CPAN::Meta::History::Meta_1_4(3p) Perl Programmers Reference Guide #
CPAN::Meta::History::Meta_1_4(3p) Perl Programmers Reference Guide
NNAAMMEE #
CPAN::Meta::History::Meta_1_4 - Version 1.4 metadata specification for
META.yml
PPRREEFFAACCEE #
This is a historical copy of the version 1.4 specification for _M_E_T_A_._y_m_l
files, copyright by Ken Williams and licensed under the same terms as
Perl itself.
Modifications from the original:
• Various spelling corrections
• Include list of valid licenses from Module::Build 0.2807 rather than
linking to the module, with minor updates to text and links to
reflect versions at the time of publication.
• Fixed some dead links to point to active resources.
SSYYNNOOPPSSIISS #
— #YAML:1.0 #
name: Module-Build
abstract: Build and install Perl modules
version: 0.20
author:
- Ken Williams <kwilliams@cpan.org>
license: perl
distribution_type: module
requires:
Config: 0
Cwd: 0
Data::Dumper: 0
ExtUtils::Install: 0
File::Basename: 0
File::Compare: 0
File::Copy: 0
File::Find: 0
File::Path: 0
File::Spec: 0
IO::File: 0
perl: 5.005_03
recommends:
Archive::Tar: 1.00
ExtUtils::Install: 0.3
ExtUtils::ParseXS: 2.02
Pod::Text: 0
YAML: 0.35 #
build_requires:
Test: 0
resources:
license: http://dev.perl.org/licenses/
meta-spec:
version: 1.4
url: http://module-build.sourceforge.net/META-spec-v1.3.html
generated_by: Module::Build version 0.20
DDEESSCCRRIIPPTTIIOONN #
This document describes version 1.4 of the _M_E_T_A_._y_m_l specification.
The _M_E_T_A_._y_m_l file describes important properties of contributed Perl
distributions such as the ones found on CPAN. It is typically created by
tools like Module::Build, Module::Install, and ExtUtils::MakeMaker.
The fields in the _M_E_T_A_._y_m_l file are meant to be helpful for people
maintaining module collections (like CPAN), for people writing
installation tools (like CPAN.pm or CPANPLUS), or just for people who
want to know some stuff about a distribution before downloading it and
starting to install it.
_N_o_t_e_: _T_h_e _l_a_t_e_s_t _s_t_a_b_l_e _v_e_r_s_i_o_n _o_f _t_h_i_s _s_p_e_c_i_f_i_c_a_t_i_o_n _c_a_n _a_l_w_a_y_s _b_e _f_o_u_n_d
_a_t _<_h_t_t_p_:_/_/_m_o_d_u_l_e_-_b_u_i_l_d_._s_o_u_r_c_e_f_o_r_g_e_._n_e_t_/_M_E_T_A_-_s_p_e_c_-_c_u_r_r_e_n_t_._h_t_m_l_>_, _a_n_d _t_h_e
_l_a_t_e_s_t _d_e_v_e_l_o_p_m_e_n_t _v_e_r_s_i_o_n _(_w_h_i_c_h _m_a_y _i_n_c_l_u_d_e _t_h_i_n_g_s _t_h_a_t _w_o_n_'_t _m_a_k_e _i_t
_i_n_t_o _t_h_e _s_t_a_b_l_e _v_e_r_s_i_o_n_) _c_a_n _a_l_w_a_y_s _b_e _f_o_u_n_d _a_t
_<_h_t_t_p_:_/_/_m_o_d_u_l_e_-_b_u_i_l_d_._s_o_u_r_c_e_f_o_r_g_e_._n_e_t_/_M_E_T_A_-_s_p_e_c_-_b_l_e_a_d_._h_t_m_l_>_.
FFOORRMMAATT #
_M_E_T_A_._y_m_l files are written in the YAML format (see
<http://www.yaml.org/>).
See the following links to learn why we chose YAML instead of, say, XML
or Data::Dumper:
• Module::Build design plans
<http://www.nntp.perl.org/group/perl.makemaker/2002/04/msg407.html>
• Not keen on YAML <http://www.nntp.perl.org/group/perl.module-
authors/2003/11/msg1353.html>
• META Concerns <http://www.nntp.perl.org/group/perl.module-
authors/2003/11/msg1385.html>
TTEERRMMIINNOOLLOOGGYY #
distribution
This is the primary object described by the _M_E_T_A_._y_m_l specification.
