery.js.

Contoh:
```
<html>
<head>
<style type="text/css">
input.hurufbesar {
text-transform:uppercase
}
</style>

<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript">
$(document).ready
(
 function()
 {
  $('input.hurufbesar').blur
  (
   function()
   {
    this.value = this.value.toUpperCase();
   }
  )
 }
)

function CheckValue()
{
 alert( "Value yang diketik adalah :" + document.getElementById('inputan').value );
}
</script>

</head>

<body>
Input ini dalam huruf besar semua <input type="text" class="hurufbesar" id="inputan">

<input type="button" value="Check" onclick="javascript:CheckValue()">

</body>

</html>
```
Membatasi hanya angka saja yang boleh diinput.
Untuk keperluan ini kita bisa menggunakan jQuery.
Selanjutnya kita buat sebuah function yang akan dijalankan pada waktu terjadi event keypress pada tag <input> yang mempunyai class angkasaja sbb:
```
$(document).ready
(
 function()
 {
  $("input.angkasaja").keypress
  (
   function( event )
   {
    return ( event.which >= 48 && event.which <= 57 );
   }
  )
 }
)
```
Code snippet di atas, intinya adalah bahwa setiap terjadi event keypress (tombol ditekan) akan dilakukan pengecekan apakah keycode dari tombol yang ditekan ada di antara 48 (ascii code dari angka 0) dan 57 (ascii code dari angka 9), apabila ya event functionnya akan mereturn TRUE artinya keypress diaccept, tapi bila tidak event functionnya akan mereturn FALSE artinya inputan ditolak.

Selanjutnya, untuk semua <input> di mana kita menghendaki bahwa yang bisa diinput hanya angka saja, cukup kita berikan class angkasaja

Contoh:
```
<html>
<head>
<script type="text/javascript" src="jquery.js"></script>
</head>

<script type="text/javascript">
$(document).ready
(
 function()
 {
  $("input.angkasaja").keypress
  (
   function( event )
   {
    return ( event.which >= 48 && event.which <= 57 );
   }
  )
 }
)
</script>

<body>
Hanya angka yang bisa diinput <input type="text" class="angkasaja">
</body>

</html>
```

Pada seri berikutnya kita akan bahas bagaimana menginput angka dengan separator ribuan dan desimal dan bagaimana kita bisa menginput data tanggal dengan mengklik kalender yang akan ditampilkan.
Semoga membantu

Debug javascript dengan Google Chrome

2011-12-02T03:01:00.001-08:00

Buat halaman html yang akan dibuat. Contoh:
hapusaja.html

<html>
<head>
</head>
<body>

<script type="text/javascript">

function Sajikan()
{
 Sel = document.getElementById( "PILIHAN" );
 alert( "Mangga dahar " + Sel.options[ Sel.selectedIndex].value );
}

</script>

Mau buah apa? 
<select id="PILIHAN" onclick="Sajikan()">
<option value="Gedhang">Pisang</option>
<option value="Kates">Pepaya</option>
<option value="Pelem">Mangga</option>
</select>


</body>

</html>

Buka di Google Chrome
Aktifkan debugger dengan klik kanan lalu klik 'Inspect Element'
Layar google chrome akan terbagi menjadi 2 bagian, bagian bawah ada windows untuk melihat elemen-elemen halaman page. Atur proporsi bagian atas dan bagian bawah dengan mendrag pembatas window ke atas atau ke bawah.
Klik Script
Klik baris 11 untuk meletakkan break point di baris tsb.
Sekarang pada pilihan 'Mau buah apa?', pilih salah satu buah:
Setelah pilihan buah diklik, maka debugger akan berhenti pada baris 11. Klik F10 untuk 'step over next function call', atau F11 untuk 'step into next function call'.

Catatan: Tidak seperti firefox anda tidak perlu menginstall addon tambahan apapun pada google chrome untuk fasilitas debugging ini.

Menginstall VoIP di Nokia E51

2011-11-08T17:05:00.000-08:00

VoIP (Voice over IP) adalah solusi koneksi telpon lewat Internet. Pada suatu jaringan VoIP ada sebuah komputer yang berfungsi sebagai Sentral Telpon atau Operator, komputer ini di sebut sebagai Server. Sedangkan pesawat-pesawat telpon pelanggannya berupa komputer atau perangkat-perangkat lain (termasuk smartphone) yang terhubung dengan internet.

