Powershell - Shebang, Hebang and Webang Command + Subshell

$.ps1

Param(
    # the commands to execute or the file to execute
    [Parameter(Mandatory=$false, ValueFromRemainingArguments = $true)]
    [string[]]$Commands
)

Function Main {
    If ($Commands) {
        Evalute-Line $Commands
    } Else {
        Enter-Shell
    }
    Exit $LastExitCode
}

Function Enter-Shell {
    while ($true) {
       $Commands = Read-Host "$"
       Evalute-Line $Commands
    }
}

Function Evalute-Line {
    Param(
        [string]$LineArgs
    )
    
    $FirstCommand = ""
        $OtherCommands = ""
        ForEach ($Command in $Commands) {
            If (-not $FirstCommand) {
                $FirstCommand = $Command
                If ($FirstCommand -eq "exit()" -or $FirstCommand -eq "exit" -or $FirstCommand -eq "close") {
                    exit
                }
            } else {
                if ($Command.Contains(" ")) {
                    $OtherCommands += "'$Command' "
                } else {
                    $OtherCommands += "$Command "
                }
            }
        }
        $Old_CD = [Environment]::CurrentDirectory
        [Environment]::CurrentDirectory = Get-Location
        $FirstCommand = Resolve-Shebang $FirstCommand
        [Environment]::CurrentDirectory = $Old_CD
        iex "$FirstCommand $OtherCommands"
}

Function Resolve-Shebang {
    Param(
        [string]$FirstCommand_
    )
    
    If ([System.IO.File]::Exists($FirstCommand_)) {
        foreach($Line in Get-Content $FirstCommand_) {
            If($Line.StartsWith("#!")){ # Shebang
                $Shebang = $Line.SubString(2, $Line.Length - 2)
                $Bangs = $Shebang.Split(" ")
                $Shebang = ""
                ForEach ($Bang in $Bangs) {
                    If ($Bang.StartsWith('/') -and ($Bang.EndsWith('/env') -or $Bang.EndsWith('/bin'))) {
                    
                    } Else {
                        $Shebang += "$Bang "
                    }
                }
                $Shebang = $Shebang -f [System.IO.Path]::GetFullPath($FirstCommand_)
                return $Shebang
                
            } ElseIf ($Line.StartsWith("//!")){ # Hebang
                $Hebang = $Line.SubString(3, $Line.Length - 3)
                $Bangs = $Hebang.Split(" ")
                $Hebang = ""
                ForEach ($Bang in $Bangs) {
                    If ($Bang.StartsWith('/') -and ($Bang.EndsWith('/env') -or $Bang.EndsWith('/bin'))) {
                    
                    } Else {
                        $Hebang += "$Bang "
                    }
                }
                $Hebang = $Hebang -f [System.IO.Path]::GetFullPath($FirstCommand_)
                return $Hebang
                
            } ElseIf ($Line.StartsWith("/*!")){ # Webang
                $Webang = $Line.SubString(3, $Line.Length - 3)
                $Bangs = $Webang.Split(" ")
                $Webang = ""
                ForEach ($Bang in $Bangs) {
                    if ($Bang.Contains("`*`/")) {
                        $BangEndIndex = $Bang.LastIndexOf("`*`/")
                        $Bang = $Bang.SubString(0, $BangEndIndex)
                    }
                    If ($Bang.StartsWith('/') -and ($Bang.EndsWith('/env') -or $Bang.EndsWith('/bin'))) {
                    
                    } Else {
                        $Webang += "$Bang "
                    }
                }
                $Webang = $Webang -f [System.IO.Path]::GetFullPath($FirstCommand_)
                return $Webang
            }
            return $FirstCommand_
        }
    }
    return $FirstCommand_
}

Main