program execution

Hi! I have a problem with program execution and output processing. I have a shell program that Outputs smth like this: MES: Starting procedure... 30 60 90 100 MES: Downloading data... 2 4 ... 100 MES: Installing... 20 40 60 80 100 FIN: OK I have to start this program from php and display a progress bar of each action like this Starting Procedure.. |===== |20% (anyway smth graphical..) I wanted to do this by starting the program with output redirection into a file and the read the file and interpret it in a layer that refreshes regularly... But I learnt that I can't send the program in background (e.g. with "&") and the execution of the php script hangs until the program exits. If anyone has any ideea of how I might go about doing this please help! Thanks! Mihai