4 Consistent formatting of this file is achieved with:
5 perl ./Porting/podtidy pod/perlsource.pod
9 perlsource - A guide to the Perl source tree
13 This document describes the layout of the Perl source tree. If you're
14 hacking on the Perl core, this will help you find what you're looking
17 =head1 FINDING YOUR WAY AROUND
19 The Perl source tree is big. Here's some of the thing you'll find in
24 The C source code and header files mostly live in the root of the
25 source tree. There are a few platform-specific directories which
26 contain C code. In addition, some of the modules shipped with Perl
29 See L<perlinterp> for more details on the files that make up the Perl
30 interpreter, as well as details on how it works.
34 Modules shipped as part of the Perl core live in four subdirectories.
35 Two of these directories contain modules that live in the core, and two
36 contain modules that can also be released separately on CPAN. Modules
37 which can be released on cpan are known as "dual-life" modules.
43 This directory contains pure-Perl modules which are only released as
44 part of the core. This directory contains I<all> of the modules and
45 their tests, unlike other core modules.
49 This directory contains XS-using modules which are only released as
50 part of the core. These modules generally have their F<Makefile.PL> and
51 are laid out more like a typical CPAN module.
55 This directory is for dual-life modules where the blead source is
56 canonical. Note that some modules in this directory may not yet have
57 been released separately on CPAN.
61 This directory contains dual-life modules where the CPAN module is
62 canonical. Do not patch these modules directly! Changes to these
63 modules should be submitted to the maintainer of the CPAN module. Once
64 those changes are applied and released, the new version of the module
65 will be incorporated into the core.
69 For some dual-life modules, it has not yet been determined if the CPAN
70 version or the blead source is canonical. Until that is done, those
71 modules should be in F<cpan/>.
75 The Perl core has an extensive test suite. If you add new tests (or new
76 modules with tests), you may need to update the F<t/TEST> file so that
83 Tests for core modules in the F<lib/> directory are right next to the
84 module itself. For example, we have F<lib/strict.pm> and
87 Tests for modules in F<ext/> and the dual-life modules are in F<t/>
88 subdirectories for each module, like a standard CPAN distribution.
92 Tests for the absolute basic functionality of Perl. This includes
93 C<if>, basic file reads and writes, simple regexes, etc. These are run
94 first in the test suite and if any of them fail, something is I<really>
99 Tests for basic control structures, C<if/else>, C<while>, subroutines,
104 Tests for basic issues of how Perl parses and compiles itself.
108 Tests for built-in IO functions, including command line arguments.
112 Tests for perl's method resolution order implementations (see L<mro>).
116 Tests for perl's built in functions that don't fit into any of the
119 =item * F<t/opbasic/>
121 Tests for perl's built in functions which, like those in F<t/op/>, do not fit
122 into any of the other directories, but which, in addition, cannot use
123 F<t/test.pl>,as that program depends on functionality which the
124 test file itself is testing.
128 Tests for regex related functions or behaviour. (These used to live in
133 Tests for features of how perl actually runs, including exit codes and
134 handling of PERL* environment variables.
138 Tests for the core support of Unicode.
142 Windows-specific tests.
144 =item * F<t/porting/>
146 Tests the state of the source tree for various common errors. For
147 example, it tests that everyone who is listed in the git log has a
148 corresponding entry in the F<AUTHORS> file.
152 The old home for the module tests, you shouldn't put anything new in
153 here. There are still some bits and pieces hanging around in here that
154 need to be moved. Perhaps you could move them? Thanks!
158 A test suite for the s2p converter.
164 All of the core documentation intended for end users lives in F<pod/>.
165 Individual modules in F<lib/>, F<ext/>, F<dist/>, and F<cpan/> usually
166 have their own documentation, either in the F<Module.pm> file or an
167 accompanying F<Module.pod> file.
169 Finally, documentation intended for core Perl developers lives in the
170 F<Porting/> directory.
172 =head2 Hacking tools and documentation
174 The F<Porting> directory contains a grab bag of code and documentation
175 intended to help porters work on Perl. Some of the highlights include:
181 These are scripts which will check the source things like ANSI C
182 violations, POD encoding issues, etc.
184 =item * F<Maintainers>, F<Maintainers.pl>, and F<Maintainers.pm>
186 These files contain information on who maintains which modules. Run
187 C<perl Porting/Maintainers -M Module::Name> to find out more
188 information about a dual-life module.
192 Tidies a pod file. It's a good idea to run this on a pod file you've
199 The Perl build system starts with the F<Configure> script in the root
202 Platform-specific pieces of the build system also live in
203 platform-specific directories like F<win32/>, F<vms/>, etc.
205 The F<Configure> script is ultimately responsible for generating a
208 The build system that Perl uses is called metaconfig. This system is
209 maintained separately from the Perl core.
211 The metaconfig system has its own git repository. Please see its README
212 file in L<http://perl5.git.perl.org/metaconfig.git/> for more details.
214 The F<Cross> directory contains various files related to
215 cross-compiling Perl. See F<Cross/README> for more details.
219 This file lists everyone who's contributed to Perl. If you submit a
220 patch, you should add your name to this file as part of the patch.
224 The F<MANIFEST> file in the root of the source tree contains a list of
225 every file in the Perl core, as well as a brief description of each
228 You can get an overview of all the files with this command:
230 % perl -lne 'print if /^[^\/]+\.[ch]\s+/' MANIFEST