> only if you code it the way you did below, which isn't terribly portable.
> see http://perl.apache.org/guide/perl.html#use_require_do_INC_and
Ahem, PerlModule is a wrapper around the perl builtin require(). One
presumes that perl knows where it lives if perl can successfully require()
it. Especially since this module is installed into the standard perl
heirarchy as a system module, from CPAN. It's not even XS.
> basically, it's a bad programming practice not to use() modules in the
code
> that needs them. it works if you call PerlModule before you use() the
> module, but again, it requires you to pay better attention to your
> httpd.conf than you ought to.
See my above point. Apache::DBI is *made* to be transparent, or at least
semi-. It exists at the server level, and without (much) interaction with
the programmer's dataspace at all. What better place for it than
httpd.conf? And as for having to pay too much attention... well... let's
just say that RedCode is spreading like it is because not enough IIS Admins
"paid better attention" to the defaults THEY were given. :-) Seriously tho,
why WOULDN'T you know what exactly is in your server configuration?
> consider writing an Apache module for CPAN, relying on, say, Apache::Log
> calls, but failing to use Apache::Log in your module. If you have a
> PerlModule Apache::Log everything works - until somebody else tries to run
> your code with a different configuration. There's what works and then
> there's how you ought to do things.
Again, server-level and mostly transparent. And as far as requiring a
module, 1) I would expect it to be clearly documented 2) and if I didn't
read the dox I deserve to have wasted the time, and 3) I'll leave 3 for
below...
> >methods on it are valid, and can be easily wrapped as I suggested
> >in an "if($ENV{MOD_PERL}) {}" block.
>
> this is just a particular gripe of mine, but I think we ought to be
> past the $ENV{MOD_PERL} thing by now... startup.pl is a mod_perl
> idiom. if you are designing web applications that depend on things
> like the mod_perl API, Apache::DBI, and using the hooks into the
> Apache request cycle then you are already way beyond making a
> startup.pl script portable between mod_perl and other web
> environments.
Portable, portable, portable... First of all, understanding that items
appearing earlier or later in a config file is significant is so common I'm
astonished you consider it bad manners to see code that depends on it. And
unless I'm very badly mistaken, it's even significant in httpd.conf as far
as *Apache* is concerned.
And secondly, you're right, this is *mod_perl*. Not IIS, NSAPI, PHP, or
Cold Fusion. startup.pl is indubitably a mod_perl idiom. I'm failing to
understand how this can be considered "portable". But if you mean portable
from system to system, well, last I heard, ActiveState hadn't quite gotten
signals or sockets mastered, but I'm pretty certain the have the %ENV
emulation worked out.
But thirdly, I consider it a convenience to be able to test a script for
syntax errors before attempting to -HUP my webserver to see if it works or
not. perl -wc is done almost before I register the cursor moving. apache
restarts take me at least a minute. It's not about the request cycle, it's
about the DEBUG cycle. Since I didn't write Apache::DBI, but I have
reasonable confidence in the guy who did, it doesn't hurt my feelings to
defer initializing it until I've finished modifying startup.pl for other
reasons. Which means I can make a change, switch windows, and perl -wc and
get a syntax check, instead of an Apache error on Apache::AuthDBI, in under
10 seconds. Or even perl -w (even tho I run w/ -w in the shebang line and
PerlWarn On) and see debug output I'm working with.
For the record, I also consider it cheesy to have to check $ENV{MOD_PERL}
but to my knowledge, the Apache $s object isn't passed to startup.pl, and
setting an environment variable is significantly cheaper than creating a
perl object in terms of C code and devel/debug time. Remember, the E in
perl is for "Eclectic." :-)
Idioms are there for a reason: They do well in shorthand a required task.
Even if there are other, longer ways to do the same thing. TIMTOWTDI. The
way I "ought to" program is in the way that makes perfect sense when one
understands all of the pieces, and document the hell out of it so that
people behind me who don't understand can at least follow the requirements
list. ESPECIALLY when the person behind me is me, 6 months later.
</rant>
L8r,
Rob
#!/usr/bin/perl -w
use Disclaimer qw/:standard/;
