1package ExtUtils::MakeMaker::FAQ; 2 3our $VERSION = '1.12'; 4 51; 6__END__ 7 8=head1 NAME 9 10ExtUtils::MakeMaker::FAQ - Frequently Asked Questions About MakeMaker 11 12=head1 DESCRIPTION 13 14FAQs, tricks and tips for C<ExtUtils::MakeMaker>. 15 16 17=head2 Module Installation 18 19=over 4 20 21=item How do I install a module into my home directory? 22 23If you're not the Perl administrator you probably don't have 24permission to install a module to its default location. Then you 25should install it for your own use into your home directory like so: 26 27 # Non-unix folks, replace ~ with /path/to/your/home/dir 28 perl Makefile.PL INSTALL_BASE=~ 29 30This will put modules into F<~/lib/perl5>, man pages into F<~/man> and 31programs into F<~/bin>. 32 33To ensure your Perl programs can see these newly installed modules, 34set your C<PERL5LIB> environment variable to F<~/lib/perl5> or tell 35each of your programs to look in that directory with the following: 36 37 use lib "$ENV{HOME}/lib/perl5"; 38 39or if $ENV{HOME} isn't set and you don't want to set it for some 40reason, do it the long way. 41 42 use lib "/path/to/your/home/dir/lib/perl5"; 43 44 45=item How do I get MakeMaker and Module::Build to install to the same place? 46 47Module::Build, as of 0.28, supports two ways to install to the same 48location as MakeMaker. 49 501) Use INSTALL_BASE / C<--install_base> 51 52MakeMaker (as of 6.31) and Module::Build (as of 0.28) both can install 53to the same locations using the "install_base" concept. See 54L<ExtUtils::MakeMaker/INSTALL_BASE> for details. To get MM and MB to 55install to the same location simply set INSTALL_BASE in MM and 56C<--install_base> in MB to the same location. 57 58 perl Makefile.PL INSTALL_BASE=/whatever 59 perl Build.PL --install_base /whatever 60 612) Use PREFIX / C<--prefix> 62 63Module::Build 0.28 added support for C<--prefix> which works like 64MakeMaker's PREFIX. 65 66 perl Makefile.PL PREFIX=/whatever 67 perl Build.PL --prefix /whatever 68 69 70=item How do I keep from installing man pages? 71 72Recent versions of MakeMaker will only install man pages on Unix like 73operating systems. 74 75For an individual module: 76 77 perl Makefile.PL INSTALLMAN1DIR=none INSTALLMAN3DIR=none 78 79If you want to suppress man page installation for all modules you have 80to reconfigure Perl and tell it 'none' when it asks where to install 81man pages. 82 83 84=item How do I use a module without installing it? 85 86Two ways. One is to build the module normally... 87 88 perl Makefile.PL 89 make 90 make test 91 92...and then set the PERL5LIB environment variable to point at the 93blib/lib and blib/arch directories. 94 95The other is to install the module in a temporary location. 96 97 perl Makefile.PL INSTALL_BASE=~/tmp 98 make 99 make test 100 make install 101 102And then set PERL5LIB to F<~/tmp/lib/perl5>. This works well when you 103have multiple modules to work with. It also ensures that the module 104goes through its full installation process which may modify it. 105 106=item PREFIX vs INSTALL_BASE from Module::Build::Cookbook 107 108The behavior of PREFIX is complicated and depends closely on how your 109Perl is configured. The resulting installation locations will vary from 110machine to machine and even different installations of Perl on the same machine. 111Because of this, its difficult to document where prefix will place your modules. 112 113In contrast, INSTALL_BASE has predictable, easy to explain installation locations. 114Now that Module::Build and MakeMaker both have INSTALL_BASE there is little reason 115to use PREFIX other than to preserve your existing installation locations. If you 116are starting a fresh Perl installation we encourage you to use INSTALL_BASE. If 117you have an existing installation installed via PREFIX, consider moving it to an 118installation structure matching INSTALL_BASE and using that instead. 119 120=back 121 122 123=head2 Philosophy and History 124 125=over 4 126 127=item Why not just use <insert other build config tool here>? 128 129Why did MakeMaker reinvent the build configuration wheel? Why not 130just use autoconf or automake or ppm or Ant or ... 131 132There are many reasons, but the major one is cross-platform 133compatibility. 