Carbon.Windows

1.0.0

Modules/Carbon.Registry/1.0.0/Carbon.Registry.psm1

# Copyright WebMD Health Services
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License

#Requires -Version 5.1
Set-StrictMode -Version 'Latest'

# Functions should use $moduleRoot as the relative root from which to find
# things. A published module has its function appended to this file, while a
# module in development has its functions in the Functions directory.
$moduleRoot = $PSScriptRoot

# Store each of your module's functions in its own file in the Functions
# directory. On the build server, your module's functions will be appended to
# this file, so only dot-source files that exist on the file system. This allows
# developers to work on a module without having to build it first. Grab all the
# functions that are in their own files.
$functionsPath = Join-Path -Path $moduleRoot -ChildPath 'Functions\*.ps1'
if( (Test-Path -Path $functionsPath) )
{
    foreach( $functionPath in (Get-Item $functionsPath) )
    {
        . $functionPath.FullName
    }
}



function Get-CRegistryKeyValue
{
    <#
    .SYNOPSIS
    Gets the value from a registry key.
 
    .DESCRIPTION
    PowerShell's `Get-ItemProperty` cmdlet is a pain to use. It doesn't actually return an object representing a
    registry key's value, but some other weird object that requires painful gyrations to get values from. This function
    returns just the value of a key.
 
    .EXAMPLE
    Get-CRegistryKeyValue -Path 'hklm:\Software\Carbon\Test' -Name 'Title'
 
    Returns the value of the 'hklm:\Software\Carbon\Test' key's `Title` value.
    #>
    [CmdletBinding()]
    param(
        # The path to the registry key where the value should be set. Will be created if it doesn't exist.
        [Parameter(Mandatory)]
        [String] $Path,

        # The name of the value being set.
        [Parameter(Mandatory)]
        [String] $Name
    )

    Set-StrictMode -Version 'Latest'
    Use-CallerPreference -Cmdlet $PSCmdlet -Session $ExecutionContext.SessionState

    if (-not (Test-CRegistryKeyValue -Path $Path -Name $Name))
    {
        return $null
    }

    $itemProperties = Get-ItemProperty -Path $Path -Name *
    $value = $itemProperties.$Name
    Write-Debug -Message ('[{0}@{1}: {2} -is {3}' -f $Path,$Name,$value,$value.GetType())
    return $value
}




function Install-CRegistryKey
{
    <#
    .SYNOPSIS
    Creates a registry key. If it already exists, does nothing.
 
    .DESCRIPTION
    Given the path to a registry key, creates the key and all its parents. If the key already exists, nothing happens.
 
    .EXAMPLE
    Install-CRegistryKey -Path 'hklm:\Software\Carbon\Test'
 
    Creates the `hklm:\Software\Carbon\Temp` registry key if it doesn't already exist.
    #>
    [CmdletBinding(SupportsShouldPRocess)]
    param(
        # The path to the registry key to create.
        [Parameter(Mandatory)]
        [String] $Path
    )

    Set-StrictMode -Version 'Latest'
    Use-CallerPreference -Cmdlet $PSCmdlet -Session $ExecutionContext.SessionState

    if (-not (Test-Path -Path $Path -PathType Container))
    {
        Write-Information " + ${Path}"
        New-Item -Path $Path -ItemType RegistryKey -Force | Out-String | Write-Verbose
    }
}



function Remove-CRegistryKeyValue
{
    <#
    .SYNOPSIS
    Removes a value from a registry key, if it exists.
 
    .DESCRIPTION
    If the given key doesn't exist, nothing happens.
 
    .EXAMPLE
    Remove-CRegistryKeyValue -Path hklm:\Software\Carbon\Test -Name 'InstallPath'
 
    Removes the `InstallPath` value from the `hklm:\Software\Carbon\Test` registry key.
    #>
    [CmdletBinding(SupportsShouldProcess)]
    param(
        # The path to the registry key where the value should be removed.
        [Parameter(Mandatory)]
        [String] $Path,

        # The name of the value to remove.
        [Parameter(Mandatory)]
        [String] $Name
    )

    Set-StrictMode -Version 'Latest'
    Use-CallerPreference -Cmdlet $PSCmdlet -Session $ExecutionContext.SessionState

    if (-not (Test-CRegistryKeyValue -Path $Path -Name $Name))
    {
        return
    }

    if (-not $PSCmdlet.ShouldProcess(("Item: ${Path} Property: ${Name}"), 'Remove Property'))
    {
        return
    }

    Write-Information " ${Path} - ${Name}"
    Remove-ItemProperty -Path $Path -Name $Name
}



function Set-CRegistryKeyValue
{
    <#
    .SYNOPSIS
    Sets a value in a registry key.
 
