commedo's blogger

[PROGRAMMING TIPS] How to trigger select action while clicking a label

2004-10-27T12:20:00.000+07:00

You need the following HTML code to make this work:

Click ME
1

Click ME
2

Click ME
3

Click ME 4

This code works for IE and Mozilla (FireFox) --> Tested.

[PROGRAMMING TIPS] Browser-Compatibility while accessing HTML element using DOM

2004-10-19T09:43:00.000+07:00

Please notice that MSIE accesses an HTML element using attribute ID, but Mozilla not. Mozilla uses attribute NAME instead of ID. So, you just simply write both attributes to make it work. See the following example:

<span id="var_name" name="var_name"></span></span>

[PROGRAMMING TIPS] Compilation Option for MSVC 2000 (v6)

2004-09-01T12:41:00.000+07:00

Having problem with application (unhandled exception) run on MS Windows 2000/XP/2003?

One of the solution key is using default option (Project Settings > tab C++) while compiling application or DLL using MSVC.
DO NOT use Maximize speed nor Minimize size options to compile because these options are causing any exception handling codes such as try...catch, pretend not to be executed properly, and then system will generate error.

You may simply try compiling the following code using compile options (default, maximize speed, minimize size) and compare the execution results:


#include <stdio.h>

#include <string.h>



int main ()

{

 char* c;

 try {

    printf("test core dump\n");

    strcpy(NULL, NULL);

 } catch (...) {

    printf("YUPI, core dump\n");

 }

 return 0;

}

Reference:
Yusron Hilmy

[PROGRAMMING TIPS] Using content-type: application/octet-stream HTTP header preventing browser opening a document automatically

2004-07-15T12:53:00.000+07:00

Some browsers such as MSIE opening a document automatically without asking to save or open the document. Some people including me it is very annoying. So how to make an application which acts to send a document to a web client such as web browser always download the document rather open it?

There is a simple way to do that by using content-type: application/octet-stream HTTP header instead of using proper MIME-TYPE content-type for a web document to be sent. Most web browsers will downloaded a web document with this content-type including MSIE.

[PROGRAMMING TIPS] Freeing a dynamic allocated variable

2004-07-12T13:42:00.000+07:00

You will be mad if you can't locate error in your program especially finally you find out that the cause is only not set your dynamic allocated variable is not set to NULL after freed it, won't you?

There are some tips for freeing a dynamic allocated variable not to cause any trouble in future:
1. Use the same function call to allocate and deallocate a dynamic allocated variable in your whole program.
2. Check if a dynamic allocated variable is NULL or not before freeing it. Please ensure you don't free a dynamic allocated variable values NULL even some function call handle NULL condition.
3. Set a freed dynamic allocated variable to NULL. This will not cause any error if this code is accessed rarely and not repetitively. By experience, this will cause error for repetitive condition.


if (sTemp)

{

   free(sTemp);

   sTemp = NULL;

}

Reference
Based on my experiences

[PROGRAMMING TIPS] Compilation Practice

2004-06-19T01:37:00.000+07:00

[gcc, egcs] use options : -O3 -s when compile your code to optimize object code (intermediate files) and strip all unnecessary comments

[LINUX] Also you can type in shell : strip -g -s EXE_FILE will give you the same effect as add options describe above

[PROGRAMMING TIPS] Coding Practice

2004-06-19T01:36:00.000+07:00

Cast any value that would be assigned to a variable, especially for pointer type (void*)

Make sure to have same type while comparing two variables (values) avoiding warning message produced when compile the source code using gcc (NOT egcs). To get all warning message might caused unpredictable errors, use option -Wall while compiling

[PROGRAMMING TIPS] Detecting memory leak (MSVC)

2004-06-19T01:33:00.000+07:00

Microsoft provided library CRTDBG to detect memory leak in source code. Here is an example how to detect memory leak using CRTDBG:


      #include <stdio.h>



      #ifdef _DEBUG

      #include <crtdbg.h>

      #include <string.h>

      #include <malloc.h>

      #define  SET_CRT_DEBUG_FIELD(a)                   _CrtSetDbgFlag((a) | _CrtSetDbgFlag(_CRTDBG_REPORT_FLAG))

      #define  CLEAR_CRT_DEBUG_FIELD(a)                   _CrtSetDbgFlag(~(a) & _CrtSetDbgFlag(_CRTDBG_REPORT_FLAG))

      #else

      #define  SET_CRT_DEBUG_FIELD(a)   ((void) 0)

      #define  CLEAR_CRT_DEBUG_FIELD(a) ((void) 0)

      #endif



      int main(int argc, char *argv[])

      {

        // variable

        char *p;



      #ifdef _DEBUG

        _CrtMemState s1, s2, s3;

        _CrtSetReportMode( _CRT_WARN, _CRTDBG_MODE_FILE );

