The shift requires the string as an argument of the script. If you want to read it from a file, you have to use
$s = <>;

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instead and provide the input file as the argument.
لսႽ† ᥲᥒ⚪⟊Ⴙᘓᖇ Ꮅᘓᖇ⎱ Ⴙᥲ𝇋ƙᘓᖇ

In reply to Re^3: Entering the land of Perl by choroba
in thread Entering the land of Perl by manbroski

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