ModPerl::Registry(3pm)

1docs::api::ModPerl::RegUissetrryC(o3n)tributed Perl Docudmoecnst:a:taipoin::ModPerl::Registry(3)
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NAME

6       ModPerl::Registry - Run unaltered CGI scripts persistently under
7       mod_perl
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Synopsis

10         # httpd.conf
11         PerlModule ModPerl::Registry
12         Alias /perl/ /home/httpd/perl/
13         <Location /perl>
14             SetHandler perl-script
15             PerlResponseHandler ModPerl::Registry
16             #PerlOptions +ParseHeaders
17             #PerlOptions -GlobalRequest
18             Options +ExecCGI
19         </Location>
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Description

22       URIs in the form of "http://example.com/perl/test.pl" will be compiled
23       as the body of a Perl subroutine and executed.  Each child process will
24       compile the subroutine once and store it in memory. It will recompile
25       it whenever the file (e.g. test.pl in our example) is updated on disk.
26       Think of it as an object oriented server with each script implementing
27       a class loaded at runtime.
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29       The file looks much like a "normal" script, but it is compiled into a
30       subroutine.
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32       For example:
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34         my $r = Apache2::RequestUtil->request;
35         $r->content_type("text/html");
36         $r->send_http_header;
37         $r->print("mod_perl rules!");
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39       XXX: STOPPED here. Below is the old Apache::Registry document which I
40       haven't worked through yet.
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42       META: document that for now we don't chdir() into the script's dir,
43       because it affects the whole process under threads. "ModPerl::Reg‐
44       istryPrefork" should be used by those who run only under prefork MPM.
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46       This module emulates the CGI environment, allowing programmers to write
47       scripts that run under CGI or mod_perl without change.  Existing CGI
48       scripts may require some changes, simply because a CGI script has a
49       very short lifetime of one HTTP request, allowing you to get away with
50       "quick and dirty" scripting.  Using mod_perl and ModPerl::Registry
51       requires you to be more careful, but it also gives new meaning to the
52       word "quick"!
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54       Be sure to read all mod_perl related documentation for more details,
55       including instructions for setting up an environment that looks exactly
56       like CGI:
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58        print "Content-type: text/html\n\n";
59        print "Hi There!";
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61       Note that each httpd process or "child" must compile each script once,
62       so the first request to one server may seem slow, but each request
63       there after will be faster.  If your scripts are large and/or make use
64       of many Perl modules, this difference should be noticeable to the human
65       eye.
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DirectoryIndex

68       If you are trying setup a DirectoryIndex under a Location covered by
69       ModPerl::Registry* you might run into some trouble.
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71       META: if this gets added to core, replace with real documenation.  See
72       http://marc.theaimsgroup.com/?l=apache-modperl&m=112805393100758&w=2
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Special Blocks

75       "BEGIN" Blocks
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77       "BEGIN" blocks defined in scripts running under the "ModPerl::Registry"
78       handler behave similarly to the normal mod_perl handlers plus:
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80       ·   Only once, if pulled in by the parent process via "Apache2::Reg‐
81           istryLoader".
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83       ·   An additional time, once per child process or Perl interpreter,
84           each time the script file changes on disk.
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86       "BEGIN" blocks defined in modules loaded from "ModPerl::Registry"
87       scripts behave identically to the normal mod_perl handlers, regardless
88       of whether they define a package or not.
89
90       "CHECK" and "INIT" Blocks
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92       Same as normal mod_perl handlers.
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94       "END" Blocks
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96       "END" blocks encountered during compilation of a script, are called
97       after the script has completed its run, including subsequent invoca‐
98       tions when the script is cached in memory. This is assuming that the
99       script itself doesn't define a package on its own. If the script
100       defines its own package, the "END" blocks in the scope of that package
101       will be executed at the end of the interpretor's life.
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103       "END" blocks residing in modules loaded by registry script will be exe‐
104       cuted only once, when the interpreter exits.
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Security

107       "ModPerl::Registry::handler" performs the same sanity checks as mod_cgi
108       does, before running the script.
109

Environment

111       The Apache function `exit' overrides the Perl core built-in function.
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Commandline Switches In First Line

114       Normally when a Perl script is run from the command line or under CGI,
115       arguments on the `#!' line are passed to the perl interpreter for pro‐
116       cessing.
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118       "ModPerl::Registry" currently only honors the -w switch and will enable
119       the "warnings" pragma in such case.
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121       Another common switch used with CGI scripts is -T to turn on taint
122       checking.  This can only be enabled when the server starts with the
123       configuration directive:
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125        PerlSwitches -T
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127       However, if taint checking is not enabled, but the -T switch is seen,
128       "ModPerl::Registry" will write a warning to the error_log file.
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Debugging

131       You may set the debug level with the $ModPerl::Registry::Debug bitmask
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133        1 => log recompile in errorlog
134        2 => ModPerl::Debug::dump in case of $@
135        4 => trace pedantically
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Caveats

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

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