summaryrefslogtreecommitdiff
path: root/Master/tlpkg/tlperl/lib/Module/Build.pm
blob: 356fd42a14ade799ddff79afadc467076bc322cd (plain)
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
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
package Module::Build;

# This module doesn't do much of anything itself, it inherits from the
# modules that do the real work.  The only real thing it has to do is
# figure out which OS-specific module to pull in.  Many of the
# OS-specific modules don't do anything either - most of the work is
# done in Module::Build::Base.

use strict;
use File::Spec ();
use File::Path ();
use File::Basename ();

use Module::Build::Base;

use vars qw($VERSION @ISA);
@ISA = qw(Module::Build::Base);
$VERSION = '0.3603';
$VERSION = eval $VERSION;

# Okay, this is the brute-force method of finding out what kind of
# platform we're on.  I don't know of a systematic way.  These values
# came from the latest (bleadperl) perlport.pod.

my %OSTYPES = qw(
		 aix       Unix
		 bsdos     Unix
		 dgux      Unix
		 dragonfly Unix
		 dynixptx  Unix
		 freebsd   Unix
		 linux     Unix
		 haiku     Unix
		 hpux      Unix
		 irix      Unix
		 darwin    Unix
		 machten   Unix
		 midnightbsd Unix
		 mirbsd    Unix
		 next      Unix
		 openbsd   Unix
		 netbsd    Unix
		 dec_osf   Unix
		 nto       Unix
		 svr4      Unix
		 svr5      Unix
		 sco_sv    Unix
		 unicos    Unix
		 unicosmk  Unix
		 solaris   Unix
		 sunos     Unix
		 cygwin    Unix
		 os2       Unix
		 interix   Unix
		 gnu       Unix
		 gnukfreebsd Unix
		 nto       Unix

		 dos       Windows
		 MSWin32   Windows

		 os390     EBCDIC
		 os400     EBCDIC
		 posix-bc  EBCDIC
		 vmesa     EBCDIC

		 MacOS     MacOS
		 VMS       VMS
		 VOS       VOS
		 riscos    RiscOS
		 amigaos   Amiga
		 mpeix     MPEiX
		);

# Inserts the given module into the @ISA hierarchy between
# Module::Build and its immediate parent
sub _interpose_module {
  my ($self, $mod) = @_;
  eval "use $mod";
  die $@ if $@;

  no strict 'refs';
  my $top_class = $mod;
  while (@{"${top_class}::ISA"}) {
    last if ${"${top_class}::ISA"}[0] eq $ISA[0];
    $top_class = ${"${top_class}::ISA"}[0];
  }

  @{"${top_class}::ISA"} = @ISA;
  @ISA = ($mod);
}

if (grep {-e File::Spec->catfile($_, qw(Module Build Platform), $^O) . '.pm'} @INC) {
  __PACKAGE__->_interpose_module("Module::Build::Platform::$^O");

} elsif (exists $OSTYPES{$^O}) {
  __PACKAGE__->_interpose_module("Module::Build::Platform::$OSTYPES{$^O}");

} else {
  warn "Unknown OS type '$^O' - using default settings\n";
}

sub os_type { $OSTYPES{$^O} }

sub is_vmsish { return ((os_type() || '') eq 'VMS') }
sub is_windowsish { return ((os_type() || '') eq 'Windows') }
sub is_unixish { return ((os_type() || '') eq 'Unix') }

1;

__END__

=for :stopwords
bindoc binhtml destdir distcheck distclean distdir distmeta distsign disttest
fakeinstall html installdirs installsitebin installsitescript installvendorbin
installvendorscript libdoc libhtml pardist ppd ppmdist realclean skipcheck
testall testcover testdb testpod testpodcoverage versioninstall

=head1 NAME

Module::Build - Build and install Perl modules


=head1 SYNOPSIS

Standard process for building & installing modules:

  perl Build.PL
  ./Build
  ./Build test
  ./Build install

Or, if you're on a platform (like DOS or Windows) that doesn't require
the "./" notation, you can do this:

  perl Build.PL
  Build
  Build test
  Build install


=head1 DESCRIPTION

C<Module::Build> is a system for building, testing, and installing
Perl modules.  It is meant to be an alternative to
C<ExtUtils::MakeMaker>.  Developers may alter the behavior of the
module through subclassing in a much more straightforward way than
with C<MakeMaker>.  It also does not require a C<make> on your system
- most of the C<Module::Build> code is pure-perl and written in a very
cross-platform way.  In fact, you don't even need a shell, so even
platforms like MacOS (traditional) can use it fairly easily.  Its only
prerequisites are modules that are included with perl 5.6.0, and it
works fine on perl 5.005 if you can install a few additional modules.

