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A girl wrote on her blog about a deceased schoolmate. She said that the death was well deserved. When she realised the insensitivity of her blog post, she decided to attend the wake to apologize to the family of the deceased, but angry teenage mutant ninja mobs attacked her outside the deceased house. Here are the Newspaper scanlations. And this is her blog.

Lesson to be learned:

  1. Blogger, in a way is similar to journalist . Although bloggers are not regulated by the journalism code of conduct, but a common sense might need to be used. Unless you are living in United States, where your freedom of speech is protected by the 2nd Amendment. But a defamation/libel lawsuit is still possible to be made against you.
  2. Blog entries are accessible to public. Whatever said in public might be used as evidence in the court of law. So please help yourself by not having any blog postings with any potential liability
  3. I really need to control my mouth (T_T) and re-checking my previous entries for any potential liability. Any comments?

About Hardono

Howdy! I'm Hardono. I am working as a Software Developer. I am working mostly in Windows, dealing with .NET, conversing in C#. But I know a bit of Linux, mainly because I need to keep this blog operational. I've been working in Logistics/Transport industry for more than 11 years.

Possibly relevant:

It was a quiet Tuesday afternoon in Singapore. The sky was greyish with clouds. The air was cool with slow wind. I sat in front of my computer mindlessly seriously reading blog posts in the neighbouring blogs.

The suddenly out of the darkness his room, Buddie approached me complaining about his Web Application. His ASP.NET web application is using Interop.Excel to read data stored in XLS file. The problem is that those Excel processes are refusing to be closed, resulting tens mega bytes of memory hogged.

Just to illustrate how the Excel process is started, please take a look of the following code which shamelessly proudly copied from MSDN:

//-----------------------------------------------------------------------
//  This file is part of the Microsoft .NET Framework SDK Code Samples.
// 
//  Copyright (C) Microsoft Corporation.  All rights reserved.
// 
//This source code is intended only as a supplement to Microsoft
//Development Tools and/or on-line documentation.  See these other
//materials for detailed information regarding Microsoft code samples.
// 
//THIS CODE AND INFORMATION ARE PROVIDED AS IS WITHOUT WARRANTY OF ANY
//KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
//IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A
//PARTICULAR PURPOSE.
//-----------------------------------------------------------------------
using System;
using System.Reflection; // For Missing.Value and BindingFlags
using System.Runtime.InteropServices; // For COMException
using Microsoft.Office.Interop.Excel;

class AutoExcel {
	public static int Main() {	
		Console.WriteLine ("Creating new Excel.Application");
		Application app = new Application();
		if (app == null) {
			Console.WriteLine("ERROR: EXCEL couldn't be started!");
			return 0;
		}
		
		Console.WriteLine ("Making application visible");		
		app.Visible = true;
		
		Console.WriteLine ("Getting the workbooks collection");
		Workbooks workbooks = app.Workbooks;

		Console.WriteLine ("Adding a new workbook");
		
		_Workbook workbook = workbooks.Add(XlWBATemplate.xlWBATWorksheet);

		Console.WriteLine ("Getting the worksheets collection");
		Sheets sheets = workbook.Worksheets;

		_Worksheet worksheet = (_Worksheet) sheets.get_Item(1);
		if (worksheet == null) {
			Console.WriteLine ("ERROR: worksheet == null");
		}
		
		Console.WriteLine ("Setting the value for cell");
		
		// This paragraph puts the value 5 to the cell G1
	    Range range1 = worksheet.get_Range("G1", Missing.Value);
		if (range1 == null) {
			Console.WriteLine ("ERROR: range == null");
		}
		const int nCells = 5;
		range1.Value2 = nCells;
		
		// This paragraph sends single dimension array to Excel
	    Range range2 = worksheet.get_Range("A1", "E1");
		int[] array2 = new int [nCells];
		for (int i=0; i < array2.GetLength(0); i++) {
			array2[i] = i+1;
		}
		range2.Value2 = array2;

		// This paragraph sends two dimension array to Excel
	    Range range3 = worksheet.get_Range("A2", "E3");
		int[,] array3 = new int [2, nCells];
		for (int i=0; i < array3.GetLength(0); i++) {
			for (int j=0; j < array3.GetLength(1); j++) {
				array3[i, j] = i*10 + j;
			}
		}
		range3.Value2 = array3;

		// This paragraph reads two dimension array from Excel
	    Range range4 = worksheet.get_Range("A2", "E3");
		Object[,] array4;
		array4 = (Object[,])range4.Value2;
		
		for (int i=array4.GetLowerBound(0); i <= array4.GetUpperBound(0); i++) {
			for (int j=array4.GetLowerBound(1); j <= array4.GetUpperBound(1); j++) {
				if ((double)array4[i, j] != array3[i-1, j-1]) {
					Console.WriteLine ("ERROR: Comparison FAILED!");
					return 0;
				}
			}
		}

