1 If you read this file _as_is_, just ignore the funny characters you see.
2 It is written in the POD format (see pod/perlpod.pod) which is specially
3 designed to be readable as is.
7 Install - Build and Installation guide for perl5.
9 =head1 Reporting Problems
11 Wherever possible please use the perlbug tool supplied with this Perl
12 to report problems, as it automatically includes summary configuration
13 information about your perl, which may help us track down problems far
14 more quickly. But first you should read the advice in this file,
15 carefully re-read the error message and check the relevant manual pages
16 on your system, as these may help you find an immediate solution. If
17 you are not sure whether what you are seeing is a bug, you can send a
18 message describing the problem to the comp.lang.perl.misc newsgroup to
21 The perlbug tool is installed along with perl, so after you have
22 completed C<make install> it should be possible to run it with plain
23 C<perlbug>. If the install fails, or you want to report problems with
24 C<make test> without installing perl, then you can use C<make nok> to
25 run perlbug to report the problem, or run it by hand from this source
26 directory with C<./perl -Ilib utils/perlbug>
28 If the build fails too early to run perlbug uninstalled, then please
29 B<run> the C<./myconfig> shell script, and mail its output along with
30 an accurate description of your problem to perlbug@perl.org
32 If Configure itself fails, and does not generate a config.sh file
33 (needed to run C<./myconfig>), then please mail perlbug@perl.org the
34 description of how Configure fails along with details of your system
35 - for example the output from running C<uname -a>
37 Please try to make your message brief but clear. Brief, clear bug
38 reports tend to get answered more quickly. Please don't worry if your
39 written English is not great - what matters is how well you describe
40 the important technical details of the problem you have encountered,
41 not whether your grammar and spelling is flawless.
43 Trim out unnecessary information. Do not include large files (such as
44 config.sh or a complete Configure or make log) unless absolutely
45 necessary. Do not include a complete transcript of your build
46 session. Just include the failing commands, the relevant error
47 messages, and whatever preceding commands are necessary to give the
48 appropriate context. Plain text should usually be sufficient--fancy
49 attachments or encodings may actually reduce the number of people who
50 read your message. Your message will get relayed to over 400
51 subscribers around the world so please try to keep it brief but clear.
53 If you are unsure what makes a good bug report please read "How to
54 report Bugs Effectively" by Simon Tatham:
55 http://www.chiark.greenend.org.uk/~sgtatham/bugs.html
59 First, make sure you have an up-to-date version of Perl. If you
60 didn't get your Perl source from CPAN, check the latest version at
61 http://www.cpan.org/src/. Perl uses a version scheme where even-numbered
62 subreleases (like 5.6.x and 5.8.x) are stable maintenance releases and
63 odd-numbered subreleases (like 5.7.x and 5.9.x) are unstable
64 development releases. Development releases should not be used in
65 production environments. Fixes and new features are first carefully
66 tested in development releases and only if they prove themselves to be
67 worthy will they be migrated to the maintenance releases.
69 The basic steps to build and install perl5 on a Unix system with all
72 rm -f config.sh Policy.sh
78 Each of these is explained in further detail below.
80 The above commands will install Perl to /usr/local (or some other
81 platform-specific directory -- see the appropriate file in hints/.)
82 If that's not okay with you, can run Configure interactively and use
84 rm -f config.sh Policy.sh
90 # You may also wish to add these:
91 (cd /usr/include && h2ph *.h sys/*.h)
93 (cd pod && make tex && <process the latex files>)
95 or you can use some of the Configure options described below.
97 If you have problems, corrections, or questions, please see
98 L<"Reporting Problems"> above.
100 For information on what's new in this release, see the
101 pod/perldelta.pod file. For more detailed information about specific
102 changes, see the Changes file.
106 This document is written in pod format as an easy way to indicate its
107 structure. The pod format is described in pod/perlpod.pod, but you can
108 read it as is with any pager or editor. Headings and items are marked
109 by lines beginning with '='. The other mark-up used is
111 B<text> embolden text, used for switches, programs or commands
113 L<name> A link (cross reference) to name
116 Although most of the defaults are probably fine for most users,
117 you should probably at least skim through this document before
120 In addition to this file, check if there is a README file specific to
121 your operating system, since it may provide additional or different
122 instructions for building Perl. If there is a hint file for your
123 system (in the hints/ directory) you should also read that hint file
124 for even more information. (Unixware users should use the svr4.sh or
125 the svr5.sh hint file.)
127 For additional information about porting Perl, see the section on
128 L<"Porting information"> below, and look at the files in the Porting/
133 =head2 Changes and Incompatibilities
135 Please see pod/perldelta.pod for a description of the changes and
136 potential incompatibilities introduced with this release. A few of
137 the most important issues are listed below, but you should refer
138 to pod/perldelta.pod for more detailed information.
140 =head3 WARNING: This version is not binary compatible with releases of
143 If you have built extensions (i.e. modules that include C code)
144 using an earlier version of Perl, you will need to rebuild and reinstall
147 Pure perl modules without XS or C code should continue to work fine
148 without reinstallation. See the discussions below on
149 L<"Coexistence with earlier versions of perl5"> and
150 L<"Upgrading from 5.005 or 5.6 to 5.8.0"> for more details.
152 The standard extensions supplied with Perl will be handled automatically.
154 On a related issue, old modules may possibly be affected by the changes
155 in the Perl language in the current release. Please see
156 pod/perldelta.pod for a description of what's changed. See your
157 installed copy of the perllocal.pod file for a (possibly incomplete)
158 list of locally installed modules. Also see CPAN::autobundle for one
159 way to make a "bundle" of your currently installed modules.
161 =head2 Space Requirements
163 The complete perl5 source tree takes up about 60 MB of disk space.
164 After completing make, it takes up roughly 100 MB, though the actual
165 total is likely to be quite system-dependent. The installation
166 directories need something on the order of 50 MB, though again that
167 value is quite system-dependent.
169 =head1 Start with a Fresh Distribution
171 If you have built perl before, you should clean out the build directory
180 The only difference between the two is that make distclean also removes
181 your old config.sh and Policy.sh files.
183 The results of a Configure run are stored in the config.sh and Policy.sh
184 files. If you are upgrading from a previous version of perl, or if you
185 change systems or compilers or make other significant changes, or if
186 you are experiencing difficulties building perl, you should probably
187 not re-use your old config.sh. Simply remove it
191 If you wish to use your old config.sh, be especially attentive to the
192 version and architecture-specific questions and answers. For example,
193 the default directory for architecture-dependent library modules
194 includes the version name. By default, Configure will reuse your old
195 name (e.g. /opt/perl/lib/i86pc-solaris/5.003) even if you're running
196 Configure for a different version, e.g. 5.004. Similarly, if you used
197 a shared libperl.so (see below) with version numbers, you will probably
198 want to adjust them as well.
200 Also, be careful to check your architecture name. For example, some
201 Linux distributions use i386, but Configure uses the output of the arch
202 command, which might be i686 instead. If you pick up a precompiled
203 binary, or compile extensions on different systems, they might not all
204 agree on the architecture name.
206 In short, if you wish to use your old config.sh, I recommend running
207 Configure interactively rather than blindly accepting the defaults.
209 If your reason to reuse your old config.sh is to save your particular
210 installation choices, then you can probably achieve the same effect by
211 using the Policy.sh file. See the section on L<"Site-wide Policy
212 settings"> below. If you wish to start with a fresh distribution, you
213 also need to remove any old Policy.sh files you may have with
219 Configure will figure out various things about your system. Some
220 things Configure will figure out for itself, other things it will ask
221 you about. To accept the default, just press RETURN. The default is
222 almost always okay. It is normal for some things to be "NOT found",
223 since Configure often searches for many different ways of performing
226 At any Configure prompt, you can type &-d and Configure will use the
227 defaults from then on.
229 After it runs, Configure will perform variable substitution on all the
230 *.SH files and offer to run make depend.
232 =head2 Common Configure options
234 Configure supports a number of useful options. Run
238 to get a listing. See the Porting/Glossary file for a complete list of
239 Configure variables you can set and their definitions.
245 To compile with gcc you should run
247 sh Configure -Dcc=gcc
249 This is the preferred way to specify gcc (or another alternative
250 compiler) so that the hints files can set appropriate defaults.
252 =item Installation prefix
254 By default, for most systems, perl will be installed in
255 /usr/local/{bin, lib, man}. (See L<"Installation Directories">
256 and L<"Coexistence with earlier versions of perl5"> below for
259 You can specify a different 'prefix' for the default installation
260 directory when Configure prompts you, or by using the Configure command
261 line option -Dprefix='/some/directory', e.g.
263 sh Configure -Dprefix=/opt/perl
265 If your prefix contains the string "perl", then the suggested
266 directory structure is simplified. For example, if you use
267 prefix=/opt/perl, then Configure will suggest /opt/perl/lib instead of
268 /opt/perl/lib/perl5/. Again, see L<"Installation Directories"> below
269 for more details. Do not include a trailing slash, (i.e. /opt/perl/)
270 or you may experience odd test failures.
272 NOTE: You must not specify an installation directory that is the same
273 as or below your perl source directory. If you do, installperl will
274 attempt infinite recursion.
278 It may seem obvious, but Perl is useful only when users can easily
279 find it. It's often a good idea to have both /usr/bin/perl and
280 /usr/local/bin/perl be symlinks to the actual binary. Be especially
281 careful, however, not to overwrite a version of perl supplied by your
282 vendor unless you are sure you know what you are doing. If you insist
283 on replacing your vendor's perl, useful information on how it was
284 configured may be found with
288 (Check the output carefully, however, since this doesn't preserve
289 spaces in arguments to Configure. For that, you have to look carefully
290 at config_arg1, config_arg2, etc.)
292 By default, Configure will not try to link /usr/bin/perl to the current
293 version of perl. You can turn on that behavior by running
295 Configure -Dinstallusrbinperl
297 or by answering 'yes' to the appropriate Configure prompt.
299 In any case, system administrators are strongly encouraged to put
300 (symlinks to) perl and its accompanying utilities, such as perldoc,
301 into a directory typically found along a user's PATH, or in another
302 obvious and convenient place.
304 =item Building a development release.
306 For development releases (odd subreleases, like 5.9.x) if you want to
307 use Configure -d, you will also need to supply -Dusedevel to Configure,
308 because the default answer to the question "do you really want to
309 Configure a development version?" is "no". The -Dusedevel skips that
314 If you are willing to accept all the defaults, and you want terse
319 For example for my Solaris/x86 system, I usually use
321 sh Configure -Dprefix=/opt/perl -Doptimize='-xpentium -xO4' -des
323 =head2 Altering config.sh variables for C compiler switches etc.
325 For most users, most of the Configure defaults are fine, or can easily
326 be set on the Configure command line. However, if Configure doesn't
327 have an option to do what you want, you can change Configure variables
328 after the platform hints have been run by using Configure's -A switch.
329 For example, here's how to add a couple of extra flags to C compiler
332 sh Configure -Accflags="-DPERL_EXTERNAL_GLOB -DPERL_POLLUTE_MALLOC"
334 To clarify, those ccflags values are not Configure options; if passed to
335 Configure directly, they won't do anything useful (that will define a config.sh
336 variable, but without taking any action based upon it). When passed to the
337 compiler, those flags will activate #ifdefd code.
339 For more help on Configure switches, run
343 =head2 Major Configure-time Build Options
345 There are several different ways to Configure and build perl for your
346 system. For most users, the defaults are sensible and will work.
347 Some users, however, may wish to further customize perl. Here are
348 some of the main things you can change.
352 On some platforms, perl can be compiled with support for threads. To
355 sh Configure -Dusethreads
357 Currently, you need to specify -Dusethreads on the Configure command
358 line so that the hint files can make appropriate adjustments.
360 The default is to compile without thread support.
362 Perl has two different internal threads implementations. The current
363 model (available internally since 5.6, and as a user-level module since
364 5.8) is called interpreter-based implementation (ithreads), with one
365 interpreter per thread, and explicit sharing of data. The 5.005
366 version (5005threads) is considered obsolete, buggy, and unmaintained.
368 By default, Configure selects ithreads if -Dusethreads is specified.
370 However, if you insist, you can select the unsupported old 5005threads behavior
372 sh Configure -Dusethreads -Duse5005threads
374 The 'threads' module is for use with the ithreads implementation. The
375 'Thread' module offers an interface to either 5005threads or ithreads
376 (whichever has been configured).
378 When using threads, perl uses a dynamically-sized buffer for some of
379 the thread-safe library calls, such as those in the getpw*() family.
