This is a live mirror of the Perl 5 development currently hosted at https://github.com/perl/perl5
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1If you read this file _as_is_, just ignore the funny characters you see.
2It is written in the POD format (see pod/perlpod.pod) which is specially
3designed to be readable as is.
4
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5=head1 NAME
6
cb8c159f 7INSTALL - Build and Installation guide for perl 5.
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8
9=head1 SYNOPSIS
10
7df75831 11First, make sure you have an up-to-date version of Perl. If you
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12didn't get your Perl source from CPAN, check the latest version at
13http://www.cpan.org/src/. Perl uses a version scheme where even-numbered
08854360 14subreleases (like 5.8.x and 5.10.x) are stable maintenance releases and
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15odd-numbered subreleases (like 5.7.x and 5.9.x) are unstable
16development releases. Development releases should not be used in
17production environments. Fixes and new features are first carefully
18tested in development releases and only if they prove themselves to be
19worthy will they be migrated to the maintenance releases.
3ce0d271 20
7df75831 21The basic steps to build and install perl 5 on a Unix system with all
dd3196cd 22the defaults are to run, from a freshly unpacked source tree:
8e07c86e 23
491517e0 24 sh Configure -de
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25 make
26 make test
27 make install
36477c24 28
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29Each of these is explained in further detail below.
30
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31The above commands will install Perl to /usr/local (or some other
32platform-specific directory -- see the appropriate file in hints/.)
7df75831 33If that's not okay with you, you can run Configure interactively, by
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34just typing "sh Configure" (without the -de args). You can also specify
35any prefix location by adding "-Dprefix='/some/dir'" to Configure's args.
36To explicitly name the perl binary, use the command
37"make install PERLNAME=myperl".
491517e0 38
668cbedd 39Building perl from source requires an ANSI compliant C compiler.
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40A minimum of C89 is required. Some features available in C99 will
41be probed for and used when found. The perl build process does not
42rely on anything more than C89.
43
ff52061e 44These options, and many more, are explained in further detail below.
7f678428 45
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46If you're building perl from a git repository, you should also consult
47the documentation in pod/perlgit.pod for information on that special
48circumstance.
49
8d74ce1c 50If you have problems, corrections, or questions, please see
ff52061e 51L<"Reporting Problems"> below.
8d74ce1c 52
7beaa944 53For information on what's new in this release, see the
37ee6528 54pod/perldelta.pod file. For more information about how to find more
9519d2ec 55specific detail about changes, see the Changes file.
c3edaffb 56
1ec51d55 57=head1 DESCRIPTION
edb1cbcb 58
c3edaffb 59This document is written in pod format as an easy way to indicate its
60structure. The pod format is described in pod/perlpod.pod, but you can
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61read it as is with any pager or editor. Headings and items are marked
62by lines beginning with '='. The other mark-up used is
63
64 B<text> embolden text, used for switches, programs or commands
65 C<code> literal code
66 L<name> A link (cross reference) to name
ce80d64e 67 F<file> A filename
1ec51d55 68
c42e3e15 69Although most of the defaults are probably fine for most users,
ce80d64e 70you should probably at least skim through this document before
1ec51d55 71proceeding.
c3edaffb 72
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73In addition to this file, check if there is a README file specific to
74your operating system, since it may provide additional or different
75instructions for building Perl. If there is a hint file for your
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76system (in the hints/ directory) you might also want to read it
77for even more information.
c42e3e15 78
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79For additional information about porting Perl, see the section on
80L<"Porting information"> below, and look at the files in the Porting/
81directory.
d56c5707 82
ce80d64e 83=head1 PRELIMINARIES
c42e3e15 84
ce80d64e 85=head2 Changes and Incompatibilities
c42e3e15 86
37ee6528 87Please see pod/perldelta.pod for a description of the changes and
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88potential incompatibilities introduced with this release. A few of
89the most important issues are listed below, but you should refer
37ee6528 90to pod/perldelta.pod for more detailed information.
c42e3e15 91
fdd3cf50 92B<WARNING:> This version is not binary compatible with prior releases of Perl.
cc65bb49 93If you have built extensions (i.e. modules that include C code)
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94using an earlier version of Perl, you will need to rebuild and reinstall
95those extensions.
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96
97Pure perl modules without XS or C code should continue to work fine
dd3196cd 98without reinstallation. See the discussion below on
7df75831 99L<"Coexistence with earlier versions of perl 5"> for more details.
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100
101The standard extensions supplied with Perl will be handled automatically.
102
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103On a related issue, old modules may possibly be affected by the changes
104in the Perl language in the current release. Please see
37ee6528 105pod/perldelta.pod for a description of what's changed. See your
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106installed copy of the perllocal.pod file for a (possibly incomplete)
107list of locally installed modules. Also see CPAN::autobundle for one
108way to make a "bundle" of your currently installed modules.
16dc217a 109
aa689395 110=head1 Run Configure
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111
112Configure will figure out various things about your system. Some
113things Configure will figure out for itself, other things it will ask
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114you about. To accept the default, just press RETURN. The default is
115almost always okay. It is normal for some things to be "NOT found",
116since Configure often searches for many different ways of performing
117the same function.
118
ce80d64e 119At any Configure prompt, you can type &-d and Configure will use the
d6baa268 120defaults from then on.
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121
122After it runs, Configure will perform variable substitution on all the
1ec51d55 123*.SH files and offer to run make depend.
8e07c86e 124
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125The results of a Configure run are stored in the config.sh and Policy.sh
126files.
127
ce80d64e 128=head2 Common Configure options
844fc9f4 129
ce80d64e 130Configure supports a number of useful options. Run
844fc9f4 131
ce80d64e 132 Configure -h
d6baa268 133
ce80d64e 134to get a listing. See the Porting/Glossary file for a complete list of
fb73857a 135Configure variables you can set and their definitions.
136
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137=over 4
138
08854360 139=item C compiler
d6baa268 140
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141To compile with gcc, if it's not the default compiler on your
142system, you should run
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143
144 sh Configure -Dcc=gcc
145
08854360 146This is the preferred way to specify gcc (or any another alternative
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147compiler) so that the hints files can set appropriate defaults.
148
d6baa268 149=item Installation prefix
4633a7c4 150
8e07c86e 151By default, for most systems, perl will be installed in
8d74ce1c 152/usr/local/{bin, lib, man}. (See L<"Installation Directories">
7df75831 153and L<"Coexistence with earlier versions of perl 5"> below for
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154further details.)
