apache2::perlsections.3

视频监控网络部分的协议ddns,的模块的实现代码,请大家大胆指正.

\&    $My::tar = 7;
\&  </Perl>
.Ve
.PP
The local global variable \f(CW$foo\fR becomes
\&\f(CW$Apache2::ReadConfig::tmp::httpd_conf::line_20::foo\fR, the other
variable remain where they are.
.PP
By default, the namespace in which \f(CW\*(C`<Perl>\*(C'\fR sections are
evaluated is cleared after each block closes. In our example nuking
\&\f(CW$Apache2::ReadConfig::tmp::httpd_conf::line_20::foo\fR, leaving the
rest untouched.
.PP
By setting \f(CW$Apache2::PerlSections::Save\fR to a true value, the content
of those namespaces will be preserved and will be available for
inspection by \f(CW\*(C`Apache2::Status\*(C'\fR and
\&\f(CW\*(C`Apache2::PerlSections\->dump\*(C'\fR
In our example \f(CW$Apache2::ReadConfig::tmp::httpd_conf::line_20::foo\fR
will still be accessible from other perl code, after the
\&\f(CW\*(C`<Perl>\*(C'\fR section was parsed.
.SH "PerlSections Dumping"
.IX Header "PerlSections Dumping"
.ie n .Sh """Apache2::PerlSections\->dump"""
.el .Sh "\f(CWApache2::PerlSections\->dump\fP"
.IX Subsection "Apache2::PerlSections->dump"
This method will dump out all the configuration variables mod_perl
will be feeding to the apache config gears. The output is suitable to
read back in via \f(CW\*(C`eval\*(C'\fR.
.PP
.Vb 1
\&  my $dump = Apache2::PerlSections\->dump;
.Ve
.ie n .IP "ret: $dump\fR ( string / \f(CW""undef"" )" 4
.el .IP "ret: \f(CW$dump\fR ( string / \f(CWundef\fR )" 4
.IX Item "ret: $dump ( string / undef )"
A string dump of all the Perl code encountered in <Perl> blocks,
suitable to be read back via \f(CW\*(C`eval\*(C'\fR
.PP
For example:
.PP
.Vb 1
\&  <Perl>
\&  
\&  $Apache2::PerlSections::Save = 1;
\&  
\&  $Listen = 8529;
\&  
\&  $Location{"/perl"} = {
\&     SetHandler => "perl\-script",
\&     PerlHandler => "ModPerl::Registry",
\&     Options => "ExecCGI",
\&  };
\&  
\&  @DirectoryIndex = qw(index.htm index.html);
\&  
\&  $VirtualHost{"www.foo.com"} = {
\&     DocumentRoot => "/tmp/docs",
\&     ErrorLog => "/dev/null",
\&     Location => {
\&       "/" => {
\&         Allowoverride => \*(AqAll\*(Aq,
\&         Order => \*(Aqdeny,allow\*(Aq,
\&         Deny  => \*(Aqfrom all\*(Aq,
\&         Allow => \*(Aqfrom foo.com\*(Aq,
\&       },
\&     },
\&  };
\&  </Perl>
\&  
\&  <Perl>
\&  print Apache2::PerlSections\->dump;
\&  </Perl>
.Ve
.PP
This will print something like this:
.PP
.Vb 1
\&  $Listen = 8529;
\&  
\&  @DirectoryIndex = (
\&    \*(Aqindex.htm\*(Aq,
\&    \*(Aqindex.html\*(Aq
\&  );
\&  
\&  $Location{\*(Aq/perl\*(Aq} = (
\&      PerlHandler => \*(AqApache2::Registry\*(Aq,
\&      SetHandler => \*(Aqperl\-script\*(Aq,
\&      Options => \*(AqExecCGI\*(Aq
\&  );
\&  
\&  $VirtualHost{\*(Aqwww.foo.com\*(Aq} = (
\&      Location => {
\&        \*(Aq/\*(Aq => {
\&          Deny => \*(Aqfrom all\*(Aq,
\&          Order => \*(Aqdeny,allow\*(Aq,
\&          Allow => \*(Aqfrom foo.com\*(Aq,
\&          Allowoverride => \*(AqAll\*(Aq
\&        }
\&      },
\&      DocumentRoot => \*(Aq/tmp/docs\*(Aq,
\&      ErrorLog => \*(Aq/dev/null\*(Aq
\&  );
\&  
\&  1;
\&  _\|_END_\|_
.Ve
.PP
It is important to put the call to \f(CW\*(C`dump\*(C'\fR in it's own \f(CW\*(C`<Perl>\*(C'\fR
section, otherwise the content of the current \f(CW\*(C`<Perl>\*(C'\fR section
will not be dumped.
.ie n .Sh """Apache2::PerlSections\->store"""
.el .Sh "\f(CWApache2::PerlSections\->store\fP"
.IX Subsection "Apache2::PerlSections->store"
This method will call the \f(CW\*(C`dump\*(C'\fR method, writing the output
to a file, suitable to be pulled in via \f(CW\*(C`require\*(C'\fR or \f(CW\*(C`do\*(C'\fR.
.PP
.Vb 1
\&  Apache2::PerlSections\->store($filename);
.Ve
.ie n .IP "arg1: $filename (string)" 4
.el .IP "arg1: \f(CW$filename\fR (string)" 4
.IX Item "arg1: $filename (string)"
The filename to save the dump output to
.IP "ret: no return value" 4
.IX Item "ret: no return value"
.SH "Advanced API"
.IX Header "Advanced API"
mod_perl 2.0 now introduces the same general concept of handlers to
\&\f(CW\*(C`<Perl>\*(C'\fR sections.  Apache2::PerlSections simply being the
default handler for them.
