hi, Thanks for your reply.
I wrote a c code program to write in fifo in file to use it instead of cat in. The result was the same. Also, if I wrote few bytes only then these bytes are not going out from the file source block, but if I wrote large number of bytes then a number of these bytes are going out from the file source block. Therefore as a result. It seems to me that buffering is in gnuradio or at least in file source block not due to cat. So, can any one help me how to send byte to byte using named fifo? Or what is the number buffered before transferring? Thanks for your help and time Best regards Hamzeh
