in reply to How to determine if a sub is defined in a package, without calling it?

You can use defined:

perl -wMstrict -E 'sub blah{}; say defined &blah'
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perl -wMstrict -E 'say defined &blah'

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Or, in another package:

perl -wMstrict -E 'package X;{sub blah{}} say defined &X::blah'
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