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Revision: 1.45
Committed: Mon Jun 27 21:56:51 2011 UTC (12 years, 10 months ago) by root
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# Content
1 =head1 NAME
2
3 staticperl - perl, libc, 100 modules, all in one 500kb file
4
5 =head1 SYNOPSIS
6
7 staticperl help # print the embedded documentation
8 staticperl fetch # fetch and unpack perl sources
9 staticperl configure # fetch and then configure perl
10 staticperl build # configure and then build perl
11 staticperl install # build and then install perl
12 staticperl clean # clean most intermediate files (restart at configure)
13 staticperl distclean # delete everything installed by this script
14 staticperl perl ... # invoke the perlinterpreter
15 staticperl cpan # invoke CPAN shell
16 staticperl instmod path... # install unpacked modules
17 staticperl instcpan modulename... # install modules from CPAN
18 staticperl mkbundle <bundle-args...> # see documentation
19 staticperl mkperl <bundle-args...> # see documentation
20 staticperl mkapp appname <bundle-args...> # see documentation
21
22 Typical Examples:
23
24 staticperl install # fetch, configure, build and install perl
25 staticperl cpan # run interactive cpan shell
26 staticperl mkperl -MConfig_heavy.pl # build a perl that supports -V
27 staticperl mkperl -MAnyEvent::Impl::Perl -MAnyEvent::HTTPD -MURI -MURI::http
28 # build a perl with the above modules linked in
29 staticperl mkapp myapp --boot mainprog mymodules
30 # build a binary "myapp" from mainprog and mymodules
31
32 =head1 DESCRIPTION
33
34 This script helps you to create single-file perl interpreters
35 or applications, or embedding a perl interpreter in your
36 applications. Single-file means that it is fully self-contained - no
37 separate shared objects, no autoload fragments, no .pm or .pl files are
38 needed. And when linking statically, you can create (or embed) a single
39 file that contains perl interpreter, libc, all the modules you need, all
40 the libraries you need and of course your actual program.
41
42 With F<uClibc> and F<upx> on x86, you can create a single 500kb binary
43 that contains perl and 100 modules such as POSIX, AnyEvent, EV, IO::AIO,
44 Coro and so on. Or any other choice of modules (and some other size :).
45
46 To see how this turns out, you can try out smallperl and bigperl, two
47 pre-built static and compressed perl binaries with many and even more
48 modules: just follow the links at L<http://staticperl.schmorp.de/>.
49
50 The created files do not need write access to the file system (like PAR
51 does). In fact, since this script is in many ways similar to PAR::Packer,
52 here are the differences:
53
54 =over 4
55
56 =item * The generated executables are much smaller than PAR created ones.
57
58 Shared objects and the perl binary contain a lot of extra info, while
59 the static nature of F<staticperl> allows the linker to remove all
60 functionality and meta-info not required by the final executable. Even
61 extensions statically compiled into perl at build time will only be
62 present in the final executable when needed.
63
64 In addition, F<staticperl> can strip perl sources much more effectively
65 than PAR.
66
67 =item * The generated executables start much faster.
68
69 There is no need to unpack files, or even to parse Zip archives (which is
70 slow and memory-consuming business).
71
72 =item * The generated executables don't need a writable filesystem.
73
74 F<staticperl> loads all required files directly from memory. There is no
75 need to unpack files into a temporary directory.
76
77 =item * More control over included files, more burden.
78
79 PAR tries to be maintenance and hassle-free - it tries to include more
80 files than necessary to make sure everything works out of the box. It
81 mostly succeeds at this, but he extra files (such as the unicode database)
82 can take substantial amounts of memory and file size.
83
84 With F<staticperl>, the burden is mostly with the developer - only direct
85 compile-time dependencies and L<AutoLoader> are handled automatically.
86 This means the modules to include often need to be tweaked manually.
87
88 All this does not preclude more permissive modes to be implemented in
89 the future, but right now, you have to resolve state hidden dependencies
90 manually.
91
92 =item * PAR works out of the box, F<staticperl> does not.
93
94 Maintaining your own custom perl build can be a pain in the ass, and while
95 F<staticperl> tries to make this easy, it still requires a custom perl
96 build and possibly fiddling with some modules. PAR is likely to produce
97 results faster.
98
99 Ok, PAR never has worked for me out of the box, and for some people,
100 F<staticperl> does work out of the box, as they don't count "fiddling with
101 module use lists" against it, but nevertheless, F<staticperl> is certainly
102 a bit more difficult to use.
103
104 =back
105
106 =head1 HOW DOES IT WORK?
107
108 Simple: F<staticperl> downloads, compile and installs a perl version of
109 your choice in F<~/.staticperl>. You can add extra modules either by
110 letting F<staticperl> install them for you automatically, or by using CPAN
111 and doing it interactively. This usually takes 5-10 minutes, depending on
112 the speed of your computer and your internet connection.
113
114 It is possible to do program development at this stage, too.
115
116 Afterwards, you create a list of files and modules you want to include,
117 and then either build a new perl binary (that acts just like a normal perl
118 except everything is compiled in), or you create bundle files (basically C
119 sources you can use to embed all files into your project).
120
121 This step is very fast (a few seconds if PPI is not used for stripping, or
122 the stripped files are in the cache), and can be tweaked and repeated as
123 often as necessary.
124
125 =head1 THE F<STATICPERL> SCRIPT
126
127 This module installs a script called F<staticperl> into your perl
128 binary directory. The script is fully self-contained, and can be
129 used without perl (for example, in an uClibc chroot environment). In
130 fact, it can be extracted from the C<App::Staticperl> distribution
131 tarball as F<bin/staticperl>, without any installation. The
132 newest (possibly alpha) version can also be downloaded from
133 L<http://staticperl.schmorp.de/staticperl>.
134
135 F<staticperl> interprets the first argument as a command to execute,
136 optionally followed by any parameters.
137
138 There are two command categories: the "phase 1" commands which deal with
139 installing perl and perl modules, and the "phase 2" commands, which deal
140 with creating binaries and bundle files.
141
142 =head2 PHASE 1 COMMANDS: INSTALLING PERL
143
144 The most important command is F<install>, which does basically
145 everything. The default is to download and install perl 5.12.3 and a few
146 modules required by F<staticperl> itself, but all this can (and should) be
147 changed - see L<CONFIGURATION>, below.
148
149 The command
150
151 staticperl install
152
153 is normally all you need: It installs the perl interpreter in
154 F<~/.staticperl/perl>. It downloads, configures, builds and installs the
155 perl interpreter if required.
