Programming

Hi everyone,
I'm trying to replicate a bittorrent program using Linux client/server programming. I have a few questions on how to approach this..

1) If I write a client/server program, can it be merged together? Usually bittorrent programs can send/receive files

2) Doing it step by step, I would like to send a file from the server to the client. Problem is, how can I find out the name of the file that I am trying to send from the server to the client? For example, image.jpg.

3) I've tried sending a flat file over, say textfile.txt, but on the client side it appends some junk character at the end of it. What causes the characters to appear?

That's the questions I have for now. Will post more if it comes up. Thanks!

---------- Post updated at 12:35 PM ---------- Previous update was at 11:28 AM ----------

Hmm I fixed the junk character appending, but somehow it only works when sending txt files from client to server. Sending any image files, results in a smaller, corrupted file for some reason.

Client code:

Code:

while ( (n = read(sock, buffer, sizeof(buffer))) > 0)
{
           fprintf(fw,buffer);
}

In the client side, sock is the socket, while fw is the file to write to (eg: image.gif)

Server code:

Code:

while (( n = read(fw,buffer2, sizeof(buffer2)))> 0 )
{
            write(fd, buffer2,sizeof(buffer2));
}

In the server, fw is the file to read from (eg: image.gif), and fd is the socket to write to.

Any help greatly appreciated =)

You need to send the file size before sending actual file. Because this is binary data, you MUST NOT treat this as string data.

Also while reading/writing you should check how bytes has been actually read/written. Based on this you should move your read/write point. e.g. while writing it should be

Code:

while (( n = read(fw,buffer2, sizeof(buffer2)))> 0 )
{
            write(fd, buffer2,n));  // use n here instead of sizeof(buffer2)
}