perlnewmod.1

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.

Let's now see how it's done.
.Sh "Step-by-step: Preparing the ground"
.IX Subsection "Step-by-step: Preparing the ground"
Before we even start scraping out the code, there are a few things we'll
want to do in advance.
.IP "Look around" 3
.IX Item "Look around"
Dig into a bunch of modules to see how they're written. I'd suggest
starting with Text::Tabs, since it's in the standard
library and is nice and simple, and then looking at something a little
more complex like File::Copy.  For object oriented
code, \f(CW\*(C`WWW::Mechanize\*(C'\fR or the \f(CW\*(C`Email::*\*(C'\fR modules provide some good
examples.
.Sp
These should give you an overall feel for how modules are laid out and
written.
.IP "Check it's new" 3
.IX Item "Check it's new"
There are a lot of modules on \s-1CPAN\s0, and it's easy to miss one that's
similar to what you're planning on contributing. Have a good plough
through the <http://search.cpan.org> and make sure you're not the one
reinventing the wheel!
.IP "Discuss the need" 3
.IX Item "Discuss the need"
You might love it. You might feel that everyone else needs it. But there
might not actually be any real demand for it out there. If you're unsure
about the demand your module will have, consider sending out feelers
on the \f(CW\*(C`comp.lang.perl.modules\*(C'\fR newsgroup, or as a last resort, ask the
modules list at \f(CW\*(C`[e-mail]\*(C'\fR. Remember that this is a closed list
with a very long turn-around time \- be prepared to wait a good while for
a response from them.
.IP "Choose a name" 3
.IX Item "Choose a name"
Perl modules included on \s-1CPAN\s0 have a naming hierarchy you should try to
fit in with. See perlmodlib for more details on how this works, and
browse around \s-1CPAN\s0 and the modules list to get a feel of it. At the very
least, remember this: modules should be title capitalised, (This::Thing)
fit in with a category, and explain their purpose succinctly.
.IP "Check again" 3
.IX Item "Check again"
While you're doing that, make really sure you haven't missed a module
similar to the one you're about to write.
.Sp
When you've got your name sorted out and you're sure that your module is
wanted and not currently available, it's time to start coding.
.Sh "Step-by-step: Making the module"
.IX Subsection "Step-by-step: Making the module"
.IP "Start with \fImodule-starter\fR or \fIh2xs\fR" 3
.IX Item "Start with module-starter or h2xs"
The \fImodule-starter\fR utility is distributed as part of the
Module::Starter \s-1CPAN\s0 package.  It creates a directory
with stubs of all the necessary files to start a new module, according
to recent \*(L"best practice\*(R" for module development, and is invoked from
the command line, thus:
.Sp
.Vb 2
\&    module\-starter \-\-module=Foo::Bar \e
\&       \-\-author="Your Name" \-\-email=[e-mail]
.Ve
.Sp
If you do not wish to install the Module::Starter
package from \s-1CPAN\s0, \fIh2xs\fR is an older tool, originally intended for the
development of \s-1XS\s0 modules, which comes packaged with the Perl
distribution.
.Sp
A typical invocation of h2xs for a pure Perl module is:
.Sp
.Vb 1
\&    h2xs \-AX \-\-skip\-exporter \-\-use\-new\-tests \-n Foo::Bar
.Ve
.Sp
The \f(CW\*(C`\-A\*(C'\fR omits the Autoloader code, \f(CW\*(C`\-X\*(C'\fR omits \s-1XS\s0 elements,
\&\f(CW\*(C`\-\-skip\-exporter\*(C'\fR omits the Exporter code, \f(CW\*(C`\-\-use\-new\-tests\*(C'\fR sets up a
modern testing environment, and \f(CW\*(C`\-n\*(C'\fR specifies the name of the module.
.IP "Use strict and warnings" 3
.IX Item "Use strict and warnings"
A module's code has to be warning and strict-clean, since you can't
guarantee the conditions that it'll be used under. Besides, you wouldn't
want to distribute code that wasn't warning or strict-clean anyway,
right?
.IP "Use Carp" 3
.IX Item "Use Carp"
The Carp module allows you to present your error messages from
the caller's perspective; this gives you a way to signal a problem with
the caller and not your module. For instance, if you say this:
.Sp
.Vb 1
\&    warn "No hostname given";
.Ve
.Sp
the user will see something like this:
.Sp
.Vb 2
\&    No hostname given at /usr/local/lib/perl5/site_perl/5.6.0/Net/Acme.pm
\&    line 123.
.Ve
.Sp
which looks like your module is doing something wrong. Instead, you want
to put the blame on the user, and say this:
.Sp
.Vb 1
\&    No hostname given at bad_code, line 10.
.Ve
.Sp
You do this by using Carp and replacing your \f(CW\*(C`warn\*(C'\fRs with
\&\f(CW\*(C`carp\*(C'\fRs. If you need to \f(CW\*(C`die\*(C'\fR, say \f(CW\*(C`croak\*(C'\fR instead. However, keep
\&\f(CW\*(C`warn\*(C'\fR and \f(CW\*(C`die\*(C'\fR in place for your sanity checks \- where it really is
your module at fault.
.IP "Use Exporter \- wisely!" 3
.IX Item "Use Exporter - wisely!"
