Mega Code Archive
Resolve Host address to IP numbers
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Title: Resolve Host address to IP numbers
Question: Describe a function that shows how to resolve Host address to IP numbers.
Answer:
Declare Winsock in the uses clause
............
function HostToIP(Name: string; var Ip: string): Boolean;
var
wsdata : TWSAData;
hostName : array [0..255] of char;
hostEnt : PHostEnt;
addr : PChar;
begin
WSAStartup ($0101, wsdata);
try
gethostname (hostName, sizeof (hostName));
StrPCopy(hostName, Name);
hostEnt := gethostbyname (hostName);
if Assigned (hostEnt) then
if Assigned (hostEnt^.h_addr_list) then begin
addr := hostEnt^.h_addr_list^;
if Assigned (addr) then begin
IP := Format ('%d.%d.%d.%d', [byte (addr [0]),
byte (addr [1]), byte (addr [2]), byte (addr [3])]);
Result := True;
end
else
Result := False;
end
else
Result := False
else begin
Result := False;
end;
finally
WSACleanup;
end
end;
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You can try this function placing a EditBox and a Button and A Label on a form and adding this code to the OnClick event of the button:
procedure TForm1.Button1Click(Sender: TObject);
var
IP: string;
begin
if HostToIp(Edit1.Text, IP) then Label1.Caption := IP;
end;
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