Get-ValidIPAddressFromString.ps1

<#
.SYNOPSIS
This cmdlet is used to extract all of the unique IPv4 addresses out from each line of a log file


.DESCRIPTION
Use a ForEach type statement to extract unique IPv4 address out from each line of a log file


.PARAMETER String
Defines the string of text that the regular expression of an IPv4 address should be tested for

.PARAMETER Path
Defines the path to a file you want to grab unique IP addresses out out


.EXAMPLE
ForEach ($Line in (Get-Content -Path C:\Temp\firewall.log)) { Get-ValidIPAddressFromString -String $Line }
# This example parses the text file firewall.log and lists any IPv4 Addresses found on each line


.EXAMPLE
Get-ValidIpAddressFromString -Path C:\Windows\System32\LogFiles\Firewall\domainfw.log


.NOTES
Author: Robert H. Osborne
Alias: tobor
Contact: rosborne@osbornepro.com


.LINK
https://osbornepro.com
https://writeups.osbornepro.com
https://btpssecpack.osbornepro.com
https://github.com/tobor88
https://gitlab.com/tobor88
https://www.powershellgallery.com/profiles/tobor
https://www.linkedin.com/in/roberthosborne/
https://www.credly.com/users/roberthosborne/badges
https://www.hackthebox.eu/profile/52286


.INPUTS
System.String


.OUTPUTS
System.String

#>
Function Get-ValidIPAddressFromString {
    [CmdletBinding(DefaultParameterSetName="Line")]
        param(
            [Parameter(
                ParameterSetName="Line",
                Position=0,
                Mandatory=$True,
                ValueFromPipeline=$True,
                ValueFromPipelineByPropertyName=$False,
                HelpMessage="`n[H] Enter a string to extract the IPv4 address out of `n[E] EXAMPLE: Log File 8/6/2020 10.10.10.10. DENY TCP")]  # End Parameter
            [String]$String,

            [Parameter(
                ParameterSetName="File",
                Mandatory=$True,
                ValueFromPipeline=$False)]  # End Parameter
            [String]$Path)  # End param


    $Obj = @()
    $Regex=‘(?<Address>((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))’

    Switch ($PsCmdlet.ParameterSetName) {
        'File' {

            $FileContents = Get-Content -Path $Path -Tail 5000
            ForEach ($Line in $FileContents) {

                If (($Line -Match $Regex) -and ($Obj -notcontains $Matches.Address)) {

                        $Obj += $Matches.Address

                }  # End If

            }  # End ForEach

            Return $Obj

        }  # End File Switch

        'Line' {

            If ($String -Match $Regex) {

                $Obj = $Matches.Address

            }  # End If

            $Obj

        }  # End Default Switch

    }  # End Switch

}  # End Function Get-ValidIPAddressFromString