Mega Code Archive
How to obtain the computer name from IP address
<![CDATA[
Title: How to obtain the computer name from IP address
uses
WinSock;
function LocalIP: string;
type
TaPInAddr = array[0..10] of PInAddr;
PaPInAddr = ^TaPInAddr;
var
phe: PHostEnt;
pptr: PaPInAddr;
Buffer: array[0..63] of Char;
I: Integer;
GInitData: TWSAData;
begin
WSAStartup($101, GInitData);
Result := '';
GetHostName(Buffer, SizeOf(Buffer));
phe := GetHostByName(buffer);
if phe = nil then Exit;
pPtr := PaPInAddr(phe^.h_addr_list);
I := 0;
while pPtr^[I] nil do
begin
Result := inet_ntoa(pptr^[I]^);
Inc(I);
end;
WSACleanup;
end;
function IPAddrToName(IPAddr: string): string;
var
SockAddrIn: TSockAddrIn;
HostEnt: PHostEnt;
WSAData: TWSAData;
begin
WSAStartup($101, WSAData);
SockAddrIn.sin_addr.s_addr := inet_addr(PChar(IPAddr));
HostEnt := gethostbyaddr(@SockAddrIn.sin_addr.S_addr, 4, AF_INET);
if HostEnt nil then
Result := StrPas(Hostent^.h_name)
else
Result := '';
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
ShowMessage(IPAddrToName(LocalIp));
end;
{**************************************}
// Function to get the IP Address from a Host
function GetIPFromHost(const HostName: string): string;
type
TaPInAddr = array[0..10] of PInAddr;
PaPInAddr = ^TaPInAddr;
var
phe: PHostEnt;
pptr: PaPInAddr;
i: Integer;
GInitData: TWSAData;
begin
WSAStartup($101, GInitData);
Result := '';
phe := GetHostByName(PChar(HostName));
if phe = nil then Exit;
pPtr := PaPInAddr(phe^.h_addr_list);
i := 0;
while pPtr^[i] nil do
begin
Result := inet_ntoa(pptr^[i]^);
Inc(i);
end;
WSACleanup;
end;
]]>