unit2.pas

实现输入IP或域名

unit Unit2;

interface

uses
  Classes,winsock,sysutils,windows;

type
  convert = class(TThread)
  private
    { Private declarations }
  protected
    procedure Execute; override;
  end;

implementation
uses unit1;

function GetIP(Name: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(Name)); //返回一个指向主机信息结构的指针
pptr := PaPInAddr(Phe^.h_addr_list); //强制转换
result:=StrPas(inet_ntoa(pptr^[0]^));//返回一个点分形式的字符串IP地址
WSACleanup;
end;

function GetDomainName(Ip:string):string;
var 
pH:PHostent;
data:twsadata;
ii:dword;  //即ii 为LongWord类型
begin
WSAStartup($101, Data);
ii:=inet_addr(pchar(ip)); // 返回一个适合Internet的数字化地址
pH:=gethostbyaddr(@ii,sizeof(ii),PF_INET);//返回一个指向主机信息结构的指针
if (ph<>nil) then
result:=pH.h_name //返回该结构的主机名
else
result:='';
WSACleanup();
end;

procedure convert.Execute;
var i:integer;temp:string;comp:boolean;
begin
temp:=form1.Edit1.Text;
comp:=false;
for i:=1 to length(temp) do begin
 if ((temp[i]>'9') or (temp[i]<'0')) and (temp[i]<>'.') then begin//是IP则要换成dns
    form1.Button1.Caption:='终止';
     Form1.Edit1.Text:=GetIp(temp);
     comp:=true;
    Form1.Button1.Caption:='转化';
 end;
 if comp then break;//完成DNS->IP的转化
end;
if not comp then begin //是IP，则完成IP->DNS的转化
    form1.Button1.Caption:='终止';
    Form1.Edit1.Text:=GetDomainName(temp);
    Form1.Button1.Caption:='转化';
end;
end;

end.