        _CrtSetReportFile( _CRT_WARN, _CRTDBG_FILE_STDOUT );

        _CrtSetReportMode( _CRT_ERROR, _CRTDBG_MODE_FILE );

        _CrtSetReportFile( _CRT_ERROR, _CRTDBG_FILE_STDOUT );

        _CrtSetReportMode( _CRT_ASSERT, _CRTDBG_MODE_FILE );

        _CrtSetReportFile( _CRT_ASSERT, _CRTDBG_FILE_STDOUT );

        _CrtMemCheckpoint( &s1 );

      #endif



        // do some work here

        p = (char *)malloc(sizeof(char)*100);

        strcpy(p,"Hello world");

        printf("%s\n",p);

        //free(p);	// Seolah2 kita lupa mem-free



      #ifdef _DEBUG

        _CrtMemCheckpoint( &s2 );

        if ( _CrtMemDifference( &s3, &s1, &s2 ) ){

          printf("\n------------\nOuups! leak detection.\n");

          _CrtMemDumpStatistics( &s3 );

        }else{

          printf("\n------------\nCongratulation! no leak detection.\n");

        }

      #endif

        return 0;

      } // end of main

Use option /MTd to compile the code, e.g. cl memdetect.c /MTd

[PROGRAMMING TIPS] Add a description to a Windows service

2004-06-19T01:29:00.000+07:00

You can add a description about a service and displayed in Description column in Services Console (MMC) by adding the following codes after created a service (CreateService()) successfully:


      #define SZDESCRIPTION               "A description about the service"



      LPSERVICE_DESCRIPTION lpInfo;



      // change service's description

      lpInfo = (LPSERVICE_DESCRIPTION)malloc(sizeof(SERVICE_DESCRIPTION));

      lpInfo->lpDescription = (LPTSTR)malloc(256);

      strcpy((char*)lpInfo->lpDescription, (char*)SZDESCRIPTION);

      if (!ChangeServiceConfig2(schService, SERVICE_CONFIG_DESCRIPTION,

          lpInfo))

         _tprintf(TEXT("Can't change service description.\n"));

      free(lpInfo->lpDescription); lpInfo->lpDescription = NULL;

      free(lpInfo); lpInfo = NULL;

If you want to start a service automatically after installing it, add the following codes after created a service (CreateService()) successfully:


      // Start Service

      if (!StartService(schService, 0, NULL))

         _tprintf(TEXT("Can't start service automatically.\n"));

[PROGRAMMING TIPS] Display custom tooltip on your web application

2004-06-19T01:25:00.000+07:00

You can use attribute title at tag anchor (<a></a>) to display a custom tooltip as following:

<a href="a" title="This is a title test">Title Test</a>

[HACKING] MSIE Custom Context Sensitive Menu

2004-06-18T20:16:00.000+07:00

If you are amazed with Google toolbar which is one of its feature is googling by right clicking on selected text, you can make it by your self.

What I Need?
1. Registry Editor, commonly you just simply typing regedit on Start | Run
2. Text/HTML editor to create an HTML file

How?
1. Run regedit from Start | Run
2. Locate section: HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\MenuExt
3. Right click, select menu New | Key
4. Edit new string (New Key #1) with &Google Search for instance. This time, we will create context selective menu to do googling for selected words. Character & indicates shortcut, in this case 'G' as a shortcut.
5. Click &Google Search. Double click on entry (Default), and fill: d:\comm\google-search.html for instance. This indicates location of file which will be executed by if selecting menu "Google Search".
6. Create new Entry, right click on right panel after entry (Default): New -> Binary Value
7. Change new entry name to "contexts" (without double-quotes)
8. Double click on that entry to change the content. Fill binary value 10 00 00 00
9. Create an HTML file name google-search.html in path filled in entry (Defaults)
Example:

<script language="JavaScript">
var parentwin = external.menuArguments;
var doc = parentwin.document;
var sel = doc.selection;
var rng = sel.createRange();
var str = new String(rng.text);
if(external.menuArguments.event.shiftKey)
parentwin.open('http://www.google.com/search?hl=en&;lr=&ie=UTF-8&oe=utf-8&q='+ escape(str) + '&btnG=Google+Search');
else
parentwin.navigate('http://www.google.com/search?hl=en&;lr=&ie=UTF-8&oe=utf-8&q='+ escape(str) + '&btnG=Google+Search');
</script>

10. After all steps 1-9 completed, please test by opening your MSIE browser, and right click on selected words ...... Abrakadabra ... a menu item Google Search shows up. If you click it, will do googling for selected words. To search on new window, press & hold SHIFT button (after selecting words and before right clicking) then click menu "Google Search".

