apache_mod_perl-101~38::mod_perl-2.0.01~3::mod_per-20.2::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:
Only once, if pulled in by the parent process via "Apache2::RegistryLoader".
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 v5.8.8 apache_mod_p::mod_perl-2.0.2::docs::api::ModPerl::Registry(3)
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