What is the goal of% mdat (compared to% udat) in Embperl?

Question

I saw that session processing mentioned a hash %mdatas well %udat. What is the difference and when and why use a hash %mdat?

Answer 1

As noted in Embperl POD ,

You can store any data in a hash %mdat, and if any request comes in the same Embperl document, you will again see the same values ​​in this hash.

Also note that the wording “you will see” in the POD above is somewhat misleading, which may have contributed to your confusion.

Embperl's core documentation provides a more accurate answer that eliminates confusion:

, Embperl, Embperl %mdat Apache::Session , .

, - . ( %udat) .

, %mdat - , .

"", %mdat .