function ConvertIpAddrToArray( $ipstr )
    dim $i, $num

    select
        case vartype($ipstr)=8      ;-- chaine de caractères --
            dim $i

            $ipstr = replace( $ipstr, " ", "" )
            $ipstr = split( $ipstr, "." )
            if ubound($ipstr)<>3        exit 1      endif

        case UBound($ipstr)=3       ;-- tableau de 4 éléments --

            ;-- le controle sera fait dans le bloc commun --
        case 1
            exit 1
    endselect

    ;-- controle des 4 entrées du tableau --
    for $i = 0 to UBound($ipstr)
        $num = val($ipstr[$i])
        if val($num) <> $ipstr[$i]        exit 1        endif
        if ($num<0) or ($num>255)        exit 1        endif

        $ipstr[$i] = $num
    next

    $ConvertIpAddrToArray = $ipstr
    exit 0
endfunction


function ConvertIPMaskToArray( $mask )
    $ConvertIPMaskToArray = ConvertIpAddrToArray($mask)
    if @error
        ;-- controleur : valeur doit être entre 1 et 32 (inclus) --
        $mask = val($mask)
        if ($mask<=0) or ($mask>32)     exit 1      endif

        redim $ConvertIPMaskToArray[3]

        dim $s, $i, $j

        $s = ""
        for $i = 1 to $mask
            $s = $s + "1"
        next

        while len($s)<32
            $s = $s + "0"
        loop

        $j = 1
        for $i = 0 to 3
            $ConvertIPMaskToArray[$i] = BinToDec( substr($s,$j,8) )
            $j = $j + 8
        next
    endif

    exit 0
endfunction

function CompareIPAddr( $ip1, $ip2 )
    $CompareIPAddr = (0=1)

    $ip1 = ConvertIpAddrToArray( $ip1 )
    if @error   exit 1  endif

    $ip2 = ConvertIpAddrToArray( $ip2 )
    if @error   exit 1  endif

    dim $i

    for $i = 0 to 3
        if $ip1[$i]<>$ip2[$i]   exit    endif
    next

    $CompareIPAddr = (1=1)
endfunction


function IsIPAddrInSubnet( $ip, $subnet, $subnetmask )
    $IsIPAddrInSubnet = (0=1)

    $ip = ConvertIpAddrToArray( $ip )
    if @error   exit 1  endif

    $subnet = ConvertIpAddrToArray( $subnet )
    if @error   exit 2  endif

    $subnetmask = ConvertIpMaskToArray( $subnetmask )
    if @error   exit 3  endif

    dim $i

    $IsIPAddrInSubnet = (1=1)
    for $i = 0 to 3
        if ($ip[$i] & $subnetmask[$i]) <> $subnet[$i]
            $IsIPAddrInSubnet = (0=1)
            exit 4
        endif
    next
endfunction


function ApplyIPMaskToIPAddr( $IPMask, $IPAddr )

    $ipaddr = ConvertIpAddrToArray( $ipaddr )
    if @error   exit 1  endif

    $ipmask = ConvertIpMaskToArray( $ipmask )
    if @error   exit 2  endif

    redim $ApplyIPMaskToIPAddr[3]
    dim $i

    for $i = 0 to 3
        $ApplyIPMaskToIPAddr[$i] = $IPAddr[$i] & $IPMask[$i]
    next
endfunction


function ConvertIPArrayToString( $ip )
    $ConvertIPArrayToString = ""
    $ip = ConvertIpAddrToArray( $ip )
    if @error   exit @error  endif

    $ConvertIPArrayToString = join( $ip, "." )
endfunction


function BinToDec( $str )
    dim $num, $i, $j
    $num = 0
    $j = 1
    for $i = len($str) to 1 step -1
        $num = $num + $j*val(substr($str,$i,1))
        $j = $j * 2
    next
    $BinToDec = $num
endfunction