380 This buffer starts small, but it will keep growing until the result
381 fits. To get a fixed upper limit, you should compile Perl with
382 PERL_REENTRANT_MAXSIZE defined to be the number of bytes you want. One
383 way to do this is to run Configure with
384 C<-Accflags=-DPERL_REENTRANT_MAXSIZE=65536>
386 =head3 Large file support.
388 Since Perl 5.6.0, Perl has supported large files (files larger than
389 2 gigabytes), and in many common platforms like Linux or Solaris this
390 support is on by default.
392 This is both good and bad. It is good in that you can use large files,
393 seek(), stat(), and -s them. It is bad in that if you are interfacing Perl
394 using some extension, the components you are connecting to must also
395 be large file aware: if Perl thinks files can be large but the other
396 parts of the software puzzle do not understand the concept, bad things
397 will happen. One popular extension suffering from this ailment is the
398 Apache extension mod_perl.
400 There's also one known limitation with the current large files
401 implementation: unless you also have 64-bit integers (see the next
402 section), you cannot use the printf/sprintf non-decimal integer formats
403 like C<%x> to print filesizes. You can use C<%d>, though.
405 =head3 64 bit support.
407 If your platform does not have run natively at 64 bits, but can
408 simulate them with compiler flags and/or C<long long> or C<int64_t>,
409 you can build a perl that uses 64 bits.
411 There are actually two modes of 64-bitness: the first one is achieved
412 using Configure -Duse64bitint and the second one using Configure
413 -Duse64bitall. The difference is that the first one is minimal and
414 the second one maximal. The first works in more places than the second.
416 The C<use64bitint> option does only as much as is required to get
417 64-bit integers into Perl (this may mean, for example, using "long
418 longs") while your memory may still be limited to 2 gigabytes (because
419 your pointers could still be 32-bit). Note that the name C<64bitint>
420 does not imply that your C compiler will be using 64-bit C<int>s (it
421 might, but it doesn't have to). The C<use64bitint> simply means that
422 you will be able to have 64 bit-wide scalar values.
424 The C<use64bitall> option goes all the way by attempting to switch
425 integers (if it can), longs (and pointers) to being 64-bit. This may
426 create an even more binary incompatible Perl than -Duse64bitint: the
427 resulting executable may not run at all in a 32-bit box, or you may
428 have to reboot/reconfigure/rebuild your operating system to be 64-bit
431 Natively 64-bit systems like Alpha and Cray need neither -Duse64bitint
434 NOTE: 64-bit support is still experimental on most platforms.
435 Existing support only covers the LP64 data model. In particular, the
436 LLP64 data model is not yet supported. 64-bit libraries and system
437 APIs on many platforms have not stabilized--your mileage may vary.
441 In some systems you may be able to use long doubles to enhance the
442 range and precision of your double precision floating point numbers
443 (that is, Perl's numbers). Use Configure -Duselongdouble to enable
444 this support (if it is available).
448 You can "Configure -Dusemorebits" to turn on both the 64-bit support
449 and the long double support.
451 =head3 Selecting File IO mechanisms
453 Executive summary: as of Perl 5.8, you should use the default "PerlIO"
454 as the IO mechanism unless you have a good reason not to.
456 In more detail: previous versions of perl used the standard IO
457 mechanisms as defined in stdio.h. Versions 5.003_02 and later of perl
458 introduced alternate IO mechanisms via a "PerlIO" abstraction, but up
459 until and including Perl 5.6, the stdio mechanism was still the default
460 and the only supported mechanism.
462 Starting from Perl 5.8, the default mechanism is to use the PerlIO
463 abstraction, because it allows better control of I/O mechanisms,
464 instead of having to work with (often, work around) vendors' I/O
467 This PerlIO abstraction can be (but again, unless you know what you
468 are doing, should not be) disabled either on the Configure command
471 sh Configure -Uuseperlio
473 or interactively at the appropriate Configure prompt.
475 =head3 Algorithmic Complexity Attacks on Hashes
477 In Perls 5.8.0 and earlier it was easy to create degenerate hashes.
478 Processing such hashes would consume large amounts of CPU time,
479 enabling a "Denial of Service" attack against Perl. Such hashes may be
480 a problem for example for mod_perl sites, sites with Perl CGI scripts
481 and web services, that process data originating from external sources.
483 In Perl 5.8.1 a security feature was introduced to make it harder to
484 create such degenerate hashes. A visible side effect of this was that
485 the keys(), values(), and each() functions may return the hash elements
486 in different order between different runs of Perl even with the same
487 data. It also had unintended binary incompatibility issues with
488 certain modules compiled against Perl 5.8.0.
490 In Perl 5.8.2 an improved scheme was introduced. Hashes will return
491 elements in the same order as Perl 5.8.0 by default. On a hash by hash
492 basis, if pathological data is detected during a hash key insertion,
493 then that hash will switch to an alternative random hash seed. As
494 adding keys can always dramatically change returned hash element order,
495 existing programs will not be affected by this, unless they
496 specifically test for pre-recorded hash return order for contrived
497 data. (eg the list of keys generated by C<map {"\0"x$_} 0..15> trigger
498 randomisation) In effect the new implementation means that 5.8.1 scheme
499 is only being used on hashes which are under attack.
501 One can still revert to the old guaranteed repeatable order (and be
502 vulnerable to attack by wily crackers) by setting the environment
503 variable PERL_HASH_SEED, see L<perlrun/PERL_HASH_SEED>. Another option
504 is to add -DUSE_HASH_SEED_EXPLICIT to the compilation flags (for
505 example by using C<Configure -Accflags=-DUSE_HASH_SEED_EXPLICIT>), in
506 which case one has to explicitly set the PERL_HASH_SEED environment
507 variable to enable the security feature, or by adding -DNO_HASH_SEED to
508 the compilation flags to completely disable the randomisation feature.
510 B<Perl has never guaranteed any ordering of the hash keys>, and the
511 ordering has already changed several times during the lifetime of Perl
512 5. Also, the ordering of hash keys has always been, and continues to
513 be, affected by the insertion order. It is likely that Perl 5.10 and
514 Perl 6 will randomise all hashes. Note that because of this
515 randomisation for example the Data::Dumper results will be different
516 between different runs of Perl since Data::Dumper by default dumps
517 hashes "unordered". The use of the Data::Dumper C<Sortkeys> option is
522 Perl can be configured to be 'socksified', that is, to use the SOCKS
523 TCP/IP proxy protocol library. SOCKS is used to give applications
524 access to transport layer network proxies. Perl supports only SOCKS
525 Version 5. You can find more about SOCKS from http://www.socks.nec.com/
527 =head3 Dynamic Loading
529 By default, Configure will compile perl to use dynamic loading if
530 your system supports it. If you want to force perl to be compiled
531 statically, you can either choose this when Configure prompts you or
532 you can use the Configure command line option -Uusedl.
534 =head3 Building a shared Perl library
536 Currently, for most systems, the main perl executable is built by
537 linking the "perl library" libperl.a with perlmain.o, your static
538 extensions, and various extra libraries, such as -lm.
540 On some systems that support dynamic loading, it may be possible to
541 replace libperl.a with a shared libperl.so. If you anticipate building
542 several different perl binaries (e.g. by embedding libperl into
543 different programs, or by using the optional compiler extension), then
544 you might wish to build a shared libperl.so so that all your binaries
545 can share the same library.
547 The disadvantages are that there may be a significant performance
548 penalty associated with the shared libperl.so, and that the overall
549 mechanism is still rather fragile with respect to different versions
552 In terms of performance, on my test system (Solaris 2.5_x86) the perl
553 test suite took roughly 15% longer to run with the shared libperl.so.
554 Your system and typical applications may well give quite different
557 The default name for the shared library is typically something like
558 libperl.so.6.2 (for Perl 5.6.2), or libperl.so.602, or simply
559 libperl.so. Configure tries to guess a sensible naming convention
560 based on your C library name. Since the library gets installed in a
561 version-specific architecture-dependent directory, the exact name
562 isn't very important anyway, as long as your linker is happy.
564 For some systems (mostly SVR4), building a shared libperl is required
565 for dynamic loading to work, and hence is already the default.
567 You can elect to build a shared libperl by
569 sh Configure -Duseshrplib
571 To build a shared libperl, the environment variable controlling shared
572 library search (LD_LIBRARY_PATH in most systems, DYLD_LIBRARY_PATH for
573 NeXTSTEP/OPENSTEP/Darwin, LIBRARY_PATH for BeOS, LD_LIBRARY_PATH/SHLIB_PATH
574 for HP-UX, LIBPATH for AIX, PATH for Cygwin) must be set up to include
575 the Perl build directory because that's where the shared libperl will
576 be created. Configure arranges makefile to have the correct shared
577 library search settings. You can find the name of the environment
578 variable Perl thinks works in your your system by
580 grep ldlibpthname config.sh
582 However, there are some special cases where manually setting the
583 shared library path might be required. For example, if you want to run
584 something like the following with the newly-built but not-yet-installed
587 cd t; ./perl misc/failing_test.t
589 ./perl -Ilib ~/my_mission_critical_test
591 then you need to set up the shared library path explicitly.
594 LD_LIBRARY_PATH=`pwd`:$LD_LIBRARY_PATH; export LD_LIBRARY_PATH
596 for Bourne-style shells, or
598 setenv LD_LIBRARY_PATH `pwd`
600 for Csh-style shells. (This procedure may also be needed if for some
601 unexpected reason Configure fails to set up makefile correctly.) (And
602 again, it may be something other than LD_LIBRARY_PATH for you, see above.)
604 You can often recognize failures to build/use a shared libperl from error
605 messages complaining about a missing libperl.so (or libperl.sl in HP-UX),
607 18126:./miniperl: /sbin/loader: Fatal Error: cannot map libperl.so
609 There is also an potential problem with the shared perl library if you
610 want to have more than one "flavor" of the same version of perl (e.g.
611 with and without -DDEBUGGING). For example, suppose you build and
612 install a standard Perl 5.8.0 with a shared library. Then, suppose you
613 try to build Perl 5.8.0 with -DDEBUGGING enabled, but everything else
614 the same, including all the installation directories. How can you
615 ensure that your newly built perl will link with your newly built
616 libperl.so.8 rather with the installed libperl.so.8? The answer is
617 that you might not be able to. The installation directory is encoded
618 in the perl binary with the LD_RUN_PATH environment variable (or
619 equivalent ld command-line option). On Solaris, you can override that
620 with LD_LIBRARY_PATH; on Linux, you can only override at runtime via
621 LD_PRELOAD, specifying the exact filename you wish to be used; and on
622 Digital Unix, you can override LD_LIBRARY_PATH by setting the
623 _RLD_ROOT environment variable to point to the perl build directory.
625 In other words, it is generally not a good idea to try to build a perl
626 with a shared library if $archlib/CORE/$libperl already exists from a
629 A good workaround is to specify a different directory for the
630 architecture-dependent library for your -DDEBUGGING version of perl.
631 You can do this by changing all the *archlib* variables in config.sh to
632 point to your new architecture-dependent library.
634 =head3 Environment access
636 Perl often needs to write to the program's environment, such as when C<%ENV>
637 is assigned to. Many implementations of the C library function C<putenv()>
638 leak memory, so where possible perl will manipulate the environment directly
639 to avoid these leaks. The default is now to perform direct manipulation
640 whenever perl is running as a stand alone interpreter, and to call the safe
641 but potentially leaky C<putenv()> function when the perl interpreter is
642 embedded in another application. You can force perl to always use C<putenv()>
643 by compiling with -DPERL_USE_SAFE_PUTENV. You can force an embedded perl to
644 use direct manipulation by setting C<PL_use_safe_putenv = 0;> after the
645 C<perl_construct()> call.
647 =head2 Installation Directories
649 The installation directories can all be changed by answering the
650 appropriate questions in Configure. For convenience, all the installation
651 questions are near the beginning of Configure. Do not include trailing
652 slashes on directory names. At any point during the Configure process,
653 you can answer a question with &-d and Configure will use the defaults
654 from then on. Alternatively, you can
656 grep '^install' config.sh
658 after Configure has run to verify the installation paths.
660 The defaults are intended to be reasonable and sensible for most
661 people building from sources. Those who build and distribute binary
662 distributions or who export perl to a range of systems will probably
663 need to alter them. If you are content to just accept the defaults,
664 you can safely skip the next section.
666 The directories set up by Configure fall into three broad categories.
670 =item Directories for the perl distribution
672 By default, Configure will use the following directories for 5.9.0.
673 $version is the full perl version number, including subversion, e.g.
674 5.9.0 or 5.9.1, and $archname is a string like sun4-sunos,
675 determined by Configure. The full definitions of all Configure
676 variables are in the file Porting/Glossary.