155
156You can specify a different 'prefix' for the default installation
ce80d64e 157directory when Configure prompts you, or by using the Configure command
8d74ce1c 158line option -Dprefix='/some/directory', e.g.
8e07c86e 159
25f94b33 160 sh Configure -Dprefix=/opt/perl
4633a7c4 161
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162If your prefix contains the string "perl", then the suggested
163directory structure is simplified. For example, if you use
164prefix=/opt/perl, then Configure will suggest /opt/perl/lib instead of
165/opt/perl/lib/perl5/. Again, see L<"Installation Directories"> below
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166for more details. Do not include a trailing slash, (i.e. /opt/perl/)
167or you may experience odd test failures.
8e07c86e 168
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169NOTE: You must not specify an installation directory that is the same
170as or below your perl source directory. If you do, installperl will
171attempt infinite recursion.
84902520 172
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173=item /usr/bin/perl
174
175It may seem obvious, but Perl is useful only when users can easily
176find it. It's often a good idea to have both /usr/bin/perl and
dd64f1c3 177/usr/local/bin/perl be symlinks to the actual binary. Be especially
d6baa268 178careful, however, not to overwrite a version of perl supplied by your
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179vendor unless you are sure you know what you are doing. If you insist
180on replacing your vendor's perl, useful information on how it was
181configured may be found with
182
183 perl -V:config_args
184
185(Check the output carefully, however, since this doesn't preserve
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186spaces in arguments to Configure. For that, you have to look carefully
187at config_arg1, config_arg2, etc.)
d6baa268 188
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189By default, Configure will not try to link /usr/bin/perl to the current
190version of perl. You can turn on that behavior by running
d6baa268 191
7d56c962 192 Configure -Dinstallusrbinperl
d6baa268 193
7d56c962 194or by answering 'yes' to the appropriate Configure prompt.
d6baa268 195
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196In any case, system administrators are strongly encouraged to put
197(symlinks to) perl and its accompanying utilities, such as perldoc,
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198into a directory typically found along a user's PATH, or in another
199obvious and convenient place.
200
71c4561b 201=item Building a development release
04d420f9 202
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203For development releases (odd subreleases, like 5.9.x) if you want to
204use Configure -d, you will also need to supply -Dusedevel to Configure,
205because the default answer to the question "do you really want to
206Configure a development version?" is "no". The -Dusedevel skips that
207sanity check.
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208
209=back
8e07c86e 210
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211If you are willing to accept all the defaults, and you want terse
212output, you can run
213
214 sh Configure -des
215
dd3196cd 216=head2 Altering Configure variables for C compiler switches etc.
46bb10fb 217
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218For most users, most of the Configure defaults are fine, or can easily
219be set on the Configure command line. However, if Configure doesn't
220have an option to do what you want, you can change Configure variables
221after the platform hints have been run by using Configure's -A switch.
222For example, here's how to add a couple of extra flags to C compiler
223invocations:
46bb10fb 224
08854360 225 sh Configure -Accflags="-DPERL_EXTERNAL_GLOB -DNO_HASH_SEED"
46bb10fb 226
5247441a 227To clarify, those ccflags values are not Configure options; if passed to
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228Configure directly, they won't do anything useful (they will define a
229variable in config.sh, but without taking any action based upon it).
230But when passed to the compiler, those flags will activate #ifdefd code.
5247441a 231
ce80d64e 232For more help on Configure switches, run
46bb10fb 233
ce80d64e 234 sh Configure -h
46bb10fb 235
ce80d64e 236=head2 Major Configure-time Build Options
46bb10fb 237
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238There are several different ways to Configure and build perl for your
239system. For most users, the defaults are sensible and will work.
240Some users, however, may wish to further customize perl. Here are
241some of the main things you can change.
46bb10fb 242
ce80d64e 243=head3 Threads
cc65bb49 244
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245On some platforms, perl can be compiled with support for threads. To
246enable this, run
4633a7c4 247
ce80d64e 248 sh Configure -Dusethreads
4633a7c4 249
ce80d64e 250The default is to compile without thread support.
cc65bb49 251
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252Perl used to have two different internal threads implementations. The current
253model (available internally since 5.6, and as a user-level module since 5.8) is
254called interpreter-based implementation (ithreads), with one interpreter per
255thread, and explicit sharing of data. The (deprecated) 5.005 version
54c46bd5 256(5005threads) was removed for release 5.10.
d6baa268 257
ce80d64e 258The 'threads' module is for use with the ithreads implementation. The
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259'Thread' module emulates the old 5005threads interface on top of the current
260ithreads model.
d6baa268 261
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262When using threads, perl uses a dynamically-sized buffer for some of
263the thread-safe library calls, such as those in the getpw*() family.
264This buffer starts small, but it will keep growing until the result
265fits. To get a fixed upper limit, you should compile Perl with
266PERL_REENTRANT_MAXSIZE defined to be the number of bytes you want. One
267way to do this is to run Configure with
08854360 268C<-Accflags=-DPERL_REENTRANT_MAXSIZE=65536>.
d6baa268 269
08854360 270=head3 Large file support
b367e8b0 271
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272Since Perl 5.6.0, Perl has supported large files (files larger than
2732 gigabytes), and in many common platforms like Linux or Solaris this
274support is on by default.
d6baa268 275
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276This is both good and bad. It is good in that you can use large files,
277seek(), stat(), and -s them. It is bad in that if you are interfacing Perl
278using some extension, the components you are connecting to must also
279be large file aware: if Perl thinks files can be large but the other
280parts of the software puzzle do not understand the concept, bad things
08854360 281will happen.
d6baa268 282
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283There's also one known limitation with the current large files
284implementation: unless you also have 64-bit integers (see the next
285section), you cannot use the printf/sprintf non-decimal integer formats
286like C<%x> to print filesizes. You can use C<%d>, though.
d6baa268 287
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288If you want to compile perl without large file support, use
289
290 sh Configure -Uuselargefiles
291
08854360 292=head3 64 bit support
d6baa268 293
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294If your platform does not run natively at 64 bits, but can simulate
295them with compiler flags and/or C<long long> or C<int64_t>,
ce80d64e 296you can build a perl that uses 64 bits.
d6baa268 297
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298There are actually two modes of 64-bitness: the first one is achieved
299using Configure -Duse64bitint and the second one using Configure
300-Duse64bitall. The difference is that the first one is minimal and
301the second one maximal. The first works in more places than the second.
d6baa268 302
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303The C<use64bitint> option does only as much as is required to get
30464-bit integers into Perl (this may mean, for example, using "long
305longs") while your memory may still be limited to 2 gigabytes (because
306your pointers could still be 32-bit). Note that the name C<64bitint>
307does not imply that your C compiler will be using 64-bit C<int>s (it
308might, but it doesn't have to). The C<use64bitint> simply means that
309you will be able to have 64 bit-wide scalar values.
d6baa268 310
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311The C<use64bitall> option goes all the way by attempting to switch
312integers (if it can), longs (and pointers) to being 64-bit. This may
313create an even more binary incompatible Perl than -Duse64bitint: the
314resulting executable may not run at all in a 32-bit box, or you may
315have to reboot/reconfigure/rebuild your operating system to be 64-bit
316aware.
d6baa268 317
08854360 318Natively 64-bit systems need neither -Duse64bitint nor -Duse64bitall.
