exec("/bin/prgPROCESS ".$line) ;

Just two little notes:

• exec may fail. You should handle that situation. RTFM for details.
• Pasting all of the arguments into a string, unquoted, begs for trouble. Imaginge $line containing the string " & ; rm -rf /". Quoting is not an option, because shells tend to have different quoting rules. Use the multi-argument form of exec to avoid the shell completely.

Alexander