    .DESCRIPTION
    The `Set-CRegistryKeyValue` function sets the value of a registry key. If the key doesn't exist, it is created
    first. Uses PowerShell's `New-ItemPropery` to create the value if doesn't exist. Otherwise uses `Set-ItemProperty`
    to set the value.
 
    `DWord` and `QWord` values are stored in the registry as unsigned integers. If you pass a negative integer for the
    `DWord` and `QWord` parameters, PowerShell will convert it to an unsigned integer before storing. You won't get the
    same negative number back.
 
    To store integer values greater than `[Int32]::MaxValue` or `[Int64]::MaxValue`, use the `UDWord` and `UQWord`
    parameters, respectively, which are unsigned integers. These parameters were in Carbon 2.0.
 
    In versions of Carbon before 2.0, you'll need to convert these large unsigned integers into signed integers. You
    can't do this with casting. Casting preservers the value, not the bits underneath. You need to re-interpret the
    bits. Here's some sample code:
 
        # Carbon 1.0
        $bytes = [BitConverter]::GetBytes( $unsignedInt )
        $signedInt = [BitConverter]::ToInt32( $bytes, 0 ) # Or use `ToInt64` if you're working with 64-bit/QWord values
        Set-CRegistryKeyValue -Path $Path -Name 'MyUnsignedDWord' -DWord $signedInt
 
        # Carbon 2.0
        Set-CRegistryKeyValue -Path $Path -Name 'MyUnsignedDWord' -UDWord $unsignedInt
 
    .LINK
    Get-CRegistryKeyValue
 
    .LINK
    Test-CRegistryKeyValue
 
    .EXAMPLE
    Set-CRegistryKeyValue -Path 'hklm:\Software\Carbon\Test -Name Status -String foobar
 
    Creates the `Status` string value under the `hklm:\Software\Carbon\Test` key and sets its value to `foobar`.
 
    .EXAMPLE
    Set-CRegistryKeyValue -Path 'hklm:\Software\Carbon\Test -Name ComputerName -String '%ComputerName%' -Expand
 
    Creates an expandable string. When retrieving this value, environment variables will be expanded.
 
    .EXAMPLE
    Set-CRegistryKeyValue -Path 'hklm:\Software\Carbon\Test -Name Movies -String ('Signs','Star Wars','Raiders of the Lost Ark')
 
    Sets a multi-string (i.e. array) value.
 
    .EXAMPLE
    Set-CRegistryKeyValue -Path hklm:\Software\Carbon\Test -Name 'SomeBytes' -Binary ([byte[]]@( 1, 2, 3, 4))
 
    Sets a binary value (i.e. `REG_BINARY`).
 
    .EXAMPLE
    Set-CRegistryKeyValue -Path hklm:\Software\Carbon\Test -Name 'AnInt' -DWord 48043
 
    Sets a binary value (i.e. `REG_DWORD`).
 
    .EXAMPLE
    Set-CRegistryKeyValue -Path hklm:\Software\Carbon\Test -Name 'AnInt64' -QWord 9223372036854775807
 
    Sets a binary value (i.e. `REG_QWORD`).
 
    .EXAMPLE
    Set-CRegistryKeyValue -Path hklm:\Software\Carbon\Test -Name 'AnUnsignedInt' -UDWord [uint32]::MaxValue
 
    Demonstrates how to set a registry value with an unsigned integer or an integer bigger than `[int]::MaxValue`.
 