678 Configure variable Default value
679 $prefixexp /usr/local
680 $binexp $prefixexp/bin
681 $scriptdirexp $prefixexp/bin
682 $privlibexp $prefixexp/lib/perl5/$version
683 $archlibexp $prefixexp/lib/perl5/$version/$archname
684 $man1direxp $prefixexp/man/man1
685 $man3direxp $prefixexp/man/man3
689 $prefixexp is generated from $prefix, with ~ expansion done to convert home
690 directories into absolute paths. Similarly for the other variables listed. As
691 file system calls do not do this, you should always reference the ...exp
692 variables, to support users who build perl in their home directory.
694 Actually, Configure recognizes the SVR3-style
695 /usr/local/man/l_man/man1 directories, if present, and uses those
696 instead. Also, if $prefix contains the string "perl", the library
697 directories are simplified as described below. For simplicity, only
698 the common style is shown here.
700 =item Directories for site-specific add-on files
702 After perl is installed, you may later wish to add modules (e.g. from
703 CPAN) or scripts. Configure will set up the following directories to
704 be used for installing those add-on modules and scripts.
706 Configure variable Default value
707 $siteprefixexp $prefixexp
708 $sitebinexp $siteprefixexp/bin
709 $sitescriptexp $siteprefixexp/bin
710 $sitelibexp $siteprefixexp/lib/perl5/site_perl/$version
711 $sitearchexp $siteprefixexp/lib/perl5/site_perl/$version/$archname
712 $siteman1direxp $siteprefixexp/man/man1
713 $siteman3direxp $siteprefixexp/man/man3
714 $sitehtml1direxp (none)
715 $sitehtml3direxp (none)
717 By default, ExtUtils::MakeMaker will install architecture-independent
718 modules into $sitelib and architecture-dependent modules into $sitearch.
720 =item Directories for vendor-supplied add-on files
722 Lastly, if you are building a binary distribution of perl for
723 distribution, Configure can optionally set up the following directories
724 for you to use to distribute add-on modules.
726 Configure variable Default value
727 $vendorprefixexp (none)
728 (The next ones are set only if vendorprefix is set.)
729 $vendorbinexp $vendorprefixexp/bin
730 $vendorscriptexp $vendorprefixexp/bin
732 $vendorprefixexp/lib/perl5/vendor_perl/$version
734 $vendorprefixexp/lib/perl5/vendor_perl/$version/$archname
735 $vendorman1direxp $vendorprefixexp/man/man1
736 $vendorman3direxp $vendorprefixexp/man/man3
737 $vendorhtml1direxp (none)
738 $vendorhtml3direxp (none)
740 These are normally empty, but may be set as needed. For example,
741 a vendor might choose the following settings:
744 $siteprefix /usr/local
747 This would have the effect of setting the following:
750 $scriptdirexp /usr/bin
751 $privlibexp /usr/lib/perl5/$version
752 $archlibexp /usr/lib/perl5/$version/$archname
753 $man1direxp /usr/man/man1
754 $man3direxp /usr/man/man3
756 $sitebinexp /usr/local/bin
757 $sitescriptexp /usr/local/bin
758 $sitelibexp /usr/local/lib/perl5/site_perl/$version
759 $sitearchexp /usr/local/lib/perl5/site_perl/$version/$archname
760 $siteman1direxp /usr/local/man/man1
761 $siteman3direxp /usr/local/man/man3
763 $vendorbinexp /usr/bin
764 $vendorscriptexp /usr/bin
765 $vendorlibexp /usr/lib/perl5/vendor_perl/$version
766 $vendorarchexp /usr/lib/perl5/vendor_perl/$version/$archname
767 $vendorman1direxp /usr/man/man1
768 $vendorman3direxp /usr/man/man3
770 Note how in this example, the vendor-supplied directories are in the
771 /usr hierarchy, while the directories reserved for the end-user are in
772 the /usr/local hierarchy.
774 The entire installed library hierarchy is installed in locations with
775 version numbers, keeping the installations of different versions distinct.
776 However, later installations of Perl can still be configured to search the
777 installed libraries corresponding to compatible earlier versions.
778 See L<"Coexistence with earlier versions of perl5"> below for more details
779 on how Perl can be made to search older version directories.
781 Of course you may use these directories however you see fit. For
782 example, you may wish to use $siteprefix for site-specific files that
783 are stored locally on your own disk and use $vendorprefix for
784 site-specific files that are stored elsewhere on your organization's
785 network. One way to do that would be something like
787 sh Configure -Dsiteprefix=/usr/local -Dvendorprefix=/usr/share/perl
791 As a final catch-all, Configure also offers an $otherlibdirs
792 variable. This variable contains a colon-separated list of additional
793 directories to add to @INC. By default, it will be empty.
794 Perl will search these directories (including architecture and
795 version-specific subdirectories) for add-on modules and extensions.
797 For example, if you have a bundle of perl libraries from a previous
798 installation, perhaps in a strange place:
800 Configure -Dotherlibdirs=/usr/lib/perl5/site_perl/5.8.1
804 There is one other way of adding paths to @INC at perl build time, and
805 that is by setting the APPLLIB_EXP C pre-processor token to a colon-
806 separated list of directories, like this
808 sh Configure -Accflags='-DAPPLLIB_EXP=\"/usr/libperl\"'
810 The directories defined by APPLLIB_EXP get added to @INC I<first>,
811 ahead of any others, and so provide a way to override the standard perl
812 modules should you, for example, want to distribute fixes without
813 touching the perl distribution proper. And, like otherlib dirs,
814 version and architecture specific subdirectories are also searched, if
815 present, at run time. Of course, you can still search other @INC
816 directories ahead of those in APPLLIB_EXP by using any of the standard
817 run-time methods: $PERLLIB, $PERL5LIB, -I, use lib, etc.
819 =item USE_SITECUSTOMIZE
821 Run-time customization of @INC can be enabled with:
823 sh Configure -Dusesitecustomize
825 Which will define USE_SITECUSTOMIZE and $Config{usesitecustomize}.
826 When enabled, make perl run F<$sitelibexp/sitecustomize.pl> before
827 anything else. This script can then be set up to add additional
832 By default, man pages will be installed in $man1dir and $man3dir, which
833 are normally /usr/local/man/man1 and /usr/local/man/man3. If you
834 want to use a .3pm suffix for perl man pages, you can do that with
836 sh Configure -Dman3ext=3pm
840 Currently, the standard perl installation does not do anything with
841 HTML documentation, but that may change in the future. Further, some
842 add-on modules may wish to install HTML documents. The html Configure
843 variables listed above are provided if you wish to specify where such
844 documents should be placed. The default is "none", but will likely
845 eventually change to something useful based on user feedback.
849 Some users prefer to append a "/share" to $privlib and $sitelib
850 to emphasize that those directories can be shared among different
853 Note that these are just the defaults. You can actually structure the
854 directories any way you like. They don't even have to be on the same
857 Further details about the installation directories, maintenance and
858 development subversions, and about supporting multiple versions are
859 discussed in L<"Coexistence with earlier versions of perl5"> below.
861 If you specify a prefix that contains the string "perl", then the
862 library directory structure is slightly simplified. Instead of
863 suggesting $prefix/lib/perl5/, Configure will suggest $prefix/lib.
865 Thus, for example, if you Configure with
866 -Dprefix=/opt/perl, then the default library directories for 5.9.0 are
868 Configure variable Default value
869 $privlib /opt/perl/lib/5.9.0
870 $archlib /opt/perl/lib/5.9.0/$archname
871 $sitelib /opt/perl/lib/site_perl/5.9.0
872 $sitearch /opt/perl/lib/site_perl/5.9.0/$archname
874 =head2 Changing the installation directory
876 Configure distinguishes between the directory in which perl (and its
877 associated files) should be installed and the directory in which it
878 will eventually reside. For most sites, these two are the same; for
879 sites that use AFS, this distinction is handled automatically.
880 However, sites that use software such as depot to manage software
881 packages, or users building binary packages for distribution may also
882 wish to install perl into a different directory and use that
883 management software to move perl to its final destination. This
884 section describes how to do that.
886 To install perl under the /tmp/perl5 directory, use the following
889 sh Configure -Dinstallprefix=/tmp/perl5
891 (replace /tmp/perl5 by a directory of your choice).
893 Beware, though, that if you go to try to install new add-on
894 modules, they too will get installed in under '/tmp/perl5' if you
895 follow this example. The next section shows one way of dealing with
898 =head2 Creating an installable tar archive
900 If you need to install perl on many identical systems, it is convenient
901 to compile it once and create an archive that can be installed on
902 multiple systems. Suppose, for example, that you want to create an
903 archive that can be installed in /opt/perl. One way to do that is by
904 using the DESTDIR variable during C<make install>. The DESTDIR is
905 automatically prepended to all the installation paths. Thus you
908 sh Configure -Dprefix=/opt/perl -des
911 make install DESTDIR=/tmp/perl5
912 cd /tmp/perl5/opt/perl
913 tar cvf /tmp/perl5-archive.tar .
915 =head2 Site-wide Policy settings
917 After Configure runs, it stores a number of common site-wide "policy"
918 answers (such as installation directories and the local perl contact
919 person) in the Policy.sh file. If you want to build perl on another
920 system using the same policy defaults, simply copy the Policy.sh file
921 to the new system and Configure will use it along with the appropriate
922 hint file for your system. This will work even if Policy.sh was
923 generated for another version of Perl, or on a system with a
924 different architecture and/or operating system. However, in such cases,
925 you should review the contents of the file before using it: for
926 example, your new target may not keep its man pages in the same place
927 as the system on which the file was generated.
929 Alternatively, if you wish to change some or all of those policy
934 to ensure that Configure doesn't re-use them.
936 Further information is in the Policy_sh.SH file itself.
938 If the generated Policy.sh file is unsuitable, you may freely edit it
939 to contain any valid shell commands. It will be run just after the
940 platform-specific hints files.
942 =head2 Disabling older versions of Perl
944 Configure will search for binary compatible versions of previously
945 installed perl binaries in the tree that is specified as target tree
946 and these will be used by the perl being built.
947 See L<"Coexistence with earlier versions of perl5"> for more details.
949 To disable this use of older perl modules, even completely valid pure perl
950 modules, you can specify to not include the paths found:
952 sh Configure -Dinc_version_list=none ...
954 When using the newer perl, you can add these paths again in the
955 $PERL5LIB environment variable or with perl's -I runtime option.
957 =head2 Building Perl outside of the source directory
959 Sometimes it is desirable to build Perl in a directory different from
960 where the sources are, for example if you want to keep your sources
961 read-only, or if you want to share the sources between different binary
962 architectures. You can do this (if your file system supports symbolic
965 mkdir /tmp/perl/build/directory
966 cd /tmp/perl/build/directory
967 sh /path/to/perl/source/Configure -Dmksymlinks ...
969 This will create in /tmp/perl/build/directory a tree of symbolic links
970 pointing to files in /path/to/perl/source. The original files are left
971 unaffected. After Configure has finished you can just say
975 as usual, and Perl will be built in /tmp/perl/build/directory.
977 =head2 Building a debugging perl
979 You can run perl scripts under the perl debugger at any time with
980 B<perl -d your_script>. If, however, you want to debug perl itself,
981 you probably want to have support for perl internal debugging code
982 (activated by adding -DDEBUGGING to ccflags), and/or support for the
983 system debugger by adding -g to optimize.
985 sh Configure -DDEBUGGING=<mode>
987 For a more eye appealing call, -DEBUGGING is defined to be an alias
988 for -DDEBUGGING. For both, the -U calls are also supported, in order
989 to be able to overrule the hints or Policy.sh settings.
995 Which is the default, and supports the old convention of
997 sh Configure -Doptimize='-g'
999 This will do two independent things: First, it will force compilation
1000 to use cc -g so that you can use your system's debugger on the
1001 executable. (Note: Your system may actually require something like
1002 cc -g2. Check your man pages for cc(1) and also any hint file for
1003 your system.) Second, it will add -DDEBUGGING to your ccflags
1004 variable in config.sh so that you can use B<perl -D> to access perl's
1005 internal state. (Note: Configure will only add -DDEBUGGING by default
1006 if you are not reusing your old config.sh. If you want to reuse your
1007 old config.sh, then you can just edit it and change the optimize and
1008 ccflags variables by hand and then propagate your changes as shown in
1009 L<"Propagating your changes to config.sh"> below.)
1011 You can actually specify -g and -DDEBUGGING independently, but usually
1012 it's convenient to have both.
