Shell Programming and Scripting

Ok I have attached another zip file, both files have 6 records, and the desired output (prod_new.dat) has 4 records. In prod.dat there are 2 records with item numbers that do not exist in prod_last.dat, and that is fine, I need that included in the output. But there are also 2 records with matching item #s but different department numbers, I would need that filtered out.

When I ran your code it filtered all 4 records and included only 2.

modified code and the order of the files matters.

Code:

awk '
{dep=substr($0,361,9)}
FNR==NR {
  f1[$1]=dep
  next
}
NF && (!($1 in f1) || f1[$1]==dep)' prod_last.dat prod.dat