docs::api::ModPerl::Registry(3)                User Contributed Perl Documentation               docs::api::ModPerl::Registry(3)



NAME
       ModPerl::Registry - Run unaltered CGI scripts persistently under mod_perl

Synopsis
         # httpd.conf
         PerlModule ModPerl::Registry
         Alias /perl/ /home/httpd/perl/
         <Location /perl>
             SetHandler perl-script
             PerlResponseHandler ModPerl::Registry
             #PerlOptions +ParseHeaders
             #PerlOptions -GlobalRequest
             Options +ExecCGI
         </Location>

Description
       URIs in the form of "http://example.com/perl/test.pl" will be compiled as the body of a Perl subroutine and executed.
       Each child process will compile the subroutine once and store it in memory. It will recompile it whenever the file (e.g.
       test.pl in our example) is updated on disk.  Think of it as an object oriented server with each script implementing a
       class loaded at runtime.

       The file looks much like a "normal" script, but it is compiled into a subroutine.

       For example:

         my $r = Apache2::RequestUtil->request;
         $r->content_type("text/html");
         $r->send_http_header;
         $r->print("mod_perl rules!");

       XXX: STOPPED here. Below is the old Apache::Registry document which I haven't worked through yet.

       META: document that for now we don't chdir() into the script's dir, because it affects the whole process under threads.
       "ModPerl::RegistryPrefork" should be used by those who run only under prefork MPM.

       This module emulates the CGI environment, allowing programmers to write scripts that run under CGI or mod_perl without
       change.  Existing CGI scripts may require some changes, simply because a CGI script has a very short lifetime of one HTTP
       request, allowing you to get away with "quick and dirty" scripting.  Using mod_perl and ModPerl::Registry requires you to
       be more careful, but it also gives new meaning to the word "quick"!

       Be sure to read all mod_perl related documentation for more details, including instructions for setting up an environment
       that looks exactly like CGI:

        print "Content-type: text/html\n\n";
        print "Hi There!";

       Note that each httpd process or "child" must compile each script once, so the first request to one server may seem slow,
       but each request there after will be faster.  If your scripts are large and/or make use of many Perl modules, this
       difference should be noticeable to the human eye.

DirectoryIndex
       If you are trying setup a DirectoryIndex under a Location covered by ModPerl::Registry* you might run into some trouble.

       META: if this gets added to core, replace with real documenation.  See
       http://marc.theaimsgroup.com/?l=apache-modperl&m=112805393100758&w=2

Special Blocks
   "BEGIN" Blocks
       "BEGIN" blocks defined in scripts running under the "ModPerl::Registry" handler behave similarly to the normal mod_perl
       handlers plus:

       o   Only once, if pulled in by the parent process via "Apache2::RegistryLoader".

       o   An additional time, once per child process or Perl interpreter, each time the script file changes on disk.

       "BEGIN" blocks defined in modules loaded from "ModPerl::Registry" scripts behave identically to the normal mod_perl
       handlers, regardless of whether they define a package or not.

   "CHECK" and "INIT" Blocks
       Same as normal mod_perl handlers.

   "END" Blocks
       "END" blocks encountered during compilation of a script, are called after the script has completed its run, including
       subsequent invocations when the script is cached in memory. This is assuming that the script itself doesn't define a
       package on its own. If the script defines its own package, the "END" blocks in the scope of that package will be executed
       at the end of the interpretor's life.

       "END" blocks residing in modules loaded by registry script will be executed only once, when the interpreter exits.

Security
       "ModPerl::Registry::handler" performs the same sanity checks as mod_cgi does, before running the script.

Environment
       The Apache function `exit' overrides the Perl core built-in function.

Commandline Switches In First Line
       Normally when a Perl script is run from the command line or under CGI, arguments on the `#!' line are passed to the perl
       interpreter for processing.

       "ModPerl::Registry" currently only honors the -w switch and will enable the "warnings" pragma in such case.

       Another common switch used with CGI scripts is -T to turn on taint checking.  This can only be enabled when the server
       starts with the configuration directive:

        PerlSwitches -T

       However, if taint checking is not enabled, but the -T switch is seen, "ModPerl::Registry" will write a warning to the
       error_log file.

Debugging
       You may set the debug level with the $ModPerl::Registry::Debug bitmask

        1 => log recompile in errorlog
        2 => ModPerl::Debug::dump in case of $@
        4 => trace pedantically

Caveats
       ModPerl::Registry makes things look just the CGI environment, however, you must understand that this *is not CGI*.  Each
       httpd child will compile your script into memory and keep it there, whereas CGI will run it once, cleaning out the entire
       process space.  Many times you have heard "always use "-w", always use "-w" and 'use strict'".  This is more important
       here than anywhere else!

Authors
       Andreas J. Koenig, Doug MacEachern and Stas Bekman.

See Also
       "ModPerl::RegistryCooker", "ModPerl::RegistryBB" and "ModPerl::PerlRun".



perl v5.12.0                                               2007-11-12                            docs::api::ModPerl::Registry(3)