Example of a PowerShell script converted to HTML with syntax highlighting

---

This is not a real script, it is a script used for testing of syntax description PowerShell.hrc for Colorer and covering related issues. Perhaps this HTML looks like a Christmas Tree, no problem, it is just a demo. One can configure Colorer according to his preferences. Take a look at how it handles and distinguishes expandable and not expandable string content and escaping rules, is not it a beauty?

---

Demo: highlighted PowerShell

EDIT: replaced large demo text with a link

Get-Drive.ps1 and Get-File.ps1 – Get all local files

---

Synopsis

The task of iterating through all local files may be not straightforward if there are several drives including removable, network or substituted drives and NTFS reparse points directories. Get-Drive.ps1 and Get-File.ps1 used together may help: Get-Drive.ps1 returns only local physical drives, Get-File.ps1 excludes reparse points.

---

Examples

# calculate total available free space in GB
(Get-Drive | Measure-Object AvailableFreeSpace -Sum).Sum/1GB

# get paths of all local .bak files
Get-File \ *.bak -Name

Get-Drive.ps1

##
## Author   : Roman Kuzmin
## Synopsis : Get physical drives
##
## Returns System.IO.DriveInfo objects
##
## *) removable, network and subst drives are excluded.
##

$subst = [string](subst)
foreach($d in [System.IO.DriveInfo]::GetDrives()) {
    if ($d.DriveType -eq 'Fixed' -and $subst -notlike "*$($d.Name):*") {
        $d
    }
}

---

Get-File.ps1

##
## Author   : Roman Kuzmin
## Synopsis : Get all files
##
## Returns System.IO.FileInfo objects or full names.
## -Root: root directory(s); single \ or // denotes all physical drives.
## -Filter: simple file system filter.
## -Name: return full names as strings.
##
## *) requires Get-Drive.ps1.
## *) access errors are silently ignored.
## *) hidden and system files are included.
## *) reparse points directories are excluded.
##

param
(
    [string[]]$Root = '.',
    [string]$Filter = '*',
    [switch]$Name
)

function DirectoryFiles([System.IO.DirectoryInfo]$di)
{
    # ignore errors
    trap {continue}

    # skip a reparse point
    if ($di.Attributes -band [System.IO.FileAttributes]::ReparsePoint) {
        return
    }

    # files
    if ($Name) {
        foreach($f in $di.GetFiles($Filter)) {
            $f.FullName
        }
    } else {
        $di.GetFiles($Filter)
    }

    # directories
    foreach($d in $di.GetDirectories()) {
        DirectoryFiles $d
    }
}

if ($Root.Count -eq 1 -and ($Root[0] -eq '\' -or $Root[0] -eq '//')) {
    foreach($d in Get-Drive) {
        DirectoryFiles $d.RootDirectory
    }
} else {
    foreach($d in $Root) {
        DirectoryFiles $d
    }
}

---

PowerShell syntax description for Colorer and Far Manager editor

---

Synopsis

PowerShell.hrc defines PowerShell syntax description for Colorer and Far Manager editor with FarColorer plugin.

EDIT: This version is obsolete. The latest PowerShell.hrc is included into the featured version of PowerShellFar plug-in for Far Manager:
http://code.google.com/p/farnet/

---

PowerShell.hrc

<?xml version="1.0" encoding="windows-1251"?>
<!DOCTYPE hrc PUBLIC "-//Cail Lomecb//DTD Colorer HRC take5//EN" "http://colorer.sf.net/2003/hrc.dtd">
<hrc version="take5" xmlns="http://colorer.sf.net/2003/hrc" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://colorer.sf.net/2003/hrc http://colorer.sf.net/2003/hrc.xsd">

<!--
Insert into catalog.xml a link to this:
<location link="<path>/PowerShell.hrc"/>
-->

<prototype name="PowerShell" group="scripts" description="PowerShell">
<filename>/(.ps1$|.ps1.bak$|.psfconsole$)/i</filename>
</prototype>

