on unix you can also use this :

# store the terminal escape sequence that clear the screen
$clear = `clear`;

# then, all you need is to print $clear
# anytime you want to clear the screen
print $clear;


# Bonus :
# if you wants to know what the "clear" sequence
# looks like (in decimal)
foreach ( split(//,$clear) ) {
  print ord($_),"\n";
}
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