    The `UDWord` parameter was added in Carbon 2.0. In earlier versions of Carbon, you have to convert the unsigned
    int's bits to a signed integer:
 
        $bytes = [BitConverter]::GetBytes( $unsignedInt )
        $signedInt = [BitConverter]::ToInt32( $bytes, 0 )
        Set-CRegistryKeyValue -Path $Path -Name 'MyUnsignedDWord' -DWord $signedInt
 
    .EXAMPLE
    Set-CRegistryKeyValue -Path hklm:\Software\Carbon\Test -Name 'AnUnsignedInt64' -UQWord [uint64]::MaxValue
 
    Demonstrates how to set a registry value with an unsigned 64-bit integer or a 64-bit integer bigger than
    `[long]::MaxValue`.
 
    The `UQWord parameter was added in Carbon 2.0. In earlier versions of Carbon, you have to convert the unsigned int's
    bits to a signed integer:
 
        $bytes = [BitConverter]::GetBytes( $unsignedInt )
        $signedInt = [BitConverter]::ToInt64( $bytes, 0 )
        Set-CRegistryKeyValue -Path $Path -Name 'MyUnsignedDWord' -DWord $signedInt
 
    .EXAMPLE
    Set-CRegistryKeyValue -Path hklm:\Software\Carbon\Test -Name 'UsedToBeAStringNowShouldBeDWord' -DWord 1 -Force
 
    Uses the `Force` parameter to delete the existing `UsedToBeAStringNowShouldBeDWord` before re-creating it. This
    flag is useful if you need to change the type of a registry value.
    #>
    [CmdletBinding(SupportsShouldPRocess, DefaultParameterSetName='String')]
    param(
        # The path to the registry key where the value should be set. Will be created if it doesn't exist.
        [Parameter(Mandatory)]
        [String] $Path,

        # The name of the value being set.
        [Parameter(Mandatory)]
        [String] $Name,

        # The value's data. Creates a value for holding string data (i.e. `REG_SZ`). If `$null`, the value will be
        # saved as an empty string.
        [Parameter(Mandatory, ParameterSetName='String')]
        [AllowEmptyString()]
        [AllowNull()]
        [String] $String,

        # The string should be expanded when retrieved. Creates a value for holding expanded string data (i.e.
        # `REG_EXPAND_SZ`).
        [Parameter(ParameterSetName='String')]
        [switch] $Expand,

        # The value's data. Creates a value for holding binary data (i.e. `REG_BINARY`).
        [Parameter(Mandatory, ParameterSetName='Binary')]
        [byte[]] $Binary,

        # The value's data. Creates a value for holding a 32-bit integer (i.e. `REG_DWORD`).
        [Parameter(Mandatory, ParameterSetName='DWord')]
        [int] $DWord,

        # The value's data as an unsigned integer (i.e. `UInt32`). Creates a value for holding a 32-bit integer (i.e.
        # `REG_DWORD`).
        [Parameter(Mandatory, ParameterSetName='DWordAsUnsignedInt')]
        [UInt32] $UDWord,

        # The value's data. Creates a value for holding a 64-bit integer (i.e. `REG_QWORD`).
        [Parameter(Mandatory, ParameterSetName='QWord')]
        [long] $QWord,

        # The value's data as an unsigned long (i.e. `UInt64`). Creates a value for holding a 64-bit integer (i.e.
        # `REG_QWORD`).
        [Parameter(Mandatory, ParameterSetName='QWordAsUnsignedInt')]
        [UInt64] $UQWord,

        # The value's data. Creates a value for holding an array of strings (i.e. `REG_MULTI_SZ`). Pass an empty array
        # or `$null` to set the value to an empty list.
        [Parameter(Mandatory, ParameterSetName='MultiString')]
        [AllowEmptyCollection()]
        [AllowNull()]
        [String[]] $Strings,

        # Removes and re-creates the value. Useful for changing a value's type.
        [switch] $Force
    )

    Set-StrictMode -Version 'Latest'
    Use-CallerPreference -Cmdlet $PSCmdlet -Session $ExecutionContext.SessionState

