Il PageRank di Google nasce nel 1998, sino ad allora non esisteva nulla del genere e pertanto era l’innovazione del momento portando Google leader nel campo del motore di ricerca.
Ho utilizzato per anni uno script in ASP per il recupero del PageRank di Google, ecco l’esempio:
<%
'**** function PRankChecker(sUrl) '****
'**** 'Make the magic '*****
Dim chSum, strRes, Rank, strTmp
'calculate
Google Checksum
chSum = CalculateChecksum(sUrl)
'Read from Google dim strurl
strurl = "http://www.google.com/search?client=navclient-auto&ch=" & chSum & "&features=Rank&q=info:" & sUrl strurl = "http://toolbarqueries.google.com/tbr?client=navclient-auto&features=Rank&ch=" & chSum & "&features=Rank&q=info:" & sUrl response.write strurl 'response.end dim objXMLHTTP set objXMLHTTP = Server.CreateObject("Microsoft.XMLHTTP") objXMLHTTP.Open "GET", strUrl, false objXMLHTTP.Send() strRes = CStr(objXMLHTTP.ResponseText) set objXMLHTTP = Nothing strTmp = Split(strRes, ":") if(ubound(strTmp)>=2)then
Rank = CInt(Mid(strTmp(2), 1, 1))
else
rank = 0
end if
if(not isnumeric(rank))then
rank = 0
end if
' response.write Rank & "/10"
PRankChecker = rank
end function
'*************************************
Const GOOGLE_MAGIC = &HE6359A60
Function sl(ByVal x, ByVal n)
If n = 0 Then
sl = x
Else
Dim k
k = CLng(2 ^ (32 - n - 1))
Dim d
d = x And (k - 1)
Dim c
c = d * CLng(2 ^ n)
If x And k Then
c = c Or &H80000000
End If
sl = c
End If
End Function
Function sr(ByVal x, ByVal n)
If n = 0 Then
sr = x
Else
Dim y
y = x And &H7FFFFFFF
Dim z
If n = 32 - 1 Then
z = 0
Else
z = y \ CLng(2 ^ n)
End If
If y <> x Then
z = z Or CLng(2 ^ (32 - n - 1))
End If
sr = z
End If
End Function
Function zeroFill(ByVal a, ByVal b)
Dim x
If (&H80000000 And a) Then
x = sr(a, 1)
x = x And (Not &H80000000)
x = x Or &H40000000
x = sr(x, b - 1)
Else
x = sr(a, b)
End If
zeroFill = x
End Function
Private Function uadd(ByVal L1, ByVal L2)
Dim L11, L12, L21, L22, L31, L32
L11 = L1 And &HFFFFFF
L12 = (L1 And &H7F000000) \ &H1000000
If L1 < 0 Then L12 = L12 Or &H80
L21 = L2 And &HFFFFFF
L22 = (L2 And &H7F000000) \ &H1000000
If L2 < 0 Then L22 = L22 Or &H80
L32 = L12 + L22
L31 = L11 + L21
If (L31 And &H1000000) Then L32 = L32 + 1
uadd = (L31 And &HFFFFFF) + (L32 And &H7F) * &H1000000
If L32 And &H80 Then uadd = uadd Or &H80000000
End Function
Private Function usub(ByVal L1, ByVal L2)
Dim L11, L12, L21, L22, L31, L32
L11 = L1 And &HFFFFFF
L12 = (L1 And &H7F000000) \ &H1000000
If L1 < 0 Then L12 = L12 Or &H80
L21 = L2 And &HFFFFFF
L22 = (L2 And &H7F000000) \ &H1000000
If L2 < 0 Then L22 = L22 Or &H80
L32 = L12 - L22
L31 = L11 - L21
If L31 < 0 Then L32 = L32 - 1 L31 = L31 + &H1000000 End If usub = L31 + (L32 And &H7F) * &H1000000 If L32 And &H80 Then usub = usub Or &H80000000 End Function Function mix(ByVal ia, ByVal ib, ByVal ic) Dim a, b, c a = ia b = ib c = ic a = usub(a, b) a = usub(a, c) a = a Xor zeroFill(c, 13) b = usub(b, c) b = usub(b, a) b = b Xor sl(a, 8) c = usub(c, a) c = usub(c, b) c = c Xor zeroFill(b, 13) a = usub(a, b) a = usub(a, c) a = a Xor zeroFill(c, 12) b = usub(b, c) b = usub(b, a) b = b Xor sl(a, 16) c = usub(c, a) c = usub(c, b) c = c Xor zeroFill(b, 5) a = usub(a, b) a = usub(a, c) a = a Xor zeroFill(c, 3) b = usub(b, c) b = usub(b, a) b = b Xor sl(a, 10) c = usub(c, a) c = usub(c, b) c = c Xor zeroFill(b, 15) Dim ret(3) ret(0) = a ret(1) = b ret(2) = c mix = ret End Function Function gc(ByVal s, ByVal i) gc = Asc(Mid(s, i + 1, 1)) End Function Function GoogleCH(ByVal sUrl) Dim iLength, a, b, c, k, iLen, m iLength = Len(sUrl) a = &H9E3779B9 b = &H9E3779B9 c = GOOGLE_MAGIC k = 0 iLen = iLength Do While iLen >= 12
