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COM port simulation: Named Pipes

Posted on 2002-04-22
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Last Modified: 2013-11-20
I do not have 2 COM ports on the back of my PC, so I am trying to use an internal software pretend comport.

I am trying to use Named Pipes, as I require bidirectional FIFO comms. However, the examples I have seen all depend on knowing whether you are programming the client or server end of the pipe.. i.e. server: CreateNamedPipe().... Client: ConnectNamedPipe()...

I am trying to encapsulate this in a class so I can use the same code in both client and server ends... which ever end starts first will create the pipe, and which ever is last out will close the pipe. (hopefully, windows is clever enough to know that when I CloseHandle() the last one out will destroy the resources??? )

Any Ideas please???

Thanks.
Nigel.
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Question by:nigel5
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by:DanRollins
ID: 6961098
THis article contains cod that creates a CNamedPipe class, derived from CFile.  It should answer all of your questions.

Garden Hoses at Work
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnpic/html/msdn_npipes.asp

A quick read indicates that the author does *not* expect to make the ends of the pipe interchangeable.  One end is the server and one is the client.  But remember that communication is bidirectional, so it doesn't really matter which end is which once the connection is established.

-- Dan
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by:danny_pav
ID: 6962871
You can't make the ends interchangeable.

The closest you can do is to make your client continuously try to connect to a server.
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Author Comment

by:nigel5
ID: 6963872
Ah, and if it can't connect, then it can open the server end...

Cool...

I'll give it a go.
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Author Comment

by:nigel5
ID: 7246175
Sorry for not getting back for a bit, but been doing lots of other things...

If you test to see if the pipe exists first you can either attach to it if it exists, or create it if it doesn't. That way you can make the same class handle the work, and you don't have to worry about the concept of server/client.

When you close the hanldes, Windows handles the cleanup, so the server can disconnect first, and the pipe can still be connected to by another process.
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by:DanRollins
ID: 7247313
nigel5,
If you have answered this question yourself, please post to Community Support and ask for a refund.  Better to finalize this now and save work for the database cleanup crew.
-- Dan
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