The Wiert Corner – irregular stream of stuff

Jeroen W. Pluimers on .NET, C#, Delphi, databases, and personal interests

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Archive for the ‘Software Development’ Category

XOR swap/exchange: nowadays an almost extinct means to exchange two distinct variables of the same size

Posted by jpluimers on 2013/12/19

Almost a year ago, a thread on “premature Delphi optimization” came by on G+ about this code:

procedure ExchangeInteger(var AValue1, AValue2: Integer);
begin
  AValue1 := AValue1 xor AValue2;
  AValue2 := AValue1 xor AValue2;
  AValue1 := AValue1 xor AValue2;
end;

I don’t think that was premature optimization, just some code from an old fart that had already been programming in the era where processors had reasons to use it:

Back then, the only efficient way to exchange two variables of the same data type was using the XOR swap algorithm.

Nowadays you have more options, and this is where the fun in that thread began, which I will show in a minute.

First a bit of history

The XOR swap algorithm was widely known in the 80s of last century and before, especially because the 6502 processor (oh the days of LISA Assembler) was vastly popular, as was the Z80. Together, they powered the majority of the home computers in the 70s and 80s.

Read the rest of this entry »

Posted in Borland Pascal, Delphi, Delphi 1, Delphi 2005, Delphi 2006, Delphi 2007, Delphi 2009, Delphi 2010, Delphi 3, Delphi 4, Delphi 5, Delphi 6, Delphi 7, Delphi 8, Delphi x64, Delphi XE, Delphi XE2, Delphi XE3, Development, History, Pascal, Software Development, Turbo Pascal, UCSD Pascal | 7 Comments »

ASP.NET – Great explanation of Server.MapPath parameters “.”, “..”, “~”, @”\”, “/” and “/path”

Posted by jpluimers on 2013/12/18

Thanks StackOverflow user splattne (Stefan Platnner) for explaining the differences between the various parameters you can pass to Server.MapPath, and giving some very clear examples.

You can also use it with HostingEnvironment.MapPath, which has the added benefit that it doesn’t require HttpContext (for more detail on it, see Working With HttpContext.Current).

–jeroen

via:

Posted in .NET, .NET 1.x, .NET 2.0, .NET 3.0, .NET 3.5, .NET 4.0, .NET 4.5, ASP.NET, Development, Software Development | Leave a Comment »

.NET/C#: On my research list is the Mono.Options arguments parser

Posted by jpluimers on 2013/12/17

The Mono.Options single .cs source file seems very well suited for arguments parsing of (especially) console application:

https://github.com/mono/mono/blob/master/mcs/class/Mono.Options/Mono.Options/Options.cs

so it is on my research list, like some other .NET/C# based command line parsing libraries (:

–jeroen

Posted in .NET, .NET 2.0, .NET 3.0, .NET 3.5, .NET 4.0, .NET 4.5, C#, C# 2.0, C# 3.0, C# 4.0, C# 5.0, Development, Software Development | Leave a Comment »

Generating complex math visualizations in SVG using C# and ILNumerics – Scott Hanselman

Posted by jpluimers on 2013/12/15

Funny how Generating complex math visualizations in SVG using C# and ILNumerics and MathViz (no, not this MathViz!) look so similar.

I hope the MathViz code becomes public one day.

–jeroen

via: Generating complex math visualizations in SVG using C# and ILNumerics – Scott Hanselman.

Posted in .NET, Delphi, Development, HTML, HTML5, iOS Development, Mobile Development, Software Development, Web Development | Leave a Comment »

Different ways of sleeping/waiting in batch files

Posted by jpluimers on 2013/12/13

About a year and a half ago, I wrote about a Batch file to “Keep Alive” a CMAK generated VPN connection in Windows 7.

It uses ping to wait a certain amount of time, but it has the drawbacks of

  • requiring TCP/IP to be installed (which some headless systems don’t).
  • using N+1 as the number of seconds

Since then, I learned that since Windows Vista and up has timeout command that just waits:

timeout /t 600 /nobreak

Two parameters are used:

  • /nobreak
    does not stop waiting when you press a key
  • /t #
    waits # seconds

(the example is 10 minutes, I use it to regularly run FlushFileCache.exe or FlushMem.exe to empty the Windows file chache and release memory – often more than a gigabyte – back to Windows)

There is also sleep.exe, but that requires the Windows Resource Kit or Windows Server 2000/2003.