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319On these systems, it might be the default compilation mode, and there
320is currently no guarantee that passing no use64bitall option to the
321Configure process will build a 32bit perl. Implementing -Duse32bit*
1ed7425e 322options is planned for a future release of perl.
d6baa268 323
ce80d64e 324=head3 Long doubles
d6baa268 325
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326In some systems you may be able to use long doubles to enhance the
327range and precision of your double precision floating point numbers
328(that is, Perl's numbers). Use Configure -Duselongdouble to enable
329this support (if it is available).
d6baa268 330
ce80d64e 331=head3 "more bits"
b367e8b0 332
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333You can "Configure -Dusemorebits" to turn on both the 64-bit support
334and the long double support.
b367e8b0 335
ce80d64e 336=head3 Algorithmic Complexity Attacks on Hashes
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337
338In Perls 5.8.0 and earlier it was easy to create degenerate hashes.
339Processing such hashes would consume large amounts of CPU time,
3debabd9 340enabling a "Denial of Service" attack against Perl. Such hashes may be
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341a problem for example for mod_perl sites, sites with Perl CGI scripts
342and web services, that process data originating from external sources.
343
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344In Perl 5.8.1 a security feature was introduced to make it harder to
345create such degenerate hashes. A visible side effect of this was that
346the keys(), values(), and each() functions may return the hash elements
347in different order between different runs of Perl even with the same
348data. It also had unintended binary incompatibility issues with
349certain modules compiled against Perl 5.8.0.
350
351In Perl 5.8.2 an improved scheme was introduced. Hashes will return
352elements in the same order as Perl 5.8.0 by default. On a hash by hash
353basis, if pathological data is detected during a hash key insertion,
354then that hash will switch to an alternative random hash seed. As
355adding keys can always dramatically change returned hash element order,
356existing programs will not be affected by this, unless they
357specifically test for pre-recorded hash return order for contrived
358data. (eg the list of keys generated by C<map {"\0"x$_} 0..15> trigger
359randomisation) In effect the new implementation means that 5.8.1 scheme
360is only being used on hashes which are under attack.
361
362One can still revert to the old guaranteed repeatable order (and be
363vulnerable to attack by wily crackers) by setting the environment
364variable PERL_HASH_SEED, see L<perlrun/PERL_HASH_SEED>. Another option
365is to add -DUSE_HASH_SEED_EXPLICIT to the compilation flags (for
f80da78e 366example by using C<Configure -Accflags=-DUSE_HASH_SEED_EXPLICIT>), in
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367which case one has to explicitly set the PERL_HASH_SEED environment
368variable to enable the security feature, or by adding -DNO_HASH_SEED to
369the compilation flags to completely disable the randomisation feature.
504f80c1 370
3debabd9 371B<Perl has never guaranteed any ordering of the hash keys>, and the
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372ordering has already changed several times during the lifetime of Perl
3735. Also, the ordering of hash keys has always been, and continues to
08854360 374be, affected by the insertion order. Note that because of this
86358043 375randomisation for example the Data::Dumper results will be different
08854360 376between different runs of Perl, since Data::Dumper by default dumps
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377hashes "unordered". The use of the Data::Dumper C<Sortkeys> option is
378recommended.
504f80c1 379
ce80d64e 380=head3 SOCKS
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381
382Perl can be configured to be 'socksified', that is, to use the SOCKS
383TCP/IP proxy protocol library. SOCKS is used to give applications
384access to transport layer network proxies. Perl supports only SOCKS
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385Version 5. The corresponding Configure option is -Dusesocks.
386You can find more about SOCKS from wikipedia at
387L<http://en.wikipedia.org/wiki/SOCKS>.
1b9c9cf5 388
ce80d64e 389=head3 Dynamic Loading
d6baa268 390
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391By default, Configure will compile perl to use dynamic loading.
392If you want to force perl to be compiled completely
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393statically, you can either choose this when Configure prompts you or
394you can use the Configure command line option -Uusedl.
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395With this option, you won't be able to use any new extension
396(XS) module without recompiling perl itself.
d6baa268 397
ce80d64e 398=head3 Building a shared Perl library
c3edaffb 399
400Currently, for most systems, the main perl executable is built by
401linking the "perl library" libperl.a with perlmain.o, your static
8ba4bff0 402extensions, and various extra libraries, such as -lm.
c3edaffb 403
08854360 404On systems that support dynamic loading, it may be possible to
9d67150a 405replace libperl.a with a shared libperl.so. If you anticipate building
c3edaffb 406several different perl binaries (e.g. by embedding libperl into
407different programs, or by using the optional compiler extension), then
9d67150a 408you might wish to build a shared libperl.so so that all your binaries
c3edaffb 409can share the same library.
410
411The disadvantages are that there may be a significant performance
9d67150a 412penalty associated with the shared libperl.so, and that the overall
aa689395 413mechanism is still rather fragile with respect to different versions
c3edaffb 414and upgrades.
415
416In terms of performance, on my test system (Solaris 2.5_x86) the perl
9d67150a 417test suite took roughly 15% longer to run with the shared libperl.so.
c3edaffb 418Your system and typical applications may well give quite different
419results.
420
421The default name for the shared library is typically something like
08854360 422libperl.so.5.8.8 (for Perl 5.8.8), or libperl.so.588, or simply
9d67150a 423libperl.so. Configure tries to guess a sensible naming convention
c3edaffb 424based on your C library name. Since the library gets installed in a
425version-specific architecture-dependent directory, the exact name
426isn't very important anyway, as long as your linker is happy.