Salah satu server VoIP indonesia adalah http://voiprakyat.or.id yang disponsori oleh bapak Onno Purbo. VoIPRakyat ini dibuat dari rakyat Indonesia untuk rakyat Indonesia alias gratis.

Baru-baru ini, aku barusan pasang wifi router di rumah. Harga router wifi sekarang sudah murah, aku beli DLink type DIR-600 seharga Rp 235 ribu rupiah dan itupun agak kemahalan karena begitu selesai beli aku check harganya di bhineka.com cuma Rp 218 ribu he..he... Kebetulan aku punya HPku adalah nokia E51 yang mempunyai fasilitas wifi dan ada fitur Internet Telephone, jadi aku pikir tentunya HP ini bisa dimanfaatkan untuk voip dan ternyata memang bisa he..he...Berikut langkah-langkahnya:

1. Registrasi

Daftar dulu untuk mendapatkan nomor telpon di voiprakyat lewat http://voiprakyat.or.id/?inc=signup&op=user , setelah pendaftaran berhasil anda akan mendapatkan voip id dan nomor telpon. Nomor telpon ini juga akan dikirim ke email anda untuk arsipnya. Di bawah ini adalah email konfirmasi pendaftaranku:

=== 8< =========

Halo Bambang Pranoto

Selamat datang di VoIP Rakyat.

Di bawah ini adalah account ID dan password anda yang dapat anda gunakan untuk login ke VoIP Rakyat baik melalui website http://www.voiprakyat.or.id atau dengan VoIP Rakyat Communicator dan SIP/IAX2 softphone lainnya.

VoIP ID : nnnnnn (berupa 6 digit angka)

IM ID : bpranoto

Password : *****

Nomor telepon VoIP anda adalah : nnnnnn (sama dengan VoIP ID di atas)

Nomor lengkap telepon VoIP anda adalah : +62 848 1001 nnnnnn (tanpa spasi)

SIP proxy atau IAX gateway kami adalah : voiprakyat.or.id

IM server kami adalah: voiprakyat.or.id

Gunakan IM ID sebagai Account ID anda untuk login ke IM server voiprakyat.or.id menggunakan VoIP Rakyat Communicator.

Summary:

SIP address anda : nnnnnnn@voiprakyat.or.id

XMPP ID/JID dan email anda : bpranoto@voiprakyat.or.id

Salam hangat,

VoIP Rakyat Development Team.

=== 8< =========

Informasi penting di sini adalah: VoIP ID, password dan alamat server yaitu voiprakyat.or.id

2. Konfigurasi SIP di Nokia E51

SIP (Session Initiation Protocol) adalah protocol yang dipergunakan untuk VoIP

Akses lewat Menu => Tools => Settings => Connection => SIP Settings

Option -> Add new -> Use Default Profile

Isikan data-datanya sbb:

Profile name : voiprakyat atau apa saja terserah anda

Service profile: IETF

Default Access Point: pilih salah satu dari access point yang ada

Public Username: sip:nnnnnn@voiprakyat.or.id (nnnnnn adalah VoIP ID anda, lihat step 1 )

User compression: No

Registration: When needed

Use Security: No

Proxy Server: (tidak usah diset, atau set sesuai kebutuhan)

Registrar Server:

Registrar Server address: sip:voiprakyat.or.id

Realm: voiprakyat.or.id

Username: nnnnnn (nnnnnn adalah VoIP ID anda dari point 1)

Password: ****** (sesuai password yang anda dapat dari point 1 )

Transport Type: UDP

Port: 5060

Konfigurasi SIP selesai.

3. Konfigurasi Internet Tel di Nokia E51

Akses lewat Menu => Tools => Settings => Connection => Internet tel.

Option -> New Profile

Name -> VoIPRakyat atau terserah anda

SIP Profiles -> VoIPRakyat (sesuai dengan yang anda set di poin 2)

4.Cara menggunakan panggilan voip

Untuk dapat melakukan panggilan VoIP pastikan ada koneksi Internet tersedia di HP anda.

Lewat home screen, tekan nomor yang akan dipanggil (contoh: 901 nomor test voiprakyat), jangan tekan tombol dial (warna hijau) tapi tekan Option -> Call -> Voice Call -> Internet Call

Untuk menyimpan di Daftar Kontak, simpan nomor telpon di field Internet telephone dengan format nomor seperti ini: 901@voiprakyat.or.id

Untuk membuat panggilan lewat Daftar Kontak, buka record kontak yang akan dihubungi, sorot Internet telephone kemudian tekan tombol dial (warna hijau).

