# Create an initial list
@list = (9,2,3,4,5,6);

# Data we wish to insert
@insert_data = 4..9;

# For every datum that we wish to
# insert, check for it's existance
# in the list and append it if it is
# not found
foreach $item (@insert_data){
    next if grep /$item/, @list;
    push @list, $item;
}

# Print out our final list
foreach $item (@list){
    print $item, ",";
}