156
157 Most of the following F<staticperl> subcommands simply run one or more
158 steps of this sequence.
159
160 If it fails, then most commonly because the compiler options I selected
161 are not supported by your compiler - either edit the F<staticperl> script
162 yourself or create F<~/.staticperl> shell script where your set working
163 C<PERL_CCFLAGS> etc. variables.
164
165 To force recompilation or reinstallation, you need to run F<staticperl
166 distclean> first.
167
168 =over 4
169
170 =item F<staticperl version>
171
172 Prints some info about the version of the F<staticperl> script you are using.
173
174 =item F<staticperl fetch>
175
176 Runs only the download and unpack phase, unless this has already happened.
177
178 =item F<staticperl configure>
179
180 Configures the unpacked perl sources, potentially after downloading them first.
181
182 =item F<staticperl build>
183
184 Builds the configured perl sources, potentially after automatically
185 configuring them.
186
187 =item F<staticperl install>
188
189 Wipes the perl installation directory (usually F<~/.staticperl/perl>) and
190 installs the perl distribution, potentially after building it first.
191
192 =item F<staticperl perl> [args...]
193
194 Invokes the compiled perl interpreter with the given args. Basically the
195 same as starting perl directly (usually via F<~/.staticperl/bin/perl>),
196 but beats typing the path sometimes.
197
198 Example: check that the Gtk2 module is installed and loadable.
199
200 staticperl perl -MGtk2 -e0
201
202 =item F<staticperl cpan> [args...]
203
204 Starts an interactive CPAN shell that you can use to install further
205 modules. Installs the perl first if necessary, but apart from that,
206 no magic is involved: you could just as well run it manually via
207 F<~/.staticperl/perl/bin/cpan>.
208
209 Any additional arguments are simply passed to the F<cpan> command.
210
211 =item F<staticperl instcpan> module...
212
213 Tries to install all the modules given and their dependencies, using CPAN.
214
215 Example:
216
217 staticperl instcpan EV AnyEvent::HTTPD Coro
218
219 =item F<staticperl instsrc> directory...
220
221 In the unlikely case that you have unpacked perl modules around and want
222 to install from these instead of from CPAN, you can do this using this
223 command by specifying all the directories with modules in them that you
224 want to have built.
225
226 =item F<staticperl clean>
227
228 Deletes the perl source directory (and potentially cleans up other
229 intermediate files). This can be used to clean up files only needed for
230 building perl, without removing the installed perl interpreter.
231
232 At the moment, it doesn't delete downloaded tarballs.
233
234 The exact semantics of this command will probably change.
235
236 =item F<staticperl distclean>
237
238 This wipes your complete F<~/.staticperl> directory. Be careful with this,
239 it nukes your perl download, perl sources, perl distribution and any
240 installed modules. It is useful if you wish to start over "from scratch"
241 or when you want to uninstall F<staticperl>.
242
243 =back
244
245 =head2 PHASE 2 COMMANDS: BUILDING PERL BUNDLES
246
247 Building (linking) a new F<perl> binary is handled by a separate
248 script. To make it easy to use F<staticperl> from a F<chroot>, the script
249 is embedded into F<staticperl>, which will write it out and call for you
250 with any arguments you pass:
251
252 staticperl mkbundle mkbundle-args...
253
254 In the oh so unlikely case of something not working here, you
255 can run the script manually as well (by default it is written to
256 F<~/.staticperl/mkbundle>).
257
258 F<mkbundle> is a more conventional command and expect the argument
259 syntax commonly used on UNIX clones. For example, this command builds
260 a new F<perl> binary and includes F<Config.pm> (for F<perl -V>),
261 F<AnyEvent::HTTPD>, F<URI> and a custom F<httpd> script (from F<eg/httpd>
262 in this distribution):
263
264 # first make sure we have perl and the required modules
265 staticperl instcpan AnyEvent::HTTPD
266
267 # now build the perl
268 staticperl mkperl -MConfig_heavy.pl -MAnyEvent::Impl::Perl \
269 -MAnyEvent::HTTPD -MURI::http \
270 --add 'eg/httpd httpd.pm'
271
272 # finally, invoke it
273 ./perl -Mhttpd
274
275 As you can see, things are not quite as trivial: the L<Config> module has
276 a hidden dependency which is not even a perl module (F<Config_heavy.pl>),
277 L<AnyEvent> needs at least one event loop backend that we have to
278 specify manually (here L<AnyEvent::Impl::Perl>), and the F<URI> module
279 (required by L<AnyEvent::HTTPD>) implements various URI schemes as extra
280 modules - since L<AnyEvent::HTTPD> only needs C<http> URIs, we only need
281 to include that module. I found out about these dependencies by carefully
282 watching any error messages about missing modules...
283
284 Instead of building a new perl binary, you can also build a standalone
285 application:
286
287 # build the app
288 staticperl mkapp app --boot eg/httpd \
289 -MAnyEvent::Impl::Perl -MAnyEvent::HTTPD -MURI::http
290
291 # run it
292 ./app
293
294 Here are the three phase 2 commands:
295
296 =over 4
297
298 =item F<staticperl mkbundle> args...
299
300 The "default" bundle command - it interprets the given bundle options and
301 writes out F<bundle.h>, F<bundle.c>, F<bundle.ccopts> and F<bundle.ldopts>
302 files, useful for embedding.
303
304 =item F<staticperl mkperl> args...
305
306 Creates a bundle just like F<staticperl mkbundle> (in fact, it's the same
307 as invoking F<staticperl mkbundle --perl> args...), but then compiles and
308 links a new perl interpreter that embeds the created bundle, then deletes
309 all intermediate files.
310
311 =item F<staticperl mkapp> filename args...
312
313 Does the same as F<staticperl mkbundle> (in fact, it's the same as
314 invoking F<staticperl mkbundle --app> filename args...), but then compiles
315 and links a new standalone application that simply initialises the perl
316 interpreter.
317
318 The difference to F<staticperl mkperl> is that the standalone application
319 does not act like a perl interpreter would - in fact, by default it would
320 just do nothing and exit immediately, so you should specify some code to
321 be executed via the F<--boot> option.
322
323 =back
324
325 =head3 OPTION PROCESSING
326
327 All options can be given as arguments on the command line (typically
328 using long (e.g. C<--verbose>) or short option (e.g. C<-v>) style). Since
329 specifying a lot of options can make the command line very long and
330 unwieldy, you can put all long options into a "bundle specification file"
331 (one option per line, with or without C<--> prefix) and specify this
332 bundle file instead.