Yang disayangkan, saat ini belum ada konektifiti antara voiprakyat dengan nomor telpon PSTN dan cellular sehingga kita hanya bisa saling berhubungan antara nomor voiprakyat saja.

Besok aku akan coba register dan install di BB istriku. Buat teman-teman (ma'af hanya bagi yang benar-benar kenal sama aku) yang sudah mencoba dan berhasil silahkan kirim message untuk nomor telpon voipku.

Recovering broken ubuntu partition

2011-10-29T00:23:00.000-07:00

Recently, one of my client's computer (Ubuntu 10.10) refused to boot. Instead of booting the operating system it fell down to grub rescue prompt. This indicated that grub could not find its configuration file and it meant the partition table was corrupted :(.

Fortunately, I finally succeeded repairing the system. What I learned from this experience is that ext file system is such a wonderful system which enabling partition recovery.

These are steps I took, unfortunately there were no screenshots (forgot to take):

Boot with Ubuntu live CD. The booting seemed took time forever because it tried to access the broken partition, but eventually the live session was up.

Open terminal, became root and checked whether the partition was still there.


#fdisk -l

Fortunately, fdisk still list the hard disk partition.

Try to repair with e2fsck.


#e2fsck -C 0 -v /dev/sda1

-C 0: means the completion information will be written in file descriptor 0 which is our console.
-v: verbose

Unfortunately, this step failed.

After some googling research, I knew that ext file system save its meta data structure in what is called "Superblock" and fortunately ext file system have several Superblocks, so if one superblock is failed we can recover from the other superblock. Now, my problem was find a way to query the superblocks. A way to query the superblock is with dumpe2fs


# dumpe2fs /dev/sda1 | grep -i superblock

Unfortunately, this step also failed. dumpe2fs could not read partition /dev/sda1

Next step, I tried testdisk. You can read how to use testdisk here: http://www.howtogeek.com/howto/15761/recover-data-like-a-forensics-expert-using-an-ubuntu-live-cd/. Unfortunately, when testdisk "Analyze" function also failed to recover the partition. Its automatic search algorithm report that what it found were ntfs partitions which obviously wrong :)

I then explored testdisk Advanced menu (File system utils). I found there was a facility to locate the superblock backups. I run this menu and fortunately it found all the superblock backups. Testdisk wrote all the findings in testdisk.log file so we didn't have to take the note manually.

Quit running e2fsck again but this time with -b (use alternative superblock) option.


#e2fsck -b nnn  -C 0 -v -p -y /dev/sda1

replace nnn with one of the superblock backup found by testdisk in the above step. Look in testdisk.log

This time e2fsck succeeded repairing the partition. I rebooted the computer, took out the live cd and the computer came to life again.

View pdf document inline in firefox linux

2010-06-28T20:05:00.000-07:00

In my bus ticketing web application, tickets are generated in form of pdf file. The problem is firefox (currently version 3.6.6) is not designed to display pdf file in its browser window out of the box, we need to install a plugin.

The first obvious option is to install adobe acrobat reader for linux which includes firefox plugin (can be freely downloaded from Adobe web site). However, there are some problems:

It is huge!
Seems there are some memory leaks (firefox 3,6.3 and acrobat reader 9.3.2), after some time it only displays white blank page. You need to restart firefox to cure it. I don't know whether the problem is in acrobat or firefox.

Fortunately, for Ubuntu, we still have another option:

Install mozzplugger and xpdf-reader:
$ sudo apt-get install mozplugger xpdf

Edit mozzplugger configuration file:
$ sudo vim /etc/mozpluggerrc

Find this line:
text/x-pdf:pdf:PDF file

Replace the blocks below that line to:
repeat noisy swallow(Xpdf) fill: xpdf "$file" repeat noisy swallow(evince) fill: evice "$file" ACROREAD() repeat noisy swallow(okular) fill: okular "$file" GV() repeat noisy fill exits: xpdf "$file"
Save the file
Restart firefox
Done. And here is a screen shot:

Installing wine on Ubuntu 9.10 from source

2009-11-16T07:24:00.000-08:00

I just upgraded my ubuntu 9.04 to ubuntu 9.10.

Before recompiling wine, we needed to install all the dependencies.