1020 =item -DEBUGGING=both
1022 Sets both -DDEBUGGING in the ccflags, and add -g to optimize.
1026 Adds -g to optimize, but does not set -DDEBUGGING.
1028 =item -DEBUGGING=none
1030 Removes -g from optimize, and -DDEBUGGING from ccflags.
1034 If you are using a shared libperl, see the warnings about multiple
1035 versions of perl under L<Building a shared Perl library>.
1039 Perl ships with a number of standard extensions. These are contained
1040 in the ext/ subdirectory.
1042 By default, Configure will offer to build every extension which appears
1043 to be supported. For example, Configure will offer to build GDBM_File
1044 only if it is able to find the gdbm library. (See examples below.)
1045 Configure does not contain code to test for POSIX compliance, so POSIX
1046 is always built by default. If you wish to skip POSIX, you can
1047 set the Configure variable useposix=false from the Configure command line.
1049 If you unpack any additional extensions in the ext/ directory before
1050 running Configure, then Configure will offer to build those additional
1051 extensions as well. Most users probably shouldn't have to do this --
1052 it is usually easier to build additional extensions later after perl
1053 has been installed. However, if you wish to have those additional
1054 extensions statically linked into the perl binary, then this offers a
1055 convenient way to do that in one step. (It is not necessary, however;
1056 you can build and install extensions just fine even if you don't have
1057 dynamic loading. See lib/ExtUtils/MakeMaker.pm for more details.)
1059 If you have dynamic loading, another way of specifying extra modules
1060 is described in L<"Adding extra modules to the build"> below.
1062 You can learn more about each of the supplied extensions by consulting the
1063 documentation in the individual .pm modules, located under the
1066 Even if you do not have dynamic loading, you must still build the
1067 DynaLoader extension; you should just build the stub dl_none.xs
1068 version. Configure will suggest this as the default.
1070 To disable certain extensions so that they are not built, use the
1071 -Dnoextensions=... and -Donlyextensions=... options. They both accept
1072 a space-separated list of extensions. The extensions listed in
1073 C<noextensions> are removed from the list of extensions to build, while
1074 the C<onlyextensions> is rather more severe and builds only the listed
1075 extensions. The latter should be used with extreme caution since
1076 certain extensions are used by many other extensions and modules:
1077 examples of such modules include Fcntl and IO. The order of processing
1078 these options is first C<only> (if present), then C<no> (if present).
1080 Of course, you may always run Configure interactively and select only
1081 the extensions you want.
1083 Note: The DB_File module will only work with version 1.x of Berkeley
1084 DB or newer releases of version 2. Configure will automatically detect
1085 this for you and refuse to try to build DB_File with earlier
1086 releases of version 2.
1088 If you re-use your old config.sh but change your system (e.g. by
1089 adding libgdbm) Configure will still offer your old choices of extensions
1090 for the default answer, but it will also point out the discrepancy to
1093 Finally, if you have dynamic loading (most modern systems do)
1094 remember that these extensions do not increase the size of your perl
1095 executable, nor do they impact start-up time, so you probably might as
1096 well build all the ones that will work on your system.
1098 =head2 Including locally-installed libraries
1100 Perl5 comes with interfaces to number of database extensions, including
1101 dbm, ndbm, gdbm, and Berkeley db. For each extension, if
1102 Configure can find the appropriate header files and libraries, it will
1103 automatically include that extension. The gdbm and db libraries
1104 are not included with perl. See the library documentation for
1105 how to obtain the libraries.
1107 If your database header (.h) files are not in a directory normally
1108 searched by your C compiler, then you will need to include the
1109 appropriate -I/your/directory option when prompted by Configure. If
1110 your database libraries are not in a directory normally
1111 searched by your C compiler and linker, then you will need to include
1112 the appropriate -L/your/directory option when prompted by Configure.
1113 See the examples below.
1119 =item gdbm in /usr/local
1121 Suppose you have gdbm and want Configure to find it and build the
1122 GDBM_File extension. This example assumes you have gdbm.h
1123 installed in /usr/local/include/gdbm.h and libgdbm.a installed in
1124 /usr/local/lib/libgdbm.a. Configure should figure all the
1125 necessary steps out automatically.
1127 Specifically, when Configure prompts you for flags for
1128 your C compiler, you should include -I/usr/local/include.
1130 When Configure prompts you for linker flags, you should include
1133 If you are using dynamic loading, then when Configure prompts you for
1134 linker flags for dynamic loading, you should again include
1137 Again, this should all happen automatically. This should also work if
1138 you have gdbm installed in any of (/usr/local, /opt/local, /usr/gnu,
1139 /opt/gnu, /usr/GNU, or /opt/GNU).
1141 =item gdbm in /usr/you
1143 Suppose you have gdbm installed in some place other than /usr/local/,
1144 but you still want Configure to find it. To be specific, assume you
1145 have /usr/you/include/gdbm.h and /usr/you/lib/libgdbm.a. You
1146 still have to add -I/usr/you/include to cc flags, but you have to take
1147 an extra step to help Configure find libgdbm.a. Specifically, when
1148 Configure prompts you for library directories, you have to add
1149 /usr/you/lib to the list.
1151 It is possible to specify this from the command line too (all on one
1155 -Dlocincpth="/usr/you/include" \
1156 -Dloclibpth="/usr/you/lib"
1158 locincpth is a space-separated list of include directories to search.
1159 Configure will automatically add the appropriate -I directives.
1161 loclibpth is a space-separated list of library directories to search.
1162 Configure will automatically add the appropriate -L directives. If
1163 you have some libraries under /usr/local/ and others under
1164 /usr/you, then you have to include both, namely
1167 -Dlocincpth="/usr/you/include /usr/local/include" \
1168 -Dloclibpth="/usr/you/lib /usr/local/lib"
1172 =head2 Building DB, NDBM, and ODBM interfaces with Berkeley DB 3
1174 A Perl interface for DB3 is part of Berkeley DB, but if you want to
1175 compile the standard Perl DB/ODBM/NDBM interfaces, you must follow
1176 following instructions.
1178 Berkeley DB3 from Sleepycat Software is by default installed without
1179 DB1 compatibility code (needed for the DB_File interface) and without
1180 links to compatibility files. So if you want to use packages written
1181 for the DB/ODBM/NDBM interfaces, you need to configure DB3 with
1182 --enable-compat185 (and optionally with --enable-dump185) and create
1183 additional references (suppose you are installing DB3 with
1186 ln -s libdb-3.so /usr/lib/libdbm.so
1187 ln -s libdb-3.so /usr/lib/libndbm.so
1188 echo '#define DB_DBM_HSEARCH 1' >dbm.h
1189 echo '#include <db.h>' >>dbm.h
1190 install -m 0644 dbm.h /usr/include/dbm.h
1191 install -m 0644 dbm.h /usr/include/ndbm.h
1193 Optionally, if you have compiled with --enable-compat185 (not needed
1196 ln -s libdb-3.so /usr/lib/libdb1.so
1197 ln -s libdb-3.so /usr/lib/libdb.so
1199 ODBM emulation seems not to be perfect, but is quite usable,
1202 lib/odbm.............FAILED at test 9
1203 Failed 1/64 tests, 98.44% okay
1205 =head2 Overriding an old config.sh
1207 If you want to use your old config.sh but override some of the items
1208 with command line options, you need to use B<Configure -O>.
1210 =head2 GNU-style configure
1212 If you prefer the GNU-style configure command line interface, you can
1213 use the supplied configure.gnu command, e.g.
1215 CC=gcc ./configure.gnu
1217 The configure.gnu script emulates a few of the more common configure
1220 ./configure.gnu --help
1224 (The file is called configure.gnu to avoid problems on systems
1225 that would not distinguish the files "Configure" and "configure".)
1227 See L<Cross-compilation> below for information on cross-compiling.
1229 =head2 Malloc Issues
1231 Perl relies heavily on malloc(3) to grow data structures as needed,
1232 so perl's performance can be noticeably affected by the performance of
1233 the malloc function on your system. The perl source is shipped with a
1234 version of malloc that has been optimized for the typical requests from
1235 perl, so there's a chance that it may be both faster and use less memory
1236 than your system malloc.
1238 However, if your system already has an excellent malloc, or if you are
1239 experiencing difficulties with extensions that use third-party libraries
1240 that call malloc, then you should probably use your system's malloc.
1241 (Or, you might wish to explore the malloc flags discussed below.)
1245 =item Using the system malloc
1247 To build without perl's malloc, you can use the Configure command
1249 sh Configure -Uusemymalloc
1251 or you can answer 'n' at the appropriate interactive Configure prompt.
1253 =item -DPERL_POLLUTE_MALLOC
1255 NOTE: This flag is enabled automatically on some platforms if you just
1256 run Configure to accept all the defaults on those platforms.
1258 Perl's malloc family of functions are normally called Perl_malloc(),
1259 Perl_realloc(), Perl_calloc() and Perl_mfree().
1260 These names do not clash with the system versions of these functions.
1262 If this flag is enabled, however, Perl's malloc family of functions
1263 will have the same names as the system versions. This may be required
1264 sometimes if you have libraries that like to free() data that may have
1265 been allocated by Perl_malloc() and vice versa.
1267 Note that enabling this option may sometimes lead to duplicate symbols
1268 from the linker for malloc et al. In such cases, the system probably
1269 does not allow its malloc functions to be fully replaced with custom
1272 =item -DPERL_DEBUGGING_MSTATS
1274 This flag enables debugging mstats, which is required to use the
1275 Devel::Peek::mstat() function. You cannot enable this unless you are
1276 using Perl's malloc, so a typical Configure command would be
1278 sh Configure -Accflags=-DPERL_DEBUGGING_MSTATS -Dusemymalloc='y'
1280 to enable this option.
1284 =head2 What if it doesn't work?
1286 If you run into problems, try some of the following ideas.
1287 If none of them help, then see L<"Reporting Problems"> above.
1291 =item Running Configure Interactively
1293 If Configure runs into trouble, remember that you can always run
1294 Configure interactively so that you can check (and correct) its
1297 All the installation questions have been moved to the top, so you don't
1298 have to wait for them. Once you've handled them (and your C compiler and
1299 flags) you can type &-d at the next Configure prompt and Configure
1300 will use the defaults from then on.
1302 If you find yourself trying obscure command line incantations and
1303 config.over tricks, I recommend you run Configure interactively
1304 instead. You'll probably save yourself time in the long run.
1308 Hint files tell Configure about a number of things:
1314 The peculiarities or conventions of particular platforms -- non-standard
1315 library locations and names, default installation locations for binaries,
1320 The deficiencies of the platform -- for example, library functions that,
1321 although present, are too badly broken to be usable; or limits on
1322 resources that are generously available on most platforms.
1326 How best to optimize for the platform, both in terms of binary size and/or
1327 speed, and for Perl feature support. Because of wide variations in the
1328 implementation of shared libraries and of threading, for example, Configure
1329 often needs hints in order to be able to use these features.
1333 The perl distribution includes many system-specific hints files
1334 in the hints/ directory. If one of them matches your system, Configure
1335 will offer to use that hint file. Unless you have a very good reason
1336 not to, you should accept its offer.
1338 Several of the hint files contain additional important information.
1339 If you have any problems, it is a good idea to read the relevant hint file
1340 for further information. See hints/solaris_2.sh for an extensive example.
1341 More information about writing good hints is in the hints/README.hints
1342 file, which also explains hint files known as callback-units.
1344 Note that any hint file is read before any Policy file, meaning that
1345 Policy overrides hints -- see L</Site-wide Policy settings>.
1347 =item *** WHOA THERE!!! ***
1349 If you are re-using an old config.sh, it's possible that Configure detects
1350 different values from the ones specified in this file. You will almost
1351 always want to keep the previous value, unless you have changed something
1354 For example, suppose you have added libgdbm.a to your system
1355 and you decide to reconfigure perl to use GDBM_File. When you run
1356 Configure again, you will need to add -lgdbm to the list of libraries.
1357 Now, Configure will find your gdbm include file and library and will
1360 *** WHOA THERE!!! ***
1361 The previous value for $i_gdbm on this machine was "undef"!
1362 Keep the previous value? [y]
1364 In this case, you do not want to keep the previous value, so you
1365 should answer 'n'. (You'll also have to manually add GDBM_File to
1366 the list of dynamic extensions to build.)
1368 =item Changing Compilers
1370 If you change compilers or make other significant changes, you should
1371 probably not re-use your old config.sh. Simply remove it or
1372 rename it, e.g. mv config.sh config.sh.old. Then rerun Configure
1373 with the options you want to use.
1375 This is a common source of problems. If you change from cc to
1376 gcc, you should almost always remove your old config.sh.