427
c3edaffb 428You can elect to build a shared libperl by
429
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430 sh Configure -Duseshrplib
431
432To build a shared libperl, the environment variable controlling shared
433library search (LD_LIBRARY_PATH in most systems, DYLD_LIBRARY_PATH for
434NeXTSTEP/OPENSTEP/Darwin, LIBRARY_PATH for BeOS, LD_LIBRARY_PATH/SHLIB_PATH
435for HP-UX, LIBPATH for AIX, PATH for Cygwin) must be set up to include
436the Perl build directory because that's where the shared libperl will
437be created. Configure arranges makefile to have the correct shared
438library search settings. You can find the name of the environment
439variable Perl thinks works in your your system by
440
441 grep ldlibpthname config.sh
442
443However, there are some special cases where manually setting the
444shared library path might be required. For example, if you want to run
445something like the following with the newly-built but not-yet-installed
446./perl:
447
04bd6448 448 ./perl -MTestInit t/misc/failing_test.t
08854360 449
ce80d64e 450or
08854360 451
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452 ./perl -Ilib ~/my_mission_critical_test
453
454then you need to set up the shared library path explicitly.
455You can do this with
456
457 LD_LIBRARY_PATH=`pwd`:$LD_LIBRARY_PATH; export LD_LIBRARY_PATH
458
459for Bourne-style shells, or
460
461 setenv LD_LIBRARY_PATH `pwd`
462
463for Csh-style shells. (This procedure may also be needed if for some
464unexpected reason Configure fails to set up makefile correctly.) (And
465again, it may be something other than LD_LIBRARY_PATH for you, see above.)
466
467You can often recognize failures to build/use a shared libperl from error
468messages complaining about a missing libperl.so (or libperl.sl in HP-UX),
469for example:
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470
471 18126:./miniperl: /sbin/loader: Fatal Error: cannot map libperl.so
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472
473There is also an potential problem with the shared perl library if you
474want to have more than one "flavor" of the same version of perl (e.g.
475with and without -DDEBUGGING). For example, suppose you build and
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476install a standard Perl 5.10.0 with a shared library. Then, suppose you
477try to build Perl 5.10.0 with -DDEBUGGING enabled, but everything else
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478the same, including all the installation directories. How can you
479ensure that your newly built perl will link with your newly built
480libperl.so.8 rather with the installed libperl.so.8? The answer is
481that you might not be able to. The installation directory is encoded
482in the perl binary with the LD_RUN_PATH environment variable (or
483equivalent ld command-line option). On Solaris, you can override that
484with LD_LIBRARY_PATH; on Linux, you can only override at runtime via
485LD_PRELOAD, specifying the exact filename you wish to be used; and on
486Digital Unix, you can override LD_LIBRARY_PATH by setting the
487_RLD_ROOT environment variable to point to the perl build directory.
488
489In other words, it is generally not a good idea to try to build a perl
490with a shared library if $archlib/CORE/$libperl already exists from a
491previous build.
492
493A good workaround is to specify a different directory for the
494architecture-dependent library for your -DDEBUGGING version of perl.
495You can do this by changing all the *archlib* variables in config.sh to
496point to your new architecture-dependent library.
497
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498=head3 Environment access
499
500Perl often needs to write to the program's environment, such as when C<%ENV>
501is assigned to. Many implementations of the C library function C<putenv()>
502leak memory, so where possible perl will manipulate the environment directly
503to avoid these leaks. The default is now to perform direct manipulation
504whenever perl is running as a stand alone interpreter, and to call the safe
505but potentially leaky C<putenv()> function when the perl interpreter is
506embedded in another application. You can force perl to always use C<putenv()>
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507by compiling with C<-Accflags="-DPERL_USE_SAFE_PUTENV">, see section
508L</"Altering Configure variables for C compiler switches etc.">.
509You can force an embedded perl to use direct manipulation by setting
510C<PL_use_safe_putenv = 0;> after the C<perl_construct()> call.
575e1338 511
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512=head2 Installation Directories
513
514The installation directories can all be changed by answering the
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515appropriate questions in Configure. For convenience, all the installation
516questions are near the beginning of Configure. Do not include trailing
517slashes on directory names. At any point during the Configure process,
518you can answer a question with &-d and Configure will use the defaults
519from then on. Alternatively, you can
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520
521 grep '^install' config.sh
522
523after Configure has run to verify the installation paths.
524
525The defaults are intended to be reasonable and sensible for most
526people building from sources. Those who build and distribute binary
527distributions or who export perl to a range of systems will probably
528need to alter them. If you are content to just accept the defaults,
529you can safely skip the next section.
530
531The directories set up by Configure fall into three broad categories.
532
533=over 4
534
535=item Directories for the perl distribution
536
0e79a3d1 537By default, Configure will use the following directories for 5.17.0.
ce80d64e 538$version is the full perl version number, including subversion, e.g.
8891dd8d 5395.12.3, and $archname is a string like sun4-sunos,
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540determined by Configure. The full definitions of all Configure
541variables are in the file Porting/Glossary.
542
543 Configure variable Default value
544 $prefixexp /usr/local
545 $binexp $prefixexp/bin
546 $scriptdirexp $prefixexp/bin
547 $privlibexp $prefixexp/lib/perl5/$version
548 $archlibexp $prefixexp/lib/perl5/$version/$archname
549 $man1direxp $prefixexp/man/man1
550 $man3direxp $prefixexp/man/man3
551 $html1direxp (none)
552 $html3direxp (none)
553
554$prefixexp is generated from $prefix, with ~ expansion done to convert home
555directories into absolute paths. Similarly for the other variables listed. As
556file system calls do not do this, you should always reference the ...exp
557variables, to support users who build perl in their home directory.
558
559Actually, Configure recognizes the SVR3-style
560/usr/local/man/l_man/man1 directories, if present, and uses those
561instead. Also, if $prefix contains the string "perl", the library
562directories are simplified as described below. For simplicity, only
563the common style is shown here.
564
565=item Directories for site-specific add-on files
566
567After perl is installed, you may later wish to add modules (e.g. from
568CPAN) or scripts. Configure will set up the following directories to
569be used for installing those add-on modules and scripts.
570
571 Configure variable Default value
572 $siteprefixexp $prefixexp
573 $sitebinexp $siteprefixexp/bin
574 $sitescriptexp $siteprefixexp/bin
575 $sitelibexp $siteprefixexp/lib/perl5/site_perl/$version
576 $sitearchexp $siteprefixexp/lib/perl5/site_perl/$version/$archname
577 $siteman1direxp $siteprefixexp/man/man1
578 $siteman3direxp $siteprefixexp/man/man3
579 $sitehtml1direxp (none)
580 $sitehtml3direxp (none)
581
582By default, ExtUtils::MakeMaker will install architecture-independent
583modules into $sitelib and architecture-dependent modules into $sitearch.