I grabbed the newest dependencies installation script from http://winezeug.googlecode.com/svn/trunk/install-wine-deps.sh

However, when I ran it, it stopped with an error:


Reading package lists... Done
Building dependency tree       
Reading state information... Done
Package libcupsys2-dev is a virtual package provided by:
  libcups2-dev 1.4.1-5ubuntu2.1
You should explicitly select one to install.
E: Package libcupsys2-dev has no installation candidate

From the error message, the solution is clear, edit the script and replace libcupsys2-dev with libcups2-dev

... and we can enjoy the wine again now

Ubuntu 9.10 hamachi problem

2009-11-14T19:20:00.000-08:00

I just installed Ubuntu 9.10 on a fresh new computer for a client.

For this particular computer I install hamachi. Unfortunately, when run it only displayed 'Killed' in console and then a crash report notification appeared on the notification panel.

After some googling, it turned that this new ubuntu doesn't like UPX packed application and unfortunately hamachi for linux (version hamachi-lnx-0.9.9.9-20) is one of it.

The solution is:

Install upx uncompressor:
$sudo apt-get install upx-ucl
Unpack hamachi (assuming hamachi is installed in /usr/bin):
$ sudo upx -d hamachi

After that, hamachi ran fine. This solution is also applied for other UPX packed applications. Hopefully, Ubuntu fixes this upx packed application problem which will be the best solution.

Cara mendownload video youtube yang tidak dapat didownload....

2009-09-05T11:59:00.001-07:00

Video-video di youtube.com tidak dapat didownload secara langsung, tetapi ada beberapa situs-situs dan program-program utility termasuk addon Mozila firefox dan Widget dari Opera yang memungkinkan kita mendownload video dari youtube.

Namun beberapa video tidak dapat didownload dengan program-program khusus di atas. Kelihatannya youtube melakukan proteksi sehingga beberapa video hanya dapat dimainkan tetapi tidak dapat didownload. Sebagai contoh: http://www.youtube.com/watch?v=_fgURJZebqc

Lalu bagaimana cara kita mendownload video-video yang tidak dapat didownload tersebut?

Apapun proteksi yang dilakukan youtube, sebenarnya komputer kita telah mendownload file video tersebut. Kalau tidak, bagaimana browser kita bisa memainkan video tsb? Jadi kuncinya adalah bagaimana menemukan file yang telah didownload oleh browser kita tsb. Ikuti langkah-langkah ini.

File-file video dari youtube adalah dalam format file .flv, maka pertama-tama kita harus mempunyai player dari file flv. Silahkan search di google player-player yang bisa memainkan file flv, ada banyak dan rasanya semua merupakan freeware yang dapat didownload gratis.
Buka youtube di browser kita dan nikmati videonya sampai selesai.
Tunggu video sampai tuntas dimainkan, lalu cari direktori cache dari browser kita. Untuk Opera direktori tempat browser menyimpan file-file yang didonwload dapat dilihat dengan mengetikan di address barnya opera:about, untuk Firefox kita dapat melihatnya dengan mengetikkan about:cache di address barnya. Sorot textnya dan kemudian copy ke buffer.
Buka Windows Explorer atau My Computer dan Paste di address bar lalu tekan Enter.
Selanjutnya Klik View -> Details dan kemudian View -> Arrange Icons by -> Size dan kemudian ulangi sekali lagi View -> Arrange Icons by -> Size. Setelah ini, file-file yang ada di direktori tsb. akan ditampilkan dari ukurannya yang paling besar ke paling kecil.
Dari Size dan Date Modifiednya, kita tahu bahwa (kemungkinan besar) file yang paling atas adalah file video yang kita cari. Copykan file tsb. ke folder yang kita kehendaki, rename dan berikan extension .flv Pada contoh ini, file yang aku download aku rename menjadi file origami_cow.flv
Buka file origami_cow.flv tersebut di flv player kita.

Problem installing MySQL 5.1.37 on Windows

2009-08-20T17:19:00.000-07:00

Last night, I decided to upgrade my MySQL from version 4.1 to version 5 on my Windows XP box. I went to mysql's download area and downloaded the latest windows MSI installer version 5.1.37.

After finished downloading the huge 91MB file, I backed up my MySQL database with mysqldump, uninstalled the old version 4.1 and began installed the new version, unfortunately the installation always failed with this message:

MySQL Server 5.1 Setup Wizard ended prematurely

The wizard was interrupted before MySQL Server 5.1. could be completely installed.

