If you're wanting to ensure that your code will run on perl-5.8.4 then it's best to actually test the code on perl-5.8.4. If code that contains "use 5.008_004" runs fine on perl-5.10.0 (as would generally be the case), there's no guarantee that it will run ok on perl-5.8.4.
For example, this script: use strict; use warnings; use 5.008_004; my $x = 5; my $y //= $x; print $y; runs fine on perl-5.10.0, where it outputs "5" - but on perl.008_004 it simply outputs the error message: Search pattern not terminated at try.pl line 5. This is because perl-5.8.4 (along with all other pre 5.10.0 releases) does not understand the //= (defined-or) operator which was introduced in perl-5.10.0. AFAIK, the only surefire method of catching such an incompatibility is to run the code on perl-5.8.4 and see how it fares. Cheers, Rob On Sat, Dec 22, 2018 at 10:04 PM Leam Hall <leamh...@gmail.com> wrote: > Ah, so if the node has perl 5.8.4 and I use a code construct that came in > 5.10, my code will fail? > > I thought the "use" precluded me from using later code constructs. Drat, > now I have to figure out how to enforce that. > > Thanks! > > > On Sat, Dec 22, 2018 at 5:07 AM sisyphus <sisyphus...@gmail.com> wrote: > >> "use 5.008_004" ensures that perl is at version 5.8.4 or later. >> Try to run that script using perl-5.8.3 or earlier and it will croak with >> a message that you need to be running version 5.8.4 or later. >> >> Cheers, >> Rob >> >> On Sat, Dec 22, 2018 at 8:44 PM Leam Hall <leamh...@gmail.com> wrote: >> >>> I've seen code that has "use 5.008_004;" in the files. Yet the code also >>> uses tools like Build.PL that came after Perl 5.008. What does the "use >>> $perl_version" actually affect? >>> >>> Thanks! >>> >>> -- >>> To unsubscribe, e-mail: beginners-unsubscr...@perl.org >>> For additional commands, e-mail: beginners-h...@perl.org >>> http://learn.perl.org/ >>> >>> >>>
