Sending a file over TCP sockets in Python

Question

I ve successfully been able to copy the file contents  image  to a new file  However when I try the same thing over TCP sockets I m facing issues  The server loop is not exiting  The client loop exits when it reaches the EOF  however the server is unable to recognize EOF   Here s the code   Server  import socket                 Import socket module  s   socket socket             Create a socket object host   socket gethostname     Get local machine name port   12345                   Reserve a port for your service  s bind  host  port            Bind to the port f   open  torecv png   wb   s listen 5                    Now wait for client connection  while True      c  addr   s accept         Establish connection with client      print  Got connection from   addr     print  Receiving         l   c recv 1024      while  l           print  Receiving             f write l          l   c recv 1024      f close       print  Done Receiving      c send  Thank you for connecting       c close                    Close the connection   Client  import socket                 Import socket module  s   socket socket             Create a socket object host   socket gethostname     Get local machine name port   12345                   Reserve a port for your service   s connect  host  port   s send  Hello server    f   open  tosend png   rb   print  Sending     l   f read 1024  while  l       print  Sending         s send l      l   f read 1024  f close   print  Done Sending  print s recv 1024  s close                       Close the socket when done   Here s the screenshot   Server   Client   Edit 1  Extra data copied over  Making the file  not complete   The first column shows the image that has been received  It seems to be larger than the one sent  Because of this  I m not able to open the image  It seems like a corrupted file     Edit 2  This is how I do it in the console  The file sizes are the same here

User · Answer

you may change your loop condition according to following code  when length of l is smaller than buffer size it means that it reached end of file   while  True       print  Receiving         l   c recv 1024              f write l      if len l   lt  1024          break

User · Answer

Remove below code  s send  Hello server      because your sending s send  Hello server    to server  so your output file is somewhat more in size

User · Answer

Put file inside while True like so  while True       f   open  torecv png   wb        c  addr   s accept         Establish connection with client       print  Got connection from   addr      print  Receiving          l   c recv 1024       while  l            print  Receiving              f write l           l   c recv 1024       f close        print  Done Receiving       c send  Thank you for connecting        c close

User · Answer

The problem is extra 13 byte which server py receives at the start  To resolve that write  l   c recv 1024   twice before the while loop as below   print  Receiving     l   c recv 1024   this receives 13 bytes which is corrupting the data l   c recv 1024    Now actual data starts receiving while  l     This resolves the issue  tried with different format and sizes of files  If anyone knows what this starting 13 bytes refers to  please reply

User · Answer

You can send some flag to stop while loop in server for example Server side  import socket s   socket socket   s bind   quot localhost quot   5000   s listen 1  c a   s accept   filetodown   open  quot img png quot    quot wb quot   while True     print  quot Receiving     quot      data   c recv 1024     if data    b quot DONE quot              print  quot Done Receiving  quot              break    filetodown write data  filetodown close   c send  quot Thank you for connecting  quot   c shutdown 2  c close   s close    Done     Client side  import socket s   socket socket   s connect   quot localhost quot   5000   filetosend   open  quot img png quot    quot rb quot   data   filetosend read 1024  while data      print  quot Sending    quot       s send data      data   filetosend read 1024  filetosend close   s send b quot DONE quot   print  quot Done Sending  quot   print s recv 1024   s shutdown 2  s close    Done

User · Answer

Client need to notify that it finished sending  using socket shutdown  not socket close which close both reading writing part of the socket        print  Done Sending  s shutdown socket SHUT WR  print s recv 1024  s close     UPDATE  Client sends Hello server  to the server  which is written to the file in the server side   s send  Hello server      Remove above line to avoid it

[python] Sending a file over TCP sockets in Python

Examples related to python

Examples related to file

Examples related to sockets

Examples related to python-2.7

Examples related to tcp