<type name="PowerShell">

<annotation>
<documentation>
PowerShell.hrc version 1.3.1, 2007.03.21
PowerShell syntax description and .psfconsole features.
Created and tested for PowerShell 1.0 with Colorer-take5.beta5
</documentation>
<contributors>
Roman Kuzmin, nightroman@hotmail.com
</contributors>
</annotation>

<import type="def"/>

<!-- Escaped -->
<scheme name="PSEscaped">
<regexp match="/`s+$/" region="def:Error"/>
<regexp match="/`./" region="def:StringContent"/>
</scheme>

<!-- Variable -->
<scheme name="PSVariable">
<regexp match="/$[w:]*w/" region="def:Var"/>
<block start="/${/" end="/}/" scheme="PSEscaped" region="def:Var" region00="def:PairStart" region10="def:PairEnd" region01="def:Var" region11="def:Var"/>
</scheme>

<!-- Expanded -->
<scheme name="PSExpanded">
<block start="/($()/" end="/())/" scheme="PowerShell" region00="def:PairStart" region10="def:PairEnd" region01="def:Var" region11="def:Var"/>
</scheme>

<!-- Array -->
<scheme name="PSArray">
<block start="/@(/" end="/)/" scheme="PowerShell" region00="def:PairStart" region10="def:PairEnd"/>
</scheme>

<!-- Hash -->
<scheme name="PSHash">
<block start="/@{/" end="/}/" scheme="PowerShell" region00="def:PairStart" region10="def:PairEnd"/>
</scheme>

<!-- Number -->
<entity name="psnumexp" value="(?:[eE][-+]?d+)"/>
<entity name="psnumsuf" value="([Ll]?(?:KB|MB|GB)?)"/>
<scheme name="PSNumber">
<regexp match="/B.?~1.d+%psnumexp;?%psnumsuf;b/i" region0="def:NumberFloat" region1="def:NumberSuffix"/>
<regexp match="/bd+..?!d*(?:%psnumexp;?%psnumsuf;b|B)/i" region0="def:NumberFloat" region1="def:NumberSuffix"/>
<regexp match="/bd+%psnumexp;%psnumsuf;b/i" region0="def:NumberFloat" region1="def:NumberSuffix"/>
<regexp match="/b0[xX][da-fA-F]+%psnumsuf;b/i" region0="def:NumberHex" region1="def:NumberSuffix"/>
<regexp match="/bd+%psnumsuf;b/i" region0="def:NumberDec" region1="def:NumberSuffix"/>
</scheme>

<!-- Content in '' -->
<scheme name="PSAposContent">
<regexp match="/''/" region="def:StringContent"/>
</scheme>

<!-- Content in "" -->
<scheme name="PSQuotContent">
<inherit scheme="PSEscaped"/>
<inherit scheme="PSVariable"/>
<inherit scheme="PSExpanded"/>
</scheme>

<!-- Content of output -->
<scheme name="PSOutputContent">
<regexp match="/^ERROR(?::|b)|<<<<(?:s|$)/" region="def:Error"/>
<regexp match="/^WARNINGb.*$/" region="def:StringContent"/>
<regexp match="/^(?  EBUG|VERBOSE)b.*$/" region="def:Comment"/>
<inherit scheme="PSNumber"/>
</scheme>

<!-- Main -->
<scheme name="PowerShell">

<!-- Output -->
<block start="/^x1A$/" end="/^x1B$/" scheme="PSOutputContent" region00="def:PairStart" region10="def:PairEnd"/>

<!-- Comments -->
<regexp match="/(?:^|s)###s+(.*)/" region="def:Comment" region1="def:Outlined"/>
<regexp match="/(?:^|s)##.*/" region="def:CommentDoc"/>
<regexp match="/(?:^|s)#.*/" region="def:Comment"/>

<!-- Apos-strings -->
<block start="/@x27$/" end="/^x27@/" scheme="PSAposContent" region="def:String" region00="def:PairStart" region10="def:PairEnd"/>
<block start="/x27/" end="/x27/" scheme="PSAposContent" region="def:String" region00="def:PairStart" region10="def:PairEnd"/>

