I am trying to pull information out of a file based on one column. I want the records that meet a certain criteria to be places in a bad file and removed from the main file. I have them going in to the bad file but since there are more than one record I am not getting them all removed from the good file. What is the best way to read in the information and have each piece removed without overwriting the file and not removing all the bad data.

The CODE:
nawk '{if (length($0) > 106) print $1}' reads | sort -u > bad
cat bad | while read METER
do
cat reads | grep $METER >> bad.daily
cat reads | grep -v $METER > daily
done

I know the problem is the second grep -v is overwriting the file but I need to find the best way to be able to delete multiple ones with out overwriting.

Thanks
Cliff