Ad 1) The subroutine check_file is declared in the scope where %files is declared. If you dereference an undefined value that's not read only, it autovivifies.

Ad 2) The declaration doesn't change the value. The assignment would - try changing it to 

my %files = ();

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لսႽ† ᥲᥒ⚪⟊Ⴙᘓᖇ Ꮅᘓᖇ⎱ Ⴙᥲ𝇋ƙᘓᖇ

In reply to Re^3: Duplicate File Finder script reporting multiples by choroba
in thread Duplicate File Finder script reporting multiples by Anonymous Monk

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