1231c1231
<   open(SINK_INFILE, "grep group $filename |") or die "Can't open $filename"; 
---
>   open(SINK_INFILE, "grep join-group $filename |") or die "Can't open $filename"; 
1243c1243,1245
<     } 
---
>     } else {
> 	print stderr "COMM PATTERN ERROR";
>     }