BUILD::mod_perl-2.0.2:UsBUILD::mod_perl-2.0.2::docs::api::ModPerl::Registry(3)NAMEModPerl::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::Reg‐
istryPrefork" 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::Reg‐
istryLoader".
· 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 invoca‐
tions 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 exe‐
cuted 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 pro‐
cessing.
"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
CaveatsModPerl::Registry makes things look just the CGI environment, however,
you must understand that this *is not CGI*. Each httpd child will com‐
pile 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::Perl‐
Run".
perl v5.8.8BUILD::mod_perl-2.0.2::docs::api::ModPerl::Registry(3)