You don't get that kind of information in your program - the shell takes it away before your program runs.

Since your primary concern is passing the arguments on correcty, why not do:

@ARGV = map { quotemeta($_) } @ARGV;
print "@ARGV";

__OUTPUT__
>  perl test.pl -s "1 2 3"
\-s 1\ 2\ 3
[download]

This depends on whether quotemeta does the kind of escaping you need, but it seems to be a reasonable start.