.PP
To specify a different handler for a given perl section, an extra
handler argument must be given to the section:
.PP
.Vb 4
\&  <Perl handler="My::PerlSection::Handler" somearg="test1">
\&    $foo = 1;
\&    $bar = 2;
\&  </Perl>
.Ve
.PP
And in My/PerlSection/Handler.pm:
.PP
.Vb 4
\&  sub My::Handler::handler : handler {
\&      my ($self, $parms, $args) = @_;
\&      #do your thing!
\&  }
.Ve
.PP
So, when that given \f(CW\*(C`<Perl>\*(C'\fR block in encountered, the code
within will first be evaluated, then the handler routine will be
invoked with 3 arguments:
.ie n .IP "arg1: $self" 4
.el .IP "arg1: \f(CW$self\fR" 4
.IX Item "arg1: $self"
self-explanatory
.ie n .IP "arg2: $parms\fR ( \f(CW""Apache2::CmdParms"" )" 4
.el .IP "arg2: \f(CW$parms\fR ( \f(CWApache2::CmdParms\fR )" 4
.IX Item "arg2: $parms ( Apache2::CmdParms )"
\&\f(CW$parms\fR is specific for the current Container, for example, you
might want to call \f(CW\*(C`$parms\->server()\*(C'\fR to get the current server.
.ie n .IP "arg3: $args\fR ( \f(CW""APR::Table object"")" 4
.el .IP "arg3: \f(CW$args\fR ( \f(CWAPR::Table object\fR)" 4
.IX Item "arg3: $args ( APR::Table object)"
the table object of the section arguments. The 2 guaranteed ones will
be:
.Sp
.Vb 2
\&  $args\->{\*(Aqhandler\*(Aq} = \*(AqMy::PerlSection::Handler\*(Aq;
\&  $args\->{\*(Aqpackage\*(Aq} = \*(AqApache2::ReadConfig\*(Aq;
.Ve
.Sp
Other \f(CW\*(C`name="value"\*(C'\fR pairs given on the \f(CW\*(C`<Perl>\*(C'\fR line will
also be included.
.PP
At this point, it's up to the handler routing to inspect the namespace
of the \f(CW$args\fR\->{'package'} and chooses what to do.
.PP
The most likely thing to do is to feed configuration data back into
apache. To do that, use Apache2::Server\->add_config(\*(L"directive\*(R"),
for example:
.PP
.Vb 1
\&  $parms\->server\->add_config("Alias /foo /bar");
.Ve
.PP
Would create a new alias. The source code of \f(CW\*(C`Apache2::PerlSections\*(C'\fR
is a good place to look for a practical example.
.ie n .SH "Verifying ""<Perl>"" Sections"
.el .SH "Verifying \f(CW<Perl>\fP Sections"
.IX Header "Verifying <Perl> Sections"
If the \f(CW\*(C`<Perl>\*(C'\fR sections include no code requiring a running
mod_perl, it is possible to check those from the command line. But the
following trick should be used:
.PP
.Vb 3
\&  # file: httpd.conf
\&  <Perl>
\&  #!perl
\&  
\&  # ... code here ...
\&  
\&  _\|_END_\|_
\&  </Perl>
.Ve
.PP
Now you can run:
.PP
.Vb 1
\&  % perl \-c httpd.conf
.Ve
.SH "Bugs"
.IX Header "Bugs"
.Sh "<Perl> directive missing closing '>'"
.IX Subsection "<Perl> directive missing closing '>'"
httpd\-2.0.47 had a bug in the configuration parser which caused the
startup failure with the following error:
.PP
.Vb 3
\&  Starting httpd:
\&  Syntax error on line ... of /etc/httpd/conf/httpd.conf:
\&  <Perl> directive missing closing \*(Aq>\*(Aq     [FAILED]
.Ve
.PP
This has been fixed in httpd\-2.0.48. If you can't upgrade to this or a
higher version, please add a space before the closing '>' of the
opening tag as a workaround. So if you had:
.PP
.Vb 3
\&  <Perl>
\&  # some code
\&  </Perl>
.Ve
.PP
change it to be:
.PP
.Vb 3
\&  <Perl >
\&  # some code
\&  </Perl>
.Ve
.Sh "<Perl>[...]> was not closed."
.IX Subsection "<Perl>[...]> was not closed."
On encountering a one-line <Perl> block, 
httpd's configuration parser will cause a startup
failure with an error similar to this one:
.PP
.Vb 3
\&  Starting httpd:
\&  Syntax error on line ... of /etc/httpd/conf/httpd.conf:
\&  <Perl>use> was not closed.
.Ve
.PP
If you have written a simple one-line <Perl>
section like this one :
.PP
.Vb 1
\&  <Perl>use Apache::DBI;</Perl>
.Ve
.PP
change it to be:
.PP
.Vb 3
\&   <Perl>
\&   use Apache::DBI;
\&   </Perl>
.Ve
.PP
This is caused by a limitation of httpd's configuration
parser and is not likely to be changed to allow one-line
block like the example above. Use multi-line blocks instead.
.SH "See Also"
.IX Header "See Also"
mod_perl 2.0 documentation.
.SH "Copyright"
.IX Header "Copyright"
mod_perl 2.0 and its core modules are copyrighted under
The Apache Software License, Version 2.0.
.SH "Authors"
.IX Header "Authors"
The mod_perl development team and numerous
contributors.