    $value = $null
    $type = $pscmdlet.ParameterSetName
    switch -Exact ($PSCmdlet.ParameterSetName)
    {
        'String'
        {
            $value = $String
            if( $Expand )
            {
                $type = 'ExpandString'
            }
        }
        'Binary' { $value = $Binary }
        'DWord' { $value = $DWord }
        'QWord' { $value = $QWord }
        'DWordAsUnsignedInt'
        {
            $value = $UDWord
            $type = 'DWord'
        }
        'QWordAsUnsignedInt'
        {
            $value = $UQWord
            $type = 'QWord'
        }
        'MultiString'
        {
            if ($null -eq $Strings)
            {
                $Strings = [String[]]::New(0)
            }
            $value = $Strings
        }
    }

    Install-CRegistryKey -Path $Path

    if ($Force)
    {
        Remove-CRegistryKeyValue -Path $Path -Name $Name
    }

    if (Test-CRegistryKeyValue -Path $Path -Name $Name)
    {
        $updateValue = $false
        $currentValue = Get-CRegistryKeyValue -Path $Path -Name $Name
        if ($PSCmdlet.ParameterSetName -eq 'MultiString')
        {
            [String[]] $currentValues = $currentValue
            if ($null -eq $currentValues)
            {
                $currentValues = @()
            }

            $firstLineWritten = $false
            $msgPrefix = " ${Path} ${Name}"
            for ($idx = 0 ; $idx -lt ([Math]::Max($currentValues.Length, $value.Length)) ; ++$idx)
            {
                $fromValue = $null
                $noFromValue = $true
                $toValue = $null
                $noToValue = $true

                $changeMsg = ''
                if ($idx -lt $currentValues.Length)
                {
                    $fromValue = $currentValues[$idx]
                    $noFromValue = $false
                }

                if ($idx -lt $value.Length)
                {
                    $toValue = $value[$idx]
                    $noToValue = $false
                }

                if ($fromValue -eq $toValue)
                {
                    continue
                }

                $changeMsg = " ${fromValue} -> ${toValue}"
                if ($noFromValue)
                {
                    $changeMsg = "+ ${toValue}"
                }
                elseif ($noToValue)
                {
                    $changeMsg = "- ${fromValue}"
                }

                $updateValue = $true
                $msg = "${msgPrefix}[${idx}] ${changeMsg}"
                Write-Information $msg

                if (-not $firstLineWritten)
                {
                    $msgPrefix = ' ' * $msgPrefix.Length
                    $firstLineWritten = $true
                }
            }
        }
        else
        {
            $updateValue = ($currentValue -ne $value)
            if ($updateValue)
            {
                Write-Information -Message " ${Path} ${Name} ${currentValue} -> ${value}"
            }
        }

        if ($updateValue)
        {
            Set-ItemProperty -Path $Path -Name $Name -Value $value
        }
    }
    else
    {
        if ($PSCmdlet.ParameterSetName -eq 'MultiString')
        {
            $msgPrefix = " ${Path} + ${Name}"
            $firstLineWritten = $false
            for ($idx = 0 ; $idx -lt $value.Length ; ++$idx)
            {
                Write-Information "${msgPrefix}[${idx}] $($value[$idx])"
                if (-not $firstLineWritten)
                {
                    $firstLineWritten = $true
                    $msgPrefix = ' ' * $msgPrefix.Length
                }
            }
        }
        else
        {
            Write-Information -Message " ${Path} + ${Name} ${value}"
        }
        $null = New-ItemProperty -Path $Path -Name $Name -Value $value -PropertyType $type
    }
}



function Test-CRegistryKeyValue
{
    <#
    .SYNOPSIS
    Tests if a registry value exists.
 
    .DESCRIPTION
    The usual ways for checking if a registry value exists don't handle when a value simply has an empty or null value.
    This function actually checks if a key has a value with a given name.
 
    .EXAMPLE
    Test-CRegistryKeyValue -Path 'hklm:\Software\Carbon\Test' -Name 'Title'
 
    Returns `True` if `hklm:\Software\Carbon\Test` contains a value named 'Title'. `False` otherwise.
    #>
    [CmdletBinding()]
    param(
        # The path to the registry key where the value should be set. Will be created if it doesn't exist.
        [Parameter(Mandatory)]
        [String] $Path,

        # The name of the value being set.
        [Parameter(Mandatory)]
        [String] $Name
    )

    Set-StrictMode -Version 'Latest'
    Use-CallerPreference -Cmdlet $PSCmdlet -Session $ExecutionContext.SessionState

    if (-not (Test-Path -Path $Path -PathType Container))
    {
        return $false
    }

    $properties = Get-ItemProperty -Path $Path
    if (-not $properties)
    {
        return $false
    }

    $member = Get-Member -InputObject $properties -Name $Name
    if ($member)
    {
        return $true
    }

    return $false
}



function Use-CallerPreference
{
    <#
    .SYNOPSIS
    Sets the PowerShell preference variables in a module's function based on the callers preferences.
 