See L<"MOTIVATIONS"> for more comparisons between C<ExtUtils::MakeMaker>
and C<Module::Build>.

To install C<Module::Build>, and any other module that uses
C<Module::Build> for its installation process, do the following:

  perl Build.PL       # 'Build.PL' script creates the 'Build' script
  ./Build             # Need ./ to ensure we're using this "Build" script
  ./Build test        # and not another one that happens to be in the PATH
  ./Build install

This illustrates initial configuration and the running of three
'actions'.  In this case the actions run are 'build' (the default
action), 'test', and 'install'.  Other actions defined so far include:

<action_list>

You can run the 'help' action for a complete list of actions.


=head1 GUIDE TO DOCUMENTATION

The documentation for C<Module::Build> is broken up into three sections:

=over

=item General Usage (L<Module::Build>)

This is the document you are currently reading. It describes basic
usage and background information.  Its main purpose is to assist the
user who wants to learn how to invoke and control C<Module::Build>
scripts at the command line.

=item Authoring Reference (L<Module::Build::Authoring>)

This document describes the structure and organization of
C<Module::Build>, and the relevant concepts needed by authors who are
writing F<Build.PL> scripts for a distribution or controlling
C<Module::Build> processes programmatically.

=item API Reference (L<Module::Build::API>)

This is a reference to the C<Module::Build> API.

=item Cookbook (L<Module::Build::Cookbook>)

This document demonstrates how to accomplish many common tasks.  It
covers general command line usage and authoring of F<Build.PL>
scripts.  Includes working examples.

=back


=head1 ACTIONS

There are some general principles at work here.  First, each task when
building a module is called an "action".  These actions are listed
above; they correspond to the building, testing, installing,
packaging, etc., tasks.

Second, arguments are processed in a very systematic way.  Arguments
are always key=value pairs.  They may be specified at C<perl Build.PL>
time (i.e. C<perl Build.PL destdir=/my/secret/place>), in which case
their values last for the lifetime of the C<Build> script.  They may
also be specified when executing a particular action (i.e.
C<Build test verbose=1>), in which case their values last only for the
lifetime of that command.  Per-action command line parameters take
precedence over parameters specified at C<perl Build.PL> time.

The build process also relies heavily on the C<Config.pm> module.
If the user wishes to override any of the
values in C<Config.pm>, she may specify them like so:

  perl Build.PL --config cc=gcc --config ld=gcc

The following build actions are provided by default.

=over 4

=item build

[version 0.01]

If you run the C<Build> script without any arguments, it runs the
C<build> action, which in turn runs the C<code> and C<docs> actions.

This is analogous to the C<MakeMaker> I<make all> target.

=item clean

[version 0.01]

This action will clean up any files that the build process may have
created, including the C<blib/> directory (but not including the
C<_build/> directory and the C<Build> script itself).

=item code

[version 0.20]

This action builds your code base.

By default it just creates a C<blib/> directory and copies any C<.pm>
and C<.pod> files from your C<lib/> directory into the C<blib/>
directory.  It also compiles any C<.xs> files from C<lib/> and places
them in C<blib/>.  Of course, you need a working C compiler (probably
the same one that built perl itself) for the compilation to work
properly.

The C<code> action also runs any C<.PL> files in your F<lib/>
directory.  Typically these create other files, named the same but
without the C<.PL> ending.  For example, a file F<lib/Foo/Bar.pm.PL>
could create the file F<lib/Foo/Bar.pm>.  The C<.PL> files are
processed first, so any C<.pm> files (or other kinds that we deal
with) will get copied correctly.