134 135Perl is one of the most ported pieces of software ever. It works on 136operating systems I've never even heard of (see perlport for details). 137It needs a build tool that can work on all those platforms and with 138any wacky C compilers and linkers they might have. 139 140No such build tool exists. Even make itself has wildly different 141dialects. So we have to build our own. 142 143 144=item What is Module::Build and how does it relate to MakeMaker? 145 146Module::Build is a project by Ken Williams to supplant MakeMaker. 147Its primary advantages are: 148 149=over 8 150 151=item * pure perl. no make, no shell commands 152 153=item * easier to customize 154 155=item * cleaner internals 156 157=item * less cruft 158 159=back 160 161Module::Build is the official heir apparent to MakeMaker and we 162encourage people to work on M::B rather than spending time adding features 163to MakeMaker. 164 165=back 166 167 168=head2 Module Writing 169 170=over 4 171 172=item How do I keep my $VERSION up to date without resetting it manually? 173 174Often you want to manually set the $VERSION in the main module 175distribution because this is the version that everybody sees on CPAN 176and maybe you want to customize it a bit. But for all the other 177modules in your dist, $VERSION is really just bookkeeping and all that's 178important is it goes up every time the module is changed. Doing this 179by hand is a pain and you often forget. 180 181Simplest way to do it automatically is to use your version control 182system's revision number (you are using version control, right?). 183 184In CVS, RCS and SVN you use $Revision$ (see the documentation of your 185version control system for details). Every time the file is checked 186in the $Revision$ will be updated, updating your $VERSION. 187 188SVN uses a simple integer for $Revision$ so you can adapt it for your 189$VERSION like so: 190 191 ($VERSION) = q$Revision$ =~ /(\d+)/; 192 193In CVS and RCS version 1.9 is followed by 1.10. Since CPAN compares 194version numbers numerically we use a sprintf() to convert 1.9 to 1.009 195and 1.10 to 1.010 which compare properly. 196 197 $VERSION = sprintf "%d.%03d", q$Revision$ =~ /(\d+)\.(\d+)/g; 198 199If branches are involved (ie. $Revision: 1.5.3.4$) its a little more 200complicated. 201 202 # must be all on one line or MakeMaker will get confused. 203 $VERSION = do { my @r = (q$Revision$ =~ /\d+/g); sprintf "%d."."%03d" x $#r, @r }; 204 205In SVN, $Revision$ should be the same for every file in the project so 206they would all have the same $VERSION. CVS and RCS have a different 207$Revision$ per file so each file will have a differnt $VERSION. 208Distributed version control systems, such as SVK, may have a different 209$Revision$ based on who checks out the file leading to a different $VERSION 210on each machine! Finally, some distributed version control systems, such 211as darcs, have no concept of revision number at all. 212 213 214=item What's this F<META.yml> thing and how did it get in my F<MANIFEST>?! 215 216F<META.yml> is a module meta-data file pioneered by Module::Build and 217automatically generated as part of the 'distdir' target (and thus 218'dist'). See L<ExtUtils::MakeMaker/"Module Meta-Data">. 219 220To shut off its generation, pass the C<NO_META> flag to C<WriteMakefile()>. 221 222 223=item How do I delete everything not in my F<MANIFEST>? 224 225Some folks are surpried that C<make distclean> does not delete 226everything not listed in their MANIFEST (thus making a clean 227distribution) but only tells them what they need to delete. This is 228done because it is considered too dangerous. While developing your 229module you might write a new file, not add it to the MANIFEST, then 230run a C<distclean> and be sad because your new work was deleted. 231 232If you really want to do this, you can use 233C<ExtUtils::Manifest::manifind()> to read the MANIFEST and File::Find 234to delete the files. But you have to be careful. Here's a script to 235do that. Use at your own risk. Have fun blowing holes in your foot. 236 237 #!/usr/bin/perl -w 238 239 use strict; 240 241 use File::Spec; 242 use File::Find; 243 use ExtUtils::Manifest qw(maniread); 244 245 my %manifest = map {( $_ => 1 )} 246 grep { File::Spec->canonpath($_) } 247 keys %{ maniread() }; 248 249 if( !keys %manifest ) { 250 print "No files found in MANIFEST. Stopping.