<!-- Escaped -->
<inherit scheme="PSEscaped"/>

<!-- Expanded -->
<inherit scheme="PSExpanded"/>

<!-- Array -->
<inherit scheme="PSArray"/>

<!-- Hash -->
<inherit scheme="PSHash"/>

<!-- Quot-strings -->
<block start="/@x22$/" end="/^x22@/" scheme="PSQuotContent" region="def:String" region00="def:PairStart" region10="def:PairEnd"/>
<block start="/x22/" end="/x22/" scheme="PSQuotContent" region="def:String" region00="def:PairStart" region10="def:PairEnd"/>

<!-- Types [xxx.xxx], [xxx[]] except [1], [$i] -->
<regexp match="/[[A-Za-z][w.]*(?:[])*]/" region="def:TypeKeyword"/>

<!-- Brackets -->
<inherit scheme="def:PairedBrackets">
<virtual scheme="def:PairedBrackets" subst-scheme="PowerShell"/>
</inherit>

<!-- Function -->
<regexp match="/(?:^|~|[;}]?#1)s*(function|filter)s+([^s(]+)/i" region1="def:FunctionKeyword" region2="def:Identifier" region="def:Outlined"/>

<!-- Pipeline and redirection -->
<keywords ignorecase="yes" region="def:KeywordStrong">
<symb name="|"/>
<symb name="&gt;"/>
<symb name="&gt;&gt;"/>
<symb name="2&gt;"/>
<symb name="2&gt;&amp;1"/>
<symb name="2&gt;&gt;"/>
</keywords>

<!-- Redirection operators (not yet) -->
<keywords ignorecase="yes" region="def:Error">
<word name="&lt;"/>
<word name="1&gt;&amp;2"/>
</keywords>