333
334 For example, the command given earlier to link a new F<perl> could also
335 look like this:
336
337 staticperl mkperl httpd.bundle
338
339 With all options stored in the F<httpd.bundle> file (one option per line,
340 everything after the option is an argument):
341
342 use "Config_heavy.pl"
343 use AnyEvent::Impl::Perl
344 use AnyEvent::HTTPD
345 use URI::http
346 add eg/httpd httpd.pm
347
348 All options that specify modules or files to be added are processed in the
349 order given on the command line.
350
351 =head3 BUNDLE CREATION WORKFLOW / STATICPELR MKBUNDLE OPTIONS
352
353 F<staticperl mkbundle> works by first assembling a list of candidate
354 files and modules to include, then filtering them by include/exclude
355 patterns. The remaining modules (together with their direct dependencies,
356 such as link libraries and L<AutoLoader> files) are then converted into
357 bundle files suitable for embedding. F<staticperl mkbundle> can then
358 optionally build a new perl interpreter or a standalone application.
359
360 =over 4
361
362 =item Step 0: Generic argument processing.
363
364 The following options influence F<staticperl mkbundle> itself.
365
366 =over 4
367
368 =item C<--verbose> | C<-v>
369
370 Increases the verbosity level by one (the default is C<1>).
371
372 =item C<--quiet> | C<-q>
373
374 Decreases the verbosity level by one.
375
376 =item any other argument
377
378 Any other argument is interpreted as a bundle specification file, which
379 supports all options (without extra quoting), one option per line, in the
380 format C<option> or C<option argument>. They will effectively be expanded
381 and processed as if they were directly written on the command line, in
382 place of the file name.
383
384 =back
385
386 =item Step 1: gather candidate files and modules
387
388 In this step, modules, perl libraries (F<.pl> files) and other files are
389 selected for inclusion in the bundle. The relevant options are executed
390 in order (this makes a difference mostly for C<--eval>, which can rely on
391 earlier C<--use> options to have been executed).
392
393 =over 4
394
395 =item C<--use> F<module> | C<-M>F<module>
396
397 Include the named module or perl library and trace direct
398 dependencies. This is done by loading the module in a subprocess and
399 tracing which other modules and files it actually loads.
400
401 Example: include AnyEvent and AnyEvent::Impl::Perl.
402
403 staticperl mkbundle --use AnyEvent --use AnyEvent::Impl::Perl
404
405 Sometimes you want to load old-style "perl libraries" (F<.pl> files), or
406 maybe other weirdly named files. To support this, the C<--use> option
407 actually tries to do what you mean, depending on the string you specify:
408
409 =over 4
410
411 =item a possibly valid module name, e.g. F<common::sense>, F<Carp>,
412 F<Coro::Mysql>.
413
414 If the string contains no quotes, no F</> and no F<.>, then C<--use>
415 assumes that it is a normal module name. It will create a new package and
416 evaluate a C<use module> in it, i.e. it will load the package and do a
417 default import.
418
419 The import step is done because many modules trigger more dependencies
420 when something is imported than without.
421
422 =item anything that contains F</> or F<.> characters,
423 e.g. F<utf8_heavy.pl>, F<Module/private/data.pl>.
424
425 The string will be quoted and passed to require, as if you used C<require
426 $module>. Nothing will be imported.
427
428 =item "path" or 'path', e.g. C<"utf8_heavy.pl">.
429
430 If you enclose the name into single or double quotes, then the quotes will
431 be removed and the resulting string will be passed to require. This syntax
432 is form compatibility with older versions of staticperl and should not be
433 used anymore.
434
435 =back
436
437 Example: C<use> AnyEvent::Socket, once using C<use> (importing the
438 symbols), and once via C<require>, not importing any symbols. The first
439 form is preferred as many modules load some extra dependencies when asked
440 to export symbols.
441
442 staticperl mkbundle -MAnyEvent::Socket # use + import
443 staticperl mkbundle -MAnyEvent/Socket.pm # require only
444
445 Example: include the required files for F<perl -V> to work in all its
446 glory (F<Config.pm> is included automatically by the dependency tracker).
447
448 # shell command
449 staticperl mkbundle -MConfig_heavy.pl
450
451 # bundle specification file
452 use Config_heavy.pl
453
454 The C<-M>module syntax is included as a convenience that might be easier
455 to remember than C<--use> - it's the same switch as perl itself uses
456 to load modules. Or maybe it confuses people. Time will tell. Or maybe
457 not. Sigh.
458
459 =item C<--eval> "perl code" | C<-e> "perl code"
460
461 Sometimes it is easier (or necessary) to specify dependencies using perl
462 code, or maybe one of the modules you use need a special use statement. In
463 that case, you can use C<--eval> to execute some perl snippet or set some
464 variables or whatever you need. All files C<require>'d or C<use>'d while
465 executing the snippet are included in the final bundle.
466
467 Keep in mind that F<mkbundle> will not import any symbols from the modules
468 named by the C<--use> option, so do not expect the symbols from modules
469 you C<--use>'d earlier on the command line to be available.
470
471 Example: force L<AnyEvent> to detect a backend and therefore include it
472 in the final bundle.
473
474 staticperl mkbundle --eval 'use AnyEvent; AnyEvent::detect'
475
476 # or like this
477 staticperl mkbundle -MAnyEvent --eval 'AnyEvent::detect'
478
479 Example: use a separate "bootstrap" script that C<use>'s lots of modules
480 and also include this in the final bundle, to be executed automatically
481 when the interpreter is initialised.
482
483 staticperl mkbundle --eval 'do "bootstrap"' --boot bootstrap
484
485 =item C<--boot> F<filename>
486
487 Include the given file in the bundle and arrange for it to be
488 executed (using C<require>) before the main program when the new perl
489 is initialised. This can be used to modify C<@INC> or do similar
490 modifications before the perl interpreter executes scripts given on the
491 command line (or via C<-e>). This works even in an embedded interpreter -
492 the file will be executed during interpreter initialisation in that case.
493
494 =item C<--incglob> pattern
495
496 This goes through all standard library directories and tries to match any
497 F<.pm> and F<.pl> files against the extended glob pattern (see below). If
498 a file matches, it is added. The pattern is matched against the full path
499 of the file (sans the library directory prefix), e.g. F<Sys/Syslog.pm>.
500
501 This is very useful to include "everything":
502
503 --incglob '*'
504
505 It is also useful for including perl libraries, or trees of those, such as
506 the unicode database files needed by some perl built-ins, the regex engine
507 and other modules.
