use Encode;

# pick one of the following lines to uncomment
# (depends on what sort of display terminal you use):
#binmode STDOUT, ":utf8";
#binmode STDOUT, ":encoding(shiftjis)";

$_ = join( '', map { chr() } 0x21 .. 0x7e ) . "\n";  # this is a test string
print;

s/([!-~])/chr(ord($1)+0xFEE0)/eg;  # convert plain ASCII to CJK fullwidth ASCII

# print;  # uncomment this when you have chosen which binmode line to use