–jeroen

via:

Posted in Batch-Files, Development, Power User, Scripting, Software Development, Windows | Tagged: | Leave a Comment »

Delphi postbuild events: interesting take by David Heffernan (via: Stack Overflow)

Posted by jpluimers on 2013/12/12

StackOverflow user David Heffernan – Stack Overflow has an interesting take on Delphi postbuild events:

At the moment my actiona read:

if exist PostBuild.bat call PostBuild.bat $(Platform) $(Config) $(OutputDir)

And then the PostBuild.bat script calls a Python script so that I can write my scripts in a real language.

I actually impose the build actions in a shared option set that I reference from all of my projects. That way I enforce consistency and predictability.

I know others use tools like FinalBuilder but building is so important that I feel it’s worth my effort in rolling my own tooling.
– David Heffernan Feb 14 at 20:24

–jeroen

via: Delphi XE3: Problems with complex pre-build events – Stack Overflow.

Posted in Delphi, Delphi 2007, Delphi 2009, Delphi 2010, Delphi XE, Delphi XE2, Delphi XE3, Development, Software Development | Leave a Comment »

Windows batch files: How to set a variable with the result of a command (via: Stack Overflow)

Posted by jpluimers on 2013/12/11

One of the easy things in *nix is to set the value of an environment with the output of a command.

Something like this is possible in Windows too, but you have to instruct Windows to keep an empty set of delimiters to capture the full first line.

There is also a small but important difference between Windows and *nix upon command failure: *nix will always return an empty value, but in Windows you must make sure to empty the value first.

Thanks Jesse Dearing for this summary: Read the rest of this entry »

Posted in Batch-Files, Development, Power User, Scripting, Software Development, Windows | Leave a Comment »

Attach attach a debugger to a WebService (via: Stack Overflow)

Posted by jpluimers on 2013/12/10

Some things you have done for ages, are already phrased so nicely, the only thing you can do is quote.

Thanks Dave Coulter:

You can attach the Visual Studio debugger to a process by:

Debug > Attach to Process > Attach Read the rest of this entry »

Posted in .NET, .NET 1.x, .NET 2.0, .NET 3.0, .NET 3.5, .NET 4.0, .NET 4.5, C#, C# 1.0, C# 2.0, C# 3.0, C# 4.0, C# 5.0, Development, Software Development, Visual Studio 11, Visual Studio 2002, Visual Studio 2003, Visual Studio 2005, Visual Studio 2008, Visual Studio 2010, Visual Studio and tools | Leave a Comment »

Funny Delphi code of the day: on literals

Posted by jpluimers on 2013/12/09

The fact that the [WayBack] 31-character limit on ClientDataSet field and index names is worse, but I just encountered this GetParamNameWODog function in a Delphi 3rd party library:


function GetParamNameWODog(const ParamName: _string): _string;
begin
if (ParamName <> '') and (ParamName[1] = '@') then
Result := Copy(ParamName, 2, 1000)
else
Result := ParamName;
end;

What’s wrong with using the Length function here?

Yes, SQL Parameter names will probably less than 1000 characters, but then the 1000 literal should be a constant with a meaningful name, and the '@' literal should be too. Read the rest of this entry »

Posted in Delphi, Delphi XE3, Development, QC, Software Development | Tagged: , , | 12 Comments »

Owly CI should team up with Ohloh

Posted by jpluimers on 2013/12/05

This was originally scheduled for December 1st at noon and therefore made it to the “Missed Schedule” list as well:

Two interesting sites I found recently:

OwlyCI is like NuGet for Delphi. They add Delphi open source repositories, and provide them as installable packages, and shows build statistics.

Ohloh provides statistics (including build statistics!) for open source repositories (any language and environment)  and shows various other statistics like check in counts, LoC, etc. Koders merged into Oholoh about a year ago.

I think they should team up (:

–jeroen

Posted in Delphi, Development, Software Development | Leave a Comment »