1PERLSOURCE(1) Perl Programmers Reference Guide PERLSOURCE(1)
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6 perlsource - A guide to the Perl source tree
7
9 This document describes the layout of the Perl source tree. If you're
10 hacking on the Perl core, this will help you find what you're looking
11 for.
12
14 The Perl source tree is big. Here's some of the thing you'll find in
15 it:
16 C code
18 The C source code and header files mostly live in the root of the
19 source tree. There are a few platform-specific directories which
20 contain C code. In addition, some of the modules shipped with Perl
21 include C or XS code.
22 See perlinterp for more details on the files that make up the Perl
24 interpreter, as well as details on how it works.
25 Core modules
27 Modules shipped as part of the Perl core live in four subdirectories.
28 Two of these directories contain modules that live in the core, and two
29 contain modules that can also be released separately on CPAN. Modules
30 which can be released on cpan are known as "dual-life" modules.
31 • lib/
33 This directory contains pure-Perl modules which are only released
35 as part of the core. This directory contains all of the modules and
36 their tests, unlike other core modules.
37 • ext/
39 Like lib/, this directory contains modules which are only released
41 as part of the core. Unlike lib/, however, a module under ext/
42 generally has a CPAN-style directory- and file-layout and its own
43 Makefile.PL. There is no expectation that a module under ext/ will
44 work with earlier versions of Perl 5. Hence, such a module may
45 take full advantage of syntactical and other improvements in Perl 5
46 blead.
47 • dist/
49 This directory is for dual-life modules where the blead source is
51 canonical. Note that some modules in this directory may not yet
52 have been released separately on CPAN. Modules under dist/ should
53 make an effort to work with earlier versions of Perl 5.
54 • cpan/
56 This directory contains dual-life modules where the CPAN module is
58 canonical. Do not patch these modules directly! Changes to these
59 modules should be submitted to the maintainer of the CPAN module.
60 Once those changes are applied and released, the new version of the
61 module will be incorporated into the core.
62 For some dual-life modules, it has not yet been determined if the CPAN
64 version or the blead source is canonical. Until that is done, those
65 modules should be in cpan/.
66 Tests
68 The Perl core has an extensive test suite. If you add new tests (or new
69 modules with tests), you may need to update the t/TEST file so that the
70 tests are run.
71 • Module tests
73 Tests for core modules in the lib/ directory are right next to the
75 module itself. For example, we have lib/strict.pm and lib/strict.t.
76 Tests for modules in ext/ and the dual-life modules are in t/
78 subdirectories for each module, like a standard CPAN distribution.
79 • t/base/
81 Tests for the absolute basic functionality of Perl. This includes
83 "if", basic file reads and writes, simple regexes, etc. These are
84 run first in the test suite and if any of them fail, something is
85 really broken.
86 • t/cmd/
88 Tests for basic control structures, "if"/"else", "while",
90 subroutines, etc.
91 • t/comp/
93 Tests for basic issues of how Perl parses and compiles itself.
95 • t/io/
97 Tests for built-in IO functions, including command line arguments.
99 • t/mro/
101 Tests for perl's method resolution order implementations (see mro).
103 • t/op/
105 Tests for perl's built in functions that don't fit into any of the
107 other directories.
108 • t/opbasic/
110 Tests for perl's built in functions which, like those in t/op/, do
112 not fit into any of the other directories, but which, in addition,
113 cannot use t/test.pl,as that program depends on functionality which
114 the test file itself is testing.
115 • t/re/
117 Tests for regex related functions or behaviour. (These used to live
119 in t/op).
120 • t/run/
122 Tests for features of how perl actually runs, including exit codes
124 and handling of PERL* environment variables.
125 • t/uni/
127 Tests for the core support of Unicode.
129 • t/win32/
131 Windows-specific tests.
133 • t/porting/
135 Tests the state of the source tree for various common errors. For
137 example, it tests that everyone who is listed in the git log has a
138 corresponding entry in the AUTHORS file.
139 • t/lib/
141 The old home for the module tests, you shouldn't put anything new
143 in here. There are still some bits and pieces hanging around in
144 here that need to be moved. Perhaps you could move them? Thanks!
145 Documentation
147 All of the core documentation intended for end users lives in pod/.
148 Individual modules in lib/, ext/, dist/, and cpan/ usually have their
149 own documentation, either in the Module.pm file or an accompanying
150 Module.pod file.
151 Finally, documentation intended for core Perl developers lives in the
153 Porting/ directory.
154 Hacking tools and documentation
156 The Porting directory contains a grab bag of code and documentation
157 intended to help porters work on Perl. Some of the highlights include:
158 • check*
160 These are scripts which will check the source things like ANSI C
162 violations, POD encoding issues, etc.
163 • Maintainers, Maintainers.pl, and Maintainers.pm
165 These files contain information on who maintains which modules. Run
167 "perl Porting/Maintainers -M Module::Name" to find out more
168 information about a dual-life module.
169 • podtidy
171 Tidies a pod file. It's a good idea to run this on a pod file
173 you've patched.
174 Build system
176 The Perl build system on *nix-like systems starts with the Configure
177 script in the root directory.
178 Platform-specific pieces of the build system also live in platform-
180 specific directories like win32/, vms/, etc. Windows and VMS have
181 their own Configure-like scripts, in their respective directories.
182 The Configure script (or a platform-specific similar script) is
184 ultimately responsible for generating a Makefile from Makefile.SH.
185 The build system that Perl uses is called metaconfig. This system is
187 maintained separately from the Perl core, and knows about the platform-
188 specific Configure-like scripts, as well as Configure itself.
189 The metaconfig system has its own git repository. Please see its README
191 file in <https://github.com/Perl/metaconfig> for more details.
192 The Cross directory contains various files related to cross-compiling
194 Perl. See Cross/README for more details.
195 AUTHORS
197 This file lists everyone who's contributed to Perl. If you submit a
198 patch, you should add your name to this file as part of the patch.
199 MANIFEST
201 The MANIFEST file in the root of the source tree contains a list of
202 every file in the Perl core, as well as a brief description of each
203 file.
204 You can get an overview of all the files with this command:
206 % perl -lne 'print if /^[^\/]+\.[ch]\s+/' MANIFEST
208perl v5.36.0 2022-08-30 PERLSOURCE(1)