508
509 --incglob '/unicore/**.pl'
510
511 =item C<--add> F<file> | C<--add> "F<file> alias"
512
513 Adds the given (perl) file into the bundle (and optionally call it
514 "alias"). The F<file> is either an absolute path or a path relative to the
515 current directory. If an alias is specified, then this is the name it will
516 use for C<@INC> searches, otherwise the path F<file> will be used as the
517 internal name.
518
519 This switch is used to include extra files into the bundle.
520
521 Example: embed the file F<httpd> in the current directory as F<httpd.pm>
522 when creating the bundle.
523
524 staticperl mkperl --add "httpd httpd.pm"
525
526 # can be accessed via "use httpd"
527
528 Example: add a file F<initcode> from the current directory.
529
530 staticperl mkperl --add 'initcode &initcode'
531
532 # can be accessed via "do '&initcode'"
533
534 Example: add local files as extra modules in the bundle.
535
536 # specification file
537 add file1 myfiles/file1.pm
538 add file2 myfiles/file2.pm
539 add file3 myfiles/file3.pl
540
541 # then later, in perl, use
542 use myfiles::file1;
543 require myfiles::file2;
544 my $res = do "myfiles/file3.pl";
545
546 =item C<--binadd> F<file> | C<--add> "F<file> alias"
547
548 Just like C<--add>, except that it treats the file as binary and adds it
549 without any postprocessing (perl files might get stripped to reduce their
550 size).
551
552 If you specify an alias you should probably add a C<&> prefix to avoid
553 clashing with embedded perl files (whose paths never start with C<&>),
554 and/or use a special directory prefix, such as C<&res/name>.
555
556 You can later get a copy of these files by calling C<staticperl::find
557 "alias">.
558
559 An alternative way to embed binary files is to convert them to perl and
560 use C<do> to get the contents - this method is a bit cumbersome, but works
561 both inside and outside of a staticperl bundle:
562
563 # a "binary" file, call it "bindata.pl"
564 <<'SOME_MARKER'
565 binary data NOT containing SOME_MARKER
566 SOME_MARKER
567
568 # load the binary
569 chomp (my $data = do "bindata.pl");
570
571 =back
572
573 =item Step 2: filter all files using C<--include> and C<--exclude> options.
574
575 After all candidate files and modules are added, they are I<filtered>
576 by a combination of C<--include> and C<--exclude> patterns (there is an
577 implicit C<--include *> at the end, so if no filters are specified, all
578 files are included).
579
580 All that this step does is potentially reduce the number of files that are
581 to be included - no new files are added during this step.
582
583 =over 4
584
585 =item C<--include> pattern | C<-i> pattern | C<--exclude> pattern | C<-x> pattern
586
587 These specify an include or exclude pattern to be applied to the candidate
588 file list. An include makes sure that the given files will be part of the
589 resulting file set, an exclude will exclude remaining files. The patterns
590 are "extended glob patterns" (see below).
591
592 The patterns are applied "in order" - files included via earlier
593 C<--include> specifications cannot be removed by any following
594 C<--exclude>, and likewise, and file excluded by an earlier C<--exclude>
595 cannot be added by any following C<--include>.
596
597 For example, to include everything except C<Devel> modules, but still
598 include F<Devel::PPPort>, you could use this:
599
600 --incglob '*' -i '/Devel/PPPort.pm' -x '/Devel/**'
601
602 =back
603
604 =item Step 3: add any extra or "hidden" dependencies.
605
606 F<staticperl> currently knows about three extra types of depdendencies
607 that are added automatically. Only one (F<.packlist> files) is currently
608 optional and can be influenced, the others are always included:
609
610 =over 4
611
612 =item C<--usepacklists>
613
614 Read F<.packlist> files for each distribution that happens to match a
615 module name you specified. Sounds weird, and it is, so expect semantics to
616 change somehow in the future.
617
618 The idea is that most CPAN distributions have a F<.pm> file that matches
619 the name of the distribution (which is rather reasonable after all).
620
621 If this switch is enabled, then if any of the F<.pm> files that have been
622 selected match an install distribution, then all F<.pm>, F<.pl>, F<.al>
623 and F<.ix> files installed by this distribution are also included.
624
625 For example, using this switch, when the L<URI> module is specified, then
626 all L<URI> submodules that have been installed via the CPAN distribution
627 are included as well, so you don't have to manually specify them.
628
629 =item L<AutoLoader> splitfiles
630
631 Some modules use L<AutoLoader> - less commonly (hopefully) used functions
632 are split into separate F<.al> files, and an index (F<.ix>) file contains
633 the prototypes.
634
635 Both F<.ix> and F<.al> files will be detected automatically and added to
636 the bundle.
637
638 =item link libraries (F<.a> files)
639
640 Modules using XS (or any other non-perl language extension compiled at
641 installation time) will have a static archive (typically F<.a>). These
642 will automatically be added to the linker options in F<bundle.ldopts>.
643
644 Should F<staticperl> find a dynamic link library (typically F<.so>) it
645 will warn about it - obviously this shouldn't happen unless you use
646 F<staticperl> on the wrong perl, or one (probably wrongly) configured to
647 use dynamic loading.
648
649 =item extra libraries (F<extralibs.ld>)
650
651 Some modules need linking against external libraries - these are found in
652 F<extralibs.ld> and added to F<bundle.ldopts>.
653
654 =back
655
656 =item Step 4: write bundle files and optionally link a program
657
658 At this point, the select files will be read, processed (stripped) and
659 finally the bundle files get written to disk, and F<staticperl mkbundle>
660 is normally finished. Optionally, it can go a step further and either link
661 a new F<perl> binary with all selected modules and files inside, or build
662 a standalone application.
663
664 Both the contents of the bundle files and any extra linking is controlled
665 by these options:
666
667 =over 4
668
669 =item C<--strip> C<none>|C<pod>|C<ppi>
670
671 Specify the stripping method applied to reduce the file of the perl
672 sources included.
673
674 The default is C<pod>, which uses the L<Pod::Strip> module to remove all
675 pod documentation, which is very fast and reduces file size a lot.
676
677 The C<ppi> method uses L<PPI> to parse and condense the perl sources. This
678 saves a lot more than just L<Pod::Strip>, and is generally safer,
679 but is also a lot slower (some files take almost a minute to strip -
680 F<staticperl> maintains a cache of stripped files to speed up subsequent
681 runs for this reason). Note that this method doesn't optimise for raw file
682 size, but for best compression (that means that the uncompressed file size
683 is a bit larger, but the files compress better, e.g. with F<upx>).