1378 =item Propagating your changes to config.sh
1380 If you make any changes to config.sh, you should propagate
1381 them to all the .SH files by running
1385 You will then have to rebuild by running
1390 =item config.over and config.arch
1392 You can also supply a shell script config.over to over-ride
1393 Configure's guesses. It will get loaded up at the very end, just
1394 before config.sh is created. You have to be careful with this,
1395 however, as Configure does no checking that your changes make sense.
1396 This file is usually good for site-specific customizations.
1398 There is also another file that, if it exists, is loaded before the
1399 config.over, called config.arch. This file is intended to be per
1400 architecture, not per site, and usually it's the architecture-specific
1401 hints file that creates the config.arch.
1405 Many of the system dependencies are contained in config.h.
1406 Configure builds config.h by running the config_h.SH script.
1407 The values for the variables are taken from config.sh.
1409 If there are any problems, you can edit config.h directly. Beware,
1410 though, that the next time you run Configure, your changes will be
1415 If you have any additional changes to make to the C compiler command
1416 line, they can be made in cflags.SH. For instance, to turn off the
1417 optimizer on toke.c, find the line in the switch structure for
1418 toke.c and put the command optimize='-g' before the ;; . You
1419 can also edit cflags directly, but beware that your changes will be
1420 lost the next time you run Configure.
1422 To explore various ways of changing ccflags from within a hint file,
1423 see the file hints/README.hints.
1425 To change the C flags for all the files, edit config.sh and change either
1426 $ccflags or $optimize, and then re-run
1433 If you don't have sh, you'll have to copy the sample file
1434 Porting/config.sh to config.sh and edit your config.sh to reflect your
1435 system's peculiarities. See Porting/pumpkin.pod for more information.
1436 You'll probably also have to extensively modify the extension building
1439 =item Digital UNIX/Tru64 UNIX and BIN_SH
1441 In Digital UNIX/Tru64 UNIX, Configure might abort with
1443 Build a threading Perl? [n]
1444 Configure[2437]: Syntax error at line 1 : `config.sh' is not expected.
1446 This indicates that Configure is being run with a broken Korn shell
1447 (even though you think you are using a Bourne shell by using
1448 "sh Configure" or "./Configure"). The Korn shell bug has been reported
1449 to Compaq as of February 1999 but in the meanwhile, the reason ksh is
1450 being used is that you have the environment variable BIN_SH set to
1451 'xpg4'. This causes /bin/sh to delegate its duties to /bin/posix/sh
1452 (a ksh). Unset the environment variable and rerun Configure.
1454 =item HP-UX 11, pthreads, and libgdbm
1456 If you are running Configure with -Dusethreads in HP-UX 11, be warned
1457 that POSIX threads and libgdbm (the GNU dbm library) compiled before
1458 HP-UX 11 do not mix. This will cause a basic test run by Configure to
1461 Pthread internal error: message: __libc_reinit() failed, file: ../pthreads/pthread.c, line: 1096
1462 Return Pointer is 0xc082bf33
1463 sh: 5345 Quit(coredump)
1465 and Configure will give up. The cure is to recompile and install
1466 libgdbm under HP-UX 11.
1468 =item Porting information
1470 Specific information for the OS/2, Plan 9, VMS and Win32 ports is in the
1471 corresponding README files and subdirectories. Additional information,
1472 including a glossary of all those config.sh variables, is in the Porting
1473 subdirectory. Porting/Glossary should especially come in handy.
1475 Ports for other systems may also be available. You should check out
1476 http://www.cpan.org/ports for current information on ports to
1477 various other operating systems.
1479 If you plan to port Perl to a new architecture, study carefully the
1480 section titled "Philosophical Issues in Patching and Porting Perl"
1481 in the file Porting/pumpkin.pod and the file Porting/patching.pod.
1482 Study also how other non-UNIX ports have solved problems.
1486 =head2 Adding extra modules to the build
1488 You can specify extra modules or module bundles to be fetched from the
1489 CPAN and installed as part of the Perl build. Either use the -Dextras=...
1490 command line parameter to Configure, for example like this:
1492 Configure -Dextras="Bundle::LWP DBI"
1494 or answer first 'y' to the question 'Install any extra modules?' and
1495 then answer "Bundle::LWP DBI" to the 'Extras?' question.
1496 The module or the bundle names are as for the CPAN module 'install' command.
1497 This will only work if those modules are to be built as dynamic
1498 extensions. If you wish to include those extra modules as static
1499 extensions, see L<"Extensions"> above.
1501 Notice that because the CPAN module will be used to fetch the extra
1502 modules, you will need access to the CPAN, either via the Internet,
1503 or via a local copy such as a CD-ROM or a local CPAN mirror. If you
1504 do not, using the extra modules option will die horribly.
1506 Also notice that you yourself are responsible for satisfying any extra
1507 dependencies such as external headers or libraries BEFORE trying the build.
1508 For example: you will need to have the Foo database specific
1509 headers and libraries installed for the DBD::Foo module. The Configure
1510 process or the Perl build process will not help you with these.
1514 suidperl is an optional component, which is normally neither built
1515 nor installed by default. From perlfaq1:
1517 On some systems, setuid and setgid scripts (scripts written
1518 in the C shell, Bourne shell, or Perl, for example, with the
1519 set user or group ID permissions enabled) are insecure due to
1520 a race condition in the kernel. For those systems, Perl versions
1521 5 and 4 attempt to work around this vulnerability with an optional
1522 component, a special program named suidperl, also known as sperl.
1523 This program attempts to emulate the set-user-ID and set-group-ID
1524 features of the kernel.
1526 Because of the buggy history of suidperl, and the difficulty
1527 of properly security auditing as large and complex piece of
1528 software as Perl, we cannot recommend using suidperl and the feature
1529 should be considered deprecated.
1530 Instead, use a tool specifically designed to handle changes in
1531 privileges, such as B<sudo>, http://www.courtesan.com/sudo/ .
1535 This will look for all the includes. The output is stored in makefile.
1536 The only difference between Makefile and makefile is the dependencies at
1537 the bottom of makefile. If you have to make any changes, you should edit
1538 makefile, not Makefile, since the Unix make command reads makefile first.
1539 (On non-Unix systems, the output may be stored in a different file.
1540 Check the value of $firstmakefile in your config.sh if in doubt.)
1542 Configure will offer to do this step for you, so it isn't listed
1547 This will attempt to make perl in the current directory.
1549 =head2 Expected errors
1551 These errors are normal, and can be ignored:
1554 make: [extra.pods] Error 1 (ignored)
1556 make: [extras.make] Error 1 (ignored)
1558 =head2 What if it doesn't work?
1560 If you can't compile successfully, try some of the following ideas.
1561 If none of them help, and careful reading of the error message and
1562 the relevant manual pages on your system doesn't help,
1563 then see L<"Reporting Problems"> above.
1569 If you used a hint file, try reading the comments in the hint file
1570 for further tips and information.
1574 If you can successfully build miniperl, but the process crashes
1575 during the building of extensions, run
1579 to test your version of miniperl.
1583 If you have any locale-related environment variables set, try unsetting
1584 them. I have some reports that some versions of IRIX hang while
1585 running B<./miniperl configpm> with locales other than the C locale.
1586 See the discussion under L<"make test"> below about locales and the
1587 whole L<"Locale problems"> section in the file pod/perllocale.pod.
1588 The latter is especially useful if you see something like this
1590 perl: warning: Setting locale failed.
1591 perl: warning: Please check that your locale settings:
1594 are supported and installed on your system.
1595 perl: warning: Falling back to the standard locale ("C").
1601 If you get varargs problems with gcc, be sure that gcc is installed
1602 correctly and that you are not passing -I/usr/include to gcc. When using
1603 gcc, you should probably have i_stdarg='define' and i_varargs='undef'
1604 in config.sh. The problem is usually solved by installing gcc
1605 correctly. If you do change config.sh, don't forget to propagate
1606 your changes (see L<"Propagating your changes to config.sh"> below).
1607 See also the L<"vsprintf"> item below.
1611 If you get error messages such as the following (the exact line
1612 numbers and function name may vary in different versions of perl):
1614 util.c: In function `Perl_form':
1615 util.c:1107: number of arguments doesn't match prototype
1616 proto.h:125: prototype declaration
1618 it might well be a symptom of the gcc "varargs problem". See the
1619 previous L<"varargs"> item.
1621 =item LD_LIBRARY_PATH
1623 If you run into dynamic loading problems, check your setting of
1624 the LD_LIBRARY_PATH environment variable. If you're creating a static
1625 Perl library (libperl.a rather than libperl.so) it should build
1626 fine with LD_LIBRARY_PATH unset, though that may depend on details
1627 of your local set-up.
1631 If Configure seems to be having trouble finding library functions,
1632 try not using nm extraction. You can do this from the command line
1635 sh Configure -Uusenm
1637 or by answering the nm extraction question interactively.
1638 If you have previously run Configure, you should not reuse your old
1641 =item umask not found
1643 If the build processes encounters errors relating to umask(), the problem
1644 is probably that Configure couldn't find your umask() system call.
1645 Check your config.sh. You should have d_umask='define'. If you don't,
1646 this is probably the L<"nm extraction"> problem discussed above. Also,
1647 try reading the hints file for your system for further information.
1651 If you run into problems with vsprintf in compiling util.c, the
1652 problem is probably that Configure failed to detect your system's
1653 version of vsprintf(). Check whether your system has vprintf().
1654 (Virtually all modern Unix systems do.) Then, check the variable
1655 d_vprintf in config.sh. If your system has vprintf, it should be:
1659 If Configure guessed wrong, it is likely that Configure guessed wrong
1660 on a number of other common functions too. This is probably
1661 the L<"nm extraction"> problem discussed above.
1665 If you run into problems relating to do_aspawn or do_spawn, the
1666 problem is probably that Configure failed to detect your system's
1667 fork() function. Follow the procedure in the previous item
1668 on L<"nm extraction">.
1670 =item __inet_* errors
1672 If you receive unresolved symbol errors during Perl build and/or test
1673 referring to __inet_* symbols, check to see whether BIND 8.1 is
1674 installed. It installs a /usr/local/include/arpa/inet.h that refers to
1675 these symbols. Versions of BIND later than 8.1 do not install inet.h
1676 in that location and avoid the errors. You should probably update to a
1677 newer version of BIND (and remove the files the old one left behind).
1678 If you can't, you can either link with the updated resolver library provided
1679 with BIND 8.1 or rename /usr/local/bin/arpa/inet.h during the Perl build and
1680 test process to avoid the problem.
1682 =item *_r() prototype NOT found
1684 On a related note, if you see a bunch of complaints like the above about
1685 reentrant functions - specifically networking-related ones - being present
1686 but without prototypes available, check to see if BIND 8.1 (or possibly
1687 other BIND 8 versions) is (or has been) installed. They install
1688 header files such as netdb.h into places such as /usr/local/include (or into
1689 another directory as specified at build/install time), at least optionally.
1690 Remove them or put them in someplace that isn't in the C preprocessor's
1691 header file include search path (determined by -I options plus defaults,
1692 normally /usr/include).
1694 =item #error "No DATAMODEL_NATIVE specified"
1696 This is a common error when trying to build perl on Solaris 2.6 with a
1697 gcc installation from Solaris 2.5 or 2.5.1. The Solaris header files
1698 changed, so you need to update your gcc installation. You can either
1699 rerun the fixincludes script from gcc or take the opportunity to
1700 update your gcc installation.
1704 If you can't compile successfully, try turning off your compiler's
1705 optimizer. Edit config.sh and change the line
1713 then propagate your changes with B<sh Configure -S> and rebuild
1714 with B<make depend; make>.
1716 =item Missing functions and Undefined symbols
1718 If the build of miniperl fails with a long list of missing functions or
1719 undefined symbols, check the libs variable in the config.sh file. It
1720 should look something like
1722 libs='-lsocket -lnsl -ldl -lm -lc'
1724 The exact libraries will vary from system to system, but you typically
1725 need to include at least the math library -lm. Normally, Configure
1726 will suggest the correct defaults. If the libs variable is empty, you
1727 need to start all over again. Run
1731 and start from the very beginning. This time, unless you are sure of
1732 what you are doing, accept the default list of libraries suggested by
1735 If the libs variable looks correct, you might have the
1736 L<"nm extraction"> problem discussed above.
1738 If you stil have missing routines or undefined symbols, you probably
1739 need to add some library or other, or you need to undefine some feature
1740 that Configure thought was there but is defective or incomplete. If
1741 you used a hint file, see if it has any relevant advice. You can also
1742 look through through config.h for likely suspects.