584
585=item Directories for vendor-supplied add-on files
586
587Lastly, if you are building a binary distribution of perl for
588distribution, Configure can optionally set up the following directories
589for you to use to distribute add-on modules.
590
591 Configure variable Default value
592 $vendorprefixexp (none)
593 (The next ones are set only if vendorprefix is set.)
594 $vendorbinexp $vendorprefixexp/bin
595 $vendorscriptexp $vendorprefixexp/bin
596 $vendorlibexp
597 $vendorprefixexp/lib/perl5/vendor_perl/$version
598 $vendorarchexp
599 $vendorprefixexp/lib/perl5/vendor_perl/$version/$archname
600 $vendorman1direxp $vendorprefixexp/man/man1
601 $vendorman3direxp $vendorprefixexp/man/man3
602 $vendorhtml1direxp (none)
603 $vendorhtml3direxp (none)
604
605These are normally empty, but may be set as needed. For example,
606a vendor might choose the following settings:
607
608 $prefix /usr
609 $siteprefix /usr/local
610 $vendorprefix /usr
611
612This would have the effect of setting the following:
613
614 $binexp /usr/bin
615 $scriptdirexp /usr/bin
616 $privlibexp /usr/lib/perl5/$version
617 $archlibexp /usr/lib/perl5/$version/$archname
618 $man1direxp /usr/man/man1
619 $man3direxp /usr/man/man3
620
621 $sitebinexp /usr/local/bin
622 $sitescriptexp /usr/local/bin
623 $sitelibexp /usr/local/lib/perl5/site_perl/$version
624 $sitearchexp /usr/local/lib/perl5/site_perl/$version/$archname
625 $siteman1direxp /usr/local/man/man1
626 $siteman3direxp /usr/local/man/man3
627
628 $vendorbinexp /usr/bin
629 $vendorscriptexp /usr/bin
630 $vendorlibexp /usr/lib/perl5/vendor_perl/$version
631 $vendorarchexp /usr/lib/perl5/vendor_perl/$version/$archname
632 $vendorman1direxp /usr/man/man1
633 $vendorman3direxp /usr/man/man3
634
635Note how in this example, the vendor-supplied directories are in the
668cbedd 636/usr hierarchy, while the directories reserved for the end user are in
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637the /usr/local hierarchy.
638
639The entire installed library hierarchy is installed in locations with
640version numbers, keeping the installations of different versions distinct.
641However, later installations of Perl can still be configured to search the
642installed libraries corresponding to compatible earlier versions.
7df75831 643See L<"Coexistence with earlier versions of perl 5"> below for more details
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644on how Perl can be made to search older version directories.
645
646Of course you may use these directories however you see fit. For
647example, you may wish to use $siteprefix for site-specific files that
648are stored locally on your own disk and use $vendorprefix for
649site-specific files that are stored elsewhere on your organization's
650network. One way to do that would be something like
651
652 sh Configure -Dsiteprefix=/usr/local -Dvendorprefix=/usr/share/perl
653
654=item otherlibdirs
655
656As a final catch-all, Configure also offers an $otherlibdirs
657variable. This variable contains a colon-separated list of additional
658directories to add to @INC. By default, it will be empty.
659Perl will search these directories (including architecture and
660version-specific subdirectories) for add-on modules and extensions.
661
662For example, if you have a bundle of perl libraries from a previous
663installation, perhaps in a strange place:
664
665 Configure -Dotherlibdirs=/usr/lib/perl5/site_perl/5.8.1
666
667=item APPLLIB_EXP
668
669There is one other way of adding paths to @INC at perl build time, and
670that is by setting the APPLLIB_EXP C pre-processor token to a colon-
671separated list of directories, like this
672
673 sh Configure -Accflags='-DAPPLLIB_EXP=\"/usr/libperl\"'
674
675The directories defined by APPLLIB_EXP get added to @INC I<first>,
676ahead of any others, and so provide a way to override the standard perl
677modules should you, for example, want to distribute fixes without
678touching the perl distribution proper. And, like otherlib dirs,
679version and architecture specific subdirectories are also searched, if
680present, at run time. Of course, you can still search other @INC
681directories ahead of those in APPLLIB_EXP by using any of the standard
682run-time methods: $PERLLIB, $PERL5LIB, -I, use lib, etc.
683
785aa5e3 684=item usesitecustomize
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685
686Run-time customization of @INC can be enabled with:
687
36de116d 688 sh Configure -Dusesitecustomize
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690which will define USE_SITECUSTOMIZE and $Config{usesitecustomize}.
691When enabled, this makes perl run F<$sitelibexp/sitecustomize.pl> before
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692anything else. This script can then be set up to add additional
693entries to @INC.
694
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695=item Man Pages
696
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697By default, man pages will be installed in $man1dir and $man3dir, which
698are normally /usr/local/man/man1 and /usr/local/man/man3. If you
699want to use a .3pm suffix for perl man pages, you can do that with
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700
701 sh Configure -Dman3ext=3pm
702
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703=item HTML pages
704
705Currently, the standard perl installation does not do anything with
706HTML documentation, but that may change in the future. Further, some
707add-on modules may wish to install HTML documents. The html Configure
708variables listed above are provided if you wish to specify where such
709documents should be placed. The default is "none", but will likely
710eventually change to something useful based on user feedback.
711
712=back
713
714Some users prefer to append a "/share" to $privlib and $sitelib
715to emphasize that those directories can be shared among different
716architectures.
717
718Note that these are just the defaults. You can actually structure the
719directories any way you like. They don't even have to be on the same
720filesystem.
c3edaffb 721
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722Further details about the installation directories, maintenance and
723development subversions, and about supporting multiple versions are
7df75831 724discussed in L<"Coexistence with earlier versions of perl 5"> below.
10c7e831 725
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726If you specify a prefix that contains the string "perl", then the
727library directory structure is slightly simplified. Instead of
728suggesting $prefix/lib/perl5/, Configure will suggest $prefix/lib.
