Path: utzoo!utgpu!watmath!iuvax!khan
From: khan@iuvax.cs.indiana.edu
Newsgroups: comp.protocols.tcp-ip
Subject: Bidirectional communication (HELP)
Message-ID: <44500001@iuvax>
Date: 9 Apr 89 20:24:00 GMT
Organization: Indiana University CSCI, Bloomington
Lines: 53
Nf-ID: #N:iuvax:44500001:000:1160
Nf-From: iuvax.cs.indiana.edu!khan    Apr  9 15:24:00 1989



Can anyone tell me how to use bidirectional communication in UNIX tcp-ip,
using STREAM sockets.  I am trying to implement a CLIENT-SERVER model
application.  Here is what each of them successfully do:

CLIENT:
...
s = socket(AF_INT,SOCK_STREAM,0);
if (s < 0)
...

if (connect(s,(char *)&server, sizeof(server)) < 0)
...

if (write(s,msg,strlen(msg)) < 0)
...


SERVER:

f = socket(AF_INET, SOCK_STREAM, 0);
...
if (bind(f,(struct sockaddr *) &sin, sizeof(sin)) < 0) 
...

listen(f,5)
for (;;)
...
len = sizeof(from);
g = accept(f,(struct sockaddr *)&from,&len);
...
if ((rval = read(g,msg,1024)) < 0)
...


The CLIENT succeeds in establishing a connection with the SERVER and sends
it a message which the SERVER receives.  Now the problem is that the server
cannot send a message back to the CLIENT.  I tried writing on the socket
"g" on the SERVER side but it doesn't send the message.

Could somebody tell me what I am doing wrong or what I am not doing.

Thank you (you can send me mail if you like).


------------------
Iqbal Mustafa Khan
------------------
khan@iuvax.bacs.indiana.edu
Computer Science Department
Indiana University
Bloomington, Indiana