Please help. Here is my problem. I have 9000 lines in file a and 500,000 lines in file b. For each line in file a I need to search file b and remove that line. I am currently using the grep -v command and loading the output into a new file. However, because of the size of file b this takes an extremely long time to do and I have 50 files similiar to file b. Is there a simpler way to accomplish this. Here is a code snippet of what I have so far.

cat $1 | while read LINE
do
echo $LINE

grep -v $LINE fileName > OutputFile

cp OutputFile fineName

done