=item config_data

[version 0.26]

...

=item diff

[version 0.14]

This action will compare the files about to be installed with their
installed counterparts.  For .pm and .pod files, a diff will be shown
(this currently requires a 'diff' program to be in your PATH).  For
other files like compiled binary files, we simply report whether they
differ.

A C<flags> parameter may be passed to the action, which will be passed
to the 'diff' program.  Consult your 'diff' documentation for the
parameters it will accept - a good one is C<-u>:

  ./Build diff flags=-u

=item dist

[version 0.02]

This action is helpful for module authors who want to package up their
module for source distribution through a medium like CPAN.  It will create a
tarball of the files listed in F<MANIFEST> and compress the tarball using
GZIP compression.

By default, this action will use the C<Archive::Tar> module. However, you can
force it to use binary "tar" and "gzip" executables by supplying an explicit
C<tar> (and optional C<gzip>) parameter:

  ./Build dist --tar C:\path\to\tar.exe --gzip C:\path\to\zip.exe

=item distcheck

[version 0.05]

Reports which files are in the build directory but not in the
F<MANIFEST> file, and vice versa.  (See L<manifest> for details.)

=item distclean

[version 0.05]

Performs the 'realclean' action and then the 'distcheck' action.

=item distdir

[version 0.05]

Creates a "distribution directory" named C<$dist_name-$dist_version>
(if that directory already exists, it will be removed first), then
copies all the files listed in the F<MANIFEST> file to that directory.
This directory is what the distribution tarball is created from.

=item distmeta

[version 0.21]

Creates the F<META.yml> file that describes the distribution.

F<META.yml> is a file containing various bits of I<metadata> about the
distribution.  The metadata includes the distribution name, version,
abstract, prerequisites, license, and various other data about the
distribution.  This file is created as F<META.yml> in YAML format.
It is recommended that the C<YAML::Tiny> module be installed to create it.
If the C<YAML::Tiny> module is not installed, an internal module supplied
with Module::Build will be used to write the META.yml file, and this
will most likely be fine.

F<META.yml> file must also be listed in F<MANIFEST> - if it's not, a
warning will be issued.

The current version of the F<META.yml> specification can be found at
L<http://module-build.sourceforge.net/META-spec-current.html>

=item distsign

[version 0.16]

Uses C<Module::Signature> to create a SIGNATURE file for your
distribution, and adds the SIGNATURE file to the distribution's
MANIFEST.

=item disttest

[version 0.05]

Performs the 'distdir' action, then switches into that directory and
runs a C<perl Build.PL>, followed by the 'build' and 'test' actions in
that directory.

=item docs

[version 0.20]

This will generate documentation (e.g. Unix man pages and HTML
documents) for any installable items under B<blib/> that
contain POD.  If there are no C<bindoc> or C<libdoc> installation
targets defined (as will be the case on systems that don't support
Unix manpages) no action is taken for manpages.  If there are no
C<binhtml> or C<libhtml> installation targets defined no action is
taken for HTML documents.

=item fakeinstall

[version 0.02]

This is just like the C<install> action, but it won't actually do
anything, it will just report what it I<would> have done if you had
actually run the C<install> action.

=item help

[version 0.03]

This action will simply print out a message that is meant to help you
use the build process.  It will show you a list of available build
actions too.

With an optional argument specifying an action name (e.g. C<Build help
test>), the 'help' action will show you any POD documentation it can
find for that action.

=item html

[version 0.26]

This will generate HTML documentation for any binary or library files
under B<blib/> that contain POD.  The HTML documentation will only be
installed if the install paths can be determined from values in
C<Config.pm>.  You can also supply or override install paths on the
command line by specifying C<install_path> values for the C<binhtml>
and/or C<libhtml> installation targets.

=item install

[version 0.01]

This action will use C<ExtUtils::Install> to install the files from
C<blib/> into the system.  See L<"INSTALL PATHS">
for details about how Module::Build determines where to install
things, and how to influence this process.

