Source code for apipa.ps

```
param(
```

	[parameter( ValueFromRemainingArguments = $true )]

	[string[]]$args # Leave all argument validation to the script, not to PowerShell

```
)
```
```
 
```
```
function Show-Help {
```
```
	#
```
```
	# APIPA.ps1,  Version 1.00
```

	# Get or set the IP AutoConfiguration status (aka APIPA) for all network adapters

```
	#
```

	# Usage:  powershell  ./APIPA.ps1  [ newstatus ]

```
	#
```

	# Where:  newstatus   is either Enabled (or 1, On, Set, True or Yes),

	#                     or Disabled (or 0, Off, Reset, False or No).

```
	#
```

	# Notes:  Be careful when changing system settings in the registry; if you

	#         do not fully understand what this script does, then don't use it.

	#         More information on APIPA: http://www.tech-faq.com/apipa.html

```
	#
```
```
	# Written by Rob van der Woude
```
```
	# http://www.robvanderwoude.com
```
```
	#
```
```
 
```
```
	Clear-Host
```
```
 
```
```
	Write-Host
```
```
	Write-Host "APIPA.ps1,  Version 1.00"
```
```
 
```

	Write-Host "Get or set the IP AutoConfiguration status (aka APIPA) for " -NoNewline

	Write-Host "all " -ForegroundColor White -NoNewline

```
	Write-Host "network adapters"
```
```
 
```
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	Write-Host
```
```
 
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	Write-Host "Usage:  " -NoNewline
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	Write-Host "powershell  ./APIPA.ps1  [ newstatus ]" -ForegroundColor White

```
 
```
```
	Write-Host
```
```
 
```
```
	Write-Host "Where:  " -NoNewline
```

	Write-Host "newstatus   " -ForegroundColor White -NoNewline

```
	Write-Host "is either " -NoNewline
```

	Write-Host "Enabled " -ForegroundColor White -NoNewline

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	Write-Host "(or " -NoNewline
```

	Write-Host "1" -ForegroundColor White -NoNewline

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	Write-Host ", " -NoNewline
```

	Write-Host "On" -ForegroundColor White -NoNewline

```
	Write-Host ", " -NoNewline
```

	Write-Host "Set" -ForegroundColor White -NoNewline

```
	Write-Host ", " -NoNewline
```

	Write-Host "True " -ForegroundColor White -NoNewline

```
	Write-Host "or " -NoNewline
```

	Write-Host "Yes" -ForegroundColor White -NoNewline

```
	Write-Host "),"
```
```
 
```

	Write-Host "                    or " -NoNewline

	Write-Host "Disabled " -ForegroundColor White -NoNewline

```
	Write-Host "(or " -NoNewline
```

	Write-Host "0" -ForegroundColor White -NoNewline

```
	Write-Host ", " -NoNewline
```

	Write-Host "Off" -ForegroundColor White -NoNewline

```
	Write-Host ", " -NoNewline
```

	Write-Host "Reset" -ForegroundColor White -NoNewline

```
	Write-Host ", " -NoNewline
```

	Write-Host "False " -ForegroundColor White -NoNewline

```
	Write-Host "or " -NoNewline
```

	Write-Host "No" -ForegroundColor White -NoNewline

```
	Write-Host ")."
```
```
 
```
```
	Write-Host
```

	Write-Host "Notes:  Be careful when changing system settings in the registry; if you"

	Write-Host "        do not fully understand what this script does, then don't use it."

	Write-Host "        More information on APIPA: " -NoNewline

	Write-Host "http://www.tech-faq.com/apipa.html" -ForegroundColor DarkGray

```
	Write-Host
```

	Write-Host "Written by Rob van der Woude"

	Write-Host "http://www.robvanderwoude.com"

```
	Write-Host
```
```
 
```
```
	Exit 1
```
```
}
```
```
 
```
```
if ( ( $args.Length -gt 1 ) -or $h ) {
```
```
	Show-Help
```
```
}
```
```
 