<!-- Numbers -->
<inherit scheme="PSNumber"/>

<!-- Cmdlets -->
<keywords ignorecase="yes" region="def:Keyword" worddiv="[s(){};=|]">
<word name="Add-Content"/>
<word name="Add-History"/>
<word name="Add-Member"/>
<word name="Add-PSSnapin"/>
<word name="Clear-Content"/>
<word name="Clear-Host"/>
<word name="Clear-Item"/>
<word name="Clear-ItemProperty"/>
<word name="Clear-Variable"/>
<word name="Compare-Object"/>
<word name="ConvertFrom-SecureString"/>
<word name="Convert-Path"/>
<word name="ConvertTo-Html"/>
<word name="ConvertTo-SecureString"/>
<word name="Copy-Item"/>
<word name="Copy-ItemProperty"/>
<word name="Export-Alias"/>
<word name="Export-Clixml"/>
<word name="Export-Console"/>
<word name="Export-Csv"/>
<word name="ForEach-Object"/>
<word name="Format-Custom"/>
<word name="Format-List"/>
<word name="Format-Table"/>
<word name="Format-Wide"/>
<word name="Get-Acl"/>
<word name="Get-Alias"/>
<word name="Get-AuthenticodeSignature"/>
<word name="Get-ChildItem"/>
<word name="Get-Command"/>
<word name="Get-Content"/>
<word name="Get-Credential"/>
<word name="Get-Culture"/>
<word name="Get-Date"/>
<word name="Get-EventLog"/>
<word name="Get-ExecutionPolicy"/>
<word name="Get-Help"/>
<word name="Get-History"/>
<word name="Get-Host"/>
<word name="Get-Item"/>
<word name="Get-ItemProperty"/>
<word name="Get-Location"/>
<word name="Get-Member"/>
<word name="Get-PfxCertificate"/>
<word name="Get-Process"/>
<word name="Get-PSDrive"/>
<word name="Get-PSProvider"/>
<word name="Get-PSSnapin"/>
<word name="Get-Service"/>
<word name="Get-TraceSource"/>
<word name="Get-UICulture"/>
<word name="Get-Unique"/>
<word name="Get-Variable"/>
<word name="Get-WmiObject"/>
<word name="Group-Object"/>
<word name="Import-Alias"/>
<word name="Import-Clixml"/>
<word name="Import-Csv"/>
<word name="Invoke-Expression"/>
<word name="Invoke-History"/>
<word name="Invoke-Item"/>
<word name="Join-Path"/>
<word name="Measure-Command"/>
<word name="Measure-Object"/>
<word name="Move-Item"/>
<word name="Move-ItemProperty"/>
<word name="New-Alias"/>
<word name="New-Item"/>
<word name="New-ItemProperty"/>
<word name="New-Object"/>
<word name="New-PSDrive"/>
<word name="New-Service"/>
<word name="New-TimeSpan"/>
<word name="New-Variable"/>
<word name="Out-Default"/>
<word name="Out-File"/>
<word name="Out-Host"/>
<word name="Out-Null"/>
<word name="Out-Printer"/>
<word name="Out-String"/>
<word name="Pop-Location"/>
<word name="Push-Location"/>
<word name="Read-Host"/>
<word name="Remove-Item"/>
<word name="Remove-ItemProperty"/>
<word name="Remove-PSDrive"/>
<word name="Remove-PSSnapin"/>
<word name="Remove-Variable"/>
<word name="Rename-Item"/>
<word name="Rename-ItemProperty"/>
<word name="Resolve-Path"/>
<word name="Restart-Service"/>
<word name="Resume-Service"/>
<word name="Select-Object"/>
<word name="Select-String"/>
<word name="Set-Acl"/>
<word name="Set-Alias"/>
<word name="Set-AuthenticodeSignature"/>
<word name="Set-Content"/>
<word name="Set-Date"/>
<word name="Set-ExecutionPolicy"/>
<word name="Set-Item"/>
<word name="Set-ItemProperty"/>
<word name="Set-Location"/>
<word name="Set-PSDebug"/>
<word name="Set-Service"/>
<word name="Set-TraceSource"/>
<word name="Set-Variable"/>
<word name="Sort-Object"/>
<word name="Split-Path"/>
<word name="Start-Service"/>
<word name="Start-Sleep"/>
<word name="Start-Transcript"/>
<word name="Stop-Process"/>
<word name="Stop-Service"/>
<word name="Stop-Transcript"/>
<word name="Suspend-Service"/>
<word name="Tee-Object"/>
<word name="Test-Path"/>
<word name="Trace-Command"/>
<word name="Update-FormatData"/>
<word name="Update-TypeData"/>
<word name="Where-Object"/>
<word name="Write-Debug"/>
<word name="Write-Error"/>
<word name="Write-Host"/>
<word name="Write-Output"/>
<word name="Write-Progress"/>
<word name="Write-Verbose"/>
<word name="Write-Warning"/>
</keywords>

<!-- System variables -->
<keywords ignorecase="yes" region="def:Constant">
<word name="$$"/>
<word name="$?"/>
<word name="$^"/>
<word name="$_"/>
<word name="$args"/>
<word name="$ConfirmPreference"/>
<word name="$ConsoleFileName"/>
<word name="$DebugPreference"/>
<word name="$Error"/>
<word name="$ErrorActionPreference"/>
<word name="$ErrorView"/>
<word name="$ExecutionContext"/>
<word name="$false"/>
<word name="$FormatEnumerationLimit"/>
<word name="$HOME"/>
<word name="$Host"/>
<word name="$input"/>
<word name="$LastExitCode"/>
<word name="$Matches"/>
<word name="$MaximumAliasCount"/>
<word name="$MaximumDriveCount"/>
<word name="$MaximumErrorCount"/>
<word name="$MaximumFunctionCount"/>
<word name="$MaximumHistoryCount"/>
<word name="$MaximumVariableCount"/>
<word name="$MyInvocation"/>
<word name="$NestedPromptLevel"/>
<word name="$null"/>
<word name="$OFS"/>
<word name="$PID"/>
<word name="$PROFILE"/>
<word name="$ProgressPreference"/>
<word name="$PSHOME"/>
<word name="$PWD"/>
<word name="$ReportErrorShowExceptionClass"/>
<word name="$ReportErrorShowInnerException"/>
<word name="$ReportErrorShowSource"/>
<word name="$ReportErrorShowStackTrace"/>
<word name="$ShellId"/>
<word name="$this"/>
<word name="$true"/>
<word name="$VerbosePreference"/>
<word name="$WarningPreference"/>
<word name="$WhatIfPreference"/>
</keywords>

