My Blog is moving to a hosted solution with Gigabit Networks

Hey all,

This blog is currently a simple wordpress blog hosted on WordPress.com. It will shortly change to a new website hosted at Gigabit Networks.

One of my goals is to move to a completely BSD or similar licensed  solution. I have chosen to have my final site use FreeBSD (OS), Apache (Web Server), Postgresql (DB), Silverstripe (CMS and blog).  This will take me a long time.

Step 1 (Almost complete) – Move my current wordpress blog to a hosted solution that uses FreeBSD.  With my blog moving to Gigabit Networks, this step is complete.

Step 2 (Just starting) – Migrate the blog to Silverstripe and postgresql is already in progress, but I expect it will take a year (as I do this in my spare time).

A couple of things to note:

1. This will come with a new design for my website, so don’t be surprised if when you see it. Hopefully it will be a better look.
2. A couple changes are that my posts will no longer dumped to the home page, but to a Posts page.
3. Subscribers will have to subscribe again as I will use email subscription “Delivered by FeedBurner.”
   Subscribe to Rhyous by Email

Hopefully this is a smooth transition.  If you have any questions, please comment on this post.

C# (Mono) on FreeBSD

Well, if you have read my blog at all, you will realize that I have a developer job writing in C# on Windows, but it is my personal hobby to use FreeBSD.

I am very excited about Mono.I love the C# language. I also love FreeBSD.

I am going to go ahead and say something bold. Few people know realize this yet, but the ability to code in C# on open source platforms is going to be the single most important feature in the coming years. It will eventually be a standard library that will exist or be one of the first items installed on every system.

For more information:

http://www.mono-project.com/Mono:FreeBSD
Packaging for Mono and related applications on FreeBSD (http://www.freebsd.org) is handled by the BSD# Project. The purpose of this project is to maintain the existing Mono/C# ports in the FreeBSD ports tree, port new applications, and work on resolving FreeBSD specific issues with Mono. BSD# is entirely user supported and is not an official FreeBSD or Mono project.

For Licensing information:

http://www.mono-project.com/Licensing“

Installing Mono

Mono is a port and as always a port is easy to install on FreeBSD.

# #	cd /usr/ports/lang/mono make BATCH=yes install

Compiling Hello World in Mono

The mono compiler is gmcs. It is simple to compile C# code.

1. Create a new file called hw.cs.  C# class files end in .cs.
2. Add this text to the file:
   

   using System;
   
   namespace HelloWord
   {
       class HelloWord
       {
           static void Main(string[] args)
           {
               System.Console.WriteLine("Hello World");
           }
       }
   }
   

3. Save the file.
4. Compile the code to create an hw.exe program.
   # gmcs hw.cs

Running a Mono Program

Mono programs must be run using the “mono” command.

# mono hw.exe
Hello World

A Mono IDE: Mono Develop

There is an IDE for Mono called Mono Develop. Mono Develop is a port and as always a port is easy to install on FreeBSD.

# #	cd /usr/ports/devel/monodevelop make BATCH=yes install

The Mono Develop port integrated with KDE to add itself to the KDE menu under Applications | Development | MonoDevelop. So you can run it from there.

This IDE allows you to create C# solutions. It is possible to

Is It Really Cross Platform

C# and Mono are supposed to be cross platform. So I can write it in Windows using Visual Studio or I can write in FreeBSD using Mono Develop and either way it should run on both Windows and FreeBSD and any other platform that supports mono.

So here are the results of my quick tests:

Test 1 – Does the Hello World app run in Windows.

Yes.  I copied the file to a Windows 7 64 bit box and ran it.  It worked.

Test 2 – Does a GTK# 2.0 Project run in Windows

No. I created a GTK# 2.0 project on FreeBSD in Mono Develop, and didn’t add anything to it, I just compiled it. I copied the file to windows and ran it. However, it still crashed.

Test 3 – Does a Windows Form Application compiled in Visual Studio 2010 in Window 7 run on FreeBSD

Not at first. I created a basic Windows Form application, and didn’t add anything to it, I just compiled it. I copied it to FreeBSD and ran it.  It crashed. However, by default .NET 4.0 is used.

Yes, if compiled with .NET 3.5 or earlier. I changed the project to use .NET 3.5 and tried again.

Test 4 – Does a Windows Presentation Foundation project compiled in Visual Studio 2010 in Window 7 run on FreeBSD

No. There is PresentationFramework assembly so the application crashes immediately. I tried multiple .NET versions.

Note: I didn’t really test much more than the basics. I just created new projects, left them as is and tried them. It would be interesting to see a more fully developed application tested and working on both platform and to know what issues were encountered in doing this.

No WPF

Unfortunately there is no WPF and no plans for it. Of course, WPF stand for Windows Presentation Foundation, and so the who “Windows” part of that might need to be changed to something like XPF, Xorg Presentation foundation.

However since there is Moonlight, which is to Silverlight as Mono is to C# and .NET, and Silverlight is a subset of WPF, I have to assume that WPF will arrive in mono eventually, even if it is by way of Moonlight first.

Oracle Installer: Wow, can you say poor and unprofessional

So I am installing the Oracle client for the first time in my life (Yes, there are still some geek things I haven’t done yet) and wow was I surprised at the poor quality of the installer.

Here is the ugly:

1. I start the install and immediate a big black Command Prompt window comes up.
2. Once it comes up, it tries to install to a c:\app\jbarneck folder.  Really?  You haven’t figured out C:\Program Files\Oracle yet?
3. I installed only Instant Client. I needed Administrator as well. On reinstall it installed a new second instance of the Oracle Client.  No it didn’t work and I have reverted my VM to try again.
4. When you have gone through their wizard and it is time to start the install, you click Finish. Yes, you heard correctly, you click Finish to start.  When the install finishes, there is a small line of text letting me know it was successful and a close button.
5. Then I have to go get some text file called a .ORA file and copy it myself.

Anyway.  If it was an Open Source project it wouldn’t be this poor.  This is something I would have expected in the NT 4.0 days.

So if this is the lack of enterprise quality that I can expect from Oracle, which is a very rich “enterprise”, I will continue to stay away and recommend others do the same.

All I can say is: Wow, Oracle! Get your act together.

FreeBSD Wireless – Configuring a wireless interface on FreeBSD 8.1

FreeBSD Wireless

FreeBSD has strong support for wireless devices. Here is a quick overview of how to manage wireless interfaces on FreeBSD.

Prerequisites

For Wireless access requires the following:

1. A wireless interface card
2. wpa_supplicant
3. An Access Point

Note: In later of versions of FreeBSD, since 2008, wpa_supplicant was included in base. If you are running an older version of FreeBSD, then wpa_supplicant was a port.  So if you are on FreeBSD 8, you have wpa_supplicant.

To complete this guide, we will also use:

1. A FreeBSD desktop environment.
2. wpa_gui

Note: wpa_gui is not included in the base system but is found in ports.

Step 1 – Determine what wireless interface card you have

Some wireless cards are built into the kernel, and may already be loaded.  If you know what card you have, skip this step.

1. First, we need to find out what wireless card you have. Run ifconfig and look at the network cards you have.  Then to see which one is your wireless card, compare them to the wireless kernel module list here:
   http://www.freebsd.org/releases/8.1R/hardware.html#WLAN 

   $ ifconfig
   em0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
           options=219b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,TSO4,WOL_MAGIC>
           ether 00:1e:37:d0:91:cb
           media: Ethernet autoselect
           status: no carrier
   lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> metric 0 mtu 16384
           options=3<RXCSUM,TXCSUM>
           inet6 fe80::1%lo0 prefixlen 64 scopeid 0x3
           inet6 ::1 prefixlen 128
           inet 127.0.0.1 netmask 0xff000000
           nd6 options=3<PERFORMNUD,ACCEPT_RTADV>

   Notice in the above configuration, no wireless card was discovered. Here is an example of one with a wireless card.

   em0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
           options=219b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,TSO4,WOL_MAGIC>
           ether 00:1e:37:d0:91:cb
           media: Ethernet autoselect
           status: no carrier
   iwn0: flags=8843 metric 0 mtu 2290
           ether 00:1e:37:d0:91:cb
           media: IEEE 802.11 Wireless Ethernet autoselect mode 11g
           status: associated
   lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> metric 0 mtu 16384
           options=3<RXCSUM,TXCSUM>
           inet6 fe80::1%lo0 prefixlen 64 scopeid 0x3
           inet6 ::1 prefixlen 128
           inet 127.0.0.1 netmask 0xff000000
           nd6 options=3<PERFORMNUD,ACCEPT_RTADV>

2. Most wireless cards are PCI devices.  Run pciconf to look for your wireless network card type. This outputs a lot of information, I have snipped my output to isolate only the information about the wireless PCI card.

   $pciconf -lv
   ...
   none1@pci0:3:0:0:       class=0x028000 card=0x10108086 chip=0x42308086 rev=0x61 hdr=0x00
       vendor     = 'Intel Corporation'
       device     = 'Intel Wireless WiFi Link 4965AGN (Intel 4965AGN)'
       class      = network
   ...

3. Now go to the current release notes for FreeBSD and look through the wireless kernel modules to see which one supports your hardware.
   http://www.freebsd.org/releases/8.1R/hardware.html#WLAN
   
   Note: I searched for 4965AGN and found my kernel module immediately.
4. Keep the link open as you move to Step 2.

Step 2 – Make sure the kernel module is loading

If your wireless card is already detected and loading, skip this step.  If not, configure /boot/loader.conf to load your wireless card.

1. Read the man page for your wireless kernel module, there is a link to it in the hardware notes, to see any special information about loading the kernel module for your kernel module.
2. Configure the /boot/loader.conf to load the kernel module and make any other required settings to use the kernel module.Example 1 – The Intel iwn kernel module requires a line to load the kernel module and a second line to load the firmware.

   # Wireless
   if_iwn_load="YES"
   iwn4965fw_load="YES"

   Example 2 – The Intel iwi kernel module requires that you accept a license agreement:

   # Wireless
   if_iwi_load="YES"
   legal.intel_iwi.license_ack=1

3. Save and close the /boot/loader.conf
4. Now you can either reboot, or you can use kldload to load the kernel modules without rebooting.

Step 3 – Configure the wireless settings in /etc/rc.conf

The rc.conf is where the wireless network card is configured.

1. In FreeBSD 8 and later, all wireless interfaces should be configured to use the generic wlan device. Then to enable wpa_supplicant, the wlan should be configured to use WPA.
   To make these configurations, add these lines to the /etc/rc.conf. 

   wlans_iwn0="wlan0"
   ifconfig_wlan0="WPA DHCP"

2. Save and close /etc/rc.conf.

Step 4 – Add your Access Point’s (AP) SSID to your /etc/wpa_supplicant.conf

There is a lot of information on how to add an SSID to your /etc/wpa_supplicant.conf file in the man page for wpa_supplicant.conf. But the process is simple.

1. If you don’t know the SSID, discover or scan for the SSID by running ifconfig wlan0 scan.  Below is an example.

   $ ifconfig wlan0 scan
   SSID/MESH ID    BSSID              CHAN RATE   S:N     INT CAPS
   MyWifi          00:20:e1:96:54:32    6   11M -75:-95  100 E
   OpenNet         da:ce:41:d3:af:3a    6   54M -85:-95  100 IS
   MyWPA           00:24:7b:6b:71:27    1   54M -89:-95  100 EP   RSN WPA WPS
                   00:00:00:00:00:00    1   54M -89:-95  100 E

2. Now add a network entry for the desired wireless device.  Examples are below:
   

   Open or no authentication

   network={
           ssid="MyWifi"
           key_mgmt=NONE
   }

   WPA or WPA2

   network={
           ssid="MyWPA"
           psk="SomeP@sswd!"
   }

   More examples

   For more examples, read the man page for wpa_supplicant.conf.

   $ man wpa_supplicant.conf

   Once the SSID is configured properly in the /etc/wpa_supplicant.conf, then an automatic connection to this AP will occur whenever the device is within range.

Step 5 – Install wpa_gui from ports

Often you don’t always know what wireless you are going to connect to and also often you don’t care to store the SSID configuration permanently in the /etc/wpa_supplicant.conf. This is common if you are getting online at an airport, coffee shop, or any hotspot that you don’t frequent. It would be nice to have a graphical interface that shows you the SSIDs available, allows you to connect, but doesn’t store the information. wpa_gui is this tool.

1. Install wpa_gui from ports

   # cd /usr/ports/net/wpa_giu
   # make install

2. Add the following two lines to the top of the /etc/wpa_supplicant.conf.

   ctrl_interface=/var/run/wpa_supplicant
   ctrl_interface_group=wheel

3. Restart the wpa_supplicant.# /etc/rc.d/wpa_supplicant restart wlan0
4. Run wpa_gui.

   $ wpa_gui
   Selected interface 'wlan0'
   Trying to connect to '/var/run/wpa_supplicant/wlan0'

   wpa_gui opens.
   

5. Click Scan and a window listing the available SSIDs appears.
6. Double-click on an SSID to get the configuration windows.  It will try to select the correct settings as best it can, so often you only need to add the psk or passkey, which is essentially a password.
7. This will connect you to that SSID.

Note: If you do want to save the networks to the wpa_supplicant.conf by default, then add this line. Otherwise, they are not saved. You may or may not want them to be saved.

update_config=1

Additonal Notes

Note 1: PC-BSD has a network configuration tool, so if you are running PC-BSD, wpa_gui is not necessary.

Note 2: There is a command line tool called wpa_cli that is included in the base system.  wpa_cli is useful if you don’t have a graphical environment.

Note 3: I also configured link aggregation, or lagg, so my wired and wireless interfaces share the same MAC.

ifconfig_em0="up"
ifconfig_iwn0="`ifconfig em0 ether`"
ifconfig_iwn0="ether ${ifconfig_iwn0##*ether }"
wlans_iwn0="wlan0"
ifconfig_wlan0="WPA"
cloned_interfaces="lagg0"
ifconfig_lagg0="laggproto failover laggport em0 laggport wlan0 DHCP"

Resources

http://www.freebsd.org/doc/handbook/network-wireless.html

http://www.freebsd.org/releases/8.1R/hardware.html#WLAN

man wpa_supplicant
man wpa_supplicant.conf
man iwn
man iwi

---

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WPF databinding to methods encapulated in an ICommand

Databinding in WPF allows binding the Command property to methods encapulated in an ICommand. By creating an ICommand object to hold an event function, the Command value can bind to the event function as an ICommand.

The goal of Model-View-ViewModel is to have zero code in the code behind of a WPF Control Instead, everything the WPF Control does happens using databinding.

While this article will show you how to do this, you be left a little fuzzy as to understanding of the implementation. It may take some time and research to fully understand everything this is doing. Understand that methods can be objects, and this is a process to turn a method object into an ICommand so it can be using in WPF for databinding.

Preparation and Prereqs

You should have Visual Studio 2008/2010.

In Visual Studio, create a new WPF Application project and give it a name.

Step 1 – Creating an new class that inherits from ICommand

1. In your new project in Visual Studio, add a new class called RelayCommand.
   Note: It can be named anything, but since that is the name used by Microsoft when discussing MVVM, I will use the same name.
2. Change the using statements to implement the following : System, System.Diagnostic, System.Windows.Input
3. Make the new RelayComand class public.
4. Make the new RelayCommand class implement ICommand.

using System;
using System.Windows.Input;

namespace WpfDataBindingToICommand
{
    public class RelayCommand : ICommand
    {
        #region Constructors
        public RelayCommand()
        {
        }
        #endregion
    }
}

5. Right-click on the ICommand text and choose Implement Interface | Implement Interface. This adds the following code to the bottom of your class.
   

