1 package ExtUtils::MakeMaker::FAQ;
11 ExtUtils::MakeMaker::FAQ - Frequently Asked Questions About MakeMaker
15 FAQs, tricks and tips for C<ExtUtils::MakeMaker>.
18 =head2 Module Installation
22 =item How do I install a module into my home directory?
24 If you're not the Perl administrator you probably don't have
25 permission to install a module to its default location. Then you
26 should install it for your own use into your home directory like so:
28 perl Makefile.PL INSTALL_BASE=~
30 This will put modules into F<~/lib/perl5>, man pages into F<~/man> and
31 programs into F<~/bin>.
33 To ensure your Perl programs can see these newly installed modules,
34 set your C<PERL5LIB> environment variable to F<~/lib/perl5> or tell
35 each of your programs to look in that directory with the following:
37 use lib "$ENV{HOME}/lib/perl5";
40 =item How do I get MakeMaker and Module::Build to install to the same place?
42 Module::Build, as of 0.28, supports two ways to install to the same
43 location as MakeMaker.
45 1) Use INSTALL_BASE / C<--install_base>
47 MakeMaker (as of 6.31) and Module::Build (as of 0.28) both can install
48 to the same locations using the "install_base" concept. See
49 L<ExtUtils::MakeMaker/INSTALL_BASE> for details. To get MM and MB to
50 install to the same location simply set INSTALL_BASE in MM and
51 C<--install_base> in MB to the same location.
53 perl Makefile.PL INSTALL_BASE=/whatever
54 perl Build.PL --install_base /whatever
56 2) Use PREFIX / C<--prefix>
58 Module::Build 0.28 added support for C<--prefix> which works like
61 perl Makefile.PL PREFIX=/whatever
62 perl Build.PL --prefix /whatever
65 =item How do I keep from installing man pages?
67 Recent versions of MakeMaker will only install man pages on Unix like
70 For an individual module:
72 perl Makefile.PL INSTALLMAN1DIR=none INSTALLMAN3DIR=none
74 If you want to suppress man page installation for all modules you have
75 to reconfigure Perl and tell it 'none' when it asks where to install
79 =item How do I use a module without installing it?
81 Two ways. One is to build the module normally...
87 ...and then set the PERL5LIB environment variable to point at the
88 blib/lib and blib/arch directories.
90 The other is to install the module in a temporary location.
92 perl Makefile.PL INSTALL_BASE=~/tmp
97 And then set PERL5LIB to F<~/tmp/lib/perl5>. This works well when you
98 have multiple modules to work with. It also ensures that the module
99 goes through its full installation process which may modify it.
104 =head2 Philosophy and History
108 =item Why not just use <insert other build config tool here>?
110 Why did MakeMaker reinvent the build configuration wheel? Why not
111 just use autoconf or automake or ppm or Ant or ...
113 There are many reasons, but the major one is cross-platform
116 Perl is one of the most ported pieces of software ever. It works on
117 operating systems I've never even heard of (see perlport for details).
118 It needs a build tool that can work on all those platforms and with
119 any wacky C compilers and linkers they might have.
121 No such build tool exists. Even make itself has wildly different
122 dialects. So we have to build our own.
125 =item What is Module::Build and how does it relate to MakeMaker?
127 Module::Build is a project by Ken Williams to supplant MakeMaker.
128 Its primary advantages are:
132 =item * pure perl. no make, no shell commands
134 =item * easier to customize
136 =item * cleaner internals
142 Module::Build is the official heir apparent to MakeMaker and we
143 encourage people to work on M::B rather than spending time adding features
149 =head2 Module Writing
153 =item How do I keep my $VERSION up to date without resetting it manually?
155 Often you want to manually set the $VERSION in the main module
156 distribution because this is the version that everybody sees on CPAN
157 and maybe you want to customize it a bit. But for all the other
158 modules in your dist, $VERSION is really just bookkeeping and all that's
159 important is it goes up every time the module is changed. Doing this
160 by hand is a pain and you often forget.
162 Simplest way to do it automatically is to use your version control
163 system's revision number (you are using version control, right?).
165 In CVS, RCS and SVN you use $Revision$ (see the documentation of your
166 version control system for details). Every time the file is checked
167 in the $Revision$ will be updated, updating your $VERSION.
169 SVN uses a simple integer for $Revision$ so you can adapt it for your
172 $VERSION = (q$Revision$) =~ /(\d+)/g;
174 In CVS and RCS version 1.9 is followed by 1.10. Since CPAN compares
175 version numbers numerically we use a sprintf() to convert 1.9 to 1.009
176 and 1.10 to 1.010 which compare properly.
178 $VERSION = sprintf "%d.%03d", q$Revision$ =~ /(\d+)\.(\d+)/g;
180 If branches are involved (ie. $Revision: 1.5.3.4$) its a little more
183 # must be all on one line or MakeMaker will get confused.
184 $VERSION = do { my @r = (q$Revision$ =~ /\d+/g); sprintf "%d."."%03d" x $#r, @r };
186 In SVN, $Revision$ should be the same for every file in the project so
187 they would all have the same $VERSION. CVS and RCS have a different
188 $Revision$ per file so each file will have a differnt $VERSION.