<!-- User variables -->
<inherit scheme="PSVariable"/>

<!-- Operators -->
<keywords ignorecase="yes" region="def:Operator">
<word name="-eq"/>
<word name="-ne"/>
<word name="-ge"/>
<word name="-gt"/>
<word name="-lt"/>
<word name="-le"/>
<word name="-like"/>
<word name="-notlike"/>
<word name="-match"/>
<word name="-notmatch"/>
<word name="-replace"/>
<word name="-contains"/>
<word name="-notcontains"/>
<word name="-ieq"/>
<word name="-ine"/>
<word name="-ige"/>
<word name="-igt"/>
<word name="-ile"/>
<word name="-ilt"/>
<word name="-ilike"/>
<word name="-inotlike"/>
<word name="-imatch"/>
<word name="-inotmatch"/>
<word name="-ireplace"/>
<word name="-icontains"/>
<word name="-inotcontains"/>
<word name="-ceq"/>
<word name="-cne"/>
<word name="-cge"/>
<word name="-cgt"/>
<word name="-clt"/>
<word name="-cle"/>
<word name="-clike"/>
<word name="-cnotlike"/>
<word name="-cmatch"/>
<word name="-cnotmatch"/>
<word name="-creplace"/>
<word name="-ccontains"/>
<word name="-cnotcontains"/>
<word name="-is"/>
<word name="-isnot"/>
<word name="-as"/>
<word name="-and"/>
<word name="-not"/>
<word name="-or"/>
<word name="-xor"/>
<word name="-band"/>
<word name="-bor"/>
<word name="-bxor"/>
<word name="-f"/>
<symb name="--"/>
<symb name="++"/>
<symb name="+="/>
<symb name="-="/>
<symb name="*="/>
<symb name="/="/>
<symb name="%="/>
<symb name="="/>
<symb name="+"/>
<symb name="*"/>
<symb name="/"/>
<symb name="%"/>
</keywords>

<!-- Operator - -->
<regexp match="/-[A-Za-z_]?!/" region="def:Operator"/>

<!-- Keywords (filter and function are excluded) -->
<keywords ignorecase="yes" region="def:Keyword" worddiv="[s(){};]">
<word name="begin"/>
<word name="break"/>
<word name="continue"/>
<word name="default"/>
<word name="do"/>
<word name="else"/>
<word name="elseif"/>
<word name="end"/>
<word name="exit"/>
<word name="finally"/>
<word name="for"/>
<word name="foreach"/>
<word name="if"/>
<word name="in"/>
<word name="param"/>
<word name="process"/>
<word name="return"/>
<word name="switch"/>
<word name="throw"/>
<word name="trap"/>
<word name="until"/>
<word name="while"/>
</keywords>

<!-- Identifiers (very simplified) -->
<regexp match="/[A-Za-z_][-w]*/" region="def:Identifier"/>

<!-- Error: (ok, warning): redundant semicolon -->
<regexp match="/;s*}?(?:s*|s+#.*)$/" region="def:Error"/>

<!-- Error: bad string: symbols after @' or @" -->
<regexp match="/@[x22x27].$/" region="def:Error"/>

<!-- Separators -->
<regexp match="/[,;]/" region="def:Operator"/>

</scheme>

</type>
</hrc>

<!-- ***** BEGIN LICENSE BLOCK *****
- Version: MPL 1.1/GPL 2.0/LGPL 2.1
-
- The contents of this file are subject to the Mozilla Public License Version
- 1.1 (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.mozilla.org/MPL/