GUIDE
1. You may do this for other purposes such as query ke other sites http://www.kamus.web.id for instance by creating new HTML file with the following contents:

<script language="JavaScript">
var parentwin = external.menuArguments;
var doc = parentwin.document;
var sel = doc.selection;
var rng = sel.createRange();
var str = new String(rng.text);
if(external.menuArguments.event.shiftKey)
parentwin.open("http://www.kamus.web.id/english.asp?pilih=eng&;kata=" + escape(str));
else
parentwin.navigate("http://www.kamus.web.id/english.asp?pilih=eng&;kata=" + escape(str));
</script>

2. Or, launching new popup-window, execute programs, etc. by changing contexts value with certain value.

DISCLAIMER
1. Author is not responsible about any DAMAGE/DATA LOST caused by this experience.

[HACKING] Change default Microsoft Windows 2000/XP default boot logo

2004-06-18T19:58:00.000+07:00

To whom are bored with MS Windows 2000/XP default logo with your favourite one. You may simply change it easily.

What I Need?
1. Resource Hacker (http://www.users.on.net/johnson/resourcehacker/)
2. Image Editor, such as PhotoShop Pro, Adobe Photoshop, etc.

How?
1. Copy %WINNT\system32\ntoskrnl.exe to other name, mine.exe for instance (at the same folder)
2. Run Resource Hacker. From File | Open, open file mine.exe
3. Expand tree Bitmap -> 1 from right panel of Resource Hacker. Click number 1033. You'll see the default boot logo.
4. Your logo must be a Windows Bitmap image (BMP) with 640x480 16 colors (4 bit). To change it, select menu Action | Replace Bitmap, then click Open file with the new bitmap button.
5. When finished, save file by selecting menu File | Save
6. There are mine_original.exe and mine.exe. File mine.exe is the new kernel file which is ready as new boot logo. Please ensure to copy it to %WINNT\system32.
7. You may try your new boot logo by editing file C:\boot.ini. If you can't find this file, please ensure to set set Folder Options at Windows Explorer (menu Tools | Folder Options at View tab, option Show hidden files and folders).
CAUTION: Content of the following file boot.ini may differ with your file boot.ini content on your computer
Example:

Original boot.ini

[boot loader]
timeout=30
default=multi(0)disk(0)rdisk(0)partition(1)\WINDOWS
[operating systems]
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Professional" /fastdetect

Modified boot.ini:

[boot loader]
timeout=30
default=multi(0)disk(0)rdisk(0)partition(1)\WINDOWS
[operating systems]
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Professional" /fastdetect
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Custom Boot Screen" /KERNEL=mine.exe /fastdetect

Please NOTICE the last line of modified boot.ini!
Option /KERNEL=mine.exe is pointer to your new kernel file as new boot logo.
9. You may this by restarting your computer.
10. While booting, there are 2 options: "Microsoft Windows XP Professional" and "Custom Boot Screen". Choose "Custom Boot Screen", then You'll see your new boot logo.
11. If you are sure with this configuration, You may remove the first option.

multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Professional" /fastdetect

so your computer will boot with your new boot logo automatically.

DISCLAIMER
1. Author is not responsible about any DAMAGE/DATA LOST caused by this experience.
2. Author already experience this on MS Windows XP Professional and MS Windows 2000 Professional. There is no problem at all. For other version of MS Windows such as Windows 2000 Server/Advanced Server, please visit my references.

Reference
1. http://www.littlewhitedog.com
2. http://www.thecrackaz.com/articles/tipsandtricks/How%20To%20Change%20the%20Windows%202000%20Boot%20Logo.php
3. http://www.themexp.com

[PROGRAMMING TIPS] Shortcut/Hotkey on your web form application

2004-06-18T19:38:00.000+07:00

You may create shortcut/hotkey for a field in a web form by using tag label and attribute id of a form input-type (field). Please notice to following bold written text!

CODE


<tr>

  <td align="right" width="43%"><img src="frontpage/imgname.gif" width="80" height="12"></td>

  <td width="57%">

    <label for="user" accesskey="U"></label><input type="text" name="user" id="user" class="input" size="15">

  </td>

</tr>

<tr>

  <td align="right" width="43%"><img src="frontpage/imgpass.gif" width="80" height="12"></td>



  <td width="57%">

    <label for="pass" accesskey="P"></label><input type="password" name="pass" id="pass" class="input" size="15">

  </td>

</tr>

By above code, you may using ALT+U to move the pointer into a form field named user or ALT+P to move the pointer into a form field named pass.

[PROGRAMMING TIPS] Closing a socket connection on Windows and Linux

2004-06-18T19:33:00.000+07:00

There is a difference to close a scoket connection on Windows and Linux.

On Linux, we may simply use close() function to close a socket connection, but you CAN NOT use this function on Windows. Use closesocket() function instead. If using close() function on Windows to close a socket connection, it will remain Close Wait connection status means unable to close socket successfully.

How to get a gmail account?

2004-06-18T19:17:00.000+07:00

Any one can help? Or Google itself would like invite me?