In the context of this document it usually refers to a collection of
modules, scripts, and/or documents that are distributed together for
other developers to use. Examples of distributions are
"Class-Container", "libwww-perl", or "DBI".
module
This refers to a reusable library of code typically contained in a
single file. Currently, we primarily talk of perl modules, but this
specification should be open enough to apply to other languages as
well (ex. python, ruby). Examples of modules are "Class::Container",
"LWP::Simple", or "DBD::File".
HHEEAADDEERR #
The first line of a _M_E_T_A_._y_m_l file should be a valid YAML document header
like "--- #YAML:1.0".
FFIIEELLDDSS #
The rest of the _M_E_T_A_._y_m_l file is one big YAML mapping whose keys are
described here.
mmeettaa--ssppeecc Example:
meta-spec:
version: 1.4
url: http://module-build.sourceforge.net/META-spec-v1.3.html
(Spec 1.1) [required] {URL} This field indicates the location of the
version of the META.yml specification used.
nnaammee Example:
name: Module-Build
(Spec 1.0) [required] {string} The name of the distribution which is
often created by taking the "main module" in the distribution and
changing "::" to "-". Sometimes it's completely different, however, as
in the case of the libwww-perl distribution (see
<http://search.cpan.org/dist/libwww-perl/>).
vveerrssiioonn Example:
version: 0.20
(Spec 1.0) [required] {version} The version of the distribution to which
the _M_E_T_A_._y_m_l file refers.
aabbssttrraacctt Example:
abstract: Build and install Perl modules.
(Spec 1.1) [required] {string} A short description of the purpose of the
distribution.
aauutthhoorr Example:
author:
- Ken Williams <kwilliams@cpan.org>
(Spec 1.1) [required] {list of strings} A YAML sequence indicating the
author(s) of the distribution. The preferred form is author-name
<email-address>.
lliicceennssee Example:
license: perl
(Spec 1.0) [required] {string} The license under which this distribution
may be used and redistributed.
Must be one of the following licenses:
apache
The distribution is licensed under the Apache Software License
version 1.1 (<http://opensource.org/licenses/Apache-1.1>).
artistic
The distribution is licensed under the Artistic License version 1, as
specified by the Artistic file in the standard perl distribution
(<http://opensource.org/licenses/Artistic-Perl-1.0>).
bsd The distribution is licensed under the BSD 3-Clause License
(<http://opensource.org/licenses/BSD-3-Clause>).
gpl The distribution is distributed under the terms of the GNU General
Public License version 2 (<http://opensource.org/licenses/GPL-2.0>).
lgpl
The distribution is distributed under the terms of the GNU Lesser
General Public License version 2
(<http://opensource.org/licenses/LGPL-2.1>).
mit The distribution is licensed under the MIT License
(<http://opensource.org/licenses/MIT>).
mozilla
The distribution is licensed under the Mozilla Public License.
(<http://opensource.org/licenses/MPL-1.0> or
<http://opensource.org/licenses/MPL-1.1>)
open_source
The distribution is licensed under some other Open Source Initiative-
approved license listed at <http://www.opensource.org/licenses/>.
perl
The distribution may be copied and redistributed under the same terms
as perl itself (this is by far the most common licensing option for
modules on CPAN). This is a dual license, in which the user may
choose between either the GPL or the Artistic license.
restrictive
The distribution may not be redistributed without special permission
from the author and/or copyright holder.
unrestricted
The distribution is licensed under a license that is not approved by
www.opensource.org <http://www.opensource.org/> but that allows
distribution without restrictions.
ddiissttrriibbuuttiioonn__ttyyppee Example:
distribution_type: module
(Spec 1.0) [optional] {string} What kind of stuff is contained in this
distribution. Most things on CPAN are "module"s (which can also mean a
collection of modules), but some things are "script"s.