684
685 Last not least, if you need accurate line numbers in error messages,
686 or in the unlikely case where C<pod> is too slow, or some module gets
687 mistreated, you can specify C<none> to not mangle included perl sources in
688 any way.
689
690 =item C<--perl>
691
692 After writing out the bundle files, try to link a new perl interpreter. It
693 will be called F<perl> and will be left in the current working
694 directory. The bundle files will be removed.
695
696 This switch is automatically used when F<staticperl> is invoked with the
697 C<mkperl> command instead of C<mkbundle>.
698
699 Example: build a new F<./perl> binary with only L<common::sense> inside -
700 it will be even smaller than the standard perl interpreter as none of the
701 modules of the base distribution (such as L<Fcntl>) will be included.
702
703 staticperl mkperl -Mcommon::sense
704
705 =item C<--app> F<name>
706
707 After writing out the bundle files, try to link a new standalone
708 program. It will be called C<name>, and the bundle files get removed after
709 linking it.
710
711 This switch is automatically used when F<staticperl> is invoked with the
712 C<mkapp> command instead of C<mkbundle>.
713
714 The difference to the (mutually exclusive) C<--perl> option is that the
715 binary created by this option will not try to act as a perl interpreter -
716 instead it will simply initialise the perl interpreter, clean it up and
717 exit.
718
719 This means that, by default, it will do nothing but burn a few CPU cycles
720 - for it to do something useful you I<must> add some boot code, e.g. with
721 the C<--boot> option.
722
723 Example: create a standalone perl binary called F<./myexe> that will
724 execute F<appfile> when it is started.
725
726 staticperl mkbundle --app myexe --boot appfile
727
728 =item C<--ignore-env>
729
730 Generates extra code to unset some environment variables before
731 initialising/running perl. Perl supports a lot of environment variables
732 that might alter execution in ways that might be undesirablre for
733 standalone applications, and this option removes those known to cause
734 trouble.
735
736 Specifically, these are removed:
737
738 C<PERL_HASH_SEED_DEBUG> and C<PERL_DEBUG_MSTATS> can cause underaible
739 output, C<PERL5OPT>, C<PERL_DESTRUCT_LEVEL>, C<PERL_HASH_SEED> and
740 C<PERL_SIGNALS> can alter execution significantly, and C<PERL_UNICODE>,
741 C<PERLIO_DEBUG> and C<PERLIO> can affect input and output.
742
743 The variables C<PERL_LIB> and C<PERL5_LIB> are always ignored because the
744 startup code used by F<staticperl> overrides C<@INC> in all cases.
745
746 This option will not make your program more secure (unless you are
747 running with elevated privileges), but it will reduce the surprise effect
748 when a user has these environment variables set and doesn't expect your
749 standalone program to act like a perl interpreter.
750
751 =item C<--static>
752
753 Add C<-static> to F<bundle.ldopts>, which means a fully static (if
754 supported by the OS) executable will be created. This is not immensely
755 useful when just creating the bundle files, but is most useful when
756 linking a binary with the C<--perl> or C<--app> options.
757
758 The default is to link the new binary dynamically (that means all perl
759 modules are linked statically, but all external libraries are still
760 referenced dynamically).
761
762 Keep in mind that Solaris doesn't support static linking at all, and
763 systems based on GNU libc don't really support it in a very usable
764 fashion either. Try uClibc if you want to create fully statically linked
765 executables, or try the C<--staticlib> option to link only some libraries
766 statically.
767
768 =item C<--staticlib> libname
769
770 When not linking fully statically, this option allows you to link specific
771 libraries statically. What it does is simply replace all occurrences of
772 C<-llibname> with the GCC-specific C<-Wl,-Bstatic -llibname -Wl,-Bdynamic>
773 option.
774
775 This will have no effect unless the library is actually linked against,
776 specifically, C<--staticlib> will not link against the named library
777 unless it would be linked against anyway.
778
779 Example: link libcrypt statically into the final binary.
780
781 staticperl mkperl -MIO::AIO --staticlib crypt
782
783 # ldopts might now contain:
784 # -lm -Wl,-Bstatic -lcrypt -Wl,-Bdynamic -lpthread
785
786 =back
787
788 =back
789
790 =head3 EXTENDED GLOB PATTERNS
791
792 Some options of F<staticperl mkbundle> expect an I<extended glob
793 pattern>. This is neither a normal shell glob nor a regex, but something
794 in between. The idea has been copied from rsync, and there are the current
795 matching rules:
796
797 =over 4
798
799 =item Patterns starting with F</> will be a anchored at the root of the library tree.
800
801 That is, F</unicore> will match the F<unicore> directory in C<@INC>, but
802 nothing inside, and neither any other file or directory called F<unicore>
803 anywhere else in the hierarchy.
804
805 =item Patterns not starting with F</> will be anchored at the end of the path.
806
807 That is, F<idna.pl> will match any file called F<idna.pl> anywhere in the
808 hierarchy, but not any directories of the same name.
809
810 =item A F<*> matches anything within a single path component.
811
812 That is, F</unicore/*.pl> would match all F<.pl> files directly inside
813 C</unicore>, not any deeper level F<.pl> files. Or in other words, F<*>
814 will not match slashes.
815
816 =item A F<**> matches anything.
817
818 That is, F</unicore/**.pl> would match all F<.pl> files under F</unicore>,
819 no matter how deeply nested they are inside subdirectories.
820
821 =item A F<?> matches a single character within a component.
822
823 That is, F</Encode/??.pm> matches F</Encode/JP.pm>, but not the
824 hypothetical F</Encode/J/.pm>, as F<?> does not match F</>.
825
826 =back
827
828 =head2 F<STATICPERL> CONFIGURATION AND HOOKS
829
830 During (each) startup, F<staticperl> tries to source some shell files to
831 allow you to fine-tune/override configuration settings.
832
833 In them you can override shell variables, or define shell functions
834 ("hooks") to be called at specific phases during installation. For
835 example, you could define a C<postinstall> hook to install additional
836 modules from CPAN each time you start from scratch.
837
838 If the env variable C<$STATICPERLRC> is set, then F<staticperl> will try
839 to source the file named with it only. Otherwise, it tries the following
840 shell files in order:
841
842 /etc/staticperlrc
843 ~/.staticperlrc
844 $STATICPERL/rc
845
846 Note that the last file is erased during F<staticperl distclean>, so
847 generally should not be used.
