RE: Sock Programming help

["Bob Crothers" <bob@xxxxxxxxxxxxxx>]

Hendry,

You need to check the return code of EVERY socket call.  Any of them can
return a failed in which case your conversation will be hosed.  And if you
keep trying to use the connection, undesirable results can occur.  Eg: Your
next read can just wait forever.

For your second question, do not do the listen() again until after you have
disconnected the first socket.

Another common thing many do not handle when first getting into the sockets
world is buffer block/un-blocking.  When using TCP, your data will get to
the other end, but it might not be blocked the same way.  Eg: You might send
a single 2048 byte block, but it might arrive as 4 128 byte blocks and then
a 1024 byte block (remaining 512 bytes of first send and 512 bytes of the
NEXT send).  Many times we have heard of folks not taking this into
consideration.  It works fine for a while.  And then something on the
network changes and it all comes crashing down.

For this reason (and others), it is a good idea to encapsulate all of your
sockets stuff into a single service program.  JMHO.

Regards,
Bob Crothers
Cornerstone Communications
Business: www.theunifier.com and www.faxserver401.com
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Email: Bob@CStoneIndy.com
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-----Original Message-----
From: owner-c400-l@midrange.com [mailto:owner-c400-l@midrange.com]On Behalf
Of hendry tionardi
Sent: Friday, June 16, 2000 7:08 AM
To: C400-L@midrange.com
Subject: Sock Programming help

Dear All,

Now I'm coding a socks Programming in AS400 using C.

I had a problem to detect Socket Error when the remote host had already
closed the socket.
Acttually I already put 'Select' Statement for read the socket, but it
didn't  return any error value.

Another thing, I want to make an single connection, So i put :

      Listen(sock,0) but the server still can receive an 2 connection for
the same socket, What should i do if i just want to make 1 connection, and
the rest connection will automaticly rejected.

Thank You


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