All values should be undefined: $a = [+ $a || '' +]
$b = [+ $b || '' +]
$c = [+ $c || '' +]
$d = [+ $d || '' +]
$e = [+ $e || '' +]
First of all assign a value: [- $a = '(this is the value in $a)' -]
Now we have some 'Umlaute': [- $b = "$a äöü" -] Now lets look what we are getting from this:
[+ $a +] [+ $b +]
And now a and b together: [+ "$a$b" +]

Here we have some HTML tags within the perl code,
Embperl will not delete them when optRawInput is set !
[+ $c = "
6 + 17 * 3" +] Here we have something which looks like a HTML tag, but does not start with
a character, Embperl does not change them!
[+ "SELECT * FROM a ORDER BY b USING <; Hi There>" +] Embperl will not translate HMTL escapes to the right characters
when optRawInput is set
[- $e = 2 -] [+ $d = "$e < 6" +] Now they should have a value $a = [+ $a +]
$b = [+ $b +]
$c = [+ $c +]
$d = [+ $d +]
$e = [+ $e +]

Ok.

optRawInput is now: [+ $optRawInput +]
optRawInput is set now to: [+ $optRawInput = 1 +]
optRawInput is now: [+ $optRawInput +]
[+ $c = "
6 + 17 * 3" +] [- $b = "$a äöü" -] Now lets look what we are getting from this:
$a = [+ $a +]
$b = [+ $b +]
$c = [+ $c +]
optRawInput is now: [+ $optRawInput +]
optRawInput is set now to: [+ $optRawInput = 0 +]
optRawInput is now: [+ $optRawInput +]
[+ $c = "
6 + 17 * 3" +] [- $b = "$a äöü" -] Now lets look what we are getting from this:
$a = [+ $a +]
$b = [+ $b +]
$c = [+ $c +]