If you want the installation process to look around in C<@INC> for
other versions of the stuff you're installing and try to delete it,
you can use the C<uninst> parameter, which tells C<ExtUtils::Install> to
do so:

  ./Build install uninst=1

This can be a good idea, as it helps prevent multiple versions of a
module from being present on your system, which can be a confusing
situation indeed.

=item installdeps

[version 0.36]

This action will use the C<cpan_client> parameter as a command to install
missing prerequisites.  You will be prompted whether to install
optional dependencies.

The C<cpan_client> option defaults to 'cpan' but can be set as an option or in
F<.modulebuildrc>.  It must be a shell command that takes a list of modules to
install as arguments (e.g. 'cpanp -i' for CPANPLUS).  If the program part is a
relative path (e.g. 'cpan' or 'cpanp'), it will be located relative to the perl
program that executed Build.PL.

  /opt/perl/5.8.9/bin/perl Build.PL
  ./Build installdeps --cpan_client 'cpanp -i'
  # installs to 5.8.9

=item manifest

[version 0.05]

This is an action intended for use by module authors, not people
installing modules.  It will bring the F<MANIFEST> up to date with the
files currently present in the distribution.  You may use a
F<MANIFEST.SKIP> file to exclude certain files or directories from
inclusion in the F<MANIFEST>.  F<MANIFEST.SKIP> should contain a bunch
of regular expressions, one per line.  If a file in the distribution
directory matches any of the regular expressions, it won't be included
in the F<MANIFEST>.

The following is a reasonable F<MANIFEST.SKIP> starting point, you can
add your own stuff to it:

  ^_build
  ^Build$
  ^blib
  ~$
  \.bak$
  ^MANIFEST\.SKIP$
  CVS

See the L<distcheck> and L<skipcheck> actions if you want to find out
what the C<manifest> action would do, without actually doing anything.

=item manpages

[version 0.28]

This will generate man pages for any binary or library files under
B<blib/> that contain POD.  The man pages will only be installed if the
install paths can be determined from values in C<Config.pm>.  You can
also supply or override install paths by specifying there values on
the command line with the C<bindoc> and C<libdoc> installation
targets.

=item pardist

[version 0.2806]

Generates a PAR binary distribution for use with L<PAR> or L<PAR::Dist>.

It requires that the PAR::Dist module (version 0.17 and up) is
installed on your system.

=item ppd

[version 0.20]

Build a PPD file for your distribution.

This action takes an optional argument C<codebase> which is used in
the generated PPD file to specify the (usually relative) URL of the
distribution.  By default, this value is the distribution name without
any path information.

Example:

  ./Build ppd --codebase "MSWin32-x86-multi-thread/Module-Build-0.21.tar.gz"

=item ppmdist

[version 0.23]

Generates a PPM binary distribution and a PPD description file.  This
action also invokes the C<ppd> action, so it can accept the same
C<codebase> argument described under that action.

This uses the same mechanism as the C<dist> action to tar & zip its
output, so you can supply C<tar> and/or C<gzip> parameters to affect
the result.

=item prereq_data

[version 0.32]

This action prints out a Perl data structure of all prerequisites and the versions
required.  The output can be loaded again using C<eval()>.  This can be useful for
external tools that wish to query a Build script for prerequisites.

=item prereq_report

[version 0.28]

This action prints out a list of all prerequisites, the versions required, and
the versions actually installed.  This can be useful for reviewing the
configuration of your system prior to a build, or when compiling data to send
for a bug report.

=item pure_install

[version 0.28]

This action is identical to the C<install> action.  In the future,
though, when C<install> starts writing to the file
F<$(INSTALLARCHLIB)/perllocal.pod>, C<pure_install> won't, and that
will be the only difference between them.

=item realclean

[version 0.01]

This action is just like the C<clean> action, but also removes the
C<_build> directory and the C<Build> script.  If you run the
C<realclean> action, you are essentially starting over, so you will
have to re-create the C<Build> script again.

=item retest

[version 0.2806]

This is just like the C<test> action, but doesn't actually build the
distribution first, and doesn't add F<blib/> to the load path, and
therefore will test against a I<previously> installed version of the
distribution.  This can be used to verify that a certain installed
distribution still works, or to see whether newer versions of a
distribution still pass the old regression tests, and so on.

