Connected to Internet OR NOT Connected?
Hey all,
I need to find out if the user is connected to the Internet. I've
looked at a ton of examples. Most of them have drawbacks to
using them because they don't work for every type of
connection. So I have an idea I want to clarify.....
It is my understanding that if I retrieve the local IP Address,
and it is 127.0.0.1, then the user is NOT connected. Right?
If so, is this always the case? I mean, is every computers
local IP Address 127.0.0.1 when they are not connected?
If all of this is right, why couldn't I use the following code...
(I don't know where I got this, so if it is yours...Thanks)
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'Put this in a Module:
Option Explicit
Public Const MIN_SOCKETS_REQD As Long = 1
Public Const WS_VERSION_REQD As Long = &H101
Public Const WS_VERSION_MAJOR As Long = WS_VERSION_REQD \ &H100 And &HFF&
Public Const WS_VERSION_MINOR As Long = WS_VERSION_REQD And &HFF&
Public Const SOCKET_ERROR As Long = -1
Public Const ERROR_SUCCESS = 0&
Public Const WSADESCRIPTION_LEN = 257
Public Const WSASYS_STATUS_LEN = 129
Public Const MAX_WSADescription = 256
Public Const MAX_WSASYSStatus = 128
Public Type WSAData
wVersion As Integer
wHighVersion As Integer
szDescription(0 To MAX_WSADescription) As Byte
szSystemStatus(0 To MAX_WSASYSStatus) As Byte
wMaxSockets As Integer
wMaxUDPDG As Integer
dwVendorInfo As Long
End Type
Type WSADataInfo
wVersion As Integer
wHighVersion As Integer
szDescription As String * WSADESCRIPTION_LEN
szSystemStatus As String * WSASYS_STATUS_LEN
iMaxSockets As Integer
iMaxUdpDg As Integer
lpVendorInfo As String
End Type
Public Type HOSTENT
hName As Long
hAliases As Long
hAddrType As Integer
hLen As Integer
hAddrList As Long
End Type
Declare Function WSAStartupInfo Lib "WSOCK32" Alias "WSAStartup" (ByVal wVersionRequested As Integer, lpWSADATA As WSADataInfo) As Long
Declare Function WSACleanup Lib "WSOCK32" () As Long
Declare Function WSAGetLastError Lib "WSOCK32" () As Long
Declare Function WSAStartup Lib "WSOCK32" (ByVal wVersionRequired As Long, lpWSADATA As WSAData) As Long
Declare Function gethostname Lib "WSOCK32" (ByVal szHost As String, ByVal dwHostLen As Long) As Long
Declare Function gethostbyname Lib "WSOCK32" (ByVal szHost As String) As Long
Declare Sub CopyMemoryIP Lib "kernel32" Alias "RtlMoveMemory" (hpvDest As Any, ByVal hpvSource As Long, ByVal cbCopy As Long)
Public Function GetIPAddress() As String
Dim sHostName As String * 256
Dim lpHost As Long
Dim HOST As HOSTENT
Dim dwIPAddr As Long
Dim tmpIPAddr() As Byte
Dim I As Integer
Dim sIPAddr As String
If Not SocketsInitialize() Then
GetIPAddress = ""
Exit Function
End If
If gethostname(sHostName, 256) = SOCKET_ERROR Then
GetIPAddress = ""
MsgBox "Windows Sockets error " & Str$(WSAGetLastError()) & " has occurred. Unable to successfully get Host Name."
SocketsCleanup
Exit Function
End If
sHostName = Trim$(sHostName)
lpHost = gethostbyname(sHostName)
If lpHost = 0 Then
GetIPAddress = ""
MsgBox "Windows Sockets are not responding. " & "Unable to successfully get Host Name."
SocketsCleanup
Exit Function
End If
CopyMemoryIP HOST, lpHost, Len(HOST)
CopyMemoryIP dwIPAddr, HOST.hAddrList, 4
ReDim tmpIPAddr(1 To HOST.hLen)
CopyMemoryIP tmpIPAddr(1), dwIPAddr, HOST.hLen
For I = 1 To HOST.hLen
sIPAddr = sIPAddr & tmpIPAddr(I) & "."
Next
GetIPAddress = Mid$(sIPAddr, 1, Len(sIPAddr) - 1)
SocketsCleanup
End Function
Public Function GetIPHostName() As String
Dim sHostName As String * 256
If Not SocketsInitialize() Then
GetIPHostName = ""
Exit Function
End If
If gethostname(sHostName, 256) = SOCKET_ERROR Then
GetIPHostName = ""
MsgBox "Windows Sockets error " & Str$(WSAGetLastError()) & " has occurred. Unable to successfully get Host Name."
SocketsCleanup
Exit Function
End If
GetIPHostName = Left$(sHostName, InStr(sHostName, Chr(0)) - 1)
SocketsCleanup
End Function
Public Function HiByte(ByVal wParam As Integer)
HiByte = wParam \ &H100 And &HFF&
End Function
Public Function LoByte(ByVal wParam As Integer)
LoByte = wParam And &HFF&
End Function
Public Sub SocketsCleanup()
If WSACleanup() <> ERROR_SUCCESS Then
MsgBox "Socket error occurred in Cleanup."
End If
End Sub
Public Function SocketsInitialize() As Boolean
Dim WSAD As WSAData
Dim sLoByte As String
Dim sHiByte As String
If WSAStartup(WS_VERSION_REQD, WSAD) <> ERROR_SUCCESS Then
MsgBox "The 32-bit Windows Socket is not responding."
SocketsInitialize = False
Exit Function
End If
If WSAD.wMaxSockets < MIN_SOCKETS_REQD Then
MsgBox "This application requires a minimum of " & CStr(MIN_SOCKETS_REQD) & " supported sockets."
SocketsInitialize = False
Exit Function
End If
If LoByte(WSAD.wVersion) < WS_VERSION_MAJOR Or (LoByte(WSAD.wVersion) = WS_VERSION_MAJOR And HiByte(WSAD.wVersion) < WS_VERSION_MINOR) Then
sHiByte = CStr(HiByte(WSAD.wVersion))
sLoByte = CStr(LoByte(WSAD.wVersion))
MsgBox "Sockets version " & sLoByte & "." & sHiByte & " is not supported by 32-bit Windows Sockets."
SocketsInitialize = False
Exit Function
End If
'must be OK, so lets do it
SocketsInitialize = True
End Function
'Put this in the Form:
Private Sub Command1_Click()
Text1.Text = GetIPAddress
End Sub
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So, the point is...if the returned local IP Address is 127.0.0.1,
then I know they are not connected, and can tell them they need
to be connected to do what I want them to do.
I hope this makes sense. I don't even know anymore because
I've been at this for about 6 hours straight.
Anyway, I sure would appreciate you guys checking this out, and
telling me what you think.
Thanks in advance,
Ron
Re: Connected to Internet OR NOT Connected?
Quote:
Originally posted by rdcody
It is my understanding that if I retrieve the local IP Address,
and it is 127.0.0.1, then the user is NOT connected. Right?
If so, is this always the case? I mean, is every computers
local IP Address 127.0.0.1 when they are not connected?
Ron
I might be mistaken, but isn't 127.0.1 just the LocalHost?
