Non-blocking stream read

[akiross]

Hello,
does Qt provide some way for reading something from a stream (qtextstream, associated with stdin/stdout) in a non-blocking fashon?

Here's what i've to do:
my application checks every N msec if new data has arrived - a timer calls readData(). This method should check if there are new data on the stream for reading. If there aren't, just return, else read the data and process them.

I'm not using threads and i'd like to avoid them.
There is some way? (maybe using tell() or something similar?)
I tried with bytesAvailable() but returns always 0...

Thanks!

Edit:
pos() and size() return always 0, isSequential() returns true, but bytesAvailable() is always 0, too.