2bf2710f 729
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730Thus, for example, if you Configure with
731-Dprefix=/opt/perl, then the default library directories for 5.9.0 are
2bf2710f 732
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733 Configure variable Default value
734 $privlib /opt/perl/lib/5.9.0
735 $archlib /opt/perl/lib/5.9.0/$archname
736 $sitelib /opt/perl/lib/site_perl/5.9.0
737 $sitearch /opt/perl/lib/site_perl/5.9.0/$archname
2bf2710f 738
ce80d64e 739=head2 Changing the installation directory
c3edaffb 740
ce80d64e 741Configure distinguishes between the directory in which perl (and its
7df75831 742associated files) should be installed, and the directory in which it
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743will eventually reside. For most sites, these two are the same; for
744sites that use AFS, this distinction is handled automatically.
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745However, sites that use package management software such as rpm or
746dpkg, or users building binary packages for distribution may also
747wish to install perl into a different directory before moving perl
748to its final destination. There are two ways to do that:
749
750=over 4
751
752=item installprefix
c3edaffb 753
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754To install perl under the /tmp/perl5 directory, use the following
755command line:
c3edaffb 756
7df75831 757 sh Configure -Dinstallprefix=/tmp/perl5
c3edaffb 758
ce80d64e 759(replace /tmp/perl5 by a directory of your choice).
2bf2710f 760
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761Beware, though, that if you go to try to install new add-on
762modules, they too will get installed in under '/tmp/perl5' if you
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763follow this example. That's why it's usually better to use DESTDIR,
764as shown in the next section.
c3edaffb 765
7df75831 766=item DESTDIR
9d67150a 767
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768If you need to install perl on many identical systems, it is convenient
769to compile it once and create an archive that can be installed on
770multiple systems. Suppose, for example, that you want to create an
771archive that can be installed in /opt/perl. One way to do that is by
772using the DESTDIR variable during C<make install>. The DESTDIR is
773automatically prepended to all the installation paths. Thus you
774simply do:
830717a7 775
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776 sh Configure -Dprefix=/opt/perl -des
777 make
778 make test
779 make install DESTDIR=/tmp/perl5
780 cd /tmp/perl5/opt/perl
781 tar cvf /tmp/perl5-archive.tar .
9d67150a 782
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783=back
784
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785=head2 Relocatable @INC
786
787To create a relocatable perl tree, use the following command line:
788
789 sh Configure -Duserelocatableinc
790
791Then the paths in @INC (and everything else in %Config) can be
792optionally located via the path of the perl executable.
793
794That means that, if the string ".../" is found at the start of any
795path, it's substituted with the directory of $^X. So, the relocation
796can be configured on a per-directory basis, although the default with
797"-Duserelocatableinc" is that everything is relocated. The initial
798install is done to the original configured prefix.
799
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800This option is not compatible with the building of a shared libperl
801("-Duseshrplib"), because in that case perl is linked with an hard-coded
802rpath that points at the libperl.so, that cannot be relocated.
803
ce80d64e 804=head2 Site-wide Policy settings
55479bb6 805
ce80d64e 806After Configure runs, it stores a number of common site-wide "policy"
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807answers (such as installation directories) in the Policy.sh file.
808If you want to build perl on another system using the same policy
809defaults, simply copy the Policy.sh file to the new system's perl build
810directory, and Configure will use it. This will work even if Policy.sh was
a0a8d9d3 811generated for another version of Perl, or on a system with a
da1b4322 812different architecture and/or operating system. However, in such cases,
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813you should review the contents of the file before using it: for
814example, your new target may not keep its man pages in the same place
815as the system on which the file was generated.
55479bb6 816
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817Alternatively, if you wish to change some or all of those policy
818answers, you should
c3edaffb 819
ce80d64e 820 rm -f Policy.sh
aa689395 821
ce80d64e 822to ensure that Configure doesn't re-use them.
2ae324a7 823
ce80d64e 824Further information is in the Policy_sh.SH file itself.
aa689395 825
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826If the generated Policy.sh file is unsuitable, you may freely edit it
827to contain any valid shell commands. It will be run just after the
828platform-specific hints files.
aa689395 829
ce80d64e 830=head2 Disabling older versions of Perl
aa689395 831
ce80d64e 832Configure will search for binary compatible versions of previously
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833installed perl binaries in the tree that is specified as target tree,
834and these will be used as locations to search for modules by the perl
835being built. The list of perl versions found will be put in the Configure
836variable inc_version_list.
86058a2d 837
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838To disable this use of older perl modules, even completely valid pure perl
839modules, you can specify to not include the paths found:
b2a6d19e 840
ce80d64e 841 sh Configure -Dinc_version_list=none ...
d6baa268 842
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843If you do want to use modules from some previous perl versions, the variable
844must contain a space separated list of directories under the site_perl
845directory, and has to include architecture-dependent directories separately,
846eg.
847
0e79a3d1 848 sh Configure -Dinc_version_list="5.17.0/x86_64-linux 5.14.0" ...
274ca399 849
ce80d64e 850When using the newer perl, you can add these paths again in the
668cbedd 851PERL5LIB environment variable or with perl's -I runtime option.
86058a2d 852
ce80d64e 853=head2 Building Perl outside of the source directory
86058a2d 854
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855Sometimes it is desirable to build Perl in a directory different from
856where the sources are, for example if you want to keep your sources
857read-only, or if you want to share the sources between different binary
858architectures. You can do this (if your file system supports symbolic
859links) by
06c896bb 860
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861 mkdir /tmp/perl/build/directory
862 cd /tmp/perl/build/directory
863 sh /path/to/perl/source/Configure -Dmksymlinks ...
06c896bb 864
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865This will create in /tmp/perl/build/directory a tree of symbolic links
866pointing to files in /path/to/perl/source. The original files are left
867unaffected. After Configure has finished you can just say
06c896bb 868
ce80d64e 869 make
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870 make test
871 make install
06c896bb 872
ce80d64e 873as usual, and Perl will be built in /tmp/perl/build/directory.
aa689395 874
3bf462b8
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875=head2 Building a debugging perl
876
877You can run perl scripts under the perl debugger at any time with
3fe9a6f1 878B<perl -d your_script>. If, however, you want to debug perl itself,
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879you probably want to have support for perl internal debugging code
880(activated by adding -DDEBUGGING to ccflags), and/or support for the
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881system debugger by adding -g to the optimisation flags. For that,
882use the parameter:
eaf812ae 883
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884 sh Configure -DDEBUGGING
885
886or
887
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888 sh Configure -DDEBUGGING=<mode>
889
890For a more eye appealing call, -DEBUGGING is defined to be an alias
891for -DDEBUGGING. For both, the -U calls are also supported, in order
892to be able to overrule the hints or Policy.sh settings.