	    // This paragraph fills two dimension array with points for two curves and sends it to Excel
	    Range range5 = worksheet.get_Range("A5", "J6");
		double[,] array5 = new double[2, 10];
		for (int j=0; j < array5.GetLength(1); j++) {
			double arg = Math.PI/array5.GetLength(1) * j;
			array5[0, j] = Math.Sin(arg);
			array5[1, j] = Math.Cos(arg);
		}
		range5.Value2 = array5;
		
		// The following code draws the chart
		range5.Select();
		ChartObjects chartobjects = (ChartObjects) worksheet.ChartObjects(Missing.Value);
		
		ChartObject chartobject = (ChartObject) chartobjects.Add(10 /*Left*/, 100 /*Top*/, 450 /*Width*/, 250 /*Height*/);
		_Chart chart = (_Chart) chartobject.Chart;
		
		// Call to chart.ChartWizard() is shown using late binding technique solely for the demonstration purposes
		Object[] args7 = new Object[11];
		args7[0] = range5; // Source
		args7[1] = XlChartType.xl3DColumn; // Gallery
		args7[2] = Missing.Value; // Format
		args7[3] = XlRowCol.xlRows; // PlotBy
		args7[4] = 0; // CategoryLabels
		args7[5] = 0; // SeriesLabels
		args7[6] = true; // HasLegend
		args7[7] = "Sample Chart"; // Title
		args7[8] = "Sample Category Type"; // CategoryTitle
		args7[9] = "Sample Value Type"; // ValueTitle
		args7[10] = Missing.Value; // ExtraTitle
		chart.GetType().InvokeMember("ChartWizard", BindingFlags.InvokeMethod, null, chart, args7);
	    
		Console.WriteLine ("Press ENTER to finish the sample:");
		Console.ReadLine();		
		
		try {
			// If user interacted with Excel it will not close when the app object is destroyed, so we close it explicitely
			workbook.Saved = true;
			app.UserControl = false;
			app.Quit();
		} catch (COMException) {
			Console.WriteLine ("User closed Excel manually, so we don't have to do that");
		}
		
		Console.WriteLine ("Sample successfully finished!");
		return 100;
	}
}

I don't know how the exact code in his ASPX file, but it should be similar to the example detailed above. Actually, Buddie inherited the code from previous programmer which use the following brutal method to terminate the Excel Process:

Process[] procs = Process.GetProcessesByName("EXCEL");
foreach (Process p in procs)
{
   p.Kill();
}

When I was consulted about the code before, I said that this method might pose a problem with many concurrent accesses to the ASPX page. He then decided to comment the portion of code described above. 😀 Which of course, resulting the memory hogged by many unclosed Excel processes. 😀

After fooling around with the code (huhu.. I thought fooling around only used by a person to the opposite sex :-D), I came up with a solution:

Process[] procs = Process.GetProcessesByName("EXCEL");
foreach (Process p in procs)
{
    int baseAdd = p.MainModule.BaseAddress.ToInt32();
    //oXL is Excel.ApplicationClass object
    if (baseAdd == oXL.Hinstance)
        p.Kill();
}

Basically the idea is to compare the lowest memory address of the Excel Application and the Process obtained by GetProcessesByName(). This way, the ASPX page will terminate exclusively the Excel Application that started by it.

Comments?

UPDATE: Please check the track back on the comments below.

About Hardono

Howdy! I'm Hardono. I am working as a Software Developer. I am working mostly in Windows, dealing with .NET, conversing in C#. But I know a bit of Linux, mainly because I need to keep this blog operational. I've been working in Logistics/Transport industry for more than 11 years.

Possibly relevant:

Starting June 2007, sending unsolicited electronic message in Singapore will be charged as civil offence. The online document can be viewed here.

Summary of the Bill (please READ the online document for clarification, I might summarized it incorrectly):

  1. It applies to commercial email, commercial SMS/MMS
  2. It doesn’t apply to telemarketers
  3. unsubscribe request is effective maximum 10 business days after the submission of the unsubscribe request
  4. It applies if the SPAM committed in Singapore (sender/organization is physically reside in Singapore)
  5. sending email to addresses obtained by harvesting email address in the internet is ILLEGAL
  6. Buying email address list obtained by harvesting email address in the internet is also ILLEGAL
  7. The damage is not to exceed SGD$25 per message, and not to exceed SGD$1 Million in total, unless the plaintiff able to show that the SPAM has caused damage more than SGD$1 Million

So in order not violating the SPAM law, the email/SMS/MMS should:

  1. for email, the subject must started with “<ADV>”
  2. Must have unsubscribe facility

Hopefully this article helps, If you are going to send any commercial (please refer to the document, the description is quite long) message, please make sure you are not violating the law.

PS: Hmm… although it sounds like I’m advocating the spammers, I’m not. I hate spammers.

About Hardono

Howdy! I'm Hardono. I am working as a Software Developer. I am working mostly in Windows, dealing with .NET, conversing in C#. But I know a bit of Linux, mainly because I need to keep this blog operational. I've been working in Logistics/Transport industry for more than 11 years.

Possibly relevant: