PowerShell Friday: Kerstspecial

Gepubliceerd op 24 december 2015 • 5 min leestijd • 1.019 woorden

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Morgen is het Kerstmis, dus dit bericht is een dag te vroeg, maar ik wilde je iets geven waarmee je kunt spelen als je klaar bent met eten, drinken en…

Morgen is het Kerstmis, dus dit bericht is een dag te vroeg, maar ik wilde je iets geven waarmee je kunt spelen als je klaar bent met eten, drinken en vrolijk zijn. Dat is de reden dat ik je geen PowerShell- of PowerCLI-scripts geef die iets met werk te maken hebben.

U kunt veel meer met PowerShell doen dan u misschien denkt. Alles wat u maar kunt bedenken, kunt u maken met PowerShell. Het maakt niet uit of het muziek afspeelt, ASCII-kunst weergeeft, of iets compleet verbijsterends.

Wij wensen u prettige kerstdagen

Wij hier bij VMGuru willen u een vrolijk kerstfeest wensen. Natuurlijk willen we dat op een nerd-manier doen. Vorig jaar plaatste Øyvind Kallstad een script dat het nummer ‘We wish you a merry Christmas’ afspeelt vanaf de opdrachtregel. Dit is echt iets meer dan wat u waarschijnlijk normaal met PowerShell doet.

Het geluid ervan roept herinneringen op. Oh, die herinneringen aan op maat gemaakte printerpoort-add-ons zoals de Covox Speech plug die MOD-muziek afspelen via je printerpoort.

Verwacht geen audio van hoge kwaliteit van dit script, maar toch: geniet van de muziek.

Powershell
try {
Add-Type -TypeDefinition @"
    public enum Duration
    {
        WHOLE     = 1600,
        HALF      = WHOLE/2,
        QUARTER   = HALF/2,
        EIGHTH    = QUARTER/2,
        SIXTEENTH = EIGHTH/2,
    }
"@
}
catch{ }

function ConvertTo-NoteFrequency {
    <#
        .SYNOPSIS
            Convert note names to MIDI note number and frequency.
        .DESCRIPTION
            This function takes a note name and will convert it to it's MIDI note number
            as well as the frequency of the note. It uses the 12-tone scale and
            supports both the 'regular', and the 'German' scale where 'H' is used instead of 'B'.
        .EXAMPLE
            ConvertTo-NoteFrequency 'A#4'
        .EXAMPLE
            ConvertTo-NoteFrequency 'b5' -UseAlternateScale
        .EXAMPLE
            (ConvertTo-NoteFrequency 'e5').Play(200)
        .EXAMPLE
            (ConvertTo-NoteFrequency 'e5').Play(\[Duration\]::QUARTER)
        .NOTES
            Author: Øyvind Kallstad
            Date: 14.12.2014
            Version: 1.0
    #>
    \[CmdletBinding()\]
    param (
        # The name of the note.
        \[Parameter(Position = 0, Mandatory = $true)\]
        \[ValidateNotNullorEmpty()\]
        \[string\] $Note,

        # Default octave to append to note if none are present.
        \[Parameter()\]
        \[ValidateRange(0,8)\]
        \[int\] $DefaultOctave = 0,

        # Use this switch to use the alternate scale used in parts of northern europe where B = H.
        \[Parameter()\]
        \[switch\] $UseAlternateScale
    )

    # split note input into the note part and the octave part
    $noteSplit = $Note -split '(\\d)'
    $noteName = $noteSplit\[0\]
    \[int\]$octave = $noteSplit\[1\]
    Write-Verbose "Note Name: $noteName"

    # convert to lower case
    $noteName = $noteName.ToLower()

    # replace flats with sharps
    $noteName = $noteName -replace 'db', 'c#'
    $noteName = $noteName -replace 'eb', 'd#'
    $noteName = $noteName -replace 'gb', 'f#'

    # handle alternate scale
    if($UseAlternateScale) {
        $scale  = @('a','a#','h','c','c#','d','d#','e','f','f#','g','g#')
        $noteName = $noteName -replace 'b', 'a#'
        $regexString = '^\[acdefgh\]#{0,1}$'
    }
    else {
        $scale  = @('a','a#','b','c','c#','d','d#','e','f','f#','g','g#')
        $noteName = $noteName -replace 'bb', 'a#'
        $regexString = '^\[abcdefg\]#{0,1}$'
    }

    Write-Verbose "Note Name after conversion: $noteName"

    # validate note name
    if (-not($noteName -match $regexString)) {
        Write-Warning "'$($Note)' is not a valid note name!"
    }

    else {
        # if no octave information is given, add default octave
        if(-not($octave)) {
            $octave = $DefaultOctave
        }
        Write-Verbose "Ocatave: $octave"

        # if note is above 'c', subtract 1 to the octave - since 'c' marks the beginning of the next octave
        $inputOctave = $octave
        if(-not($scale\[0..2\] -contains $noteName)) {
            if($octave -gt 0) {
                $octave--
                Write-Verbose "Octave after conversion: $($octave)"
            }
        }

        # find the number of half-steps up from 'A'
        $halfSteps = 0
        foreach ($scaleNote in $scale) {
            if(-not($scaleNote -eq $noteName)) {
                $halfSteps++
            }
            else {
                break
            }
        }
        Write-Verbose "Number of half-steps up from A: $($halfSteps)"

        # we initially set the frequency of A0
        # then update it with the frequency of 'A' in the same octave as the Note
        $aFrequencyInNoteOctave = 27.5
        for ($i = 0; $i -lt $octave; $i++) {
            $aFrequencyInNoteOctave = $aFrequencyInNoteOctave \* 2
        }
        Write-Verbose "The frequency of 'A' in octave $($octave) is $($aFrequencyInNoteOctave)"

        # calculate the note frequency
        $noteFrequency = \[math\]::Pow(\[math\]::Pow(2,(1/12)),$halfSteps) \* $aFrequencyInNoteOctave

        # calculate the MIDI note number of the note
        $midiNoteNumber = \[math\]::Round(12 \* \[math\]::Log(($noteFrequency/440),2)) + 69

        $output = New-Object -TypeName 'PSObject'
        $output | Add-Member -MemberType NoteProperty -Name 'Input' -Value $Note
        $output | Add-Member -MemberType NoteProperty -Name 'Note' -Value ($notaName + $inputOctave)
        $output | Add-Member -MemberType NoteProperty -Name 'Frequency' -Value $noteFrequency
        $output | Add-Member -MemberType NoteProperty -Name 'MidiNumber' -Value $midiNoteNumber
        $output | Add-Member -Name 'Play' -MemberType ScriptMethod -Value {param(\[int\]$Length)\[System.Console\]::Beep($this.Frequency,$Length)}
        
        Write-Output $output
    }
}

# define melody
$melody = @(
    @('g4',\[Duration\]::EIGHTH), @('PAUSE',\[Duration\]::SIXTEENTH),
    @('c5',\[Duration\]::EIGHTH), @('PAUSE',\[Duration\]::SIXTEENTH),
    @('c5',\[Duration\]::EIGHTH),
    @('d5',\[Duration\]::EIGHTH),
    @('c5',\[Duration\]::EIGHTH),
    @('b4',\[Duration\]::EIGHTH),
    @('a4',\[Duration\]::EIGHTH), @('PAUSE',\[Duration\]::SIXTEENTH),
    @('a4',\[Duration\]::EIGHTH), @('PAUSE',\[Duration\]::SIXTEENTH),
    @('a4',\[Duration\]::EIGHTH), @('PAUSE',\[Duration\]::SIXTEENTH),
    @('d5',\[Duration\]::EIGHTH), @('PAUSE',\[Duration\]::SIXTEENTH),
    @('d5',\[Duration\]::EIGHTH),
    @('e5',\[Duration\]::EIGHTH),
    @('d5',\[Duration\]::EIGHTH),
    @('c5',\[Duration\]::EIGHTH),
    @('b4',\[Duration\]::EIGHTH), @('PAUSE',\[Duration\]::SIXTEENTH),
    @('g4',\[Duration\]::EIGHTH), @('PAUSE',\[Duration\]::SIXTEENTH)
    @('g4',\[Duration\]::EIGHTH), @('PAUSE',\[Duration\]::SIXTEENTH),
    @('e5',\[Duration\]::EIGHTH), @('PAUSE',\[Duration\]::SIXTEENTH),
    @('e5',\[Duration\]::EIGHTH),
    @('f5',\[Duration\]::EIGHTH),
    @('e5',\[Duration\]::EIGHTH),
    @('d5',\[Duration\]::EIGHTH),
    @('c5',\[Duration\]::EIGHTH), @('PAUSE',\[Duration\]::SIXTEENTH),
    @('a4',\[Duration\]::EIGHTH), @('PAUSE',\[Duration\]::SIXTEENTH),
    @('g4',\[Duration\]::EIGHTH), @('PAUSE',\[Duration\]::SIXTEENTH),
    @('a4',\[Duration\]::EIGHTH), @('PAUSE',\[Duration\]::SIXTEENTH),
    @('d5',\[Duration\]::EIGHTH), @('PAUSE',\[Duration\]::SIXTEENTH),
    @('b4',\[Duration\]::EIGHTH), @('PAUSE',\[Duration\]::SIXTEENTH),
    @('c5',\[Duration\]::EIGHTH)
)

# play melody
foreach ($note in $melody) {
    if (-not($note\[0\] -eq 'PAUSE')) {
        (ConvertTo-NoteFrequency $note\[0\]).Play($note\[1\])
    }
    else {
        Start-Sleep -Milliseconds $note\[1\]
    }
}

Ik heb nog een kerstscript ‘geschreven’ dat je ASCII-kunst laat zien. Het is niet erg geavanceerd en flitsend, maar toch.

Powershell
$christmas = @"
     \_\_,\_,\_,\_\_\_)          \_\_\_\_\_\_\_
    (--| | |             (--/    ),\_)        ,\_) 
       | | |  \_ ,\_,\_        |     |\_ ,\_ ' , \_|\_,\_,\_, \_  ,
     \_\_| | | (/\_| | (\_|     |     | ||  |/\_)\_| | | |(\_|/\_)\_\_\_,
    (      |\_\_\_,   ,\_\_|     \\\_\_\_\_)  |\_\_,           |\_\_,

                            |                         \_....\_
                         \\  \_  /                    .:⭕::::.
                          (\\o/)                    .:::''''⭕.
                      --- / \\  --- ⭕\_    \_:::
                           >\*<                     \`:}\_>()<\_{:'
                          >0<@<                 @    \`'//\\\\'\`    @ 
                         >>>@<<\*              @ #     //  \\\\     # @
                        >@>\*<0<<<           \_\_#\_#\_\_\_\_/'\_\_\_\_'\\\_\_\_\_#\_#\_\_
                       >\*>>@<<<@<<         \[\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\]
                      >@>>0<<<\*<<@<         |=\_- .-/\\ /\\ /\\ /\\--. =\_-|
                     >\*>>0<<@<<<@<<<        |-\_= | \\ \\\\ \\\\ \\\\ \\ |-\_=-|
                    >@>>\*<<@<>\*<<0<\*<       |\_=-=| / // // // / |\_=-\_|
      \\\*/          >0>>\*<<@<>0><<\*<@<<      |=\_- |\`-'\`-'\`-'\`-'  |=\_=-|
  \_\_\_\\\\U//\_\_\_     >\*>>@><0<<\*>>@><\*<0<<     | =\_-| o          o |\_==\_| 
  |\\\\ | | \\\\|    >@>>0<\*<<0>>@<<0<<<\*<@<    |=\_- | !     (    ! |=-\_=|
  | \\\\| | \_(UU)\_ >((\*))\_>0><\*<0><@<<<0<\*<  \_|-,-=| !    ).    ! |-\_-=|\_
  |\\ \\| || / //||.\*.\*.\*.|>>@<<\*<<@>><0<<@</=-((=\_| ! \_\_(:')\_\_ ! |=\_==\_-\\
  |\\\\\_|\_|&&\_// ||\*.\*.\*.\*|\_\\\\db//\_\_     (\\\_/)-=))-|/^\\=^=^^=^=/^\\| \_=-\_-\_\\
  """"|'.'.'.|~~|.\*.\*.\*|     \_\_\_\_|\_   =('.')=//   ,------------.      
  jgs |'.'.'.|   ^^^^^^|\_\_\_\_|>>>>>>|  ( ~~~ )/   (((((((())))))))   
      ~~~~~~~~         '""""\`------'  \`w---w\`     \`------------'
"@

Clear-Host

$christmas