893
7df75831 894Here are the DEBUGGING modes:
3bf462b8 895
7df75831 896=over 4
3bf462b8 897
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898=item -DDEBUGGING
899
900=item -DEBUGGING
901
902=item -DEBUGGING=both
903
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904Sets both -DDEBUGGING in the ccflags, and adds -g to optimize.
905
906You can actually specify -g and -DDEBUGGING independently (see below),
907but usually it's convenient to have both.
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908
909=item -DEBUGGING=-g
910
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911=item -Doptimize=-g
912
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913Adds -g to optimize, but does not set -DDEBUGGING.
914
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915(Note: Your system may actually require something like cc -g2.
916Check your man pages for cc(1) and also any hint file for your system.)
917
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918=item -DEBUGGING=none
919
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920=item -UDEBUGGING
921
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922Removes -g from optimize, and -DDEBUGGING from ccflags.
923
924=back
925
3bf462b8 926If you are using a shared libperl, see the warnings about multiple
a522f097 927versions of perl under L<Building a shared Perl library>.
3bf462b8 928
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929Note that a perl built with -DDEBUGGING will be much bigger and will run
930much, much more slowly than a standard perl.
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931
932=head2 DTrace support
933
934On platforms where DTrace is available, it may be enabled by
935using the -Dusedtrace option to Configure. DTrace probes are available for
936subroutine entry (sub-entry) and subroutine exit (sub-exit). Here's a
937simple D script that uses them:
938
939 perl$target:::sub-entry, perl$target:::sub-return {
940 printf("%s %s (%s:%d)\n", probename == "sub-entry" ? "->" : "<-",
941 copyinstr(arg0), copyinstr(arg1), arg2);
942 }
943
944
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945=head2 Extensions
946
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947Perl ships with a number of standard extensions. These are contained
948in the ext/ subdirectory.
949
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950By default, Configure will offer to build every extension which appears
951to be supported. For example, Configure will offer to build GDBM_File
7df75831 952only if it is able to find the gdbm library.
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953
954To disable certain extensions so that they are not built, use the
955-Dnoextensions=... and -Donlyextensions=... options. They both accept
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956a space-separated list of extensions, such as C<IPC/SysV>. The extensions
957listed in
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958C<noextensions> are removed from the list of extensions to build, while
959the C<onlyextensions> is rather more severe and builds only the listed
960extensions. The latter should be used with extreme caution since
961certain extensions are used by many other extensions and modules:
962examples of such modules include Fcntl and IO. The order of processing
963these options is first C<only> (if present), then C<no> (if present).
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964
965Of course, you may always run Configure interactively and select only
966the extensions you want.
967
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968If you unpack any additional extensions in the ext/ directory before
969running Configure, then Configure will offer to build those additional
970extensions as well. Most users probably shouldn't have to do this --
971it is usually easier to build additional extensions later after perl
972has been installed. However, if you wish to have those additional
973extensions statically linked into the perl binary, then this offers a
974convenient way to do that in one step. (It is not necessary, however;
975you can build and install extensions just fine even if you don't have
976dynamic loading. See lib/ExtUtils/MakeMaker.pm for more details.)
977Another way of specifying extra modules is described in
978L<"Adding extra modules to the build"> below.
8d74ce1c 979
dd3196cd 980If you re-use an old config.sh but change your system (e.g. by
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981adding libgdbm) Configure will still offer your old choices of extensions
982for the default answer, but it will also point out the discrepancy to
983you.
984
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985=head2 Including locally-installed libraries
986
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987Perl comes with interfaces to number of libraries, including threads,
988dbm, ndbm, gdbm, and Berkeley db. For the *db* extension, if
8d74ce1c 989Configure can find the appropriate header files and libraries, it will
7df75831 990automatically include that extension. The threading extension needs
27021420 991to be specified explicitly (see L</Threads>).
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992
993Those libraries are not distributed with perl. If your header (.h) files
994for those libraries are not in a directory normally searched by your C
995compiler, then you will need to include the appropriate -I/your/directory
996option when prompted by Configure. If your libraries are not in a
997directory normally searched by your C compiler and linker, then you will
998need to include the appropriate -L/your/directory option when prompted
999by Configure. See the examples below.
8d74ce1c 1000
ce80d64e 1001=head3 Examples
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1002
1003=over 4
1004
1005=item gdbm in /usr/local
1006
1007Suppose you have gdbm and want Configure to find it and build the
d6baa268 1008GDBM_File extension. This example assumes you have gdbm.h
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1009installed in /usr/local/include/gdbm.h and libgdbm.a installed in
1010/usr/local/lib/libgdbm.a. Configure should figure all the
1011necessary steps out automatically.
1012
1013Specifically, when Configure prompts you for flags for
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1014your C compiler, you should include -I/usr/local/include, if it's
1015not here yet. Similarly, when Configure prompts you for linker flags,
1016you should include -L/usr/local/lib.
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1017
1018If you are using dynamic loading, then when Configure prompts you for
1019linker flags for dynamic loading, you should again include
1020-L/usr/local/lib.
1021
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1022Again, this should all happen automatically. This should also work if
1023you have gdbm installed in any of (/usr/local, /opt/local, /usr/gnu,
1024/opt/gnu, /usr/GNU, or /opt/GNU).
8d74ce1c 1025
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1026=item BerkeleyDB in /usr/local/BerkeleyDB
1027
668cbedd 1028The version of BerkeleyDB distributed by Oracle installs in a
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1029version-specific directory by default, typically something like
1030/usr/local/BerkeleyDB.4.7. To have Configure find that, you need to add
1031-I/usr/local/BerkeleyDB.4.7/include to cc flags, as in the previous example,
1032and you will also have to take extra steps to help Configure find -ldb.
1033Specifically, when Configure prompts you for library directories,
1034add /usr/local/BerkeleyDB.4.7/lib to the list. Also, you will need to
1035add appropriate linker flags to tell the runtime linker where to find the
1036BerkeleyDB shared libraries.
1037
1038It is possible to specify this from the command line (all on one
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1039line):
1040
7df75831 1041 sh Configure -de \
e8b9ce60
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1042 -Dlocincpth='/usr/local/BerkeleyDB.4.7/include /usr/local/include' \
1043 -Dloclibpth='/usr/local/BerkeleyDB.4.7/lib /usr/local/lib' \
1044 -Aldflags='-R/usr/local/BerkeleyDB.4.7/lib'
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1045
1046locincpth is a space-separated list of include directories to search.
1047Configure will automatically add the appropriate -I directives.