=item skipcheck

[version 0.05]

Reports which files are skipped due to the entries in the
F<MANIFEST.SKIP> file (See L<manifest> for details)

=item test

[version 0.01]

This will use C<Test::Harness> or C<TAP::Harness> to run any regression
tests and report their results. Tests can be defined in the standard
places: a file called C<test.pl> in the top-level directory, or several
files ending with C<.t> in a C<t/> directory.

If you want tests to be 'verbose', i.e. show details of test execution
rather than just summary information, pass the argument C<verbose=1>.

If you want to run tests under the perl debugger, pass the argument
C<debugger=1>.

If you want to have Module::Build find test files with different file
name extensions, pass the C<test_file_exts> argument with an array
of extensions, such as C<[qw( .t .s .z )]>.

If you want test to be run by C<TAP::Harness>, rather than C<Test::Harness>,
pass the argument C<tap_harness_args> as an array reference of arguments to
pass to the TAP::Harness constructor.

In addition, if a file called C<visual.pl> exists in the top-level
directory, this file will be executed as a Perl script and its output
will be shown to the user.  This is a good place to put speed tests or
other tests that don't use the C<Test::Harness> format for output.

To override the choice of tests to run, you may pass a C<test_files>
argument whose value is a whitespace-separated list of test scripts to
run.  This is especially useful in development, when you only want to
run a single test to see whether you've squashed a certain bug yet:

  ./Build test --test_files t/something_failing.t

You may also pass several C<test_files> arguments separately:

  ./Build test --test_files t/one.t --test_files t/two.t

or use a C<glob()>-style pattern:

  ./Build test --test_files 't/01-*.t'

=item testall

[version 0.2807]

[Note: the 'testall' action and the code snippets below are currently
in alpha stage, see
L<"http://www.nntp.perl.org/group/perl.module.build/2007/03/msg584.html"> ]

Runs the C<test> action plus each of the C<test$type> actions defined by
the keys of the C<test_types> parameter.

Currently, you need to define the ACTION_test$type method yourself and
enumerate them in the test_types parameter.

  my $mb = Module::Build->subclass(
    code => q(
      sub ACTION_testspecial { shift->generic_test(type => 'special'); }
      sub ACTION_testauthor  { shift->generic_test(type => 'author'); }
    )
  )->new(
    ...
    test_types  => {
      special => '.st',
      author  => ['.at', '.pt' ],
    },
    ...

=item testcover

[version 0.26]

Runs the C<test> action using C<Devel::Cover>, generating a
code-coverage report showing which parts of the code were actually
exercised during the tests.

To pass options to C<Devel::Cover>, set the C<$DEVEL_COVER_OPTIONS>
environment variable:

  DEVEL_COVER_OPTIONS=-ignore,Build ./Build testcover

=item testdb

[version 0.05]

This is a synonym for the 'test' action with the C<debugger=1>
argument.

=item testpod

[version 0.25]

This checks all the files described in the C<docs> action and
produces C<Test::Harness>-style output.  If you are a module author,
this is useful to run before creating a new release.

=item testpodcoverage

[version 0.28]

This checks the pod coverage of the distribution and
produces C<Test::Harness>-style output. If you are a module author,
this is useful to run before creating a new release.

=item versioninstall

[version 0.16]

** Note: since C<only.pm> is so new, and since we just recently added
support for it here too, this feature is to be considered
experimental. **

If you have the C<only.pm> module installed on your system, you can
use this action to install a module into the version-specific library
trees.  This means that you can have several versions of the same
module installed and C<use> a specific one like this:

  use only MyModule => 0.55;

To override the default installation libraries in C<only::config>,
specify the C<versionlib> parameter when you run the C<Build.PL> script:

  perl Build.PL --versionlib /my/version/place/

To override which version the module is installed as, specify the
C<versionlib> parameter when you run the C<Build.PL> script:

  perl Build.PL --version 0.50

See the C<only.pm> documentation for more information on
version-specific installs.

=back


=head1 OPTIONS

=head2 Command Line Options

The following options can be used during any invocation of C<Build.PL>
or the Build script, during any action.  For information on other
options specific to an action, see the documentation for the
respective action.