848
849 =head3 CONFIGURATION VARIABLES
850
851 =head4 Variables you I<should> override
852
853 =over 4
854
855 =item C<EMAIL>
856
857 The e-mail address of the person who built this binary. Has no good
858 default, so should be specified by you.
859
860 =item C<CPAN>
861
862 The URL of the CPAN mirror to use (e.g. L<http://mirror.netcologne.de/cpan/>).
863
864 =item C<EXTRA_MODULES>
865
866 Additional modules installed during F<staticperl install>. Here you can
867 set which modules you want have to installed from CPAN.
868
869 Example: I really really need EV, AnyEvent, Coro and AnyEvent::AIO.
870
871 EXTRA_MODULES="EV AnyEvent Coro AnyEvent::AIO"
872
873 Note that you can also use a C<postinstall> hook to achieve this, and
874 more.
875
876 =back
877
878 =head4 Variables you might I<want> to override
879
880 =over 4
881
882 =item C<STATICPERL>
883
884 The directory where staticperl stores all its files
885 (default: F<~/.staticperl>).
886
887 =item C<DLCACHE>
888
889 The path to a directory (will be created if it doesn't exist) where
890 downloaded perl sources are being cached, to avoid downloading them
891 again. The default is empty, which means there is no cache.
892
893 =item C<PERL_VERSION>
894
895 The perl version to install - default is currently C<5.12.3>, but C<5.8.9>
896 is also a good choice (5.8.9 is much smaller than 5.12.3, while 5.10.1 is
897 about as big as 5.12.3).
898
899 =item C<PERL_MM_USE_DEFAULT>, C<EV_EXTRA_DEFS>, ...
900
901 Usually set to C<1> to make modules "less inquisitive" during their
902 installation. You can set (and export!) any environment variable you want
903 - some modules (such as L<Coro> or L<EV>) use environment variables for
904 further tweaking.
905
906 =item C<PERL_PREFIX>
907
908 The prefix where perl gets installed (default: F<$STATICPERL/perl>),
909 i.e. where the F<bin> and F<lib> subdirectories will end up.
910
911 =item C<PERL_CONFIGURE>
912
913 Additional Configure options - these are simply passed to the perl
914 Configure script. For example, if you wanted to enable dynamic loading,
915 you could pass C<-Dusedl>. To enable ithreads (Why would you want that
916 insanity? Don't! Use L<forks> instead!) you would pass C<-Duseithreads>
917 and so on.
918
919 More commonly, you would either activate 64 bit integer support
920 (C<-Duse64bitint>), or disable large files support (-Uuselargefiles), to
921 reduce filesize further.
922
923 =item C<PERL_CC>, C<PERL_CCFLAGS>, C<PERL_OPTIMIZE>, C<PERL_LDFLAGS>, C<PERL_LIBS>
924
925 These flags are passed to perl's F<Configure> script, and are generally
926 optimised for small size (at the cost of performance). Since they also
927 contain subtle workarounds around various build issues, changing these
928 usually requires understanding their default values - best look at
929 the top of the F<staticperl> script for more info on these, and use a
930 F<~/.staticperlrc> to override them.
931
932 Most of the variables override (or modify) the corresponding F<Configure>
933 variable, except C<PERL_CCFLAGS>, which gets appended.
934
935 You should have a look near the beginning of the F<staticperl> script -
936 staticperl tries to default C<PERL_OPTIMIZE> to some psace-saving options
937 suitable for newer gcc versions. For other compilers or older versions you
938 need to adjust these, for example, in your F<~/.staticperlrc>.
939
940 =back
941
942 =head4 Variables you probably I<do not want> to override
943
944 =over 4
945
946 =item C<MAKE>
947
948 The make command to use - default is C<make>.
949
950 =item C<MKBUNDLE>
951
952 Where F<staticperl> writes the C<mkbundle> command to
953 (default: F<$STATICPERL/mkbundle>).
954
955 =item C<STATICPERL_MODULES>
956
957 Additional modules needed by C<mkbundle> - should therefore not be changed
958 unless you know what you are doing.
959
960 =back
961
962 =head3 OVERRIDABLE HOOKS
963
964 In addition to environment variables, it is possible to provide some
965 shell functions that are called at specific times. To provide your own
966 commands, just define the corresponding function.
967
968 The actual order in which hooks are invoked during a full install
969 from scratch is C<preconfigure>, C<patchconfig>, C<postconfigure>,
970 C<postbuild>, C<postinstall>.
971
972 Example: install extra modules from CPAN and from some directories
973 at F<staticperl install> time.
974
975 postinstall() {
976 rm -rf lib/threads* # weg mit Schaden
977 instcpan IO::AIO EV
978 instsrc ~/src/AnyEvent
979 instsrc ~/src/XML-Sablotron-1.0100001
980 instcpan Anyevent::AIO AnyEvent::HTTPD
981 }
982
983 =over 4
984
985 =item preconfigure
986
987 Called just before running F<./Configure> in the perl source
988 directory. Current working directory is the perl source directory.
989
990 This can be used to set any C<PERL_xxx> variables, which might be costly
991 to compute.
992
993 =item patchconfig
994
995 Called after running F<./Configure> in the perl source directory to create
996 F<./config.sh>, but before running F<./Configure -S> to actually apply the
997 config. Current working directory is the perl source directory.
998
999 Can be used to tailor/patch F<config.sh> or do any other modifications.
1000
1001 =item postconfigure
1002
1003 Called after configuring, but before building perl. Current working
1004 directory is the perl source directory.
1005
1006 =item postbuild
1007
1008 Called after building, but before installing perl. Current working
1009 directory is the perl source directory.
1010
1011 I have no clue what this could be used for - tell me.
1012
1013 =item postinstall
1014
1015 Called after perl and any extra modules have been installed in C<$PREFIX>,
1016 but before setting the "installation O.K." flag.
1017
1018 The current working directory is C<$PREFIX>, but maybe you should not rely
1019 on that.
1020
1021 This hook is most useful to customise the installation, by deleting files,
1022 or installing extra modules using the C<instcpan> or C<instsrc> functions.
1023
1024 The script must return with a zero exit status, or the installation will
1025 fail.
1026
1027 =back
1028
1029 =head1 ANATOMY OF A BUNDLE
1030
1031 When not building a new perl binary, C<mkbundle> will leave a number of
1032 files in the current working directory, which can be used to embed a perl
1033 interpreter in your program.