189 Distributed version control systems, such as SVK, may have a different
190 $Revision$ based on who checks out the file leading to a different $VERSION
191 on each machine! Finally, some distributed version control systems, such
192 as darcs, have no concept of revision number at all.
195 =item What's this F<META.yml> thing and how did it get in my F<MANIFEST>?!
197 F<META.yml> is a module meta-data file pioneered by Module::Build and
198 automatically generated as part of the 'distdir' target (and thus
199 'dist'). See L<ExtUtils::MakeMaker/"Module Meta-Data">.
201 To shut off its generation, pass the C<NO_META> flag to C<WriteMakefile()>.
204 =item How do I delete everything not in my F<MANIFEST>?
206 Some folks are surpried that C<make distclean> does not delete
207 everything not listed in their MANIFEST (thus making a clean
208 distribution) but only tells them what they need to delete. This is
209 done because it is considered too dangerous. While developing your
210 module you might write a new file, not add it to the MANIFEST, then
211 run a C<distclean> and be sad because your new work was deleted.
213 If you really want to do this, you can use
214 C<ExtUtils::Manifest::manifind()> to read the MANIFEST and File::Find
215 to delete the files. But you have to be careful. Here's a script to
216 do that. Use at your own risk. Have fun blowing holes in your foot.
224 use ExtUtils::Manifest qw(maniread);
226 my %manifest = map {( $_ => 1 )}
227 grep { File::Spec->canonpath($_) }
228 keys %{ maniread() };
230 if( !keys %manifest ) {
231 print "No files found in MANIFEST. Stopping.\n";
237 my $path = File::Spec->canonpath($_);
239 return unless -f $path;
240 return if exists $manifest{ $path };
242 print "unlink $path\n";
257 =item How to I prevent "object version X.XX does not match bootstrap parameter Y.YY" errors?
259 XS code is very sensitive to the module version number and will
260 complain if the version number in your Perl module doesn't match. If
261 you change your module's version # without rerunning Makefile.PL the old
262 version number will remain in the Makefile causing the XS code to be built
263 with the wrong number.
265 To avoid this, you can force the Makefile to be rebuilt whenever you
266 change the module containing the version number by adding this to your
267 WriteMakefile() arguments.
269 depend => { '$(FIRST_MAKEFILE)' => '$(VERSION_FROM)' }
272 =item How do I make two or more XS files coexist in the same directory?
274 Sometimes you need to have two and more XS files in the same package.
275 One way to go is to put them into separate directories, but sometimes
276 this is not the most suitable solution. The following technique allows
277 you to put two (and more) XS files in the same directory.
279 Let's assume that we have a package C<Cool::Foo>, which includes
280 C<Cool::Foo> and C<Cool::Bar> modules each having a separate XS
281 file. First we use the following I<Makefile.PL>:
283 use ExtUtils::MakeMaker;
287 VERSION_FROM => 'Foo.pm',
288 OBJECT => q/$(O_FILES)/,
289 # ... other attrs ...
292 Notice the C<OBJECT> attribute. MakeMaker generates the following
293 variables in I<Makefile>:
295 # Handy lists of source code files:
303 Therefore we can use the C<O_FILES> variable to tell MakeMaker to use
304 these objects into the shared library.
306 That's pretty much it. Now write I<Foo.pm> and I<Foo.xs>, I<Bar.pm>
307 and I<Bar.xs>, where I<Foo.pm> bootstraps the shared library and
308 I<Bar.pm> simply loading I<Foo.pm>.
310 The only issue left is to how to bootstrap I<Bar.xs>. This is done
313 MODULE = Cool::Foo PACKAGE = Cool::Foo
316 # boot the second XS file
317 boot_Cool__Bar(aTHX_ cv);
319 If you have more than two files, this is the place where you should
320 boot extra XS files from.
322 The following four files sum up all the details discussed so far.
330 our @ISA = qw(DynaLoader);
331 our $VERSION = '0.01';
332 bootstrap Cool::Foo $VERSION;
340 use Cool::Foo; # bootstraps Bar.xs
350 MODULE = Cool::Foo PACKAGE = Cool::Foo
353 # boot the second XS file
354 boot_Cool__Bar(aTHX_ cv);
356 MODULE = Cool::Foo PACKAGE = Cool::Foo PREFIX = cool_foo_
359 cool_foo_perl_rules()
362 fprintf(stderr, "Cool::Foo says: Perl Rules\n");
370 MODULE = Cool::Bar PACKAGE = Cool::Bar PREFIX = cool_bar_
373 cool_bar_perl_rules()
376 fprintf(stderr, "Cool::Bar says: Perl Rules\n");
378 And of course a very basic test:
383 BEGIN { plan tests => 1 };
386 Cool::Foo::perl_rules();
387 Cool::Bar::perl_rules();
390 This tip has been brought to you by Nick Ing-Simmons and Stas Bekman.
396 If you have a question you'd like to see added to the FAQ (whether or
397 not you have the answer) please send it to makemaker@perl.org.
401 The denizens of makemaker@perl.org.
405 L<ExtUtils::MakeMaker>