    .DESCRIPTION
    Script module functions do not automatically inherit their caller's variables, including preferences set by common
    parameters. This means if you call a script with switches like `-Verbose` or `-WhatIf`, those that parameter don't
    get passed into any function that belongs to a module.
 
    When used in a module function, `Use-CallerPreference` will grab the value of these common parameters used by the
    function's caller:
 
     * ErrorAction
     * Debug
     * Confirm
     * InformationAction
     * Verbose
     * WarningAction
     * WhatIf
     
    This function should be used in a module's function to grab the caller's preference variables so the caller doesn't
    have to explicitly pass common parameters to the module function.
 
    This function is adapted from the [`Get-CallerPreference` function written by David Wyatt](https://gallery.technet.microsoft.com/scriptcenter/Inherit-Preference-82343b9d).
 
    There is currently a [bug in PowerShell](https://connect.microsoft.com/PowerShell/Feedback/Details/763621) that
    causes an error when `ErrorAction` is implicitly set to `Ignore`. If you use this function, you'll need to add
    explicit `-ErrorAction $ErrorActionPreference` to every `Write-Error` call. Please vote up this issue so it can get
    fixed.
 
    .LINK
    about_Preference_Variables
 
    .LINK
    about_CommonParameters
 
    .LINK
    https://gallery.technet.microsoft.com/scriptcenter/Inherit-Preference-82343b9d
 
    .LINK
    http://powershell.org/wp/2014/01/13/getting-your-script-module-functions-to-inherit-preference-variables-from-the-caller/
 
    .EXAMPLE
    Use-CallerPreference -Cmdlet $PSCmdlet -SessionState $ExecutionContext.SessionState
 
    Demonstrates how to set the caller's common parameter preference variables in a module function.
    #>
    [CmdletBinding()]
    param (
        [Parameter(Mandatory)]
        #[Management.Automation.PSScriptCmdlet]
        # The module function's `$PSCmdlet` object. Requires the function be decorated with the `[CmdletBinding()]`
        # attribute.
        $Cmdlet,

        [Parameter(Mandatory)]
        # The module function's `$ExecutionContext.SessionState` object. Requires the function be decorated with the
        # `[CmdletBinding()]` attribute.
        #
        # Used to set variables in its callers' scope, even if that caller is in a different script module.
        [Management.Automation.SessionState]$SessionState
    )

    Set-StrictMode -Version 'Latest'

    # List of preference variables taken from the about_Preference_Variables and their common parameter name (taken
    # from about_CommonParameters).
    $commonPreferences = @{
                              'ErrorActionPreference' = 'ErrorAction';
                              'DebugPreference' = 'Debug';
                              'ConfirmPreference' = 'Confirm';
                              'InformationPreference' = 'InformationAction';
                              'VerbosePreference' = 'Verbose';
                              'WarningPreference' = 'WarningAction';
                              'WhatIfPreference' = 'WhatIf';
                          }

    foreach( $prefName in $commonPreferences.Keys )
    {
        $parameterName = $commonPreferences[$prefName]

        # Don't do anything if the parameter was passed in.
        if( $Cmdlet.MyInvocation.BoundParameters.ContainsKey($parameterName) )
        {
            continue
        }

        $variable = $Cmdlet.SessionState.PSVariable.Get($prefName)
        # Don't do anything if caller didn't use a common parameter.
        if( -not $variable )
        {
            continue
        }

        if( $SessionState -eq $ExecutionContext.SessionState )
        {
            Set-Variable -Scope 1 -Name $variable.Name -Value $variable.Value -Force -Confirm:$false -WhatIf:$false
        }
        else
        {
            $SessionState.PSVariable.Set($variable.Name, $variable.Value)
        }
    }
}