a = uadd(a, (uadd(gc(sUrl, k + 0), uadd(sl(gc(sUrl, k + 1), 8), uadd(sl(gc(sUrl, k + 2), 16), sl(gc(sUrl, k + 3), 24))))))
b = uadd(b, (uadd(gc(sUrl, k + 4), uadd(sl(gc(sUrl, k + 5), 8), uadd(sl(gc(sUrl, k + 6), 16), sl(gc(sUrl, k + 7), 24))))))
c = uadd(c, (uadd(gc(sUrl, k + 8), uadd(sl(gc(sUrl, k + 9), 8), uadd(sl(gc(sUrl, k + 10), 16), sl(gc(sUrl, k + 11), 24))))))
m = mix(a, b, c)
a = m(0)
b = m(1)
c = m(2)
k = k + 12
iLen = iLen - 12
Loop
c = uadd(c, iLength)
Select Case iLen ' all the case statements fall through
Case 11
c = uadd(c, sl(gc(sUrl, k + 10), 24))
c = uadd(c, sl(gc(sUrl, k + 9), 16))
c = uadd(c, sl(gc(sUrl, k + 8), 8))
b = uadd(b, sl(gc(sUrl, k + 7), 24))
b = uadd(b, sl(gc(sUrl, k + 6), 16))
b = uadd(b, sl(gc(sUrl, k + 5), 8))
b = uadd(b, gc(sUrl, k + 4))
a = uadd(a, sl(gc(sUrl, k + 3), 24))
a = uadd(a, sl(gc(sUrl, k + 2), 16))
a = uadd(a, sl(gc(sUrl, k + 1), 8))
a = uadd(a, gc(sUrl, k + 0))
Case 10
c = uadd(c, sl(gc(sUrl, k + 9), 16))
c = uadd(c, sl(gc(sUrl, k + 8), 8))
b = uadd(b, sl(gc(sUrl, k + 7), 24))
b = uadd(b, sl(gc(sUrl, k + 6), 16))
b = uadd(b, sl(gc(sUrl, k + 5), 8))
b = uadd(b, gc(sUrl, k + 4))
a = uadd(a, sl(gc(sUrl, k + 3), 24))
a = uadd(a, sl(gc(sUrl, k + 2), 16))
a = uadd(a, sl(gc(sUrl, k + 1), 8))
a = uadd(a, gc(sUrl, k + 0))
Case 9
c = uadd(c, sl(gc(sUrl, k + 8), 8))
b = uadd(b, sl(gc(sUrl, k + 7), 24))
b = uadd(b, sl(gc(sUrl, k + 6), 16))
b = uadd(b, sl(gc(sUrl, k + 5), 8))
b = uadd(b, gc(sUrl, k + 4))
a = uadd(a, sl(gc(sUrl, k + 3), 24))
a = uadd(a, sl(gc(sUrl, k + 2), 16))
a = uadd(a, sl(gc(sUrl, k + 1), 8))
a = uadd(a, gc(sUrl, k + 0))
Case 8
b = uadd(b, sl(gc(sUrl, k + 7), 24))
b = uadd(b, sl(gc(sUrl, k + 6), 16))
b = uadd(b, sl(gc(sUrl, k + 5), 8))
b = uadd(b, gc(sUrl, k + 4))
a = uadd(a, sl(gc(sUrl, k + 3), 24))
a = uadd(a, sl(gc(sUrl, k + 2), 16))
a = uadd(a, sl(gc(sUrl, k + 1), 8))
a = uadd(a, gc(sUrl, k + 0))
Case 7
b = uadd(b, sl(gc(sUrl, k + 6), 16))
b = uadd(b, sl(gc(sUrl, k + 5), 8))
b = uadd(b, gc(sUrl, k + 4))
a = uadd(a, sl(gc(sUrl, k + 3), 24))
a = uadd(a, sl(gc(sUrl, k + 2), 16))
a = uadd(a, sl(gc(sUrl, k + 1), 8))
a = uadd(a, gc(sUrl, k + 0))
Case 6
b = uadd(b, sl(gc(sUrl, k + 5), 8))
b = uadd(b, gc(sUrl, k + 4))
a = uadd(a, sl(gc(sUrl, k + 3), 24))
a = uadd(a, sl(gc(sUrl, k + 2), 16))
a = uadd(a, sl(gc(sUrl, k + 1), 8))
a = uadd(a, gc(sUrl, k + 0))
Case 5
b = uadd(b, gc(sUrl, k + 4))
a = uadd(a, sl(gc(sUrl, k + 3), 24))
a = uadd(a, sl(gc(sUrl, k + 2), 16))
a = uadd(a, sl(gc(sUrl, k + 1), 8))
a = uadd(a, gc(sUrl, k + 0))
Case 4
a = uadd(a, sl(gc(sUrl, k + 3), 24))
a = uadd(a, sl(gc(sUrl, k + 2), 16))
a = uadd(a, sl(gc(sUrl, k + 1), 8))
a = uadd(a, gc(sUrl, k + 0))
Case 3
a = uadd(a, sl(gc(sUrl, k + 2), 16))
a = uadd(a, sl(gc(sUrl, k + 1), 8))
a = uadd(a, gc(sUrl, k + 0))
Case 2
a = uadd(a, sl(gc(sUrl, k + 1), 8))
a = uadd(a, gc(sUrl, k + 0))
Case 1
a = uadd(a, gc(sUrl, k + 0))
End Select
m = mix(a, b, c)
GoogleCH = m(2)
End Function
Function CalculateChecksum(sUrl)
CalculateChecksum = "6" & CStr(GoogleCH("info:" & sUrl)) ' AND &H7FFFFFFF)
End Function
'************
%>
Lo script non funziona più perchè Google da poco ha deciso di non rendere pubblica questa informazione in quanto non esternava il vero valore del sito, in pratica non abbracciava tutti i parametri relativi all’importanza di un sito.