You are viewing a plain text version of this content. The canonical link for it is here.
Posted to docs-cvs@perl.apache.org by go...@apache.org on 2003/06/09 07:06:34 UTC
cvs commit: modperl-docs/src/docs/2.0/api/Apache PerlSections.pod
gozer 2003/06/08 22:06:34
Modified: src/docs/2.0/api config.cfg
Added: src/docs/2.0/api/Apache PerlSections.pod
Log:
Initial shot at documenting <Perl > sections in mp2. Extended from an
e-mail on dev@perl.apache.org
Revision Changes Path
1.25 +1 -0 modperl-docs/src/docs/2.0/api/config.cfg
Index: config.cfg
===================================================================
RCS file: /home/cvs/modperl-docs/src/docs/2.0/api/config.cfg,v
retrieving revision 1.24
retrieving revision 1.25
diff -u -r1.24 -r1.25
--- config.cfg 23 May 2003 05:20:53 -0000 1.24
+++ config.cfg 9 Jun 2003 05:06:34 -0000 1.25
@@ -24,6 +24,7 @@
Apache/Filter.pod
Apache/FilterRec.pod
Apache/Log.pod
+ Apache/PerlSections.pod
Apache/RequestRec.pod
Apache/RequestUtil.pod
Apache/ServerUtil.pod
1.1 modperl-docs/src/docs/2.0/api/Apache/PerlSections.pod
Index: PerlSections.pod
===================================================================
=head1 NAME
Apache::PerlSections - Default Handler for C<E<lt>Perl E<gt>> sections
=head1 Synopsis
<Perl >
@PerlModule = qw(Mail::Send Devel::Peek);
#run the server as whoever starts it
$User = getpwuid(>) || >;
$Group = getgrgid()) || );
$ServerAdmin = $User;
</Perl>
=head1 Description
With C<E<lt>Perl E<gt>>...C<E<lt>/PerlE<gt>> sections, it is possible
to configure your server entirely in Perl.
C<E<lt>Perl E<gt>> sections can contain I<any> and as much Perl code as
you wish. These sections are compiled into a special package whose
symbol table mod_perl can then walk and grind the names and values of
Perl variables/structures through the Apache core configuration gears.
Block sections such as C<E<lt>LocationE<gt>>..C<E<lt>/LocationE<gt>>
are represented in a C<%Location> hash, e.g.:
<Perl>
$Location{"/~dougm/"} = {
AuthUserFile => '/tmp/htpasswd',
AuthType => 'Basic',
AuthName => 'test',
DirectoryIndex => [qw(index.html index.htm)],
Limit => {
METHODS => 'GET POST',
require => 'user dougm',
},
};
</Perl>
If an Apache directive can take two or three arguments you may push
strings (the lowest number of arguments will be shifted off the
C<@list>) or use an array reference to handle any number greater than
the minimum for that directive:
push @Redirect, "/foo", "http://www.foo.com/";
push @Redirect, "/imdb", "http://www.imdb.com/";
push @Redirect, [qw(temp "/here" "http://www.there.com")];
Other section counterparts include C<%VirtualHost>, C<%Directory> and
C<%Files>.
To pass all environment variables to the children with a single
configuration directive, rather than listing each one via C<PassEnv>
or C<PerlPassEnv>, a C<E<lt>Perl E<gt>> section could read in a file and:
push @PerlPassEnv, [$key => $val];
or
Apache->httpd_conf("PerlPassEnv $key $val");
These are somewhat simple examples, but they should give you the basic
idea. You can mix in any Perl code you desire. See I<eg/httpd.conf.pl>
and I<eg/perl_sections.txt> in the mod_perl distribution for more
examples.
Assume that you have a cluster of machines with similar configurations
and only small distinctions between them: ideally you would want to
maintain a single configuration file, but because the configurations
aren't I<exactly> the same (e.g. the C<ServerName> directive) it's not
quite that simple.
C<E<lt>Perl E<gt>> sections come to rescue. Now you have a single
configuration file and the full power of Perl to tweak the local
configuration. For example to solve the problem of the C<ServerName>
directive you might have this C<E<lt>Perl E<gt>> section:
<Perl>
$ServerName = `hostname`;
</Perl>
For example if you want to allow personal directories on all machines
except the ones whose names start with I<secure>:
<Perl>
$ServerName = `hostname`;
if ( $ServerName !~ /^secure/) {
$UserDir = "public.html";
} else {
$UserDir = "DISABLED";
}
</Perl>
=head1 Configuration Variables
There are a few variables that can be set to change the default behaviour of C<E<lt>Perl
E<gt>> sections.
=head2 C<$Apache::Server::SaveConfig>
By default, the namespace in which C<E<lt>Perl E<gt>> sections are evaluated is cleared after
each block closes. By setting it to a true value, the content of those namespaces will be preserved
and will be available for inspection by modules like L<Apache::Status>
=head2 C<$Apache::Server::StrictPerlSections>
By default, compilation and run-time errors within C<E<lt>Perl E<gt>> sections will cause a warning
to be printed in the error_log. By setting this variable to a true value, code in the sections will
be evaluated as if "use strict" was in usage, and all warning and errors will cause the server to
abort startup and report the first error.
=head1 Advanced API
mod_perl 2.0 now introduces the same general concept of handlers to C<E<lt>Perl E<gt>> sections.
Apache::PerlSections simply being the default handler for them.
To specify a different handler for a given perl section, an extra handler argument must be given to
the section:
<Perl handler="My::PerlSection::Handler" somearg="test1">
$foo = 1;
$bar = 2;
</Perl>
And in My/PerlSection/Handler.pm:
sub My::Handler::handler : handler {
my($self, $parms, $args) = @_;
#do your thing!
}
So, when that given C<E<lt>Perl E<gt>> block in encountered, the code within will first be evaluated, then
the handler routine will be invoked with 3 arguments
C<$self> is self-explanatory
C<$parms> is the L<Apache::CmdParms> for this Container, for example, you might want to call C<$parms>-E<gt>server()
to get the current server.
C<$args> is a L<APR::Table> of the section arguments, the 2 guaranteed ones will be:
$args->{'handler'} = 'My::PerlSection::Handler';
$args->{'package'} = 'Apache::ReadConfig';
Other name="value" pairs given on the C<E<lt>Perl E<gt>> line will also be included.
At this point, it's up to the handler routing to inspect the namespace of the C<$args>-E<gt>{'package'} and
chooses what to do.
The most likely thing to do is to feed configuration data back into apache. To do that, use
Apache::Server-E<gt>add_config("directive"), for example:
$parms->server->add_config("Alias /foo /bar");
Would create a new alias. The source code of L<Apache::PerlSections> is a good place to look for a practical
example.
=cut
---------------------------------------------------------------------
To unsubscribe, e-mail: docs-cvs-unsubscribe@perl.apache.org
For additional commands, e-mail: docs-cvs-help@perl.apache.org