           #region ICommand Members
   
           public bool CanExecute(object parameter)
           {
               throw new NotImplementedException();
           }
   
           public event EventHandler CanExecuteChanged;
   
           public void Execute(object parameter)
           {
               throw new NotImplementedException();
           }
   
           #endregion
   

6. Create two member variables or fields that we will use to hep use inside the ICommand interface functions.
   1. Action<Object>
   2. Predicate<Object>
   

           #region Member Variables
           readonly Action<object> _ActionToExecute;
           readonly Predicate<object> __ActionCanExecute;
           #endregion
   

7. Implement the CanExecute(object parameter) function.
   

           public bool CanExecute(object parameter)
           {
               return __ActionCanExecute== null ? true : __ActionCanExecute(parameter);
           }
   

8. Implement the EventHandler CanExecuteChanged. In doing this the MVVM experts used the CommandManager, which might be worth reading about.
   

           public event EventHandler CanExecuteChanged
           {
               add { CommandManager.RequerySuggested += value; }
               remove { CommandManager.RequerySuggested -= value; }
           }
   

9. Implement the Execute(object parameter) function.
   

           public void Execute(object parameter)
           {
               _ActionToExecute(parameter);
           }
   

10. Create constructors that allow us to initialize the object by passing in the Action

The final class looks as follows:

using System;
using System.Windows.Input;

namespace WpfDataBindingToICommand
{
    /// <summary>
    /// This RelayCommand object is used to encapsulate function logic into an oject that inherits ICommand.
    /// </summary>
    public class RelayCommand : ICommand
    {
        #region Member Variables
        readonly Action<object> _ActionToExecute;
        readonly Predicate<object> _ActionCanExecute;
        #endregion

        #region Constructors
        /// <summary>
        /// This creates a new RelayCommand.
        /// </summary>
        /// <param name="inActionToExecute">This is the logic of the actin to execute. This objects is usually a method that returns void.</param>
        public RelayCommand(Action<object> inActionToExecute)
            : this(inActionToExecute, null)
        {
        }

        /// <summary>
        /// This creates a new RelayCommand.
        /// </summary>
        /// <param name="inActionToExecute">This is the logic of the actin to execute. This objects is usually a method that returns void.</param>
        /// <param name="inActionCanExecute">This is the logic for whether the action can execute.</param>
        public RelayCommand(Action<object> inActionToExecute, Predicate<Object> inActionCanExecute)
        {
            if (inActionToExecute == null)
                throw new ArgumentNullException("execute");

            _ActionToExecute = inActionToExecute;
            _ActionCanExecute = inActionCanExecute;
        }
        #endregion

        #region ICommand Members
        public bool CanExecute(object parameter)
        {
            return _ActionCanExecute == null ? true : _ActionCanExecute(parameter);
        }

        public event EventHandler CanExecuteChanged
        {
            add { CommandManager.RequerySuggested += value; }
            remove { CommandManager.RequerySuggested -= value; }
        }

        public void Execute(object parameter)
        {
            _ActionToExecute(parameter);
        }
        #endregion
    }
}

Step 2 – Creating a ViewModelBase abstract base class

This object is used to create common logic for all objects that will be using in Binding. This object will implement INotifyPropertyChanged so it only has to be implemented once.

1. Create a new class named ViewModelBase.
2. Change the using statements to implement the following : System, System.CompenentModel
3. Make the new ViewModelBase class public and abstract.
4. Make the new ViewModelBase class implement INotifyPropertyChanged.
5. Make the constructor protected.
   

6. Right-click on the INotifyPropertyChanged text and choose Implement Interface | Implement Interface. This adds the following code to the bottom of your class. Yes, it is just a one line event handler object.
   

           #region INotifyPropertyChanged Members
   
           public event PropertyChangedEventHandler PropertyChanged;
   
           #endregion
   

7. Create a function called NotifyPropertyChanged to help implement the object. Make sure it has a permission level of at least protected.
   

           #region Functions
           protected void NotifyPropertyChanged(String inPropertyName)
           {
               if (PropertyChanged != null)
               {
                   PropertyChanged(this, new PropertyChangedEventArgs(inPropertyName));
               }
           }
           #endregion
   

8. Make the new ViewModelBase class public and abstract.

The final object looks as follows:

using System;
using System.ComponentModel;

namespace WpfDataBindingToICommand
{
    public abstract class ViewModelBase : INotifyPropertyChanged
    {
        #region Constructors
        public ViewModelBase()
        {
        }
        #endregion

        #region Functions
        protected void NotifyPropertyChanged(String inPropertyName)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new PropertyChangedEventArgs(inPropertyName));
            }
        }
        #endregion

        #region INotifyPropertyChanged Members
        public event PropertyChangedEventHandler PropertyChanged;
        #endregion
    }
}

Note: You may also want to implement IDisposable.

Step 3 – Creating the ViewModel and Model

We are going to have the ViewModel and business in the same object for this example, but sometimes you will have a separate ViewModel object that represents your data/business.

1. Create a new class named SampleViewModel.
2. Change the using statements to implement the following : System, System.Windows, System.Windows.Input
3. Make the new SampleViewModel class public.
4. Make the new SampleViewModel class inherit ViewModelBase.
   

   using System;
   using System.Windows;
   using System.Windows.Input;
   
   namespace WpfDataBindingToICommand
   {
       public class SampleViewModel : ViewModelBase
       {
           #region Constructors
           public SampleViewModel()
           {
           }
           #endregion
       }
   }
   

5. Create a string field and property and make sure to have the property’s set function call NotifyPropertyChanged.
   

       public class SampleViewModel : ViewModelBase
       {
           string _Message = "Hello. This is the default message.";
   
           public string Message
           {
               get { return _Message; }
               set
               {
                   _Message = value;
                   NotifyPropertyChanged("Message");
               }
           }
       }
   

6. Create a simple function to show a MessageBox.
   

           public void ShowMessage(String inMessage)
           {
               MessageBox.Show(inMessage);
           }
   

7. Create an ICommand field and property. Make sure the property returns a RelayCommand object that references the ShowMessage method. This is a read only property.
   