NOTE: There is some preliminary support for options to use the more
familiar long option style.  Most options can be preceded with the
C<--> long option prefix, and the underscores changed to dashes
(e.g. C<--use-rcfile>).  Additionally, the argument to boolean options is
optional, and boolean options can be negated by prefixing them with
C<no> or C<no-> (e.g. C<--noverbose> or C<--no-verbose>).

=over 4

=item quiet

Suppress informative messages on output.

=item verbose

Display extra information about the Build on output.

=item cpan_client

Sets the C<cpan_client> command for use with the C<installdeps> action.
See C<installdeps> for more details.

=item use_rcfile

Load the F<~/.modulebuildrc> option file.  This option can be set to
false to prevent the custom resource file from being loaded.

=item allow_mb_mismatch

Suppresses the check upon startup that the version of Module::Build
we're now running under is the same version that was initially invoked
when building the distribution (i.e. when the C<Build.PL> script was
first run).  As of 0.3601, a mismatch results in a warning instead of
a fatal error, so this option effectively just suppresses the warning.

=item debug

Prints Module::Build debugging information to STDOUT, such as a trace of
executed build actions.

=back

=head2 Default Options File (F<.modulebuildrc>)

[version 0.28]

When Module::Build starts up, it will look first for a file,
F<$ENV{HOME}/.modulebuildrc>.  If it's not found there, it will look
in the the F<.modulebuildrc> file in the directories referred to by
the environment variables C<HOMEDRIVE> + C<HOMEDIR>, C<USERPROFILE>,
C<APPDATA>, C<WINDIR>, C<SYS$LOGIN>.  If the file exists, the options
specified there will be used as defaults, as if they were typed on the
command line.  The defaults can be overridden by specifying new values
on the command line.

The action name must come at the beginning of the line, followed by any
amount of whitespace and then the options.  Options are given the same
as they would be on the command line.  They can be separated by any
amount of whitespace, including newlines, as long there is whitespace at
the beginning of each continued line.  Anything following a hash mark (C<#>)
is considered a comment, and is stripped before parsing.  If more than
one line begins with the same action name, those lines are merged into
one set of options.

Besides the regular actions, there are two special pseudo-actions: the
key C<*> (asterisk) denotes any global options that should be applied
to all actions, and the key 'Build_PL' specifies options to be applied
when you invoke C<perl Build.PL>.

  *           verbose=1   # global options
  diff        flags=-u
  install     --install_base /home/ken
              --install_path html=/home/ken/docs/html
  installdeps --cpan_client 'cpanp -i'

If you wish to locate your resource file in a different location, you
can set the environment variable C<MODULEBUILDRC> to the complete
absolute path of the file containing your options.

=head2 Environment variables

=over

=item MODULEBUILDRC

[version 0.28]

Specifies an alternate location for a default options file as described above.

=item PERL_MB_OPT

[version 0.36]

Command line options that are applied to Build.PL or any Build action.  The
string is split as the shell would (e.g. whitespace) and the result is
prepended to any actual command-line arguments.

=back

=head1 INSTALL PATHS

[version 0.19]

When you invoke Module::Build's C<build> action, it needs to figure
out where to install things.  The nutshell version of how this works
is that default installation locations are determined from
F<Config.pm>, and they may be overridden by using the C<install_path>
parameter.  An C<install_base> parameter lets you specify an
alternative installation root like F</home/foo>, and a C<destdir> lets
you specify a temporary installation directory like F</tmp/install> in
case you want to create bundled-up installable packages.

Natively, Module::Build provides default installation locations for
the following types of installable items:

=over 4

=item lib

Usually pure-Perl module files ending in F<.pm>.

=item arch

"Architecture-dependent" module files, usually produced by compiling
XS, L<Inline>, or similar code.

=item script

Programs written in pure Perl.  In order to improve reuse, try to make
these as small as possible - put the code into modules whenever
possible.

=item bin

"Architecture-dependent" executable programs, i.e. compiled C code or
something.  Pretty rare to see this in a perl distribution, but it
happens.

