Re: [NASL2] Auto-conversion with + and -

"Pavel Kankovsky" <[email protected]> writes:

> BTW: what happens when you use + to concatenate a pure string and an
> impure string? Will the result be pure? Impure?

Pure

> Will the impure argument be auto-purified?

No. 'a'+"\n" will give 'a\\n' (a + antislash + n)
If you want to "purify" it, use the string function.
BTW, I am adding a strcat function. Maybe we'll get rid of this +
operator (we'll have to do something with - too)

> I think the whole concept of pure/impure strings creates considerably more
> problems than it solves.

So do I. That's why I implemented "pure strings". But we cannot
get rid of "impure strings" without rewriting many plugins. That's why
I used a different separator for pure strings (single quote instead of
double quote)

> Is there any script that (really) needs to work with impure strings

It's easier to declare regex patterns with "impure strings" than with
pure strings. That's the only example I can think of.
e.g. ereg_replace(string: s, pattern: "A(.*)B", replace: "\1");

> I suggest to get rid of impure strings completely and interpret escape
> sequences in string literals.

Too hard for a little gain IMHO.
And do not forget that when Nessus 1.4.x is out, there will be a time
where we'll have to maintain two brands of scripts: some for the old
1.2 parser, and others for the new one. 

I cannot see a painless way to do it. I suppose that this time will
have to be the shortest possible.
But considering the fact that Debian still ships the obsolete 1.0.x
Nessus, I am pessimistic.