1034
1035 Intimate knowledge of L<perlembed> and preferably some experience with
1036 embedding perl is highly recommended.
1037
1038 C<mkperl> (or the C<--perl> option) basically does this to link the new
1039 interpreter (it also adds a main program to F<bundle.>):
1040
1041 $Config{cc} $(cat bundle.ccopts) -o perl bundle.c $(cat bundle.ldopts)
1042
1043 =over 4
1044
1045 =item bundle.h
1046
1047 A header file that contains the prototypes of the few symbols "exported"
1048 by bundle.c, and also exposes the perl headers to the application.
1049
1050 =over 4
1051
1052 =item staticperl_init (xs_init = 0)
1053
1054 Initialises the perl interpreter. You can use the normal perl functions
1055 after calling this function, for example, to define extra functions or
1056 to load a .pm file that contains some initialisation code, or the main
1057 program function:
1058
1059 XS (xsfunction)
1060 {
1061 dXSARGS;
1062
1063 // now we have items, ST(i) etc.
1064 }
1065
1066 static void
1067 run_myapp(void)
1068 {
1069 staticperl_init (0);
1070 newXSproto ("myapp::xsfunction", xsfunction, __FILE__, "$$;$");
1071 eval_pv ("require myapp::main", 1); // executes "myapp/main.pm"
1072 }
1073
1074 When your bootcode already wants to access some XS functions at
1075 compiletime, then you need to supply an C<xs_init> function pointer that
1076 is called as soon as perl is initialised enough to define XS functions,
1077 but before the preamble code is executed:
1078
1079 static void
1080 xs_init (pTHX)
1081 {
1082 newXSproto ("myapp::xsfunction", xsfunction, __FILE__, "$$;$");
1083 }
1084
1085 static void
1086 run_myapp(void)
1087 {
1088 staticperl_init (xs_init);
1089 }
1090
1091 =item staticperl_cleanup ()
1092
1093 In the unlikely case that you want to destroy the perl interpreter, here
1094 is the corresponding function.
1095
1096 =item staticperl_xs_init (pTHX)
1097
1098 Sometimes you need direct control over C<perl_parse> and C<perl_run>, in
1099 which case you do not want to use C<staticperl_init> but call them on your
1100 own.
1101
1102 Then you need this function - either pass it directly as the C<xs_init>
1103 function to C<perl_parse>, or call it as one of the first things from your
1104 own C<xs_init> function.
1105
1106 =item PerlInterpreter *staticperl
1107
1108 The perl interpreter pointer used by staticperl. Not normally so useful,
1109 but there it is.
1110
1111 =back
1112
1113 =item bundle.ccopts
1114
1115 Contains the compiler options required to compile at least F<bundle.c> and
1116 any file that includes F<bundle.h> - you should probably use it in your
1117 C<CFLAGS>.
1118
1119 =item bundle.ldopts
1120
1121 The linker options needed to link the final program.
1122
1123 =back
1124
1125 =head1 RUNTIME FUNCTIONALITY
1126
1127 Binaries created with C<mkbundle>/C<mkperl> contain extra functions, which
1128 are required to access the bundled perl sources, but might be useful for
1129 other purposes.
1130
1131 In addition, for the embedded loading of perl files to work, F<staticperl>
1132 overrides the C<@INC> array.
1133
1134 =over 4
1135
1136 =item $file = staticperl::find $path
1137
1138 Returns the data associated with the given C<$path>
1139 (e.g. C<Digest/MD5.pm>, C<auto/POSIX/autosplit.ix>), which is basically
1140 the UNIX path relative to the perl library directory.
1141
1142 Returns C<undef> if the file isn't embedded.
1143
1144 =item @paths = staticperl::list
1145
1146 Returns the list of all paths embedded in this binary.
1147
1148 =back
1149
1150 =head1 FULLY STATIC BINARIES - UCLIBC AND BUILDROOT
1151
1152 To make truly static (Linux-) libraries, you might want to have a look at
1153 buildroot (L<http://buildroot.uclibc.org/>).
1154
1155 Buildroot is primarily meant to set up a cross-compile environment (which
1156 is not so useful as perl doesn't quite like cross compiles), but it can also compile
1157 a chroot environment where you can use F<staticperl>.
1158
1159 To do so, download buildroot, and enable "Build options => development
1160 files in target filesystem" and optionally "Build options => gcc
1161 optimization level (optimize for size)". At the time of writing, I had
1162 good experiences with GCC 4.4.x but not GCC 4.5.
1163
1164 To minimise code size, I used C<-pipe -ffunction-sections -fdata-sections
1165 -finline-limit=8 -fno-builtin-strlen -mtune=i386>. The C<-mtune=i386>
1166 doesn't decrease codesize much, but it makes the file much more
1167 compressible (and the execution a lot slower...).
1168
1169 If you don't need Coro or threads, you can go with "linuxthreads.old" (or
1170 no thread support). For Coro, it is highly recommended to switch to a
1171 uClibc newer than 0.9.31 (at the time of this writing, I used the 20101201
1172 snapshot) and enable NPTL, otherwise Coro needs to be configured with the
1173 ultra-slow pthreads backend to work around linuxthreads bugs (it also uses
1174 twice the address space needed for stacks).
1175
1176 If you use C<linuxthreads.old>, then you should also be aware that
1177 uClibc shares C<errno> between all threads when statically linking. See
1178 L<http://lists.uclibc.org/pipermail/uclibc/2010-June/044157.html> for a
1179 workaround (and L<https://bugs.uclibc.org/2089> for discussion).
1180
1181 C<ccache> support is also recommended, especially if you want
1182 to play around with buildroot options. Enabling the C<miniperl>
1183 package will probably enable all options required for a successful
1184 perl build. F<staticperl> itself additionally needs either C<wget>
1185 (recommended, for CPAN) or C<curl>.
1186
1187 As for shells, busybox should provide all that is needed, but the default
1188 busybox configuration doesn't include F<comm> which is needed by perl -
1189 either make a custom busybox config, or compile coreutils.
1190
1191 For the latter route, you might find that bash has some bugs that keep
1192 it from working properly in a chroot - either use dash (and link it to
1193 F</bin/sh> inside the chroot) or link busybox to F</bin/sh>, using it's
1194 built-in ash shell.
1195
1196 Finally, you need F</dev/null> inside the chroot for many scripts to work
1197 - either F<cp /dev/null output/target/dev> or bind-mounting your F</dev>
1198 will provide this.
