QIODevice::bytesAvailable() always returning 0

[wysota]

Could be because you connected the readyRead signal to a slot which may cause the data to be read before the other slot fires and has a chance to call bytesAvailable(). Also check if your file isSequential().

[quickNitin]

thanks .i will check that. my file is a QFile object opening a fifo . i will check for that also

[quickNitin]

fifoFile is not sequential

[wysota]

fifoFile is not sequential

I think bytesAvailable() will always return 0 in that case. But this is strange... fifos should be sequential... It might be a bug in QFile -- it might not check if file is a fifo. In that case you'll have to rely on readyRead() signal.

[quickNitin]

in doc sth ambiguous is said about readyRead(). It says readyRead() is emitted everytime when new data is available or appeneded to file. In next para it says in a loop it may not be emitted again.
I cannot understand this distiction fully.

[quickNitin]

readyRead() signal is also not being generated while on other side of fifo brazenhem's line drawing algo is continuously puttin the points.
I checked it by adding statement

connect(&fileFifo,SIGNAL(readyRead()),qApp,SLOT(aboutQt()));

connect(&fileFifo,SIGNAL(readyRead()),qApp,SLOT(aboutQt()));

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is it something abnormal or i am missing sth about behaviour of QIODevice with fifos.