The code above only covers array and hashes of strings, and undef is not a string. Below is a variation that supports undef. Anything more complicated should definitely use FreezeThaw.

sub serialize_string_list {
   return join('|',
      map {
         (defined($_)
            ? do { local $_=$_; s/\^/^1/g; s/\|/^2/g; $_ }
            : '^0'
         )
      } @_
   );
}

sub deserialize_string_list {
   return map {
      ($_ eq '^0'
         ? undef
         : do { local $_=$_; s/\^1/^/g; s/\^2/|/g; $_ }
      )
   } split(/\|/, $_[0]);
}

$s = serialize_string_list(%test_hash);
%test_hash = deserialize_string_list($s);

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In reply to Re^3: Pass a hash as parameter to a CGI? by ikegami
in thread Pass a hash as parameter to a CGI? by C_T

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