1746 Some compilers will not compile or optimize the larger files (such as
1747 toke.c) without some extra switches to use larger jump offsets or
1748 allocate larger internal tables. You can customize the switches for
1749 each file in cflags. It's okay to insert rules for specific files into
1750 makefile since a default rule only takes effect in the absence of a
1753 =item Missing dbmclose
1755 SCO prior to 3.2.4 may be missing dbmclose(). An upgrade to 3.2.4
1756 that includes libdbm.nfs (which includes dbmclose()) may be available.
1758 =item Note (probably harmless): No library found for -lsomething
1760 If you see such a message during the building of an extension, but
1761 the extension passes its tests anyway (see L<"make test"> below),
1762 then don't worry about the warning message. The extension
1763 Makefile.PL goes looking for various libraries needed on various
1764 systems; few systems will need all the possible libraries listed.
1765 For example, a system may have -lcposix or -lposix, but it's
1766 unlikely to have both, so most users will see warnings for the one
1767 they don't have. The phrase 'probably harmless' is intended to
1768 reassure you that nothing unusual is happening, and the build
1769 process is continuing.
1771 On the other hand, if you are building GDBM_File and you get the
1774 Note (probably harmless): No library found for -lgdbm
1776 then it's likely you're going to run into trouble somewhere along
1777 the line, since it's hard to see how you can use the GDBM_File
1778 extension without the -lgdbm library.
1780 It is true that, in principle, Configure could have figured all of
1781 this out, but Configure and the extension building process are not
1782 quite that tightly coordinated.
1784 =item sh: ar: not found
1786 This is a message from your shell telling you that the command 'ar'
1787 was not found. You need to check your PATH environment variable to
1788 make sure that it includes the directory with the 'ar' command. This
1789 is a common problem on Solaris, where 'ar' is in the /usr/ccs/bin
1792 =item db-recno failure on tests 51, 53 and 55
1794 Old versions of the DB library (including the DB library which comes
1795 with FreeBSD 2.1) had broken handling of recno databases with modified
1796 bval settings. Upgrade your DB library or OS.
1798 =item Bad arg length for semctl, is XX, should be ZZZ
1800 If you get this error message from the ext/IPC/SysV/t/sem test, your System
1801 V IPC may be broken. The XX typically is 20, and that is what ZZZ
1802 also should be. Consider upgrading your OS, or reconfiguring your OS
1803 to include the System V semaphores.
1805 =item ext/IPC/SysV/t/sem........semget: No space left on device
1807 Either your account or the whole system has run out of semaphores. Or
1808 both. Either list the semaphores with "ipcs" and remove the unneeded
1809 ones (which ones these are depends on your system and applications)
1810 with "ipcrm -s SEMAPHORE_ID_HERE" or configure more semaphores to your
1815 If you mix GNU binutils (nm, ld, ar) with equivalent vendor-supplied
1816 tools you may be in for some trouble. For example creating archives
1817 with an old GNU 'ar' and then using a new current vendor-supplied 'ld'
1818 may lead into linking problems. Either recompile your GNU binutils
1819 under your current operating system release, or modify your PATH not
1820 to include the GNU utils before running Configure, or specify the
1821 vendor-supplied utilities explicitly to Configure, for example by
1822 Configure -Dar=/bin/ar.
1824 =item THIS PACKAGE SEEMS TO BE INCOMPLETE
1826 The F<Configure> program has not been able to find all the files which
1827 make up the complete Perl distribution. You may have a damaged source
1828 archive file (in which case you may also have seen messages such as
1829 C<gzip: stdin: unexpected end of file> and C<tar: Unexpected EOF on
1830 archive file>), or you may have obtained a structurally-sound but
1831 incomplete archive. In either case, try downloading again from the
1832 official site named at the start of this document. If you do find
1833 that any site is carrying a corrupted or incomplete source code
1834 archive, please report it to the site's maintainer.
1836 =item invalid token: ##
1838 You are using a non-ANSI-compliant C compiler. To compile Perl, you
1839 need to use a compiler that supports ANSI C. If there is a README
1840 file for your system, it may have further details on your compiler
1845 Some additional things that have been reported for either perl4 or perl5:
1847 Genix may need to use libc rather than libc_s, or #undef VARARGS.
1849 NCR Tower 32 (OS 2.01.01) may need -W2,-Sl,2000 and #undef MKDIR.
1851 UTS may need one or more of -K or -g, and undef LSTAT.
1853 FreeBSD can fail the ext/IPC/SysV/t/sem.t test if SysV IPC has not been
1854 configured in the kernel. Perl tries to detect this, though, and
1855 you will get a message telling you what to do.
1857 HP-UX 11 Y2K patch "Y2K-1100 B.11.00.B0125 HP-UX Core OS Year 2000
1858 Patch Bundle" has been reported to break the io/fs test #18 which
1859 tests whether utime() can change timestamps. The Y2K patch seems to
1860 break utime() so that over NFS the timestamps do not get changed
1861 (on local filesystems utime() still works).
1863 Building Perl on a system that has also BIND (headers and libraries)
1864 installed may run into troubles because BIND installs its own netdb.h
1865 and socket.h, which may not agree with the operating system's ideas of
1866 the same files. Similarly, including -lbind may conflict with libc's
1867 view of the world. You may have to tweak -Dlocincpth and -Dloclibpth
1872 =head2 Cross-compilation
1874 Perl can be cross-compiled. It is just not trivial, cross-compilation
1875 rarely is. Perl is routinely cross-compiled for many platforms (as of
1876 June 2005 at least PocketPC aka WinCE, Open Zaurus, EPOC, Symbian, and
1877 the IBM OS/400). These platforms are known as the B<target> platforms,
1878 while the systems where the compilation takes place are the B<host>
1881 What makes the situation difficult is that first of all,
1882 cross-compilation environments vary significantly in how they are set
1883 up and used, and secondly because the primary way of configuring Perl
1884 (using the rather large Unix-tool-dependent Configure script) is not
1885 awfully well suited for cross-compilation. However, starting from
1886 version 5.8.0, the Configure script also knows one way of supporting
1887 cross-compilation support, please keep reading.
1889 See the following files for more information about compiling Perl for
1890 the particular platforms:
1894 =item WinCE/PocketPC
1916 Packaging and transferring either the core Perl modules or CPAN
1917 modules to the target platform is also left up to the each
1918 cross-compilation environment. Often the cross-compilation target
1919 platforms are somewhat limited in diskspace: see the section
1920 L<Minimizing the Perl installation> to learn more of the minimal set
1921 of files required for a functional Perl installation.
1923 For some cross-compilation environments the Configure option
1924 C<-Dinstallprefix=...> might be handy, see L<Changing the installation
1927 About the cross-compilation support of Configure: what is known to
1928 work is running Configure in a cross-compilation environment and
1929 building the miniperl executable. What is known not to work is
1930 building the perl executable because that would require building
1931 extensions: Dynaloader statically and File::Glob dynamically, for
1932 extensions one needs MakeMaker and MakeMaker is not yet
1933 cross-compilation aware, and neither is the main Makefile.
1935 The cross-compilation setup of Configure has successfully been used in
1936 at least two Linux cross-compilation environments. The setups were
1937 both such that the host system was Intel Linux with a gcc built for
1938 cross-compiling into ARM Linux, and there was a SSH connection to the
1941 To run Configure in cross-compilation mode the basic switch that
1942 has to be used is C<-Dusecrosscompile>.
1944 sh ./Configure -des -Dusecrosscompile -D...
1946 This will make the cpp symbol USE_CROSS_COMPILE and the %Config
1947 symbol C<usecrosscompile> available, and C<xconfig.h> will be used
1948 for cross-compilation.
1950 During the Configure and build, certain helper scripts will be created
1951 into the Cross/ subdirectory. The scripts are used to execute a
1952 cross-compiled executable, and to transfer files to and from the
1953 target host. The execution scripts are named F<run-*> and the
1954 transfer scripts F<to-*> and F<from-*>. The part after the dash is
1955 the method to use for remote execution and transfer: by default the
1956 methods are B<ssh> and B<scp>, thus making the scripts F<run-ssh>,
1957 F<to-scp>, and F<from-scp>.
1959 To configure the scripts for a target host and a directory (in which
1960 the execution will happen and which is to and from where the transfer
1961 happens), supply Configure with
1963 -Dtargethost=so.me.ho.st -Dtargetdir=/tar/get/dir
1965 The targethost is what e.g. ssh will use as the hostname, the targetdir
1966 must exist (the scripts won't create it), the targetdir defaults to /tmp.
1967 You can also specify a username to use for ssh/rsh logins
1971 but in case you don't, "root" will be used.
1973 Because this is a cross-compilation effort, you will also need to specify
1974 which target environment and which compilation environment to use.
1975 This includes the compiler, the header files, and the libraries.
1976 In the below we use the usual settings for the iPAQ cross-compilation
1979 -Dtargetarch=arm-linux
1981 -Dusrinc=/skiff/local/arm-linux/include
1982 -Dincpth=/skiff/local/arm-linux/include
1983 -Dlibpth=/skiff/local/arm-linux/lib
1985 If the name of the C<cc> has the usual GNU C semantics for cross
1986 compilers, that is, CPU-OS-gcc, the names of the C<ar>, C<nm>, and
1987 C<ranlib> will also be automatically chosen to be CPU-OS-ar and so on.
1988 (The C<ld> requires more thought and will be chosen later by Configure
1989 as appropriate.) Also, in this case the incpth, libpth, and usrinc
1990 will be guessed by Configure (unless explicitly set to something else,
1991 in which case Configure's guesses with be appended).
1993 In addition to the default execution/transfer methods you can also
1994 choose B<rsh> for execution, and B<rcp> or B<cp> for transfer,
1997 -Dtargetrun=rsh -Dtargetto=rcp -Dtargetfrom=cp
1999 Putting it all together:
2001 sh ./Configure -des -Dusecrosscompile \
2002 -Dtargethost=so.me.ho.st \
2003 -Dtargetdir=/tar/get/dir \
2005 -Dtargetarch=arm-linux \
2006 -Dcc=arm-linux-gcc \
2007 -Dusrinc=/skiff/local/arm-linux/include \
2008 -Dincpth=/skiff/local/arm-linux/include \
2009 -Dlibpth=/skiff/local/arm-linux/lib \
2012 or if you are happy with the defaults:
2014 sh ./Configure -des -Dusecrosscompile \
2015 -Dtargethost=so.me.ho.st \
2016 -Dcc=arm-linux-gcc \
2019 Another example where the cross-compiler has been installed under
2020 F</usr/local/arm/2.95.5>:
2022 sh ./Configure -des -Dusecrosscompile \
2023 -Dtargethost=so.me.ho.st \
2024 -Dcc=/usr/local/arm/2.95.5/bin/arm-linux-gcc \
2025 -Dincpth=/usr/local/arm/2.95.5/include \
2026 -Dusrinc=/usr/local/arm/2.95.5/include \
2027 -Dlibpth=/usr/local/arm/2.95.5/lib
2031 This will run the regression tests on the perl you just made. If
2032 'make test' doesn't say "All tests successful" then something went
2033 wrong. See the file t/README in the t subdirectory.
2035 Note that you can't run the tests in background if this disables
2036 opening of /dev/tty. You can use 'make test-notty' in that case but
2037 a few tty tests will be skipped.
2039 =head2 What if make test doesn't work?
2041 If make test bombs out, just cd to the t directory and run ./TEST
2042 by hand to see if it makes any difference. If individual tests
2043 bomb, you can run them by hand, e.g.,
2047 Another way to get more detailed information about failed tests and
2048 individual subtests is to cd to the t directory and run
2052 (this assumes that most basic tests succeed, since harness uses
2053 complicated constructs). For extension and library tests you
2054 need a little bit more: you need to setup your environment variable
2055 PERL_CORE to a true value (like "1"), and you need to supply the
2056 right Perl library path:
2059 ./perl -I../lib ../ext/Socket/Socket.t
2060 ./perl -I../lib ../lib/less.t
2062 (For csh-like shells on UNIX; adjust appropriately for other platforms.)
2063 You should also read the individual tests to see if there are any helpful
2064 comments that apply to your system. You may also need to setup your
2065 shared library path if you get errors like:
2067 /sbin/loader: Fatal Error: cannot map libperl.so
2069 See L</"Building a shared Perl library"> earlier in this document.
2075 Note: One possible reason for errors is that some external programs
2076 may be broken due to the combination of your environment and the way
2077 B<make test> exercises them. For example, this may happen if you have
2078 one or more of these environment variables set: LC_ALL LC_CTYPE
2079 LC_COLLATE LANG. In some versions of UNIX, the non-English locales
2080 are known to cause programs to exhibit mysterious errors.