           RelayCommand _ShowMessageCommand;
   
           public ICommand ShowMessageCommand
           {
               get
               {
                   if (_ShowMessageCommand == null)
                   {
                       _ShowMessageCommand = new RelayCommand(param => this.ShowMessage(Message));
                   }
                   return _ShowMessageCommand;
               }
           }
   

   Note: Notice that in order to pass the ShowMessage method, instead of the return value of the function, into the RelayCommand objectwhich is void anyway, the param => syntax is used.

The final SampleViewModel looks as follows.

using System;
using System.Windows;
using System.Windows.Input;

namespace WpfDataBindingToICommand
{
    public class SampleViewModel : ViewModelBase
    {
        #region Member Variables
        string _Message = "Hello. This is the default message.";
        RelayCommand _ShowMessageCommand;
        #endregion

        #region Constructors
        public SampleViewModel()
        {
        }
        #endregion

        #region Properties
        public string Message
        {
            get { return _Message; }
            set
            {
                _Message = value;
                NotifyPropertyChanged("Message");
            }
        }

        public ICommand ShowMessageCommand
        {
            get
            {
                if (_ShowMessageCommand == null)
                {
                    _ShowMessageCommand = new RelayCommand(param => this.ShowMessage(Message));
                }
                return _ShowMessageCommand;
            }
        }
        #endregion

        #region Functions
        public void ShowMessage(String inMessage)
        {
            MessageBox.Show(inMessage);
        }
        #endregion

        #region Enums
        #endregion
    }
}

Step 4 – Using Databinding to Bind an ICommand to a WPF Control

Ok, so lets modify the XAML of the default MainWindow.xaml code that was auto-created with the project. We will keep it simple and have a text box and a button to pop up the message.

Note: For this simple program all the work we did to implement databinding for binding events to methods seems like an absurd burden. However, for large applications, this design will lead to a better way to manage your code. It will decouple your GUI from your code, making future refactoring of the GUI much easier. This also improves the ability to make minor changes to the GUI. It also makes the code more sustainable and more easily tested. Unit tests are more effective as the GUI layer is not required and most functions are in the business layer.

1. Create a reference to the current namespace.
   

   <Window x:Class="WpfDataBindingToICommand.MainWindow"
           xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
           xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
           xmlns:local="clr-namespace:WpfDataBindingToICommand"
           Title="MainWindow" Height="350" Width="525">
   

2. Add a SampleViewModel StaticResource.
   

       <Window.Resources>
           <local:SampleViewModel x:Key="Sample" />
       </Window.Resources>
   

3. Set the DataContext of the Grid to the SampleViewModel StaticResource.
   

           <Grid.RowDefinitions>
               <RowDefinition Height="*" />
               <RowDefinition Height="50" />
           </Grid.RowDefinitions>
   

4. Add two rows to the Grid.
   

       <Grid DataContext="{StaticResource ResourceKey=Sample}">
   

5. Add a TextBox and remove the sizing and alignments. Set Margin to 5. Bind the Text property to Message.
   

           <TextBox Text="{Binding Message}" Name="textBoxMessage" Margin="5"/>
   

6. Add a button. Set HorizontalAlignment to Right. Set the Width to Auto. Set Margin to 5. Bind the Command property to ShowMessageCommand.
   

   <Button Command="{Binding ShowMessageCommand}" Content="ShowMessage" Grid.Row="1" Height="23" Name="buttonShowMessage" HorizontalAlignment="Right" Width="Auto" Margin="5"/>
   

You are done. The final XAML is as follows:

<Window x:Class="WpfDataBindingToICommand.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:local="clr-namespace:WpfDataBindingToICommand"
        Title="MainWindow" Height="350" Width="525">
    <Window.Resources>
        <local:SampleViewModel x:Key="Sample" />
    </Window.Resources>
    <Grid DataContext="{StaticResource ResourceKey=Sample}">
        <Grid.RowDefinitions>
            <RowDefinition Height="*" />
            <RowDefinition Height="50" />
        </Grid.RowDefinitions>
        <TextBox Text="{Binding Message}" Name="textBoxMessage" Margin="5"/>
        <Button Command="{Binding ShowMessageCommand}" Content="ShowMessage" Grid.Row="1" Height="23" Name="buttonShowMessage" HorizontalAlignment="Right" Width="Auto" Margin="5"/>
    </Grid>
</Window>

Notice that we never touched the code behind of MainWindow. The GUI and the code are as decoupled as possible. Not event the event functions are needed in the code behind. This decoupling or GUI and code is our goal.

Resources

WPF Apps With The Model-View-ViewModel Design Pattern
Understanding Routed Events and Commands In WPF

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Playing DOS games on FreeBSD

I don’t know if many of you remember my post on old DOS games and how easy it is to play them using DOSBox.  Well, it may not surprise you that you can easily install DOSBox on FreeBSD. And yes, on FreeBSD you can play all your favorite old DOS games.

Of course, I assume you have a FreeBSD desktop.

Installing DOSBox on FreeBSD

To install from ports, do this:

# #	cd /usr/ports/emulators/dosbox make install

To install from packages do this:

#	pkg_add -r dosbox

Configuring DOSBox on FreeBSD

Create a folder, probably in your home directory but it can be where ever you want, to store your DOS games.

#	mkdir ~/Games/dos

The configuration file is in your home director: ~/.dosbox/dosbox-0.74.conf

Add the following line to the end of the config under the [autoexec] section.

