!($1 in a) && FILENAME ~ /aminer/ { print } This uses a regular expression. As regex is not actually needed in this case, you might be able to get better perfo

!($1 in a) && FILENAME ~ /aminer/ { print } This uses a regular expression. As regex is not actually needed in this case, you might be able to get better performance with something like this: !($1 in a) && index(FILENAME, "aminer") != 0 { print }