Not a refnum not working oregistry

[michele.santucci]

I need to check if a registry key exist:

Unluckly not-a-number/path/refnum does not work on registry refnums ... it always returns FALSE regardless of whether the registry exists or not.

How can I check for registry key existence?

Best regards,

 Mike

[Andrey_Dmitriev]

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@michele.santucci wrote:

How can I check for registry key existence?

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Obviously try to read your key and check Error Out instead of refnum.

[rolfk]

The registry key refnum is not a real refnum (well it actually is a queue refnum, but casted into a datalog refnum to hide the internal implementation and not let a user manipulate the content in the queue). The Is Not a Refnum node sees that the refnum is a datalog refnum and then queries the datalog cookie jar for validity and that cookie jar tells the function, no this is not a refnum that I ever have seen.

What usually works but isn't quite foolproof, is a comparison to be unequal to the Not a Refnum constant. The only foolproof way is to try to access the registry refnum, for instance by calling Query Registry Key Info.vi. If that returns an error -600, you got almost certainly an invalid refnum.