#	echo mount c /usr/home/username/Games/dos/ >> ~/.dosbox/dosbox-0.74.conf

Note: Make sure you have hte trailing slash ‘/’ as the path you mount to must end in a slash.

Running DOSBox on FreeBSD

DOSBox installs to /usr/local/bin/dosbox which is in $PATH so you can run DOSBox at anytime by simply typing in dosbox in a shell.

However, you can create an entry for it in KDE’s menu if you want.

Now before you go on, type in intro and read each page as you will get lots of important information about how to use DOSBox in the intro.

C:\> intro

Now make sure to read these pages. They tell you how to go full-screen, capture/release your mouse, etc…

Downloading DOS Games

As mentioned in my previous post about DOS games, you can go here to this cleverly named site to download a lot of DOS games.

Abandonia

Loading a DOS Game

It is just like DOS.  Change to the directory where your game is and run the games exe file.

For example, if you downloaded The Bard’s Tale II: The Destiny Knight, you would type the following:

Z:\> c:
C:\> cd BARD\BARD2
C:\BARD\BARD2> DK.EXE

And your game is launched.

Have fun.  It would takes years to play all the old DOS games at Abandonia.

FreeBSD or Linux

Ok, so if you have been on my site, you know that I started with Red Hat and never really got into it, and then, settles on FreeBSD.  Why would I choose FreeBSD over Linux? It fit me better.

I actually think that everybody needs to use what suits them.

This is NOT a FreeBSD versus Linux post.  It is a site to help others who are trying to decide whether to use FreeBSD or Linux see some pros and cons and get my recommendation.

FreeBSD

FreeBSD is not Linux or Unix exactly.  It is BSD. It has its own bsd kernel and an is surrounded by a base system.

Here are a list of positives about FreeBSD

• It is open to proprietary code that just can’t be used in Linux, such as Sun’s ZFS.
• It is easy to get a small install of just the base system with minimal to no features installed. (Security! Attach surface area is minimized when less software is included.)
• Jails
• The ports tree for compiling from source is unmatched by any Linux operating system, but if you prefer binaries, yes, it has them too.
• Installing software has less problems as you compile it on the system, with the settings you need (rather than get binaries that may have been compiled for a different system or without the settings you need).
• The documentation is far better than most other open source projects and better than most projects commercial or open source for that matter!
• OS X chose to use much of FreeBSD in its underlying operating system and so when combining the OS X and FreeBSD market share, FreeBSD code is actually used on more systems than any operating system other than Windows.
• There are not that many BSD distributions, and the ones that exist have clear focusses different than the others, that later they share.  FreeBSD is a solid server. PC-BSD is a desktop focussed on avoiding dependency problems with its software. OpenBSD is extremely securee. NetBSD is extremely compatible with lots of hardware.  They contribute back to each other often.
• The License is free and gives everyone who uses it true freedom.
• The License is free for commercial use.
• Easy Editor. Newbies can actually use this editor included in the FreeBSD base system.  Don’t forget to learn vi though.
• Patching is as simple as running freebsd-update.

Here are a list of negatives about FreeBSD

• Hardware companies tend to make drivers for Windows and Linux first and often don’t include FreeBSD, though most hardware is soon supported.
• There is not a native Flash Player in FreeBSD, instead the Linux version of Flash must be used.
• There Desktop options for FreeBSD are not as rich as those for Linux (Example: KDE network settings doesn’t work on FreeBSD, but PC-BSD has their own settings now.)
• IT/Developers forFreeBSD are harder to come by.

Linux

Linux was originally just a kernel.  The userland was separate.  Now there are plenty of projects that make a nice complete operating system using the Linux kernel and a nice base system surrounding it.

Here are a list of positives about Linux

• It has a large user base.
• Free to use.
• There are plenty of distros to choose from.
• It is no longer just a kernel but many different groups put out an actual system: Red Hat/Fedora, Debian/Ubuntu, CentOS, SUSE, Arch, Gentoo, etc…
• A lot of work is going into the desktop environment
• Development for any Linux platform could benefit all Linux platforms.
• More and more hardware companies are including Linux drivers
• Some Software companies make Linux software as well, and the number is increasing
• Strong commercial backing (which doesn’t make sense for software licensed under the GPL)

Here are some negatives

• There is often a lot of binary packages that just don’t work.
• Lack of consolidation.  There are a lot of distributions of Linux and they are not the same. Which one do you choose.
• Many Linuxes (not all) are now installing desktop software by default, and no longer are minimalistic. (Security! Attach surface area is increased when more software is included.)
• The inability to write and distribute software that touches GPL software, without having to release your software as GPL too.
• If you hope to do anything other than use the software or help the community, you need a lawyer to figure out how to interact with the various versions of GPL.
• The security settings are usually not easy to use and are result in users just turning them off (i.e. SELinux)
• Are Red Hat and SUSE open source or commercial, they sell support but the software is free, except you can’t get updates without buying support…confusing!
• IT guys who claim to know Linux usually have done little more than run Ubuntu for a few days.

This is not a flame post and any responses that appear to be trolls will be deleted.

My recommendations

Ok, so what would I recommend if I were paid by a company for consulting?

Server (LAMP)

For a Server running Apache, PHP, SQL, often mis-termed LAMP (Linux Apache MySQL PHP) but really means any OS, Web Server, SQL, Script language.

Recommended OS: FreeBSD

Commerical Appliance

If you work for a company and you need a commercial appliance. Stay away from the dangers of the GPL, just don’t go there.