Unfortunately this field is basically meaningless, since many
distributions are hybrids of several kinds of things, or some new thing,
or subjectively different in focus depending on who's using them. Tools
like Module::Build and MakeMaker will likely stop generating this field.
rreeqquuiirreess Example:
requires:
Data::Dumper: 0
File::Find: 1.03
(Spec 1.0) [optional] {map} A YAML mapping indicating the Perl
prerequisites this distribution requires for proper operation. The keys
are the names of the prerequisites (module names or 'perl'), and the
values are version specifications as described in VERSION SPECIFICATIONS.
rreeccoommmmeennddss Example:
recommends:
Data::Dumper: 0
File::Find: 1.03
(Spec 1.0) [optional] {map} A YAML mapping indicating the Perl
prerequisites this distribution recommends for enhanced operation. The
keys are the names of the prerequisites (module names or 'perl'), and the
values are version specifications as described in VERSION SPECIFICATIONS.
_A_L_T_E_R_N_A_T_I_V_E_: _I_t _m_a_y _b_e _d_e_s_i_r_a_b_l_e _t_o _p_r_e_s_e_n_t _t_o _t_h_e _u_s_e_r _w_h_i_c_h _f_e_a_t_u_r_e_s
_d_e_p_e_n_d _o_n _w_h_i_c_h _m_o_d_u_l_e_s _s_o _t_h_e_y _c_a_n _m_a_k_e _a_n _i_n_f_o_r_m_e_d _d_e_c_i_s_i_o_n _a_b_o_u_t _w_h_i_c_h
_r_e_c_o_m_m_e_n_d_e_d _m_o_d_u_l_e_s _t_o _i_n_s_t_a_l_l_.
Example:
optional_features:
foo:
description: Provides the ability to blah.
requires:
Data::Dumper: 0
File::Find: 1.03
_(_S_p_e_c _1_._1_) _[_o_p_t_i_o_n_a_l_] _{_m_a_p_} _A _Y_A_M_L _m_a_p_p_i_n_g _o_f _n_a_m_e_s _f_o_r _o_p_t_i_o_n_a_l _f_e_a_t_u_r_e_s
_w_h_i_c_h _a_r_e _m_a_d_e _a_v_a_i_l_a_b_l_e _w_h_e_n _i_t_s _r_e_q_u_i_r_e_m_e_n_t_s _a_r_e _m_e_t_. _F_o_r _e_a_c_h _f_e_a_t_u_r_e
_a _d_e_s_c_r_i_p_t_i_o_n _i_s _p_r_o_v_i_d_e_d _a_l_o_n_g _w_i_t_h _a_n_y _o_f _"_r_e_q_u_i_r_e_s_"_, _"_b_u_i_l_d___r_e_q_u_i_r_e_s_"_,
_a_n_d _"_c_o_n_f_l_i_c_t_s_"_, _w_h_i_c_h _h_a_v_e _t_h_e _s_a_m_e _m_e_a_n_i_n_g _i_n _t_h_i_s _s_u_b_c_o_n_t_e_x_t _a_s
_d_e_s_c_r_i_b_e_d _e_l_s_e_w_h_e_r_e _i_n _t_h_i_s _d_o_c_u_m_e_n_t_.
bbuuiilldd__rreeqquuiirreess Example:
build_requires:
Data::Dumper: 0
File::Find: 1.03
(Spec 1.0) [optional] {map} A YAML mapping indicating the Perl
prerequisites required for building and/or testing of this distribution.
The keys are the names of the prerequisites (module names or 'perl'), and
the values are version specifications as described in "VERSION
SPECIFICATIONS". These dependencies are not required after the
distribution is installed.
ccoonnffiigguurree__rreeqquuiirreess Example:
configure_requires:
Module::Build: 0.2809
Data::Dumper: 0
File::Find: 1.03
(Spec 1.4) [optional] {map} A YAML mapping indicating the Perl
prerequisites required before configuring this distribution. The keys
are the names of the prerequisites (module names or 'perl'), and the
values are version specifications as described in "VERSION
SPECIFICATIONS". These dependencies are not required after the
distribution is installed.
ccoonnfflliiccttss Example:
conflicts:
Data::Dumper: 0
File::Find: 1.03
(Spec 1.0) [optional] {map} A YAML mapping indicating any items that
cannot be installed while this distribution is installed. This is a
pretty uncommon situation. The keys for "conflicts" are the item names
(module names or 'perl'), and the values are version specifications as
described in "VERSION SPECIFICATIONS".