2082 If you have any of the above environment variables set, please try
2088 LC_ALL=C;export LC_ALL
2090 for Bourne or Korn shell) from the command line and then retry
2091 make test. If the tests then succeed, you may have a broken program that
2092 is confusing the testing. Please run the troublesome test by hand as
2093 shown above and see whether you can locate the program. Look for
2094 things like: exec, `backquoted command`, system, open("|...") or
2095 open("...|"). All these mean that Perl is trying to run some
2098 =item Timing problems
2100 Several tests in the test suite check timing functions, such as
2101 sleep(), and see if they return in a reasonable amount of time.
2102 If your system is quite busy and doesn't respond quickly enough,
2103 these tests might fail. If possible, try running the tests again
2104 with the system under a lighter load. These timing-sensitive
2105 and load-sensitive tests include F<t/op/alarm.t>,
2106 F<ext/Time/HiRes/HiRes.t>, F<lib/Benchmark.t>,
2107 F<lib/Memoize/t/expmod_t.t>, and F<lib/Memoize/t/speed.t>.
2111 On some systems, particularly those with smaller amounts of RAM, some
2112 of the tests in t/op/pat.t may fail with an "Out of memory" message.
2113 For example, on my SparcStation IPC with 12 MB of RAM, in perl5.5.670,
2114 test 85 will fail if run under either t/TEST or t/harness.
2116 Try stopping other jobs on the system and then running the test by itself:
2118 cd t; ./perl op/pat.t
2120 to see if you have any better luck. If your perl still fails this
2121 test, it does not necessarily mean you have a broken perl. This test
2122 tries to exercise the regular expression subsystem quite thoroughly,
2123 and may well be far more demanding than your normal usage.
2125 =item Failures from lib/File/Temp/t/security saying "system possibly insecure"
2127 First, such warnings are not necessarily serious or indicative of a
2128 real security threat. That being said, they bear investigating.
2130 Note that each of the tests is run twice. The first time is in the
2131 directory returned by File::Spec->tmpdir() (often /tmp on Unix
2132 systems), and the second time in the directory from which the test was
2133 run (usually the 't' directory, if the test was run as part of 'make
2136 The tests may fail for the following reasons:
2138 (1) If the directory the tests are being run in is owned by somebody
2139 other than the user running the tests, or by root (uid 0).
2141 This failure can happen if the Perl source code distribution is
2142 unpacked in such a way that the user ids in the distribution package
2143 are used as-is. Some tar programs do this.
2145 (2) If the directory the tests are being run in is writable by group or
2146 by others, and there is no sticky bit set for the directory. (With
2147 UNIX/POSIX semantics, write access to a directory means the right to
2148 add or remove files in that directory. The 'sticky bit' is a feature
2149 used in some UNIXes to give extra protection to files: if the bit is
2150 set for a directory, no one but the owner (or root) can remove that
2151 file even if the permissions would otherwise allow file removal by
2154 This failure may or may not be a real problem: it depends on the
2155 permissions policy used on this particular system. This failure can
2156 also happen if the system either doesn't support the sticky bit (this
2157 is the case with many non-UNIX platforms: in principle File::Temp
2158 should know about these platforms and skip the tests), or if the system
2159 supports the sticky bit but for some reason or reasons it is not being
2160 used. This is, for example, the case with HP-UX: as of HP-UX release
2161 11.00, the sticky bit is very much supported, but HP-UX doesn't use it
2162 on its /tmp directory as shipped. Also, as with the permissions, some
2163 local policy might dictate that the stickiness is not used.
2165 (3) If the system supports the POSIX 'chown giveaway' feature and if
2166 any of the parent directories of the temporary file back to the root
2167 directory are 'unsafe', using the definitions given above in (1) and
2168 (2). For Unix systems, this is usually not an issue if you are
2169 building on a local disk. See the documentation for the File::Temp
2170 module for more information about 'chown giveaway'.
2172 See the documentation for the File::Temp module for more information
2173 about the various security aspects of temporary files.
2179 This will put perl into the public directory you specified to
2180 Configure; by default this is /usr/local/bin. It will also try
2181 to put the man pages in a reasonable place. It will not nroff the man
2182 pages, however. You may need to be root to run B<make install>. If you
2183 are not root, you must still have permission to install into the directories
2184 in question and you should ignore any messages about chown not working.
2186 If "make install" just says "`install' is up to date" or something
2187 similar, you may be on a case-insensitive filesystems such as Mac's HFS+,
2188 and you should say "make install-all". (This confusion is brought to you
2189 by the Perl distribution having a file called INSTALL.)
2191 =head2 Installing perl under different names
2193 If you want to install perl under a name other than "perl" (for example,
2194 when installing perl with special features enabled, such as debugging),
2195 indicate the alternate name on the "make install" line, such as:
2197 make install PERLNAME=myperl
2199 You can separately change the base used for versioned names (like
2200 "perl5.8.9") by setting PERLNAME_VERBASE, like
2202 make install PERLNAME=perl5 PERLNAME_VERBASE=perl
2204 This can be useful if you have to install perl as "perl5" (e.g. to
2205 avoid conflicts with an ancient version in /usr/bin supplied by your vendor).
2206 Without this the versioned binary would be called "perl55.8.8".
2208 =head2 Installing perl under a different directory
2210 You can install perl under a different destination directory by using
2211 the DESTDIR variable during C<make install>, with a command like
2213 make install DESTDIR=/tmp/perl5
2215 DESTDIR is automatically prepended to all the installation paths. See
2216 the example in L<"Creating an installable tar archive"> above.
2218 =head2 Installed files
2220 If you want to see exactly what will happen without installing
2221 anything, you can run
2223 ./perl installperl -n
2224 ./perl installman -n
2226 make install will install the following:
2231 perl5.n.n where 5.n.n is the current release number. This
2232 will be a link to perl.
2234 sperl5.n.n If you requested setuid emulation.
2235 a2p awk-to-perl translator
2239 cppstdin This is used by perl -P, if your cc -E can't
2241 c2ph, pstruct Scripts for handling C structures in header files.
2242 s2p sed-to-perl translator
2243 find2perl find-to-perl translator
2244 h2ph Extract constants and simple macros from C headers
2245 h2xs Converts C .h header files to Perl extensions.
2246 perlbug Tool to report bugs in Perl.
2247 perldoc Tool to read perl's pod documentation.
2248 pl2pm Convert Perl 4 .pl files to Perl 5 .pm modules
2249 pod2html, Converters from perl's pod documentation format
2250 pod2latex, to other useful formats.
2256 splain Describe Perl warnings and errors
2257 dprofpp Perl code profile post-processor
2261 in $privlib and $archlib specified to
2262 Configure, usually under /usr/local/lib/perl5/.
2266 man pages in $man1dir, usually /usr/local/man/man1.
2268 pages in $man3dir, usually /usr/local/man/man3.
2269 pod/*.pod in $privlib/pod/.
2271 Installperl will also create the directories listed above
2272 in L<"Installation Directories">.
2274 Perl's *.h header files and the libperl library are also installed
2275 under $archlib so that any user may later build new modules, run the
2276 optional Perl compiler, or embed the perl interpreter into another
2277 program even if the Perl source is no longer available.
2279 Sometimes you only want to install the version-specific parts of the perl
2280 installation. For example, you may wish to install a newer version of
2281 perl alongside an already installed production version of perl without
2282 disabling installation of new modules for the production version.
2283 To only install the version-specific parts of the perl installation, run
2285 Configure -Dversiononly
2287 or answer 'y' to the appropriate Configure prompt. Alternatively,
2288 you can just manually run
2290 ./perl installperl -v
2292 and skip installman altogether.
2293 See also L<"Maintaining completely separate versions"> for another
2296 =head1 Coexistence with earlier versions of perl5
2298 Perl 5.9 is not binary compatible with earlier versions of Perl.
2299 In other words, you will have to recompile your XS modules.
2301 In general, you can usually safely upgrade from one version of Perl (e.g.
2302 5.8.0) to another similar version (e.g. 5.8.2) without re-compiling
2303 all of your add-on extensions. You can also safely leave the old version
2304 around in case the new version causes you problems for some reason.
2305 For example, if you want to be sure that your script continues to run
2306 with 5.8.2, simply replace the '#!/usr/local/bin/perl' line at the
2307 top of the script with the particular version you want to run, e.g.
2308 #!/usr/local/bin/perl5.8.2.
2310 Usually, most extensions will probably not need to be recompiled to be
2311 used with a newer version of Perl. Here is how it is supposed to work.
2312 (These examples assume you accept all the Configure defaults.)
2314 Suppose you already have version 5.005_03 installed. The directories
2315 searched by 5.005_03 are
2317 /usr/local/lib/perl5/5.00503/$archname
2318 /usr/local/lib/perl5/5.00503
2319 /usr/local/lib/perl5/site_perl/5.005/$archname
2320 /usr/local/lib/perl5/site_perl/5.005
2322 Beginning with 5.6.0 the version number in the site libraries are
2323 fully versioned. Now, suppose you install version 5.6.0. The directories
2324 searched by version 5.6.0 will be
2326 /usr/local/lib/perl5/5.6.0/$archname
2327 /usr/local/lib/perl5/5.6.0
2328 /usr/local/lib/perl5/site_perl/5.6.0/$archname
2329 /usr/local/lib/perl5/site_perl/5.6.0
2331 /usr/local/lib/perl5/site_perl/5.005/$archname
2332 /usr/local/lib/perl5/site_perl/5.005
2333 /usr/local/lib/perl5/site_perl/
2335 Notice the last three entries -- Perl understands the default structure
2336 of the $sitelib directories and will look back in older, compatible
2337 directories. This way, modules installed under 5.005_03 will continue
2338 to be usable by 5.005_03 but will also accessible to 5.6.0. Further,
2339 suppose that you upgrade a module to one which requires features
2340 present only in 5.6.0. That new module will get installed into
2341 /usr/local/lib/perl5/site_perl/5.6.0 and will be available to 5.6.0,
2342 but will not interfere with the 5.005_03 version.
2344 The last entry, /usr/local/lib/perl5/site_perl/, is there so that
2345 5.6.0 and above will look for 5.004-era pure perl modules.
2347 Lastly, suppose you now install 5.8.0, which is not binary compatible
2348 with 5.6.0. The directories searched by 5.8.0 (if you don't change the
2349 Configure defaults) will be:
2351 /usr/local/lib/perl5/5.8.0/$archname
2352 /usr/local/lib/perl5/5.8.0
2353 /usr/local/lib/perl5/site_perl/5.8.0/$archname
2354 /usr/local/lib/perl5/site_perl/5.8.0
2356 /usr/local/lib/perl5/site_perl/5.6.0
2358 /usr/local/lib/perl5/site_perl/5.005
2360 /usr/local/lib/perl5/site_perl/
2362 Note that the earlier $archname entries are now gone, but pure perl
2363 modules from earlier versions will still be found.
2365 Assuming the users in your site are still actively using perl 5.6.0 and
2366 5.005 after you installed 5.8.0, you can continue to install add-on
2367 extensions using any of perl 5.8.0, 5.6.0, or 5.005. The installations
2368 of these different versions remain distinct, but remember that the
2369 newer versions of perl are automatically set up to search the
2370 compatible site libraries of the older ones. This means that
2371 installing a new XS extension with 5.005 will make it visible to both
2372 5.005 and 5.6.0, but not to 5.8.0. Installing a pure perl module with
2373 5.005 will make it visible to all three versions. Later, if you
2374 install the same extension using, say, perl 5.8.0, it will override the
2375 5.005-installed version, but only for perl 5.8.0.
2377 This way, you can choose to share compatible extensions, but also upgrade
2378 to a newer version of an extension that may be incompatible with earlier
2379 versions, without breaking the earlier versions' installations.
2381 =head2 Maintaining completely separate versions
2383 Many users prefer to keep all versions of perl in completely
2384 separate directories. This guarantees that an update to one version
2385 won't interfere with another version. (The defaults guarantee this for
2386 libraries after 5.6.0, but not for executables. TODO?) One convenient
2387 way to do this is by using a separate prefix for each version, such as
2389 sh Configure -Dprefix=/opt/perl5.8.2
2391 and adding /opt/perl5.8.2/bin to the shell PATH variable. Such users
2392 may also wish to add a symbolic link /usr/local/bin/perl so that
2393 scripts can still start with #!/usr/local/bin/perl.
