According to Dale Scheetz:
> Are there any circumstances where perl-5.004 is compatible with earlier
> version like perl-4?
Most Perl 4 programs still work fine with any version of Perl 5. But
there were a couple of language changes between Perl 4 and Perl 5 that
actually make programs fail (but loudly -- no silent failures).
> I can only assume that [...] perl-5.004 is not backward compatible
> with the previous version?
All versions of Perl 5 are compatible with earlier versions of Perl 5
at the source code level -- i.e. Perl programs should work fine after
upgrades. [1]
If compiled with the default options, 5.004 is even binary-compatible
with extensions that were built for Perl 5.003. But most versions
don't retain binary compatiblity for extensions.
[1] However, each version can add new warnings, so we encourage users
to install production code without warnings or else with absolute
version paths ("#!/usr/bin/perl5.005"). [2]
[2] Debian doesn't create this specific hard link, but it should.
For example, my system has "/usr/bin/perl5.00503".
--
Chip Salzenberg - a.k.a. - <[EMAIL PROTECTED]>
"When do you work?" "Whenever I'm not busy."
