I recently came a across a problem with an application that was saving configuration data as a hash in a file and using eval to load the data back. The problem was someone had created new entries by hand and had created duplicate keys. When I was running the code through the debugger, I could see that some keys were not being loaded into the hash, the duplicates were there. But I was missing some others.

I have 2 questions

My question is there some way of catching this error?

Can someone explain what was happening internally, that some hash entries where dropped?

its using Data::Dumper to save the hash and when it restore the data it slurps the file into a string and then executes  %hash = eval $line

In reply to eval question by jhuijsing

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