2395 Others might share a common directory for maintenance sub-versions
2396 (e.g. 5.8 for all 5.8.x versions), but change directory with
2399 If you are installing a development subversion, you probably ought to
2400 seriously consider using a separate directory, since development
2401 subversions may not have all the compatibility wrinkles ironed out
2404 =head2 Upgrading from 5.005 or 5.6 to 5.8.0
2406 B<Perl 5.9.0 is binary incompatible with Perl 5.8.x, Perl 5.6.x, 5.005,
2407 and any earlier Perl release.> Perl modules having binary parts
2408 (meaning that a C compiler is used) will have to be recompiled to be
2409 used with 5.9.0. If you find you do need to rebuild an extension with
2410 5.9.0, you may safely do so without disturbing the older
2411 installations. (See L<"Coexistence with earlier versions of perl5">
2414 See your installed copy of the perllocal.pod file for a (possibly
2415 incomplete) list of locally installed modules. Note that you want
2416 perllocal.pod, not perllocale.pod, for installed module information.
2418 =head1 Coexistence with perl4
2420 You can safely install perl5 even if you want to keep perl4 around.
2422 By default, the perl5 libraries go into /usr/local/lib/perl5/, so
2423 they don't override the perl4 libraries in /usr/local/lib/perl/.
2425 In your /usr/local/bin directory, you should have a binary named
2426 perl4.036. That will not be touched by the perl5 installation
2427 process. Most perl4 scripts should run just fine under perl5.
2428 However, if you have any scripts that require perl4, you can replace
2429 the #! line at the top of them by #!/usr/local/bin/perl4.036 (or
2430 whatever the appropriate pathname is). See L<perltrap> for
2431 possible problems running perl4 scripts under perl5.
2433 =head1 cd /usr/include; h2ph *.h sys/*.h
2435 Some perl scripts need to be able to obtain information from the
2436 system header files. This command will convert the most commonly used
2437 header files in /usr/include into files that can be easily interpreted
2438 by perl. These files will be placed in the architecture-dependent
2439 library ($archlib) directory you specified to Configure.
2441 Note: Due to differences in the C and perl languages, the conversion
2442 of the header files is not perfect. You will probably have to
2443 hand-edit some of the converted files to get them to parse correctly.
2444 For example, h2ph breaks spectacularly on type casting and certain
2447 =head1 installhtml --help
2449 Some sites may wish to make perl documentation available in HTML
2450 format. The installhtml utility can be used to convert pod
2451 documentation into linked HTML files and install them.
2453 Currently, the supplied ./installhtml script does not make use of the
2454 html Configure variables. This should be fixed in a future release.
2456 The following command-line is an example of one used to convert
2461 --podpath=lib:ext:pod:vms \
2463 --htmldir=/perl/nmanual \
2464 --htmlroot=/perl/nmanual \
2465 --splithead=pod/perlipc \
2466 --splititem=pod/perlfunc \
2467 --libpods=perlfunc:perlguts:perlvar:perlrun:perlop \
2470 See the documentation in installhtml for more details. It can take
2471 many minutes to execute a large installation and you should expect to
2472 see warnings like "no title", "unexpected directive" and "cannot
2473 resolve" as the files are processed. We are aware of these problems
2474 (and would welcome patches for them).
2476 You may find it helpful to run installhtml twice. That should reduce
2477 the number of "cannot resolve" warnings.
2479 =head1 cd pod && make tex && (process the latex files)
2481 Some sites may also wish to make the documentation in the pod/ directory
2482 available in TeX format. Type
2484 (cd pod && make tex && <process the latex files>)
2486 =head1 Minimizing the Perl installation
2488 The following section is meant for people worrying about squeezing the
2489 Perl installation into minimal systems (for example when installing
2490 operating systems, or in really small filesystems).
2492 Leaving out as many extensions as possible is an obvious way:
2493 Encode, with its big conversion tables, consumes a lot of
2494 space. On the other hand, you cannot throw away everything. The
2495 Fcntl module is pretty essential. If you need to do network
2496 programming, you'll appreciate the Socket module, and so forth: it all
2497 depends on what do you need to do.
2499 In the following we offer two different slimmed down installation
2500 recipes. They are informative, not normative: the choice of files
2501 depends on what you need.
2503 Firstly, the bare minimum to run this script
2507 foreach my $f (</*>) {
2511 in Linux is as follows (under $Config{prefix}):
2514 ./lib/perl5/5.9.3/strict.pm
2515 ./lib/perl5/5.9.3/warnings.pm
2516 ./lib/perl5/5.9.3/i686-linux/File/Glob.pm
2517 ./lib/perl5/5.9.3/i686-linux/XSLoader.pm
2518 ./lib/perl5/5.9.3/i686-linux/auto/File/Glob/Glob.so
2520 Secondly, Debian perl-base package contains the following files,
2521 size about 1.9MB in its i386 version:
2526 /usr/lib/perl/5.8.4/B.pm
2527 /usr/lib/perl/5.8.4/B/Deparse.pm
2528 /usr/lib/perl/5.8.4/Config.pm
2529 /usr/lib/perl/5.8.4/Cwd.pm
2530 /usr/lib/perl/5.8.4/Data/Dumper.pm
2531 /usr/lib/perl/5.8.4/DynaLoader.pm
2532 /usr/lib/perl/5.8.4/Errno.pm
2533 /usr/lib/perl/5.8.4/Fcntl.pm
2534 /usr/lib/perl/5.8.4/File/Glob.pm
2535 /usr/lib/perl/5.8.4/IO.pm
2536 /usr/lib/perl/5.8.4/IO/File.pm
2537 /usr/lib/perl/5.8.4/IO/Handle.pm
2538 /usr/lib/perl/5.8.4/IO/Pipe.pm
2539 /usr/lib/perl/5.8.4/IO/Seekable.pm
2540 /usr/lib/perl/5.8.4/IO/Select.pm
2541 /usr/lib/perl/5.8.4/IO/Socket.pm
2542 /usr/lib/perl/5.8.4/POSIX.pm
2543 /usr/lib/perl/5.8.4/Socket.pm
2544 /usr/lib/perl/5.8.4/XSLoader.pm
2545 /usr/lib/perl/5.8.4/auto/Cwd/Cwd.bs
2546 /usr/lib/perl/5.8.4/auto/Cwd/Cwd.so
2547 /usr/lib/perl/5.8.4/auto/Data/Dumper/Dumper.bs
2548 /usr/lib/perl/5.8.4/auto/Data/Dumper/Dumper.so
2549 /usr/lib/perl/5.8.4/auto/DynaLoader/DynaLoader.a
2550 /usr/lib/perl/5.8.4/auto/DynaLoader/autosplit.ix
2551 /usr/lib/perl/5.8.4/auto/DynaLoader/dl_expandspec.al
2552 /usr/lib/perl/5.8.4/auto/DynaLoader/dl_find_symbol_anywhere.al
2553 /usr/lib/perl/5.8.4/auto/DynaLoader/dl_findfile.al
2554 /usr/lib/perl/5.8.4/auto/DynaLoader/extralibs.ld
2555 /usr/lib/perl/5.8.4/auto/Fcntl/Fcntl.bs
2556 /usr/lib/perl/5.8.4/auto/Fcntl/Fcntl.so
2557 /usr/lib/perl/5.8.4/auto/File/Glob/Glob.bs
2558 /usr/lib/perl/5.8.4/auto/File/Glob/Glob.so
2559 /usr/lib/perl/5.8.4/auto/IO/IO.bs
2560 /usr/lib/perl/5.8.4/auto/IO/IO.so
2561 /usr/lib/perl/5.8.4/auto/POSIX/POSIX.bs
2562 /usr/lib/perl/5.8.4/auto/POSIX/POSIX.so
2563 /usr/lib/perl/5.8.4/auto/POSIX/autosplit.ix
2564 /usr/lib/perl/5.8.4/auto/POSIX/load_imports.al
2565 /usr/lib/perl/5.8.4/auto/Socket/Socket.bs
2566 /usr/lib/perl/5.8.4/auto/Socket/Socket.so
2567 /usr/lib/perl/5.8.4/lib.pm
2568 /usr/lib/perl/5.8.4/re.pm
2569 /usr/share/doc/perl-base
2570 /usr/share/doc/perl/AUTHORS.gz
2571 /usr/share/doc/perl/Documentation
2572 /usr/share/doc/perl/README.Debian.gz
2573 /usr/share/doc/perl/changelog.Debian.gz
2574 /usr/share/doc/perl/copyright
2575 /usr/share/man/man1/perl.1.gz
2577 /usr/share/perl/5.8.4/AutoLoader.pm
2578 /usr/share/perl/5.8.4/Carp.pm
2579 /usr/share/perl/5.8.4/Carp/Heavy.pm
2580 /usr/share/perl/5.8.4/Exporter.pm
2581 /usr/share/perl/5.8.4/Exporter/Heavy.pm
2582 /usr/share/perl/5.8.4/File/Spec.pm
2583 /usr/share/perl/5.8.4/File/Spec/Unix.pm
2584 /usr/share/perl/5.8.4/FileHandle.pm
2585 /usr/share/perl/5.8.4/Getopt/Long.pm
2586 /usr/share/perl/5.8.4/IO/Socket/INET.pm
2587 /usr/share/perl/5.8.4/IO/Socket/UNIX.pm
2588 /usr/share/perl/5.8.4/IPC/Open2.pm
2589 /usr/share/perl/5.8.4/IPC/Open3.pm
2590 /usr/share/perl/5.8.4/List/Util.pm
2591 /usr/share/perl/5.8.4/Scalar/Util.pm
2592 /usr/share/perl/5.8.4/SelectSaver.pm
2593 /usr/share/perl/5.8.4/Symbol.pm
2594 /usr/share/perl/5.8.4/Text/ParseWords.pm
2595 /usr/share/perl/5.8.4/Text/Tabs.pm
2596 /usr/share/perl/5.8.4/Text/Wrap.pm
2597 /usr/share/perl/5.8.4/attributes.pm
2598 /usr/share/perl/5.8.4/base.pm
2599 /usr/share/perl/5.8.4/bytes.pm
2600 /usr/share/perl/5.8.4/bytes_heavy.pl
2601 /usr/share/perl/5.8.4/constant.pm
2602 /usr/share/perl/5.8.4/fields.pm
2603 /usr/share/perl/5.8.4/integer.pm
2604 /usr/share/perl/5.8.4/locale.pm
2605 /usr/share/perl/5.8.4/overload.pm
2606 /usr/share/perl/5.8.4/strict.pm
2607 /usr/share/perl/5.8.4/utf8.pm
2608 /usr/share/perl/5.8.4/utf8_heavy.pl
2609 /usr/share/perl/5.8.4/vars.pm
2610 /usr/share/perl/5.8.4/warnings.pm
2611 /usr/share/perl/5.8.4/warnings/register.pm
2613 A nice trick to find out the minimal set of Perl library files you will
2614 need to run a Perl program is
2616 perl -e 'do "prog.pl"; END { print "$_\n" for sort keys %INC }'
2618 (this will not find libraries required in runtime, unfortunately, but
2619 it's a minimal set) and if you want to find out all the files you can
2620 use something like the below
2622 strace perl -le 'do "x.pl"' 2>&1 | perl -nle '/^open\(\"(.+?)"/ && print $1'
2624 (The 'strace' is Linux-specific, other similar utilities include 'truss'
2627 =head1 DOCUMENTATION
2629 Read the manual entries before running perl. The main documentation
2630 is in the pod/ subdirectory and should have been installed during the
2631 build process. Type B<man perl> to get started. Alternatively, you
2632 can type B<perldoc perl> to use the supplied perldoc script. This is
2633 sometimes useful for finding things in the library modules.
2635 Under UNIX, you can produce a documentation book in postscript form,
2636 along with its table of contents, by going to the pod/ subdirectory and
2639 ./roffitall -groff # If you have GNU groff installed
2640 ./roffitall -psroff # If you have psroff
2642 This will leave you with two postscript files ready to be printed.
2643 (You may need to fix the roffitall command to use your local troff
2646 Note that you must have performed the installation already before running
2647 the above, since the script collects the installed files to generate
2652 Original author: Andy Dougherty doughera@lafayette.edu , borrowing very
2653 heavily from the original README by Larry Wall, with lots of helpful
2654 feedback and additions from the perl5-porters@perl.org folks.
2656 If you have problems, corrections, or questions, please see
2657 L<"Reporting Problems"> above.
2659 =head1 REDISTRIBUTION
2661 This document is part of the Perl package and may be distributed under
2662 the same terms as perl itself, with the following additional request:
2663 If you are distributing a modified version of perl (perhaps as part of
2664 a larger package) please B<do> modify these installation instructions
2665 and the contact information to match your distribution.