\n"; 251 exit; 252 } 253 254 find({ 255 wanted => sub { 256 my $path = File::Spec->canonpath($_); 257 258 return unless -f $path; 259 return if exists $manifest{ $path }; 260 261 print "unlink $path\n"; 262 unlink $path; 263 }, 264 no_chdir => 1 265 }, 266 "." 267 ); 268 269 270=item Which zip should I use on Windows for '[nd]make zipdist'? 271 272We recommend InfoZIP: L<http://www.info-zip.org/Zip.html> 273 274 275=back 276 277=head2 XS 278 279=over 4 280 281=item How to I prevent "object version X.XX does not match bootstrap parameter Y.YY" errors? 282 283XS code is very sensitive to the module version number and will 284complain if the version number in your Perl module doesn't match. If 285you change your module's version # without rerunning Makefile.PL the old 286version number will remain in the Makefile causing the XS code to be built 287with the wrong number. 288 289To avoid this, you can force the Makefile to be rebuilt whenever you 290change the module containing the version number by adding this to your 291WriteMakefile() arguments. 292 293 depend => { '$(FIRST_MAKEFILE)' => '$(VERSION_FROM)' } 294 295 296=item How do I make two or more XS files coexist in the same directory? 297 298Sometimes you need to have two and more XS files in the same package. 299One way to go is to put them into separate directories, but sometimes 300this is not the most suitable solution. The following technique allows 301you to put two (and more) XS files in the same directory. 302 303Let's assume that we have a package C<Cool::Foo>, which includes 304C<Cool::Foo> and C<Cool::Bar> modules each having a separate XS 305file. First we use the following I<Makefile.PL>: 306 307 use ExtUtils::MakeMaker; 308 309 WriteMakefile( 310 NAME => 'Cool::Foo', 311 VERSION_FROM => 'Foo.pm', 312 OBJECT => q/$(O_FILES)/, 313 # ... other attrs ... 314 ); 315 316Notice the C<OBJECT> attribute. MakeMaker generates the following 317variables in I<Makefile>: 318 319 # Handy lists of source code files: 320 XS_FILES= Bar.xs \ 321 Foo.xs 322 C_FILES = Bar.c \ 323 Foo.c 324 O_FILES = Bar.o \ 325 Foo.o 326 327Therefore we can use the C<O_FILES> variable to tell MakeMaker to use 328these objects into the shared library. 329 330That's pretty much it. Now write I<Foo.pm> and I<Foo.xs>, I<Bar.pm> 331and I<Bar.xs>, where I<Foo.pm> bootstraps the shared library and 332I<Bar.pm> simply loading I<Foo.pm>. 333 334The only issue left is to how to bootstrap I<Bar.xs>. This is done 335from I<Foo.xs>: 336 337 MODULE = Cool::Foo PACKAGE = Cool::Foo 338 339 BOOT: 340 # boot the second XS file 341 boot_Cool__Bar(aTHX_ cv); 342 343If you have more than two files, this is the place where you should 344boot extra XS files from. 345 346The following four files sum up all the details discussed so far. 347 348 Foo.pm: 349 ------- 350 package Cool::Foo; 351 352 require DynaLoader; 353 354 our @ISA = qw(DynaLoader); 355 our $VERSION = '0.01'; 356 bootstrap Cool::Foo $VERSION; 357 358 1; 359 360 Bar.pm: 361 ------- 362 package Cool::Bar; 363 364 use Cool::Foo; # bootstraps Bar.xs 365 366 1; 367 368 Foo.xs: 369 ------- 370 #include "EXTERN.h" 371 #include "perl.h" 372 #include "XSUB.h" 373 374 MODULE = Cool::Foo PACKAGE = Cool::Foo 375 376 BOOT: 377 # boot the second XS file 378 boot_Cool__Bar(aTHX_ cv); 379 380 MODULE = Cool::Foo PACKAGE = Cool::Foo PREFIX = cool_foo_ 381 382 void 383 cool_foo_perl_rules() 384 385 CODE: 386 fprintf(stderr, "Cool::Foo says: Perl Rules\n"); 387 388 Bar.xs: 389 ------- 390 #include "EXTERN.h" 391 #include "perl.h" 392 #include "XSUB.h" 393 394 MODULE = Cool::Bar PACKAGE = Cool::Bar PREFIX = cool_bar_ 395 396 void 397 cool_bar_perl_rules() 398 399 CODE: 400 fprintf(stderr, "Cool::Bar says: Perl Rules\n"); 401 402And of course a very basic test: 403 404 t/cool.t: 405 -------- 406 use Test; 407 BEGIN { plan tests => 1 }; 408 use Cool::Foo; 409 use Cool::Bar; 410 Cool::Foo::perl_rules(); 411 Cool::Bar::perl_rules(); 412 ok 1; 413 414This tip has been brought to you by Nick Ing-Simmons and Stas Bekman. 415 416=back 417 418=head1 PATCHING 419 420If you have a question you'd like to see added to the FAQ (whether or 421not you have the answer) please send it to makemaker@perl.org. 422 423=head1 AUTHOR 424 425The denizens of makemaker@perl.org. 426 427=head1 SEE ALSO 428 429L<ExtUtils::MakeMaker> 430 431=cut 432