=item bindoc

Documentation for the stuff in C<script> and C<bin>.  Usually
generated from the POD in those files.  Under Unix, these are manual
pages belonging to the 'man1' category.

=item libdoc

Documentation for the stuff in C<lib> and C<arch>.  This is usually
generated from the POD in F<.pm> files.  Under Unix, these are manual
pages belonging to the 'man3' category.

=item binhtml

This is the same as C<bindoc> above, but applies to HTML documents.

=item libhtml

This is the same as C<bindoc> above, but applies to HTML documents.

=back

Four other parameters let you control various aspects of how
installation paths are determined:

=over 4

=item installdirs

The default destinations for these installable things come from
entries in your system's C<Config.pm>.  You can select from three
different sets of default locations by setting the C<installdirs>
parameter as follows:

                          'installdirs' set to:
                   core          site                vendor

              uses the following defaults from Config.pm:

  lib     => installprivlib  installsitelib      installvendorlib
  arch    => installarchlib  installsitearch     installvendorarch
  script  => installscript   installsitebin      installvendorbin
  bin     => installbin      installsitebin      installvendorbin
  bindoc  => installman1dir  installsiteman1dir  installvendorman1dir
  libdoc  => installman3dir  installsiteman3dir  installvendorman3dir
  binhtml => installhtml1dir installsitehtml1dir installvendorhtml1dir [*]
  libhtml => installhtml3dir installsitehtml3dir installvendorhtml3dir [*]

  * Under some OS (eg. MSWin32) the destination for HTML documents is
    determined by the C<Config.pm> entry C<installhtmldir>.

The default value of C<installdirs> is "site".  If you're creating
vendor distributions of module packages, you may want to do something
like this:

  perl Build.PL --installdirs vendor

or

  ./Build install --installdirs vendor

If you're installing an updated version of a module that was included
with perl itself (i.e. a "core module"), then you may set
C<installdirs> to "core" to overwrite the module in its present
location.

(Note that the 'script' line is different from C<MakeMaker> -
unfortunately there's no such thing as "installsitescript" or
"installvendorscript" entry in C<Config.pm>, so we use the
"installsitebin" and "installvendorbin" entries to at least get the
general location right.  In the future, if C<Config.pm> adds some more
appropriate entries, we'll start using those.)

=item install_path

Once the defaults have been set, you can override them.

On the command line, that would look like this:

  perl Build.PL --install_path lib=/foo/lib --install_path arch=/foo/lib/arch

or this:

  ./Build install --install_path lib=/foo/lib --install_path arch=/foo/lib/arch

=item install_base

You can also set the whole bunch of installation paths by supplying the
C<install_base> parameter to point to a directory on your system.  For
instance, if you set C<install_base> to "/home/ken" on a Linux
system, you'll install as follows:

  lib     => /home/ken/lib/perl5
  arch    => /home/ken/lib/perl5/i386-linux
  script  => /home/ken/bin
  bin     => /home/ken/bin
  bindoc  => /home/ken/man/man1
  libdoc  => /home/ken/man/man3
  binhtml => /home/ken/html
  libhtml => /home/ken/html

Note that this is I<different> from how C<MakeMaker>'s C<PREFIX>
parameter works.  C<install_base> just gives you a default layout under the
directory you specify, which may have little to do with the
C<installdirs=site> layout.

The exact layout under the directory you specify may vary by system -
we try to do the "sensible" thing on each platform.

=item destdir

If you want to install everything into a temporary directory first
(for instance, if you want to create a directory tree that a package
manager like C<rpm> or C<dpkg> could create a package from), you can
use the C<destdir> parameter:

  perl Build.PL --destdir /tmp/foo

or

  ./Build install --destdir /tmp/foo

This will effectively install to "/tmp/foo/$sitelib",
"/tmp/foo/$sitearch", and the like, except that it will use
C<File::Spec> to make the pathnames work correctly on whatever
platform you're installing on.

=item prefix

Provided for compatibility with C<ExtUtils::MakeMaker>'s PREFIX argument.
C<prefix> should be used when you wish Module::Build to install your
modules, documentation and scripts in the same place
C<ExtUtils::MakeMaker> does.