Recommended OS: FreeBSD

Open Source Desktop

For a quick desktop for a home user that has PC hardware but doesn’t have a license for Windows and doesn’t want to buy one.

Recommended OS: Ubuntu

Note: Sorry PC-BSD friends. Keep working on it.

Commerical Desktop for Employees

If you want a good commercial desktop, you should go with one of the following depending on certain factors, the primary being that some software you may need to use only runs on these two platforms.

Recommended OS: Windows 7 or OS X

However, Ubuntu, Red Hat, SUSE, Fedora, PC-BSD, are all very usable replacements depending on the situation.

Point of Sale (POS) Device

If you need to have to have a POS device for handling sales.

Recommended OS: Depends on needs

 

Share your thoughts

Hey, please comment.  No flame wars though.  I repeat, this is not a FreeBSD versus Linux post, but a FreeBSD or Linux post, with just some information from my experience. I appreciate all technology and any rude comments will be deleted.  However, feel free to challenge and provide facts, demand facts, etc…

 

Creating or opening a password protected zip file on FreeBSD

So this works on FreeBSD but it probably works on OS X, most Linuxes, Solaris, and other Unixes as well.

Installing prerequisites

In order to create a password protected zip file and later open it, two ports are needed:

• zip
• unzip

To install these using packages, do this as root:

# #	pkg_add zip pkg_add unzip

Or using ports:

# # # #

cd /usr/ports/archivers/zip make install cd /usr/ports/archivers/unzip make install

Creating a password protected zip file

There are a couple of different ways you may want to create a zip file. You may want to zip a sing file, or two or more files, or and entire directory and all its contents. You may also want to add a file to an existing zip file.

All of these actions can be done with a binary called zip.

Example 1 – Creating a password protected zip file containing one file

The syntax is simple. The -e parameter is to encrypt with a password. Always put the zip file first and the file to be zipped second.

# zip -e myarchive.zip myfile1

Example 2 – Adding a file to your password protected zip file

Since your zip file already is encrypted with a password and adding a file does not require decrypting, you don’t need the password to add a file to the zip file.

# zip myarchive.zip myfile2

Example 3 – Creating a password protected zip file containing multiple files

This is very similar to Example 1. The -e parameter is to encrypt with a password. Always put the zip file first and the files to be zipped last separated by a space.

# zip -e myarchive.zip myfile1 myfile2 myfile3

Example 4 – Creating a password protected zip file containing a directory and all is contents.

The -r parameter is to do a recursive zip (recursive means to include the folder and all its contents). The -e parameter is to encrypt with a password. Always put the zip file first and then the directory name.

# zip -r -e myarchive.zip mydirectory

Example 5 – Delete a file from the zip

This is easier than you think. Because you are not actually reading the contents of a file in the archive, the password is not needed to delete a file inside the zip file.

# zip -d myarchive.zip myfile1

Opening a password protected zip file

The syntax for unzipping a file is a lot easier.  It uses a different binary file called unzip.

# unzip myarchive.zip

The above prompts for the password automatically and unzips the files, assuming the correct password is provided.

Tutorial – Binding to a member variable object

You have your WPF Window and you have an object that you don’t want to make a static resource. You want to declare it as a member variable in the code.

Example 1 – Binding two TextBox controls to a Person object

1. Create a New WPF Application Visual Studio.
2. Create a new Class named Person.cs.
3. Give it FirstName and a LastName properties.
4. Configure it to implement the INotifyPropertyChanged interface.
5. Create a NotifyPropertyChanged function that all properties can share (to avoid duplicate code in every single property).
6. Configure the properties to call the NotifyPropertyChanged function passing in a string that is the name of the property.

   Person.cs

   using System;
   using System.ComponentModel;
   
   namespace WPFPerson
   {
       public class Person : INotifyPropertyChanged
       {
           #region Member Variables
           String _FirstName;
           String _LastName;
           #endregion
   
           #region Constructors
           /*
   		 * The default constructor
    		 */
           public Person()
           {
           }
           #endregion
   
           #region Properties
           public String FirstName
           {
               get { return _FirstName; }
               set
               {
                   _FirstName = value;
                   NotifyPropertyChanged("FirstName");
               }
           }
   
           public String LastName
           {
               get { return _LastName; }
               set
               {
                   _LastName = value;
                   NotifyPropertyChanged("LastName");
               }
           }
           #endregion
   
           #region INotifyPropertyChanged Members
           public event PropertyChangedEventHandler PropertyChanged;
   
           private void NotifyPropertyChanged(String info)
           {
               if (PropertyChanged != null)
               {
                   PropertyChanged(this, new PropertyChangedEventArgs(info));
               }
           }
           #endregion
       }
   }
   

7. Go back tot he MainWindow.xaml.
8. Add two labels, and two text boxes, and a button.
9. Change the text boxes to be populated using binding by adding the following text:
   Text=”{Binding FirstName, Mode=TwoWay}”  

   MainWindow.xaml (WPF Window)

