socket receive file does not match sent file
I wrote two simple socket program. one for sending a file and the other for receiving the file. but when I run it, a curious thing happened. The received file was samller that the sent file. $ cat receivefile.py #!/usr/local/bin/python # -*- coding: utf-8 -*- import socket import time import string import sys sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock.bind(('', 9000)) sock.listen(5) try: while True: # 1. client connect, open file newSocket, address = sock.accept() print "Connected from ", address filename = sys.argv[1] f=open( filename, 'wb') # 2. recieve data while True: data = newSocket.recv(8192) if not data: break f.write(data) # 3.close file f.close() print filename, "Received\n" finally: sock.close() $ cat putfile.py #!/usr/local/bin/python # -*- coding: utf-8 -*- import sys import socket import string # "Usage: prog file hostip" filename = sys.argv[1] host = sys.argv[2] f=open(filename, 'rb') s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.connect((host, 9000)) while True: data = f.read(8192) if not data: break else: s.send(data) f.close() s.close() print filename, " Sent!\n" $ python receivefile.py save_apache_1.33.tar.gz $ python putfile.py apache_1.33.tar.gz localhost The result is : save_apache_1.33.tar.gz 's size was smaller then the apache_1.33.tar.gz file What is the cause of the problem, can anyone tell me? Thanks. -- http://mail.python.org/mailman/listinfo/python-list
Re: socket receive file does not match sent file
On 6 Nov 2005 09:13:03 -0800, "[EMAIL PROTECTED]" <[EMAIL PROTECTED]> wrote: >I wrote two simple socket program. >one for sending a file and the other for receiving the file. >but when I run it, a curious thing happened. >The received file was samller that the sent file. Your sender does not take care to ensure the entire file is sent. It will semi-randomly drop bytes from various areas in the middle of the file. Here's a sender that works correctly: from twisted.internet import reactor, protocol from twisted.protocols import basic from twisted.python import log filename = sys.argv[1] host = sys.argv[2] class Putter(protocol.Protocol): def connectionMade(self): fs = basic.FileSender() d = fs.beginFileTransfer(file(filename, 'b'), self.transport) d.addCallback(self.finishedTransfer) d.addErrback(self.transferFailed) def finishedTransfer(self, result): self.transport.loseConnection() def transferFailed(self, err): print 'Transfer failed' err.printTraceback() self.transport.loseConnection() def connectionLost(self, reason): reactor.stop() f = protocol.ClientFactory() f.protocol = Putter reactor.connectTCP(host, 9000, f) reactor.run() Of course, this is still not entirely correct, since the protocol specified by your code provides not mechanism for the receiving side to determine whether the connection was dropped because the file was fully transferred or because of some transient network problem or other error. One solution to this is to prefix the file's contents with its length. Jean-Paul -- http://mail.python.org/mailman/listinfo/python-list
Re: socket receive file does not match sent file
when I test the two program in the same OS, i mean from a redhat 9 OS to a redhat 9 OS, It's ok. receivefile match sent file. But when I run receiver on a Redhat 9, and send file from a windows XP, the received file's size is randomized. May be that's where the problem is. -- http://mail.python.org/mailman/listinfo/python-list
Re: socket receive file does not match sent file
[EMAIL PROTECTED] wrote: > when I test the two program in the same OS, > i mean from a redhat 9 OS to a redhat 9 OS, > It's ok. receivefile match sent file. > > > But when I run receiver on a Redhat 9, > and send file from a windows XP, > the received file's size is randomized. > > May be that's where the problem is. > No. Read Jean-Paul's reply. --Irmen -- http://mail.python.org/mailman/listinfo/python-list
Re: socket receive file does not match sent file
[EMAIL PROTECTED] wrote: > while True: >data = f.read(8192) >if not data: break >else: >s.send(data) > What is the cause of the problem, can anyone tell me? using sendall instead of send should fix this. see the library reference for details: send( string[, flags]) Send data to the socket. The socket must be connected to a remote socket. The optional flags argument has the same meaning as for recv() above. Returns the number of bytes sent. Applications are responsible for checking that all data has been sent; if only some of the data was transmitted, the application needs to attempt delivery of the remaining data. sendall( string[, flags]) Send data to the socket. The socket must be connected to a remote socket. The optional flags argument has the same meaning as for recv() above. Unlike send(), this method continues to send data from string until either all data has been sent or an error occurs. None is returned on success. On error, an exception is raised, and there is no way to determine how much data, if any, was successfully sent. -- http://mail.python.org/mailman/listinfo/python-list
Re: socket receive file does not match sent file
Thanks Fredrik Lundh, This is great! I've rewrote the code and it works! Thanks a lot. -- http://mail.python.org/mailman/listinfo/python-list