1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
|
=for :stopwords MailingList RWS subcontext
=head1 NAME
CPAN::Meta::History::Meta_1_2 - Version 1.2 metadata specification for META.yml
=head1 PREFACE
This is a historical copy of the version 1.2 specification for F<META.yml>
files, copyright by Ken Williams.
Modifications from the original:
=over
=item *
Various spelling corrections
=item *
Include list of valid licenses from L<Module::Build> 0.2611 rather than
linking to the module.
=back
=head1 SYNOPSIS
--- #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
urls:
license: http://dev.perl.org/licenses/
meta-spec:
version: 1.2
url: http://module-build.sourceforge.net/META-spec-v1.2.html
generated_by: Module::Build version 0.20
=head1 DESCRIPTION
This document describes version 1.2 of the F<META.yml> specification.
The F<META.yml> 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 F<META.yml> 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.
I<Note: The latest stable version of this specification can always be
found at L<http://module-build.sourceforge.net/META-spec-current.html>,
and the latest development version (which may include things that
won't make it into the stable version can always be found at
L<http://module-build.sourceforge.net/META-spec-blead.html>.>
=head1 FORMAT
F<META.yml> files are written in the YAML format (see
L<http://www.yaml.org/>).
See the following links to learn why we chose YAML instead of, say,
XML or Data::Dumper:
=over 4
=item *
Module::Build design plans
L<http://nntp.x.perl.org/group/perl.makemaker/406>
=item *
Not keen on YAML
L<http://nntp.x.perl.org/group/perl.module-authors/1353>
=item *
META Concerns
L<http://nntp.x.perl.org/group/perl.module-authors/1385>
=back
=head1 TERMINOLOGY
=over 4
=item distribution
This is the primary object described by the F<META.yml>
specification. In the context of this document it usually refers to a
collection of modules, scripts, and/or documents that are distributed
for other developers to use.
=item 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).
=back
=head1 VERSION SPECIFICATIONS
Some fields require a version specification (ex. L<"requires">,
L<"recommends">, L<"build_requires">, etc.). This section details the
version specifications that are currently supported.
If a single version is listed, then that version is considered to be
the minimum version supported.
If 0 is given as the version number, then any version is supported.
Additionally, for more complicated requirements, the specification
supports a list of versions, each of which may be optionally preceded
by a relational operator.
Supported operators include E<lt> (less than), E<lt>= (less than or
equal), E<gt> (greater than), E<gt>= (greater than or equal), == (equal), and !=
(not equal).
If a list is given then it is evaluated from left to right so that any
specifications in the list that conflict with a previous specification
are overridden by the later.
Examples:
>= 1.2, != 1.5, < 2.0
Any version from version 1.2 onward, except version 1.5, that also
precedes version 2.0.
=head1 HEADER
The first line of a F<META.yml> file should be a valid YAML document
header like C<"--- #YAML:1.0">.
=head1 FIELDS
The rest of the F<META.yml> file is one big YAML mapping whose keys
are described here.
=head2 meta-spec
Example:
meta-spec:
version: 1.2
url: http://module-build.sourceforge.net/META-spec-v1.2.html
(Spec 1.1) [required] {URL} This field indicates the location of the
version of the META.yml specification used.
=head2 name
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
L<http://search.cpan.org/author/GAAS/libwww-perl/>).
=head2 version
Example:
version: 0.20
(Spec 1.0) [required] {version} The version of the distribution to which the
F<META.yml> file refers.
=head2 abstract
Example:
abstract: Build and install Perl modules.
(Spec 1.1) [required] {string} A short description of the purpose of the
distribution.
=head2 author
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>.
=head2 license
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:
=over 4
=item 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.
=item gpl
The distribution is distributed under the terms of the Gnu General Public
License (L<http://www.opensource.org/licenses/gpl-license.php>).
=item lgpl
The distribution is distributed under the terms of the Gnu Lesser General
Public License (L<http://www.opensource.org/licenses/lgpl-license.php>).
=item artistic
The distribution is licensed under the Artistic License, as specified by the
Artistic file in the standard perl distribution.
=item bsd
The distribution is licensed under the BSD License
(L<http://www.opensource.org/licenses/bsd-license.php>).
=item open_source
The distribution is licensed under some other Open Source Initiative-approved
license listed at L<http://www.opensource.org/licenses/>.
=item unrestricted
The distribution is licensed under a license that is B<not> approved by
L<www.opensource.org|http://www.opensource.org> but that allows distribution
without restrictions.
=item restrictive
The distribution may not be redistributed without special permission from the
author and/or copyright holder.
=back
=head2 distribution_type
Example:
distribution_type: module
(Spec 1.0) [optional] {string} What kind of stuff is contained in this
distribution. Most things on CPAN are C<module>s (which can also mean
a collection of modules), but some things are C<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.
=head2 requires
Example:
requires:
Data::Dumper: 0
File::Find: 1.03
(Spec 1.0) [optional] {map} A YAML mapping indicating the Perl modules this
distribution requires for proper operation. The keys are the module
names, and the values are version specifications as described in
L<Module::Build> for the "requires" parameter.
=head2 recommends
Example:
recommends:
Data::Dumper: 0
File::Find: 1.03
(Spec 1.0) [optional] {map} A YAML mapping indicating the Perl modules this
distribution recommends for enhanced operation.