-
- Software distributed under the License is distributed on an "AS IS" basis,
- WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
- for the specific language governing rights and limitations under the
- License.
-
- The Original Code is the Colorer Library.
-
- The Initial Developer of the Original Code is
- Cail Lomecb <cail@nm.ru>.
- Portions created by the Initial Developer are Copyright (C) 1999-2005
- the Initial Developer. All Rights Reserved.
-
- Contributor(s):
- Roman Kuzmin <nightroman@hotmail.com>
-
- Alternatively, the contents of this file may be used under the terms of
- either the GNU General Public License Version 2 or later (the "GPL"), or
- the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
- in which case the provisions of the GPL or the LGPL are applicable instead
- of those above. If you wish to allow use of your version of this file only
- under the terms of either the GPL or the LGPL, and not to allow others to
- use your version of this file under the terms of the MPL, indicate your
- decision by deleting the provisions above and replace them with the notice
- and other provisions required by the LGPL or the GPL. If you do not delete
- the provisions above, a recipient may use your version of this file under
- the terms of any one of the MPL, the GPL or the LGPL.
-
- ***** END LICENSE BLOCK ***** -->

---

Resize-Console.ps1 – Resize console window/buffer using arrow keys

---

Synopsis

Perhaps resizing of Windows console is quite tricky. This script makes it easy with arrow keys.

---

Resize-Console.ps1

##
## Author   : Roman Kuzmin
## Synopsis : Resize console window/buffer using arrow keys
##

function Size($w, $h)
{
    New-Object System.Management.Automation.Host.Size($w, $h)
}

Write-Host '[Arrows] resize  [Esc] exit ...'
$ErrorActionPreference = 'SilentlyContinue'
for($ui = $Host.UI.RawUI;;) {
    $b = $ui.BufferSize
    $w = $ui.WindowSize
    switch($ui.ReadKey(6).VirtualKeyCode) {
        37 {
            $w = Size ($w.width - 1) $w.height
            $ui.WindowSize = $w
            $ui.BufferSize = Size $w.width $b.height
            break
        }
        39 {
            $w = Size ($w.width + 1) $w.height
            $ui.BufferSize = Size $w.width $b.height
            $ui.WindowSize = $w
            break
        }
        38 {
            $ui.WindowSize = Size $w.width ($w.height - 1)
            break
        }
        40 {
            $w = Size $w.width ($w.height + 1)
            if ($w.height -gt $b.height) {
                $ui.BufferSize = Size $b.width $w.height
            }
            $ui.WindowSize = $w
            break
        }
        27 {
            return
        }
    }
}

---

Format-Chart.ps1 – Formats output as a table with a chart column

---

Synopsis

The script formats output as a table with a pseudo-graphical chart column calculated for the last specified numeric property.

---

Examples

# Chart of process working sets
ps | Format-Chart Id, Name, WS

# Chart of file sizes in descending order
dir | sort Length -desc | Format-Chart Name, Length

---

Format-Chart.ps1

##
## Author   : Roman Kuzmin
## Synopsis : Formats output as a table with a chart column
## Modified : 2006.11.06
##
## -Property: properties where the last one is numeric for a chart.
## -Width: chart column width, default is 1/2 of screen buffer.
## -ForeChar: character for chart bars.
## -BackChar: character for appending bars.
## -InputObject: the objects to be formatted.
##

param
(
    [object[]]$Property = $(throw 'Supply properties'),
    [int]$Width = ($Host.UI.RawUI.BufferSize.Width/2),
    [char]$ForeChar = 9600,
    [char]$BackChar = 9617,
    [object[]]$InputObject
)

$set = $(if ($InputObject) {$InputObject} else {@($Input)}) |
Select-Object $Property

$max = ($set | Measure-Object ($Property[-1]) -Maximum).Maximum
if ($max -eq 0) {$max = 1}

$set | .{process{
    $_ | Add-Member -PassThru NoteProperty Chart (("$ForeChar"*(
    $_.$($Property[-1])/$max*$Width)).PadRight($Width, $BackChar))
}} |
Format-Table ($Property + 'Chart') -AutoSize

---

Get-Calendar.ps1 – Shows a month calendar control and returns selected dates

---

The idea is borrowed from the //o//’s blog //o// PowerShelled: Calendar Function (GUI). It is nice and simple. Perhaps a few touches here make it more customizable and useful for wider range of tasks.