   <Window x:Class="WPFPerson.MainWindow"
           xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
           xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
           Title="MainWindow" Height="350" Width="525" >
       <Grid Name="PersonGrid" >
           <TextBox Height="23" HorizontalAlignment="Left" Margin="173,87,0,0" Name="textBoxFirstName" VerticalAlignment="Top" Width="234" Text="{Binding FirstName, Mode=TwoWay}" />
           <TextBox Height="23" HorizontalAlignment="Left" Margin="173,116,0,0" Name="textBoxLastName" VerticalAlignment="Top" Width="234" Text="{Binding LastName, Mode=TwoWay}"/>
           <Label Content="FirstName" Height="28" HorizontalAlignment="Left" Margin="103,85,0,0" Name="labelFirstName" VerticalAlignment="Top" />
           <Label Content="LastName" Height="28" HorizontalAlignment="Left" Margin="103,114,0,0" Name="labelLastName" VerticalAlignment="Top" />
           <Button Content="Defaults" Height="23" HorizontalAlignment="Left" Margin="337,199,0,0" Name="buttonDefaults" VerticalAlignment="Top" Width="75" Click="buttonDefaults_Click" />
       </Grid>
   </Window>
   

10. Double-click the button to create the buttonDefaults_Click event function.
    This also conveniently takes you to the Code Behind of the MainWindow.cs file.
11. Have the buttonDefaults_Click function update to properties of your _Person object.
    _Person.FirstName = “Jared”;
    _Person.LastName = “Barneck”;
12. Create a field/member variable using the Person object.
    private readonly Person _Person;
13. Now in the constructor initialize the object.
    _Person = new Person();
14. Also in the constructor, make the DataContext for each TextBox the _Person object.
    textBoxFirstName.DataContext = _Person;
    textBoxLastName.DataContext = _Person;  

    MainWindow.cs (Code Behind)

    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Windows;
    using System.Windows.Controls;
    using System.Windows.Data;
    using System.Windows.Documents;
    using System.Windows.Input;
    using System.Windows.Media;
    using System.Windows.Media.Imaging;
    using System.Windows.Navigation;
    using System.Windows.Shapes;
    using System.Threading;
    
    namespace WPFPerson
    {
        /// <summary>
        /// Interaction logic for MainWindow.xaml
        /// </summary>
        public partial class MainWindow : Window
        {
            private readonly Person _Person;
    
            public MainWindow()
            {
                _Person = new Person();
                InitializeComponent();
                textBoxFirstName.DataContext = _Person;
                textBoxLastName.DataContext = _Person;
            }
    
            private void buttonDefaults_Click(object sender, RoutedEventArgs e)
            {
                _Person.FirstName = "Jared";
                _Person.LastName = "Barneck";
            }
        }
    }
    

15. Now Now compile and make sure you don’t have any errors.

Example 2 – Forthcoming…

Example 3 – Forthcoming…

Sources:

http://www.wrox.com/WileyCDA/Section/Windows-Presentation-Foundation-WPF-Data-Binding-with-C-2005.id-305562.html

Making a package from a port on FreeBSD

Some times is it the simple things that people don’t know. For example, I have always just installed software from ports. Every now and then I would use pkg_add -r to pull a pre-made package from a FreeBSD package server. But I have never actually made a package myself. I have been using FreeBSD for 10 years and many consider me an expert in some areas.  Well, like I always say, it is possible to be an expert in many areas and still be a newbie in some areas.

Recently, I am looking into steps to make a BSD appliance and so I want to keep the system as minimal as possible. So I want to build packages on on a separate build box. So I suddenly realized that I have never made a package myself and I wasn’t exactly sure how.

So is it hard to convert a port into a package? Of course not. If you want to make a package from a port, and you are familiar with ports already, then all you have to do is run make package, and you may want to make the dependent packages as well.

If you need some more granular steps, I will provide them. You just need to follow some simple steps:

FreeBSD make package

Lets assume you want to install lighttpd.

1. Download the latest ports tree. See this article: How to install ports on FreeBSD?
2. Search for the port you want.

   # #	cd /usr/ports make search name=lighttpd

   The output should look as follows:

   Port: lighttpd-1.4.28_4
   Path: /usr/ports/www/lighttpd
   Info: A secure, fast, compliant, and very flexible Web Server
   Maint: mm@FreeBSD.org
   B-deps: libtool-2.2.10 pcre-8.10 pkg-config-0.25_1
   R-deps: pcre-8.10
   WWW: http://www.lighttpd.net/
3. Look at the R-Deps. R is short for Run and deps is short for dependencies. If you want a package for lighttpd, it requires pcre-8.10 to run, so you will need a package for pcre-8.10 as well.
   Note: B-deps are not need. B is for Build. These dependencies are only need to build the package.  Once the package is built, they are not needed, so you don’t need to create packages for them.
4. Make the lighttpd package:

   # #	cd /usr/ports/www/lighttpd make package

5. This creates the file in the /usr/ports/www/lightpd. You may have a directory or share where you store your packages, and you can copy it there if you want. Especially if this is a build machine in a vm that you plan to revert, you need to copy this off the machine or you will lose it when you revert.
6. Make the pcre package.

   # #	cd /usr/ports/devel/pcre make package

7. This creates the file in the /usr/ports/www/lightpd. You may have a directory or share where you store your packages, and you can copy it there if you want. Especially if this is a build machine in a vm that you plan to revert, you need to copy this off the machine or you will lose it when you revert.

Hopefully this helps you if you ever need to make your packages on one box.

This is also something great to do before an install fest so you can have the latest packages available. Lets say you want to do an install fest for a FreeBSD desktop, you could have all the latest Xorg and Fluxbox or KDE or GNOME packages already built.

Build machine notes
On your build machine “make package” will actually install the package in the process of building the package. However, that is not really a concern as this is a build machine. My recommendation is that you create a build machine in VirtualBox and snapshot it after you download ports. Usually you just continue making packages. When you decide it is time to go back to a clean system, 1) revert your snapshot, 2) update your ports tree, 3) make your new packages.