Parse getopt from a bash script using PowerShell.

example.sh

#!/usr/bin/env bash

# Parameters and aliases
SHORT=a,b,g:,d:
LONG=alpha,beta,gamma:,delta:
# Script Name
ScriptName=Example

# Parameter values
Alpha=0
Beta=0
Gamma=""
Delta=""

Parameters=$(getopt -a -n $ScriptName --options $SHORT --longoptions $LONG -- "$@")
PARSED_ARGUMENTS=$(getopt -a -n alphabet -o abc:d: --long alpha,bravo,charlie:,delta: -- "$@")
if ! $?; then
    exit 1
fi

eval set -- "$Parameters"
while :; do
    case "$1" in
    -a | --alpha)
        echo "Processing 'alpha' option"
        Alpha=1
        shift
        ;;
    -b | --beta)
        echo "Processing 'beta' option"
        Beta=1
        shift
        ;;
    -g | --gamma)
        echo "Processing 'gamma' option. Input argument is '$2'"
        Gamma="$2"
        shift 2
        ;;
    -d | --delta)
        echo "Processing 'delta' option. Input argument is '$2'"
        Delta="$2"
        shift 2
        ;;
    --)
        shift
        break
        ;;
    esac
done

function Begin() {
    if ((Alpha == 1)); then
        echo "equal"
    fi
    if ((Beta == 1)); then
        echo "equal"
    fi
}

function Process() {
    if [[ -n "${Gamma}" ]]; then
        echo "string is not empty"
    fi
    if [[ -n "${Delta}" ]]; then
        echo "string is not empty"
    fi
}

function End() {
    Alpha=0
}

Begin
Process
End

Get-BashArguments.ps1

function Get-BashArguments {
    [CmdletBinding()]
    [OutputType([PSObject[]])]
    param(
        [Parameter(Mandatory = $true)]
        # Path to a bash script
        [string[]]
        $Path
    )
    process {
        $Path | ForEach-Object {
            $Script = $_
            $Expression = 'getopt -a -n .* (?:-o|--options) (?''short''.+) (?:-l|--longoptions|--long) (?''long''([a-zA-Z0-9]|,|:|\$)+) \-\- \"\$@\"'
            $RegexGetOpt = [Regex]::new($Expression)

            Get-Content -Path $Script | ForEach-Object {
                $MatchesGetopt = $RegexGetOpt.Match($_)
                if ($MatchesGetopt.Success) {
                    $Options = $MatchesGetopt.Groups | Where-Object { $_.Name -like "short" -or $_.Name -like "long" } | Select-Object Name, Value
                    if ($Options.Value -like "`$*") {
                        $Options.Value | ForEach-Object {
                            $Name = $_ -replace '\$'
                            [PSCustomObject]@{
                                Name  = $Name
                                Value = (Get-Content -Path $Script | Select-String -Pattern "$Name=(.*)$") -replace "$Name="
                            }
                        }
                        
                    }
                    else {
                        $Options
                    }
                }
            }
        }
    }
}
Get-BashArguments -Path .\example.sh