Your system has not been modified. To complete installation at another time, please run
setup again.

Again, the old uncle google came to help. This is MySQL's bug, didn't they test it before releasing the new version? Google pointed me to a solution: you need to download and install orca, a tool for editing MSI files, which can be downloaded from here.

Open the MySQL msi installation file, find and delete the action row SetDateTime and then save the msi file. After that, I had the new MySQL 5.1 installed on my computer. There was also no problem restoring the database.

The next step was copying the libmysql.dll file to my php installation directory. Unfortunately, another problem came! the apache server always crashed whenever I loaded my php application, and again uncle google came to rescue, he leaded me to download this zip file, put down the apache server, copying the libmysql.dll from the zip file to the php directory, restarting the apache and then everything runs well.

Kudos to uncle google!

Gnome Network Manager dispatcher.d scripts doesn't run

2009-08-14T13:54:00.000-07:00

I just set up a new linux box of Ubuntu 9.04.

This computer will connect to netware servers, so I installed ipx. However, with this particular version of Ubuntu, the ipx won't start at boot time eventhough it has starting script in the /etc/init.d which is correctly linked to startup directories (/etc/rc2.d, /etc/rc3.d, etc). I guessed the reason is Gnome Network Manager, somehow it prevented ipx to be started.

I then wrote a script in /etc/NetworkManager/dispatcher.d, I gave it a name: 02ipx.sh, so it will executed after the built in /etc/NetworkManager/01ifupdown, the content is very simple


#!/bin/bash
if [ "$1" == "eth0" ] && [ $2 == "up" ]
then
 /etc/init.d/ipx restart
fi

I assign root as the owner of script and set the permission to 775. Unfortunately, this script was never called!!

After spent 5 hours pulling my hairs, uncle Google came to help with
this page

It turns that Network Manager is very picky with the script permission and ownership. Here is the relevant quote :

Yep that is correct from the source:

Yep that is correct from the source:

http://svn.gnome.org/viewvc/NetworkManager/tags/NETWORKMANAGER_0_6_5_RELEASE/dispatcher-daemon/NetworkManagerDispatcher.c?view=markup

/* * nmd_permission_check *
* Verify that the given script has the permissions we want. Specifically,
* ensure that the file is
* - A regular file.
* - Owned by root.
* - Not writable by the group or by other.
* - Not setuid.
* - Executable by the owner.
* */

So the Network Manager doesn't like the 775 permission of my script. Changing the permission to 755 solves my problem.

Ubuntu shutdown problem, acpid: exiting...

2009-08-05T11:16:00.000-07:00

Some times ago, I uninstalled gnome network-manager on my Ubuntu 9.04 dan replaced it with WICD because it won't bring up ipx protocol on boot time. Unfortunately, WICD also has its own problem, it can't bring up your wired and wireless interface simultaneously.

Tonight, I decided to replace WICD with gnome network-manager and I planned to fix the ipx problem through its dispatcher scripts feature. Surprisingly, right after the network manager installed there is no problem with the ipx protocol, apparently the package network-manager in ubuntu repository has been updated recently.

However, when I shutdown or restarted my computer, it always hang with a blank screen displaying the message: acpid:exiting, the only way to completely shut down my laptop is only by pressing the power button for about 3 seconds.

After some googling, it turns that the problem was the network interfaces should be brought down before taking down the computer.

Here is the solution:

Edit as root the file /etc/init.d/alsa-utils
Find stop), here is what it looks like:
stop) EXITSTATUS=0 TARGET_CARD="$2"
Insert statements to bring down your network interfaces:
stop) ifconfig wlan0 down ifconfig eth0 down EXITSTATUS=0 TARGET_CARD="$2"

Problem solved ... :)

Yahoo messenger problem on Linux

2009-06-28T10:05:00.000-07:00

Recently, I can't connect to yahoo messenger through Pidgin on my Ubuntu 9.04 box. After some googling I found this page: http://news.softpedia.com/news/How-to-Fix-Yahoo-problem-in-Pidgin-114754.shtml

Unfortunately, after following the steps I still can't connect to yahoo with error message: unknown "error 1013. Logging into the Yahoo! website may fix this". Logging to yahoo website as suggested doesn't cure the problem :(

After some more googling, I found this page: http://developer.pidgin.im/ticket/9467. Removing the @yahoo.com part of your pidgen account solves the problem.