Solved

Get host name from IP address!

Posted on 1999-01-19
7
259 Views
Last Modified: 2010-04-06
How to do it?
0
Comment
Question by:mingwei
  • 4
  • 3
7 Comments
 
LVL 7

Expert Comment

by:BlackMan
ID: 1362436
Use the GetHostByAddr function, like this:

uses Winsock;

function HostByAddr(AddrStr: String): String;
  Addr: TInAddr;
  Host: PHostEnt;
begin
  AddrStr := '136.148.3.10';
  Addr.s_addr := Inet_Addr(PChar(AddrStr));
  Host := GetHostByAddr(@Addr.s_addr,4,PF_INET);
  Result := Host^.h_name;
end;

0
 
LVL 7

Expert Comment

by:BlackMan
ID: 1362437
Oops, remove the line AddrStr := '136.148.3.10'; from the function...
0
 

Author Comment

by:mingwei
ID: 1362438
GetHostByAddr(@Addr.s_addr,4,PF_INET);
return nil
0
Courses: Start Training Online With Pros, Today

Brush up on the basics or master the advanced techniques required to earn essential industry certifications, with Courses. Enroll in a course and start learning today. Training topics range from Android App Dev to the Xen Virtualization Platform.

 
LVL 7

Accepted Solution

by:
BlackMan earned 30 total points
ID: 1362439
Sorry, I cut it out of a larger unit. You need to initialize WinSock first to make it work.

uses Winsock;

Var
  VerReqd      : Word;
  WSAData      : TWSAData;
  WSErr      : Word;

function HostByAddr(AddrStr: String): String;
Var
  Addr: TInAddr;
  Host: PHostEnt;
begin
  VerReqd := $0101;
  WSErr := WSAStartup(VerReqd, WSAData);

  Addr.s_addr := Inet_Addr(PChar(AddrStr));
  Host := GetHostByAddr(@Addr.s_addr,4,PF_INET);
  Result := Host^.h_name;
end;


0
 

Author Comment

by:mingwei
ID: 1362440
But I want to say this way just return the hosts name
from local HOSTS files.
If I want to get hosts name from Internet how can I read
information from IP pack?
If you have any source tell me about that!
Thanks a lot.

0
 
LVL 7

Expert Comment

by:BlackMan
ID: 1362441
This code is not specific to the HOSTS file, it uses the normal TCP/IP conventions. This means that if you want to use it on www addresses, you must have a proper DNS configured in your TCP/IP settings, which you'd probably allready have if you are able to access www.experts-exchange.com. You need to be connected to read the names, there is no cache with names/addresses..

0
 

Author Comment

by:mingwei
ID: 1362442
Oh,I know!
Very thanks.
0

Featured Post

Live: Real-Time Solutions, Start Here

Receive instant 1:1 support from technology experts, using our real-time conversation and whiteboard interface. Your first 5 minutes are always free.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Creating an auto free TStringList The TStringList is a basic and frequently used object in Delphi. On many occasions, you may want to create a temporary list, process some items in the list and be done with the list. In such cases, you have to…
Have you ever had your Delphi form/application just hanging while waiting for data to load? This is the article to read if you want to learn some things about adding threads for data loading in the background. First, I'll setup a general applica…
With Secure Portal Encryption, the recipient is sent a link to their email address directing them to the email laundry delivery page. From there, the recipient will be required to enter a user name and password to enter the page. Once the recipient …
A short tutorial showing how to set up an email signature in Outlook on the Web (previously known as OWA). For free email signatures designs, visit https://www.mail-signatures.com/articles/signature-templates/?sts=6651 If you want to manage em…

785 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question