>>>>> On Sat, 18 Oct 1997, "HH" == Hwang Hyojung wrote:
  HH> why do you eval check ? Isn't this necessary ? Rather, I think,
  HH> $regex is checked if it is valid email address.  How do you think
  HH> about it ? If it is necessary, please explain why this is needed .
  HH> Thanks in advance !!
Please read RIPE-157, section 2.3.3., Authorization Schemes (shouldn't that
be "Authorisation", Ambrose? :-).  There is a section labeled, `The
"MAIL-FROM" scheme:', which explains that the MAIL-FROM value in the
"mntner" object is treated as a regular expression, against which From:-
headers will be matched.
So, yes the "eval" is necessary to make sure people submit a valid regex in 
their "mntner" objects.
While we are on the subject, RIPE-157 mentions that the regex should 
comply to the rules in "POSIX 1003.2 section 2.8."  Not having read that 
document, I wonder if the POSIX syntax and Perl are identical.  
"syntax.pl" checks whether the regex is Perl-compliant.  For example, does
'(abc)' mean "the literal string '(abc)'", or (a-la Perl), "the subpattern 
'abc'"?
Cheers,
Steven