The solution you want really depends on the whole sequence:

If your programs run in sequence, first the one that

• If the programs are run in sequence, the one that computes the total then the one that uses it, you can write the total to a file and then use it. The alternatives for the file format would be:

  • just a number (if that's all you want to pass),
  • var=val pairs (or any other home-brewed format) if you have several values to pass,
  • use Data::Dumper for a more robust and extensible pure-Perl solution,
  • use XML::Simple for a buzzword-compliant but also extensible and cross-platform/cross-language solution.

• if you programs are run one after the other don't forget that you can just pipe them: comp_total | use_total where the output of comp_total is the total, read from STDIN by use_total,