ddyynnaammiicc__ccoonnffiigg Example:
dynamic_config: 0
(Spec 1.0) [optional] {boolean} A boolean flag indicating whether a
_B_u_i_l_d_._P_L or _M_a_k_e_f_i_l_e_._P_L (or similar) must be executed when building this
distribution, or whether it can be built, tested and installed solely
from consulting its metadata file. The main reason to set this to a true
value is that your module performs some dynamic configuration (asking
questions, sensing the environment, etc.) as part of its build/install
process.
Currently Module::Build doesn't actually do anything with this flag -
it's probably going to be up to higher-level tools like CPAN to do
something useful with it. It can potentially bring lots of security,
packaging, and convenience improvements.
If this field is omitted, it defaults to 1 (true).
pprriivvaattee _(_D_e_p_r_e_c_a_t_e_d_) (Spec 1.0) [optional] {map} This field has been renamed to “no_index”. See below.
pprroovviiddeess Example:
provides:
Foo::Bar:
file: lib/Foo/Bar.pm
version: 0.27_02
Foo::Bar::Blah:
file: lib/Foo/Bar/Blah.pm
Foo::Bar::Baz:
file: lib/Foo/Bar/Baz.pm
version: 0.3
(Spec 1.1) [optional] {map} A YAML mapping that describes all packages
provided by this distribution. This information can be (and, in some
cases, is) used by distribution and automation mechanisms like PAUSE,
CPAN, and search.cpan.org to build indexes saying in which distribution
various packages can be found.
When using tools like Module::Build that can generate the "provides"
mapping for your distribution automatically, make sure you examine what
it generates to make sure it makes sense - indexers will usually trust
the "provides" field if it's present, rather than scanning through the
distribution files themselves to figure out packages and versions. This
is a good thing, because it means you can use the "provides" field to
tell the indexers precisely what you want indexed about your
distribution, rather than relying on them to essentially guess what you
want indexed.
nnoo__iinnddeexx Example:
no_index:
file:
- My/Module.pm
directory:
- My/Private
package:
- My::Module::Stuff
namespace:
- My::Module::Stuff
(Spec 1.1) [optional] {map} A YAML mapping that describes any files,
directories, packages, and namespaces that are private (i.e.
implementation artifacts) that are not of interest to searching and
indexing tools. This is useful when no "provides" field is present.
For example, <http://search.cpan.org/> excludes items listed in
"no_index" when searching for POD, meaning files in these directories
will not converted to HTML and made public - which is useful if you have
example or test PODs that you don't want the search engine to go through.
_f_i_l_e
(Spec 1.1) [optional] Exclude any listed file(s).
_d_i_r_e_c_t_o_r_y
(Spec 1.1) [optional] Exclude anything below the listed directory(ies).
[Note: previous editions of the spec had "dir" instead of "directory",
but I think MakeMaker and various users started using "directory", so in
deference we switched to that.]
_p_a_c_k_a_g_e
(Spec 1.1) [optional] Exclude the listed package(s).
_n_a_m_e_s_p_a_c_e
(Spec 1.1) [optional] Excludes anything below the listed namespace(s),
but _n_o_t the listed namespace(s) its self.
kkeeyywwoorrddss Example:
keywords:
- make
- build
- install
(Spec 1.1) [optional] {list} A sequence of keywords/phrases that describe
this distribution.
rreessoouurrcceess Example:
resources:
license: http://dev.perl.org/licenses/
homepage: http://sourceforge.net/projects/module-build
bugtracker: http://rt.cpan.org/NoAuth/Bugs.html?Dist=Module-Build
repository: http://sourceforge.net/cvs/?group_id=45731
MailingList: http://lists.sourceforge.net/lists/listinfo/module-build-general
(Spec 1.1) [optional] {map} A mapping of any URL resources related to
this distribution. All-lower-case keys, such as "homepage", "license",
and "bugtracker", are reserved by this specification, as they have
"official" meanings defined here in this specification. If you'd like to
add your own "special" entries (like the "MailingList" entry above), use
at least one upper-case letter.
