Configuring Custom ipython Terminal Color Scheme

In some cases ipython default terminal color scheme is not the most readable one, especially when using Powershell in Windows. One of the way to fix the problem is to use custom/non-default color scheme. The steps to accomplish that as follows (tested in ipython v7.17 and python 3.7.9):

1.  Run `pygmentize -L styles` in your terminal to check available ipython color styles/schemes. Experiment with the color scheme by starting ipython while settting the color scheme as one of its starting parameter, for example: ipython TerminalInteractiveShell.highlighting_style=native. Replace native with the color scheme that you want to test. ipython should start with the color scheme that you specify.
2. Create default ipython configuration file for the current user by running: `ipython profile create` , just use the default configuration file. See: https://ipython.readthedocs.io/en/stable/config/intro.html for more in depth explanation of this command. 
3. Edit the default configuration file located at: ~/.ipython/profile_default/ipython_config.py. In Windows, this file is located at: C:\Users\[username]\.ipython\profile_default\ipython_config.py.  Open the ipython_config.py file and edit the line that contain c.TerminalInteractiveShell.highlighting_style parameter. Set this config value to the color scheme that you want to make permanent. For example, in my config, I set the value to 'native' as follows: c.TerminalInteractiveShell.highlighting_style = 'native'. This will apply the 'native' color scheme as the default color scheme when you start ipython. 

The result of this configuration changes in my Powershell is shown below.

"Signal" Handling in Windows Console Application

Signal handling in Windows console application is quite different from what POSIX defines. Well, you could do it the POSIX way if you're using Visual Studio (see: signal). But, the behavior is not quite like POSIX in all circumstances. The Windows native "signal" handling is the way to go if you're using third party compiler suite or cross-compiling via MinGW-W64. The native "signal" handling is also known as Windows Console Control Handlers. The Console Control Handlers are "reachable" via native Windows API.

There is a peculiarity in Windows Console Control Handler compared to the way POSIX handle CTRL+C (SIGINT) signal. In Windows, a new thread is created by Windows which invoke the registered control handler to process the signal, see: CTRL+C and CTRL+BREAK Signals. Contrary, in POSIX, the OS doesn't run the signal handler in a new thread.

Now, let's look at how you would implement a native Windows signal handler for console application. The Windows API that you need is: SetConsoleCtrlHandler(). As for, how to use the function, MSDN has it covered: Registering a Control Handler Function. FYI, I have tested part of the routine with Mingw-w64 cross compiler suite and run the executable in Windows 10. I confirmed that it works as "advertised".

Free "Remote Desktop" Setup for Windows Home Editions

As you might already know, all Windows Home Edition variants don't support Microsoft Remote Desktop Protocol (RDP) https://en.wikipedia.org/wiki/Remote_Desktop_Protocol. Therefore, you need different software stack as a solution to the problem.

Enter VNC (https://en.wikipedia.org/wiki/Virtual_Network_Computing). VNC is another protocol to remotely control Windows desktop. VNC can be used as RDP replacement, especially, if you want to control Windows Home desktop from Linux. This is a verified setup that I have tested:

• The VNC client, i.e. the machine that will be used to control the Windows Home desktop, runs Linux. In my case it's a XFCE4 window manager. I'm using Vinagre (https://wiki.gnome.org/Apps/Vinagre/) as the client application to access the remote VNC server. 
• The VNC server, i.e. the machine that runs Windows Home OS, is running TigerVNC(http://tigervnc.org) as the application that implements VNC server functionality. TigerVNC is very well maintained as you can see in their github page: https://github.com/TigerVNC/tigervnc.

Hopefully, this is helpful for those thinking about remotely controlling a Windows Home desktop machine.

Batch Encoding mp4 Videos to Wav (Audio CD format) in Windows

At times, you want to listen to your favorite tunes while driving in congested roads or for extended period of time between cities. The problem is, your car's audio only support Audio CD. This dictates you to convert your favorite tunes to Audio CD. Moreover, you don't have enough time to convert them one by one. Enter the "batch encoding" realm..
Simply put, batch encoding is the process of encoding multiple files in one go. To do that, we use shell script, or batch file in Windows. Because most of my favorite tunes are mp4 videos, my batch encoding script converts those mp4s into wav files. I used VLC to carry out the encoding and I'm using a powershell script to automate the encoding into batch encoding. This is the powershell script that I use:

$outputExtension = ".wav"
$bitrate = 128
$channels = 2

foreach($inputFile in get-childitem -Filter *.mp4)
{ 
  $outputFileName = [System.IO.Path]::GetFileNameWithoutExtension($inputFile.FullName) + $outputExtension;
  $outputFileName = [System.IO.Path]::Combine($inputFile.DirectoryName, $outputFileName);
  
  echo "Output filename: $outputFileName" 
    
  $programFiles = ${env:ProgramFiles(x86)};
  echo "Program Files: $programFiles"
  
  if($programFiles -eq $null) { $programFiles = $env:ProgramFiles; }
  
  $processName = $programFiles + "\VideoLAN\VLC\vlc.exe"
  echo "processName: $processName"
  
  $processArgs = "-I dummy -vvv `"$($inputFile.FullName)`" --sout=#transcode{acodec=`"s16l`",ab=`"$bitrate`",`"channels=$channels`"}:standard{access=`"file`",mux=`"wav`",dst=`"$outputFileName`"} vlc://quit"

  echo "processArgs: $processArgs"
  
  start-process $processName $processArgs -wait

  }

It's not that complicated. It's a slightly modified script from VLC wiki (https://wiki.videolan.org/How_to_Batch_Encode/). There was one hiccup though because by default poweshell doesn't permit script execution. Therefore, I have to run powershell as administrator and then modify the execution policy to unrestricted like so:

Windows PowerShell
Copyright (C) 2013 Microsoft Corporation. All rights reserved.

PS C:\Users\zzz> Set-ExecutionPolicy Unrestricted

Anyway, the powershell script above assumes that you placed all of the mp4 in the current directory (directory where the powershell script located). The batch encoding result will be located in the current directory as well.
Now, to create audio CD, you'll need the application to burn the wav files into audio CD. I'm using cdrecord in Linux to do this because for some reason, the only machine with CD/DVD writer that I have is running Linux. You can use your favorite CD authoring application to do this.

Happy Encoding!