need help with serial communications

[Luis Aberto Rodriguez]

hi, i'm developing an application for a school project in wich i need to read the data that an open port is about to send to another. is there any way that i can do that? i have search in everywhere and it seems to be no answer for that. can anyone help me? thanks

[Jochen Arndt]

A serial port can be opened only by one application/thread at time. So there is no chance to do this in a simple way. You may use some hardware that splits the serial lines and mirrors it to another port where you get a copy of the data that has been send. You may create a special send thread that copies the data to a buffer before sending and flushes the buffer after they has been sent. You can then query the unsend data from this thread.

[CPallini]

I suppose you should hook the WriteFile function. Not an easy task, anyway.

Veni, vidi, vici.

[Lost User]

Or you can create an upperfilter driver for serial.sys and pump the data back up to your app. Of course this is extremely difficult for most people to do but should you feel up to a mammoth challenge, it is an interesting way to do it. The other way you can do it is to create a dll that manages serial.sys, ie, implements all the Win32 serial functionality and get the other app to talk to your dll instead of the stock system one. But this has its own problems in terms of replacing the system dll with yours.

[Sunil P V]

Check this link CSerialPort v1.03 - Serial Port Wrapper[^] I am sure this will help you.

Sunil

[Rolf Kristensen]

The latest version can be found here