1199
1200 After you have compiled and set up your buildroot target, you can copy
1201 F<staticperl> from the C<App::Staticperl> distribution or from your
1202 perl F<bin> directory (if you installed it) into the F<output/target>
1203 filesystem, chroot inside and run it.
1204
1205 =head1 RECIPES / SPECIFIC MODULES
1206
1207 This section contains some common(?) recipes and information about
1208 problems with some common modules or perl constructs that require extra
1209 files to be included.
1210
1211 =head2 MODULES
1212
1213 =over 4
1214
1215 =item utf8
1216
1217 Some functionality in the utf8 module, such as swash handling (used
1218 for unicode character ranges in regexes) is implemented in the
1219 C<"utf8_heavy.pl"> library:
1220
1221 -Mutf8_heavy.pl
1222
1223 Many Unicode properties in turn are defined in separate modules,
1224 such as C<"unicore/Heavy.pl"> and more specific data tables such as
1225 C<"unicore/To/Digit.pl"> or C<"unicore/lib/Perl/Word.pl">. These tables
1226 are big (7MB uncompressed, although F<staticperl> contains special
1227 handling for those files), so including them on demand by your application
1228 only might pay off.
1229
1230 To simply include the whole unicode database, use:
1231
1232 --incglob '/unicore/**.pl'
1233
1234 =item AnyEvent
1235
1236 AnyEvent needs a backend implementation that it will load in a delayed
1237 fashion. The L<AnyEvent::Impl::Perl> backend is the default choice
1238 for AnyEvent if it can't find anything else, and is usually a safe
1239 fallback. If you plan to use e.g. L<EV> (L<POE>...), then you need to
1240 include the L<AnyEvent::Impl::EV> (L<AnyEvent::Impl::POE>...) backend as
1241 well.
1242
1243 If you want to handle IRIs or IDNs (L<AnyEvent::Util> punycode and idn
1244 functions), you also need to include C<"AnyEvent/Util/idna.pl"> and
1245 C<"AnyEvent/Util/uts46data.pl">.
1246
1247 Or you can use C<--usepacklists> and specify C<-MAnyEvent> to include
1248 everything.
1249
1250 =item Cairo
1251
1252 See Glib, same problem, same solution.
1253
1254 =item Carp
1255
1256 Carp had (in older versions of perl) a dependency on L<Carp::Heavy>. As of
1257 perl 5.12.2 (maybe earlier), this dependency no longer exists.
1258
1259 =item Config
1260
1261 The F<perl -V> switch (as well as many modules) needs L<Config>, which in
1262 turn might need L<"Config_heavy.pl">. Including the latter gives you
1263 both.
1264
1265 =item Glib
1266
1267 Glib literally requires Glib to be installed already to build - it tries
1268 to fake this by running Glib out of the build directory before being
1269 built. F<staticperl> tries to work around this by forcing C<MAN1PODS> and
1270 C<MAN3PODS> to be empty via the C<PERL_MM_OPT> environment variable.
1271
1272 =item Gtk2
1273
1274 See Pango, same problems, same solution.
1275
1276 =item Pango
1277
1278 In addition to the C<MAN3PODS> problem in Glib, Pango also routes around
1279 L<ExtUtils::MakeMaker> by compiling its files on its own. F<staticperl>
1280 tries to patch L<ExtUtils::MM_Unix> to route around Pango.
1281
1282 =item Term::ReadLine::Perl
1283
1284 Also needs L<Term::ReadLine::readline>, or C<--usepacklists>.
1285
1286 =item URI
1287
1288 URI implements schemes as separate modules - the generic URL scheme is
1289 implemented in L<URI::_generic>, HTTP is implemented in L<URI::http>. If
1290 you need to use any of these schemes, you should include these manually,
1291 or use C<--usepacklists>.
1292
1293 =back
1294
1295 =head2 RECIPES
1296
1297 =over 4
1298
1299 =item Just link everything in
1300
1301 To link just about everything installed in the perl library into a new
1302 perl, try this (the first time this runs it will take a long time, as a
1303 lot of files need to be parsed):
1304
1305 staticperl mkperl -v --strip ppi --incglob '*'
1306
1307 If you don't mind the extra megabytes, this can be a very effective way of
1308 creating bundles without having to worry about forgetting any modules.
1309
1310 You get even more useful variants of this method by first selecting
1311 everything, and then excluding stuff you are reasonable sure not to need -
1312 L<bigperl|http://staticperl.schmorp.de/bigperl.html> uses this approach.
1313
1314 =item Getting rid of netdb functions
1315
1316 The perl core has lots of netdb functions (C<getnetbyname>, C<getgrent>
1317 and so on) that few applications use. You can avoid compiling them in by
1318 putting the following fragment into a C<preconfigure> hook:
1319
1320 preconfigure() {
1321 for sym in \
1322 d_getgrnam_r d_endgrent d_endgrent_r d_endhent \
1323 d_endhostent_r d_endnent d_endnetent_r d_endpent \
1324 d_endprotoent_r d_endpwent d_endpwent_r d_endsent \
1325 d_endservent_r d_getgrent d_getgrent_r d_getgrgid_r \
1326 d_getgrnam_r d_gethbyaddr d_gethent d_getsbyport \
1327 d_gethostbyaddr_r d_gethostbyname_r d_gethostent_r \
1328 d_getlogin_r d_getnbyaddr d_getnbyname d_getnent \
1329 d_getnetbyaddr_r d_getnetbyname_r d_getnetent_r \
1330 d_getpent d_getpbyname d_getpbynumber d_getprotobyname_r \
1331 d_getprotobynumber_r d_getprotoent_r d_getpwent \
1332 d_getpwent_r d_getpwnam_r d_getpwuid_r d_getsent \
1333 d_getservbyname_r d_getservbyport_r d_getservent_r \
1334 d_getspnam_r d_getsbyname
1335 # d_gethbyname
1336 do
1337 PERL_CONFIGURE="$PERL_CONFIGURE -U$sym"
1338 done
1339 }
1340
1341 This mostly gains space when linking statically, as the functions will
1342 likely not be linked in. The gain for dynamically-linked binaries is
1343 smaller.
1344
1345 Also, this leaves C<gethostbyname> in - not only is it actually used
1346 often, the L<Socket> module also exposes it, so leaving it out usually
1347 gains little. Why Socket exposes a C function that is in the core already
1348 is anybody's guess.
1349
1350 =back
1351
1352 =head1 AUTHOR
1353
1354 Marc Lehmann <schmorp@schmorp.de>
1355 http://software.schmorp.de/pkg/staticperl.html