The current set of official keys is:
homepage
The official home of this project on the web.
license
An URL for an official statement of this distribution's license.
bugtracker
An URL for a bug tracker (e.g. Bugzilla or RT queue) for this project.
ggeenneerraatteedd__bbyy Example:
generated_by: Module::Build version 0.20
(Spec 1.0) [required] {string} Indicates the tool that was used to create
this _M_E_T_A_._y_m_l file. It's good form to include both the name of the tool
and its version, but this field is essentially opaque, at least for the
moment. If _M_E_T_A_._y_m_l was generated by hand, it is suggested that the
author be specified here.
[Note: My _m_e_t_a___s_t_a_t_s_._p_l script which I use to gather statistics regarding
_M_E_T_A_._y_m_l usage prefers the form listed above, i.e. it splits on
/\s+version\s+/ taking the first field as the name of the tool that
generated the file and the second field as version of that tool. RWS]
VVEERRSSIIOONN SSPPEECCIIFFIICCAATTIIOONNSS #
Some fields require a version specification (ex. "requires",
"recommends", "build_requires", etc.) to indicate the particular
version(s) of some other module that may be required as a prerequisite.
This section details the version specification formats that are currently
supported.
The simplest format for a version specification is just the version
number itself, e.g. 2.4. This means that aatt lleeaasstt version 2.4 must be
present. To indicate that aannyy version of a prerequisite is okay, even if
the prerequisite doesn't define a version at all, use the version 0.
You may also use the operators < (less than), <= (less than or equal), >
(greater than), >= (greater than or equal), == (equal), and != (not
equal). For example, the specification "< 2.0" means that any version of
the prerequisite less than 2.0 is suitable.
For more complicated situations, version specifications may be AND-ed
together using commas. The specification ">= 1.2, != 1.5, < 2.0"
indicates a version that must be aatt lleeaasstt 1.2, lleessss tthhaann 2.0, and nnoott
eeqquuaall ttoo 1.5.
SSEEEE AALLSSOO #
CPAN <http://www.cpan.org/>
CPAN.pm
CPANPLUS #
Data::Dumper
ExtUtils::MakeMaker
Module::Build
Module::Install
XML <http://www.w3.org/XML/>
YAML <http://www.yaml.org/>
HHIISSTTOORRYY #
March 14, 2003 (Pi day)
• Created version 1.0 of this document.
May 8, 2003
• Added the "dynamic_config" field, which was missing from the
initial version.
November 13, 2003
• Added more YAML rationale articles.
• Fixed existing link to YAML discussion thread to point to new
<http://nntp.x.perl.org/group/> site.
• Added and deprecated the "private" field.
• Added "abstract", "configure", "requires_packages", "requires_os",
"excludes_os", and "no_index" fields.
• Bumped version.
November 16, 2003
• Added "generation", "authored_by" fields.
• Add alternative proposal to the "recommends" field.
• Add proposal for a "requires_build_tools" field.
December 9, 2003
• Added link to latest version of this specification on CPAN.
• Added section "VERSION SPECIFICATIONS".
• Chang name from Module::Build::META-spec to
CPAN::META::Specification.
• Add proposal for "auto_regenerate" field.
December 15, 2003
• Add "index" field as a compliment to "no_index"
• Add "keywords" field as a means to aid searching distributions.
• Add "TERMINOLOGY" section to explain certain terms that may be
ambiguous.
July 26, 2005
• Removed a bunch of items (generation, requires_build_tools,
requires_packages, configure, requires_os, excludes_os,
auto_regenerate) that have never actually been supported, but were
more like records of brainstorming.
• Changed "authored_by" to "author", since that's always been what
it's actually called in actual _M_E_T_A_._y_m_l files.
• Added the "==" operator to the list of supported version-checking
operators.
• Noted that the "distribution_type" field is basically meaningless,
and shouldn't really be used.
• Clarified "dynamic_config" a bit.
August 23, 2005
• Removed the name "CPAN::META::Specification", since that implies a
module that doesn't actually exist.
June 12, 2007
• Added "configure_requires".
perl v5.36.3 2019-02-13 CPAN::Meta::History::Meta_1_4(3p)