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In an app where a user may provide a Perl regular expression I want to
validate the regex before it's applied. Currently I'm doing something like:

{
local $SIG{__WARN__} = sub { die $_[0] };
eval { $regex = qr($regex) };
die $@ if $@;
}

In other words I rely on Perl's ability to catch errors, where also
warnings are treated as errors.

Are there other appropriate checks that could be done?

--
Gunnar Hjalmarsson
Email: http://www.gunnar.cc/cgi-bin/contact.pl

Gunnar Hjalmarsson <> wrote in comp.lang.perl.misc:
> In an app where a user may provide a Perl regular expression I want to
> validate the regex before it's applied. Currently I'm doing something like:
>
> {
> local $SIG{__WARN__} = sub { die $_[0] };
> eval { $regex = qr($regex) };
> die $@ if $@;
> }
>
> In other words I rely on Perl's ability to catch errors, where also
> warnings are treated as errors.
>
> Are there other appropriate checks that could be done?

If code interpolations are a possibility, you may want to "use re
'eval';" in the block. Or not, depending...

Anno

wrote:
> Gunnar Hjalmarsson <> wrote in comp.lang.perl.misc:
>> In an app where a user may provide a Perl regular expression I want to
>> validate the regex before it's applied. Currently I'm doing something like:
>>
>> {
>> local $SIG{__WARN__} = sub { die $_[0] };
>> eval { $regex = qr($regex) };
>> die $@ if $@;
>> }
>>
>> In other words I rely on Perl's ability to catch errors, where also
>> warnings are treated as errors.
>>
>> Are there other appropriate checks that could be done?
>
> If code interpolations are a possibility, you may want to "use re
> 'eval';" in the block. Or not, depending...

Thanks for the tip, but I really don't see a need for using (?{ ... }),
so I guess I'd better not.

--
Gunnar Hjalmarsson
Email: http://www.gunnar.cc/cgi-bin/contact.pl