my @name_array = qw(fred joe john frank );
for my $file(@file) {
    open(FILE, "<", $file) 
        or die("can't open file $file.\n");
    while (my $line = <FILE>) {
        my $match = grep { $line =~ /$_/i } @name_array; 
        print OUT $line if ( $match );
    }
}