```
```
$action = ""
```
```
 
```
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# Interpret the command line argument
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```
if ( $args.Length -eq 1 ) {
```
```
	switch ( $args[0] ) {
```
```
		"0"        { $action = "Off"; break }
```
```
		"1"        { $action = "On";  break }
```
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		"Disable"  { $action = "Off"; break }
```
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		"Disabled" { $action = "Off"; break }
```
```
		"Enable"   { $action = "On";  break }
```
```
		"Enabled"  { $action = "On";  break }
```
```
		"False"    { $action = "Off"; break }
```
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		"No"       { $action = "Off"; break }
```
```
		"Off"      { $action = "Off"; break }
```
```
		"On"       { $action = "On";  break }
```
```
		"Reset"    { $action = "Off"; break }
```
```
		"Set"      { $action = "On";  break }
```
```
		"True"     { $action = "On";  break }
```
```
		"Yes"      { $action = "On";  break }
```
```
		default    { Show-Help;       break }
```
```
	}
```
```
}
```
```
 
```
```
# Make sure the variable is not set
```

Clear-Variable apipa -ErrorAction SilentlyContinue

```
 
```

$regpath = "HKLM:\SYSTEM\CurrentControlSet\services\Tcpip\Parameters"

```
 
```
```
# Read the registry value
```

$IPParameters = ( Get-ItemProperty -Path $regpath -ErrorAction SilentlyContinue )

$apipa = $IPParameters.IPAutoconfigurationEnabled

```
 
```
```
# Show current status before change
```

Write-Host "Current APIPA Status: " -NoNewline

[string]$apipa = $IPParameters.IPAutoconfigurationEnabled

# switch( $apipa ) cannot be used here because it handles 0, null

# and whitespace all as 0, so we'll have to use if..elseif..else

```
if ( $apipa -eq "" ) {
```

	Write-Host "not set"  -ForegroundColor White

```
} elseif ( $apipa -eq 0 ) {
```

	Write-Host "disabled" -ForegroundColor White

```
} elseif ( $apipa -eq 1 ) {
```

	Write-Host "enabled"  -ForegroundColor White

```
} else {
```

	Write-Host "unknown"  -ForegroundColor White

```
}
```
```
 
```

# Change the registry value if requested

```
if ( $action ) {
```
```
	if ( $action -eq "On" ) {
```
```
		$newvalue = 1
```
```
	}
```
```
	if ( $action -eq "Off" ) {
```
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		$newvalue = 0
```
```
	}
```
```
 
```
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	# Set the new registry value
```

	New-ItemProperty -Path $regpath -Name "IPAutoconfigurationEnabled" -Value $newvalue -PropertyType DWORD -ErrorAction SilentlyContinue -ErrorVariable err | Out-Null

```
	if ( $err ) {
```

		if ( $err[0].CategoryInfo.Category -eq "ResourceExists" ) {

```
			# Clear the ResourceExists error
```
```
			$err.Clear( )
```

			# If the registry value already exists, just set it to its new value

			Set-ItemProperty -Path $regpath -Name "IPAutoconfigurationEnabled" -Value $newvalue -ErrorAction SilentlyContinue | Out-Null

```
		} else {
```

			# Abort on all errors except ResourceExists

			Write-Host "Error: " -ForegroundColor Red -NoNewline

			Write-Host $err[0].Exception.Message -ForegroundColor White

```
			Exit 1
```
```
		}
```
```
	}
```
```
 
```
```
	# Reread the registry value
```

	$IPParameters = ( Get-ItemProperty -Path $regpath -ErrorAction SilentlyContinue )

	$apipa = $IPParameters.IPAutoconfigurationEnabled

```
 
```
```
	# Show status after change
```

	Write-Host "Changed APIPA Status: " -NoNewline

```
	if ( $apipa -eq "" ) {
```

		Write-Host "not set"  -ForegroundColor White

```
	} elseif ( $apipa -eq 0 ) {
```

		Write-Host "disabled" -ForegroundColor White

```
	} elseif ( $apipa -eq 1 ) {
```

		Write-Host "enabled"  -ForegroundColor White

```
	} else {
```

		Write-Host "unknown"  -ForegroundColor White

```
	}
```
```
}
```
```
 
```