sending a file through sockets

[Guyon Morée]

wow, really thanx a lot!

this is good stuff, i have to figure out this struct module but i can handle
i guess :)

thanx,
Guyon

<brueckd at tbye.com> wrote in message
news:mailman.1025817368.17823.python-list at python.org...
> On Thu, 4 Jul 2002, Guyon Morée wrote:
>
> > so the trick is to convert a file to a string representation right?
> > i still have to try it out, but maybe you can confirm my way of thinking
> > here :)
>
> Um... you *could* do that, but it wouldn't actually help at all. The
> contents of the file already are in a string representation because Python
> strings can contain anything, including binary characters. The easiest way
> to send a file is to simply read the data from the file and send it out
> the socket, but to send the length of the file first so the receiving end
> knows if and when it got the whole thing. If you need too much more
> functionality than this it might be easier to just use one of the standard
> file transfer protocols, e.g. FTP. Anyway, here's some sample code, but if
> you're not already familiar with sockets then you should spend a little
> time experimenting with them.
>
> The sending side listens for incoming connections and sends out the file.
> The receiving side connects to the "server" and writes the file to disk.
>
> Common code:
> import struct
> PORT = 5555
> FILENAME = 'foo.bin'
> HDR = '!I'
> HDR_SZ = struct.calcsize(HDR)
>
> Sending side:
> import os
> from socket import *
> s = socket(AF_INET,SOCK_STREAM)
> s.bind(('',PORT))
> s.listen(1)
> while 1:
>   q,v = s.accept()
>   q.sendall(struct.pack(HDR, os.path.getsize(FILENAME)))
>   f = open(FILENAME,'rb')
>   while 1:
>     data = f.read(4096)
>     if not data: break
>     q.sendall(data)
>   q.close()
>
> Receiving side:
> from socket import *
> f = open(FILENAME, 'wb')
> s = socket(AF_INET, SOCK_STREAM)
> s.connect(('', PORT))
> size = s.recv(HDR_SZ)
> size = struct.unpack(HDR, size)
> while size > 0:
>   data = s.recv(4096)
>   if not data: break
>   size -= len(data)
>   f.write(data)
> s.close()
>
> Note that if you're not using Python 2.2 or later there isn't a sendall
> method in socket objects so the sending side should check the return value
> from send() to see how many bytes were actually written out and resend any
> that didn't make it.
>
> -Dave
>
>
>