The following are equivalent.

    perl Build.PL --prefix /tmp/foo
    perl Makefile.PL PREFIX=/tmp/foo

Because of the very complex nature of the prefixification logic, the
behavior of PREFIX in C<MakeMaker> has changed subtly over time.
Module::Build's --prefix logic is equivalent to the PREFIX logic found
in C<ExtUtils::MakeMaker> 6.30.

If you do not need to retain compatibility with C<ExtUtils::MakeMaker> or
are starting a fresh Perl installation we recommend you use
C<install_base> instead (and C<INSTALL_BASE> in C<ExtUtils::MakeMaker>).
See L<Module::Build::Cookbook/Instaling in the same location as
ExtUtils::MakeMaker> for further information.


=back


=head1 MOTIVATIONS

There are several reasons I wanted to start over, and not just fix
what I didn't like about C<MakeMaker>:

=over 4

=item *

I don't like the core idea of C<MakeMaker>, namely that C<make> should be
involved in the build process.  Here are my reasons:

=over 4

=item +

When a person is installing a Perl module, what can you assume about
their environment?  Can you assume they have C<make>?  No, but you can
assume they have some version of Perl.

=item +

When a person is writing a Perl module for intended distribution, can
you assume that they know how to build a Makefile, so they can
customize their build process?  No, but you can assume they know Perl,
and could customize that way.

=back

For years, these things have been a barrier to people getting the
build/install process to do what they want.

=item *

There are several architectural decisions in C<MakeMaker> that make it
very difficult to customize its behavior.  For instance, when using
C<MakeMaker> you do C<use ExtUtils::MakeMaker>, but the object created in
C<WriteMakefile()> is actually blessed into a package name that's
created on the fly, so you can't simply subclass
C<ExtUtils::MakeMaker>.  There is a workaround C<MY> package that lets
you override certain C<MakeMaker> methods, but only certain explicitly
preselected (by C<MakeMaker>) methods can be overridden.  Also, the method
of customization is very crude: you have to modify a string containing
the Makefile text for the particular target.  Since these strings
aren't documented, and I<can't> be documented (they take on different
values depending on the platform, version of perl, version of
C<MakeMaker>, etc.), you have no guarantee that your modifications will
work on someone else's machine or after an upgrade of C<MakeMaker> or
perl.

=item *

It is risky to make major changes to C<MakeMaker>, since it does so many
things, is so important, and generally works.  C<Module::Build> is an
entirely separate package so that I can work on it all I want, without
worrying about backward compatibility.

=item *

Finally, Perl is said to be a language for system administration.
Could it really be the case that Perl isn't up to the task of building
and installing software?  Even if that software is a bunch of stupid
little C<.pm> files that just need to be copied from one place to
another?  My sense was that we could design a system to accomplish
this in a flexible, extensible, and friendly manner.  Or die trying.

=back


=head1 TO DO

The current method of relying on time stamps to determine whether a
derived file is out of date isn't likely to scale well, since it
requires tracing all dependencies backward, it runs into problems on
NFS, and it's just generally flimsy.  It would be better to use an MD5
signature or the like, if available.  See C<cons> for an example.

 - append to perllocal.pod
 - add a 'plugin' functionality


=head1 AUTHOR

Ken Williams <kwilliams@cpan.org>

Development questions, bug reports, and patches should be sent to the
Module-Build mailing list at <module-build@perl.org>.

Bug reports are also welcome at
<http://rt.cpan.org/NoAuth/Bugs.html?Dist=Module-Build>.

The latest development version is available from the Subversion
repository at <https://svn.perl.org/modules/Module-Build/trunk/>


=head1 COPYRIGHT

Copyright (c) 2001-2006 Ken Williams.  All rights reserved.

This library is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.


=head1 SEE ALSO

perl(1), L<Module::Build::Cookbook>, L<Module::Build::Authoring>,
L<Module::Build::API>, L<ExtUtils::MakeMaker>, L<YAML::Tiny>

F<META.yml> Specification:
L<http://module-build.sourceforge.net/META-spec-current.html>

L<http://www.dsmit.com/cons/>

L<http://search.cpan.org/dist/PerlBuildSystem/>

=cut