---

Synopsis

The script works as date(s) viewer/picker. It shows WinForm dialog with a month calendar control with predefined date(s) selected and returns start and end date of initial or changed date range. By default 12 months (3 columns, 4 rows) are shown. Week numbers may be optionally turned on by a switch.

---

Examples

# Select dates and get number of days including the end date
$dates = Get-Calendar
($dates[1] - $dates[0]).TotalDays + 1

# Use predefined range, two months view and week numbers shown
$start, $end = Get-Calendar '2006.10.16' '2006.11.16' 2,1 -week
Write-Host "Start: $start. End: $end."

---

Get-Calendar.ps1

##
## Author   : Roman Kuzmin inspired by //o// www.ThePowerShellGuy.com
## Synopsis : Shows a month calendar control and returns selected dates
## Modified : 2006.10.15
##
## Returns an array of two selected start and end dates
## -Start <datetime>: initial start date
## -End <datetime>: initial end date
## -Dimensions <int[]>: (columns, rows) of months
## -WeekNumbers <switch>: show week numbers
##
## *) Press Enter to return currently selected dates.
## *) Press Escape or close the form to return initial dates.
##

param
(
    [datetime]$Start = [datetime]::Now,
    [datetime]$End = $Start,
    [int[]]$Dimensions = (3, 4),
    [switch]$WeekNumbers
)

# load forms
& {[void][System.Windows.Forms.Form]; trap {[void][System.Reflection.Assembly]::LoadWithPartialName('System.Windows.Forms'); continue}}

# new calendar
$cal = New-Object System.Windows.Forms.MonthCalendar
$cal.CalendarDimensions = New-Object System.Drawing.Size $Dimensions
$cal.Margin = New-Object System.Windows.Forms.Padding 0
$cal.MaxSelectionCount = 366
$cal.SelectionRange = New-Object System.Windows.Forms.SelectionRange $Start, $End
$cal.ShowWeekNumbers = $WeekNumbers

# new form
$form = New-Object System.Windows.Forms.Form
$form.AutoSize = $true
$form.AutoSizeMode = 'GrowAndShrink'
$form.FormBorderStyle = 'FixedDialog'
$form.KeyPreview = $true
$form.MaximizeBox = $false
$form.Text = 'Calendar'
$form.Controls.Add($cal)
$form.add_Shown({$form.Activate()})
$form.add_KeyDown({
    switch($_.KeyCode) {
        'Escape' {$form.Close()}
        'Return' {$form.Close(); $Start = $cal.SelectionRange.Start; $End = $cal.SelectionRange.End}
    }
})

# show and return dates
[void]$form.ShowDialog()
$Start.Date, $End.Date

---

Get-Choice.ps1 – Displays PowerShell style menu and gets a user choice

---

##
## Author   : Roman Kuzmin
## Synopsis : Displays PowerShell style menu and gets a user choice
## Modified : 2006.10.13
##
## Returns a choice index
## -caption <string>: menu caption
## -message <string>: menu message
## -choices <string[]>: pairs: item1, help1, item2, help2, ...
## -defaultChoice <int>: default choice index
##
## *) Choice keys are indicated by '&' in menu items.
##

param
(
    [string]$caption    = 'Confirm',
    [string]$message    = 'Are you sure you want to continue?',
    [string[]]$choices  = ('&Yes', 'Continue', '&No', 'Stop'),
    [int]$defaultChoice = 0
)

$choiceDescriptions = @()
for($i = 0; $i -lt $choices.Count; $i += 2)
{
    $c = [System.Management.Automation.Host.ChoiceDescription]$choices[$i]
    $c.HelpMessage = $choices[$i + 1]
    $choiceDescriptions += $c
}

$Host.UI.PromptForChoice($caption, $message, [System.Management.Automation.Host.ChoiceDescription[]]$choiceDescriptions, $defaultChoice)

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EDIT: See also the modified version for multiple choices here.