I<ALTERNATIVE: It may be desirable to present to the user which
features depend on which modules so they can make an informed
decision about which recommended modules to install.>
Example:
optional_features:
- foo:
description: Provides the ability to blah.
requires:
Data::Dumper: 0
File::Find: 1.03
- bar:
description: This feature is not available on this platform.
excludes_os: MSWin32
I<(Spec 1.1) [optional] {map} A YAML sequence of names for optional features
which are made available when its requirements are met. For each
feature a description is provided along with any of L<"requires">,
L<"build_requires">, L<"conflicts">, L<"requires_packages">,
L<"requires_os">, and L<"excludes_os"> which have the same meaning in
this subcontext as described elsewhere in this document.>
=head2 build_requires
Example:
build_requires:
Data::Dumper: 0
File::Find: 1.03
(Spec 1.0) [optional] {map} A YAML mapping indicating the Perl modules
required for building and/or testing of this distribution. These
dependencies are not required after the module is installed.
=head2 conflicts
Example:
conflicts:
Data::Dumper: 0
File::Find: 1.03
(Spec 1.0) [optional] {map} A YAML mapping indicating the Perl modules that
cannot be installed while this distribution is installed. This is a
pretty uncommon situation.
=head2 dynamic_config
Example:
dynamic_config: 0
(Spec 1.0) [optional] {boolean} A boolean flag indicating whether a F<Build.PL>
or F<Makefile.PL> (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 if 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).
=head2 private
I<(Deprecated)> (Spec 1.0) [optional] {map} This field has been renamed to
L</"no_index">. See below.
=head2 provides
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 C<Module::Build> that can generate the
C<provides> mapping for your distribution automatically, make sure you
examine what it generates to make sure it makes sense - indexers will
usually trust the C<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 C<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.
=head2 no_index
Example:
no_index:
file:
- My/Module.pm
dir:
- 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 C<provides> field is
present.
I<(Note: I'm not actually sure who looks at this field, or exactly
what they do with it. This spec could be off in some way from actual
usage.)>
=head3 file
(Spec 1.1) [optional] Exclude any listed file(s).
=head3 dir
(Spec 1.1) [optional] Exclude anything below the listed
directory(ies).
=head3 package
(Spec 1.1) [optional] Exclude the listed package(s).
=head3 namespace
(Spec 1.1) [optional] Excludes anything below the listed namespace(s),
but I<not> the listed namespace(s) its self.
=head2 keywords
Example:
keywords:
- make
- build
- install
(Spec 1.1) [optional] {list} A sequence of keywords/phrases that describe
this distribution.
=head2 resources
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
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 C<homepage>,
C<license>, and C<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:
=over 2
=item homepage
The official home of this project on the web.
=item license
An URL for an official statement of this distribution's license.
=item bugtracker
An URL for a bug tracker (e.g. Bugzilla or RT queue) for this project.
=back
=head2 generated_by
Example:
generated_by: Module::Build version 0.20
(Spec 1.0) [required] {string} Indicates the tool that was used to create this
F<META.yml> 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 F<META.yml> was generated by hand, it is suggested that
the author be specified here.
[Note: My F<meta_stats.pl> script which I use to gather statistics
regarding F<META.yml> 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]
=head1 SEE ALSO
CPAN, L<http://www.cpan.org/>
CPAN.pm, L<http://search.cpan.org/author/ANDK/CPAN/>
CPANPLUS, L<http://search.cpan.org/author/KANE/CPANPLUS/>
Data::Dumper, L<http://search.cpan.org/author/ILYAM/Data-Dumper/>
ExtUtils::MakeMaker, L<http://search.cpan.org/author/MSCHWERN/ExtUtils-MakeMaker/>
Module::Build, L<http://search.cpan.org/author/KWILLIAMS/Module-Build/>
Module::Install, L<http://search.cpan.org/author/KWILLIAMS/Module-Install/>
XML, L<http://www.w3.org/XML/>
YAML, L<http://www.yaml.org/>
=head1 HISTORY
=over 4
=item March 14, 2003 (Pi day)
=over 2
=item *
Created version 1.0 of this document.
=back
=item May 8, 2003
=over 2
=item *
Added the L</"dynamic_config"> field, which was missing from the initial
version.
=back
=item November 13, 2003
=over 2
=item *
Added more YAML rationale articles.
=item *
Fixed existing link to YAML discussion thread to point to new
L<http://nntp.x.perl.org/group/> site.
=item *
Added and deprecated the L<"private"> field.
=item *
Added L<"abstract">, L<"configure">, L<"requires_packages">,
L<"requires_os">, L<"excludes_os">, and L<"no_index"> fields.
=item *
Bumped version.
=back
=item November 16, 2003
=over 2
=item *
Added L<"generation">, L<"authored_by"> fields.
=item *
Add alternative proposal to the L<"recommends"> field.
=item *
Add proposal for a L<"requires_build_tools"> field.
=back
=item December 9, 2003
=over 2
=item *
Added link to latest version of this specification on CPAN.
=item *
Added section L<"VERSION SPECIFICATIONS">.
=item *
Chang name from Module::Build::META-spec to CPAN::META::Specification.
=item *
Add proposal for L<"auto_regenerate"> field.
=back
=item December 15, 2003
=over 2
=item *
Add L<"index"> field as a compliment to L<"no_index">
=item *
Add L<"keywords"> field as a means to aid searching distributions.
=item *
Add L<"TERMINOLOGY"> section to explain certain terms that may be
ambiguous.
=back
=item July 26, 2005
=over 2
=item *
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.
=item *
Changed C<authored_by> to C<author>, since that's always been what
it's actually called in actual F<META.yml> files.
=item *
Added the "==" operator to the list of supported version-checking
operators.
=item *
Noted that the C<distribution_type> field is basically meaningless,
and shouldn't really be used.
=item *
Clarified C<dynamic_config> a bit.
=back
=item August 23, 2005
=over 2
=item *
Removed the name C<CPAN::META::Specification>, since that implies a
module that doesn't actually exist.
=back
=back
|