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Re: Character flow
On Thu, 20 Nov 1997, Roman Shterenzon wrote:
> Hi!
>
> Does anyone know how it's possible to monitor the data flow via
> character devices?
In some unices you can I_PUSH yourself to the device when opening it but
since you probably want to monitor something without modifying it, the
easiest way is to connect the application to a certain tty (other than the
one it usually connects) and write a very simple script that connects its
pty to the right tty while also saving the data in both directions to a
file. If the application insists on opening a tty by a certain name, just
replace it with a pty temporarily.
example: you want to monitor /dev/modem traffic. you do the following:
mv /dev/modem /dev/modem.orig
ln -s /dev/ttypf /dev/modem
(now run a simple program that opens /dev/ptypf and /dev/modem.orig, and
transfer data between them while also logging it)
run your application and see the results.
rm /dev/modem
mv /dev/modem.orig /dev/modem
thats it.
btw, if what you want to monitor is a standard terminal, use an application
called "pty" instead if writing one yourself. it does the transfering
and logging.
> --
>
> --Roman Shterenzon
>
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