Exporter gives you a standard way of exporting symbols and
subroutines from your module into the caller's namespace. For instance,
saying \f(CW\*(C`use Net::Acme qw(&frob)\*(C'\fR would import the \f(CW\*(C`frob\*(C'\fR subroutine.
.Sp
The package variable \f(CW@EXPORT\fR will determine which symbols will get
exported when the caller simply says \f(CW\*(C`use Net::Acme\*(C'\fR \- you will hardly
ever want to put anything in there. \f(CW@EXPORT_OK\fR, on the other hand,
specifies which symbols you're willing to export. If you do want to
export a bunch of symbols, use the \f(CW%EXPORT_TAGS\fR and define a standard
export set \- look at Exporter for more details.
.IP "Use plain old documentation" 3
.IX Item "Use plain old documentation"
The work isn't over until the paperwork is done, and you're going to
need to put in some time writing some documentation for your module.
\&\f(CW\*(C`module\-starter\*(C'\fR or \f(CW\*(C`h2xs\*(C'\fR will provide a stub for you to fill in; if
you're not sure about the format, look at perlpod for an
introduction. Provide a good synopsis of how your module is used in
code, a description, and then notes on the syntax and function of the
individual subroutines or methods. Use Perl comments for developer notes
and \s-1POD\s0 for end-user notes.
.IP "Write tests" 3
.IX Item "Write tests"
You're encouraged to create self-tests for your module to ensure it's
working as intended on the myriad platforms Perl supports; if you upload
your module to \s-1CPAN\s0, a host of testers will build your module and send
you the results of the tests. Again, \f(CW\*(C`module\-starter\*(C'\fR and \f(CW\*(C`h2xs\*(C'\fR
provide a test framework which you can extend \- you should do something
more than just checking your module will compile.
Test::Simple and Test::More are good
places to start when writing a test suite.
.IP "Write the \s-1README\s0" 3
.IX Item "Write the README"
If you're uploading to \s-1CPAN\s0, the automated gremlins will extract the
\&\s-1README\s0 file and place that in your \s-1CPAN\s0 directory. It'll also appear in
the main \fIby-module\fR and \fIby-category\fR directories if you make it onto
the modules list. It's a good idea to put here what the module actually
does in detail, and the user-visible changes since the last release.
.Sh "Step-by-step: Distributing your module"
.IX Subsection "Step-by-step: Distributing your module"
.IP "Get a \s-1CPAN\s0 user \s-1ID\s0" 3
.IX Item "Get a CPAN user ID"
Every developer publishing modules on \s-1CPAN\s0 needs a \s-1CPAN\s0 \s-1ID\s0.  Visit
\&\f(CW\*(C`http://pause.perl.org/\*(C'\fR, select \*(L"Request \s-1PAUSE\s0 Account\*(R", and wait for
your request to be approved by the \s-1PAUSE\s0 administrators.
.ie n .IP """perl Makefile.PL; make test; make dist""" 3
.el .IP "\f(CWperl Makefile.PL; make test; make dist\fR" 3
.IX Item "perl Makefile.PL; make test; make dist"
Once again, \f(CW\*(C`module\-starter\*(C'\fR or \f(CW\*(C`h2xs\*(C'\fR has done all the work for you.
They produce the standard \f(CW\*(C`Makefile.PL\*(C'\fR you see when you download and
install modules, and this produces a Makefile with a \f(CW\*(C`dist\*(C'\fR target.
.Sp
Once you've ensured that your module passes its own tests \- always a
good thing to make sure \- you can \f(CW\*(C`make dist\*(C'\fR, and the Makefile will
hopefully produce you a nice tarball of your module, ready for upload.
.IP "Upload the tarball" 3
.IX Item "Upload the tarball"
The email you got when you received your \s-1CPAN\s0 \s-1ID\s0 will tell you how to
log in to \s-1PAUSE\s0, the Perl Authors Upload SErver. From the menus there,
you can upload your module to \s-1CPAN\s0.
.IP "Announce to the modules list" 3
.IX Item "Announce to the modules list"
Once uploaded, it'll sit unnoticed in your author directory. If you want
it connected to the rest of the \s-1CPAN\s0, you'll need to go to \*(L"Register
Namespace\*(R" on \s-1PAUSE\s0.  Once registered, your module will appear in the
by-module and by-category listings on \s-1CPAN\s0.
.IP "Announce to clpa" 3
.IX Item "Announce to clpa"
If you have a burning desire to tell the world about your release, post
an announcement to the moderated \f(CW\*(C`comp.lang.perl.announce\*(C'\fR newsgroup.
.IP "Fix bugs!" 3
.IX Item "Fix bugs!"
Once you start accumulating users, they'll send you bug reports. If
you're lucky, they'll even send you patches. Welcome to the joys of
maintaining a software project...
.SH "AUTHOR"
.IX Header "AUTHOR"
Simon Cozens, \f(CW\*(C`[e-mail]\*(C'\fR
.PP
Updated by Kirrily \*(L"Skud\*(R" Robert, \f(CW\*(C`[e-mail]\*(C'\fR
.SH "SEE ALSO"
.IX Header "SEE ALSO"
perlmod, perlmodlib, perlmodinstall, h2xs, strict,
Carp, Exporter, perlpod, Test::Simple, Test::More
ExtUtils::MakeMaker, Module::Build, Module::Starter
http://www.cpan.org/ , Ken Williams' tutorial on building your own
module at http://mathforum.org/~ken/perl_modules.html