?
Solved

Indy Trivial FTP Client/Server Example

Posted on 2004-09-13
5
Medium Priority
?
4,833 Views
Last Modified: 2012-08-14
I'm looking for an example on how to use the Indy Trivial FTP client and server components to upload and download a file.

Get and Put with the client seems clear enough, but I'm unsure how to handle the requests in te server.

Thanks in advance,

D2.
0
Comment
Question by:wavget
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
  • 2
5 Comments
 
LVL 8

Expert Comment

by:BdLm
ID: 12046177
did you check the samples from the indy homepage ?
0
 
LVL 8

Expert Comment

by:BdLm
ID: 12046247
0
 
LVL 1

Author Comment

by:wavget
ID: 12053740
First of all, Delphi comes with an example of both a TrivialFtp Server and Client, I just didn't think to look there at first :)

I downloaded the demo from indyproject.org but I am unable to find a TrivialFtp example in it.

My biggest question is how do I handle OnRead and OnWrite in the server.
0
 
LVL 1

Accepted Solution

by:
NickRyan earned 400 total points
ID: 12063094
Here's a short sample of how you could handle the file read process. The file write process is pretty similar except that you may want to put in more checks in the case of overwriting files.

This short example assumes that you're only accepting filenames, not filepaths in the TFTP server - if you want to accept file paths as well then you need to process the directory separators and ensure that it's not possible for a user to reference files outside of where you want them to. ie, strip out any "..\" items in the path.

You can use the IP address of the client as a form of access control if you need or want to restrict access to certain IP addresses or address ranges.


procedure TForm1.IdTrivialFTPServer1ReadFile( Sender:TObject;
  var FileName:String; const PeerInfo:TPeerInfo;
  var GrantAccess:Boolean; var AStream:TStream;
  var FreeStreamOnComplete:Boolean );
var
  EffectiveFileName:string;
const
  SERVER_ROOT = 'C:\TFTP\';
begin

  {First, check IP address of client, if this is what you need to do}
  // PeerInfo.PeerIP is the IP address of the client
  // if not PeerInfo.PeerIP = AllowedIPAddress then begin
  //   GrantAccess := False;
  //   Exit;
  // end; {if}

  {Process filename - in this case we assume that we are dealing with just a filename with no dir part}
  EffectiveFileName := SERVER_ROOT + ExtractFileName(FileName);
  GrantAccess := FileExists(EffectiveFileName);
  if not GrantAccess then begin
    {File doesn't exist, so obviously can't allow access}
    False;
    Exit;
  end; {if}

  {Setup file access}
  try
    {Open a file stream referencing the file}
    AStream := TFileStream.Create( EffectiveFileName, fmOpenRead or fmShareDenyWrite );
    {Allow the server FTP component to destroy the stream when the transfer process finishes}
    FreeStreamOnComplete := True;
  except
    {Handle failure to open file stream here - ie, file locked}
    GrantAccess := False;
  end; {try}

end;
0
 
LVL 1

Expert Comment

by:NickRyan
ID: 12063281
Oops - please excuse the extra "False;" line in just after the FileExists check... it's just a typo.
0

Featured Post

Independent Software Vendors: We Want Your Opinion

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

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

Objective: - This article will help user in how to convert their numeric value become words. How to use 1. You can copy this code in your Unit as function 2. than you can perform your function by type this code The Code   (CODE) The Im…
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…
In this brief tutorial Pawel from AdRem Software explains how you can quickly find out which services are running on your network, or what are the IP addresses of servers responsible for each service. Software used is freeware NetCrunch Tools (https…
This is my first video review of Microsoft Bookings, I will be doing a part two with a bit more information, but wanted to get this out to you folks.
Suggested Courses

766 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