1048
1049loclibpth is a space-separated list of library directories to search.
e8b9ce60 1050Configure will automatically add the appropriate -L directives.
8d74ce1c 1051
e8b9ce60
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1052The addition to ldflags is so that the dynamic linker knows where to find
1053the BerkeleyDB libraries. For Linux and Solaris, the -R option does that.
1054Other systems may use different flags. Use the appropriate flag for your
1055system.
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1056
1057=back
1058
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1059=head2 Overriding an old config.sh
1060
dd3196cd
RGS
1061If you want to use an old config.sh produced by a previous run of
1062Configure, but override some of the items with command line options, you
1063need to use B<Configure -O>.
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1064
1065=head2 GNU-style configure
1066
1067If you prefer the GNU-style configure command line interface, you can
1068use the supplied configure.gnu command, e.g.
1069
1070 CC=gcc ./configure.gnu
1071
1072The configure.gnu script emulates a few of the more common configure
1073options. Try
1074
1075 ./configure.gnu --help
1076
1077for a listing.
1078
1079(The file is called configure.gnu to avoid problems on systems
1080that would not distinguish the files "Configure" and "configure".)
1081
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1082=head2 Malloc Issues
1083
1084Perl relies heavily on malloc(3) to grow data structures as needed,
1085so perl's performance can be noticeably affected by the performance of
1086the malloc function on your system. The perl source is shipped with a
1087version of malloc that has been optimized for the typical requests from
1088perl, so there's a chance that it may be both faster and use less memory
1089than your system malloc.
1090
1091However, if your system already has an excellent malloc, or if you are
1092experiencing difficulties with extensions that use third-party libraries
1093that call malloc, then you should probably use your system's malloc.
1094(Or, you might wish to explore the malloc flags discussed below.)
1095
1096=over 4
1097
1098=item Using the system malloc
1099
1100To build without perl's malloc, you can use the Configure command
1101
1102 sh Configure -Uusemymalloc
1103
1104or you can answer 'n' at the appropriate interactive Configure prompt.
1105
73d6d1b0
RGS
1106Note that Perl's malloc isn't always used by default; that actually
1107depends on your system. For example, on Linux and FreeBSD (and many more
1108systems), Configure chooses to use the system's malloc by default.
1109See the appropriate file in the F<hints/> directory to see how the
1110default is set.
1111
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1112=item -DPERL_POLLUTE_MALLOC
1113
1114NOTE: This flag is enabled automatically on some platforms if you just
7df75831 1115run Configure to accept all the defaults.
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1116
1117Perl's malloc family of functions are normally called Perl_malloc(),
1118Perl_realloc(), Perl_calloc() and Perl_mfree().
1119These names do not clash with the system versions of these functions.
1120
1121If this flag is enabled, however, Perl's malloc family of functions
1122will have the same names as the system versions. This may be required
1123sometimes if you have libraries that like to free() data that may have
1124been allocated by Perl_malloc() and vice versa.
1125
1126Note that enabling this option may sometimes lead to duplicate symbols
1127from the linker for malloc et al. In such cases, the system probably
1128does not allow its malloc functions to be fully replaced with custom
1129versions.
1130
1131=item -DPERL_DEBUGGING_MSTATS
1132
1133This flag enables debugging mstats, which is required to use the
1134Devel::Peek::mstat() function. You cannot enable this unless you are
1135using Perl's malloc, so a typical Configure command would be
1136
7df75831 1137 sh Configure -Accflags=-DPERL_DEBUGGING_MSTATS -Dusemymalloc
ce80d64e
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1138
1139to enable this option.
1140
1141=back
1142
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1143=head2 What if it doesn't work?
1144
8d74ce1c 1145If you run into problems, try some of the following ideas.
ff52061e 1146If none of them help, then see L<"Reporting Problems"> below.
8d74ce1c 1147
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1148=over 4
1149
25f94b33
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1150=item Running Configure Interactively
1151
1152If Configure runs into trouble, remember that you can always run
1153Configure interactively so that you can check (and correct) its
1154guesses.
1155
1156All the installation questions have been moved to the top, so you don't
aa689395 1157have to wait for them. Once you've handled them (and your C compiler and
1ec51d55 1158flags) you can type &-d at the next Configure prompt and Configure
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1159will use the defaults from then on.
1160
1161If you find yourself trying obscure command line incantations and
1162config.over tricks, I recommend you run Configure interactively
1163instead. You'll probably save yourself time in the long run.
1164
aa689395 1165=item Hint files
8e07c86e 1166
a0a8d9d3
DD
1167Hint files tell Configure about a number of things:
1168
1169=over 4
1170
1171=item o
1172
1173The peculiarities or conventions of particular platforms -- non-standard
1174library locations and names, default installation locations for binaries,
1175and so on.
1176
1177=item o
1178
1179The deficiencies of the platform -- for example, library functions that,
1180although present, are too badly broken to be usable; or limits on
1181resources that are generously available on most platforms.
1182
1183=item o
1184
1185How best to optimize for the platform, both in terms of binary size and/or
1186speed, and for Perl feature support. Because of wide variations in the
1187implementation of shared libraries and of threading, for example, Configure
1188often needs hints in order to be able to use these features.
1189
1190=back
1191
1192The perl distribution includes many system-specific hints files
1193in the hints/ directory. If one of them matches your system, Configure
1194will offer to use that hint file. Unless you have a very good reason
1195not to, you should accept its offer.
8e07c86e
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1196
1197Several of the hint files contain additional important information.
f5b3b617
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1198If you have any problems, it is a good idea to read the relevant hint file
1199for further information. See hints/solaris_2.sh for an extensive example.
1200More information about writing good hints is in the hints/README.hints
a0a8d9d3
DD
1201file, which also explains hint files known as callback-units.
1202
1203Note that any hint file is read before any Policy file, meaning that
1204Policy overrides hints -- see L</Site-wide Policy settings>.
8e07c86e 1205
73d6d1b0 1206=item WHOA THERE!!!
edb1cbcb 1207
82c11e95
RGS
1208If you are re-using an old config.sh, it's possible that Configure detects
1209different values from the ones specified in this file. You will almost
1210always want to keep the previous value, unless you have changed something
1211on your system.
edb1cbcb 1212
1213For example, suppose you have added libgdbm.a to your system
1214and you decide to reconfigure perl to use GDBM_File. When you run
1215Configure again, you will need to add -lgdbm to the list of libraries.
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1216Now, Configure will find your gdbm include file and library and will
1217issue a message:
edb1cbcb 1218
1219 *** WHOA THERE!!! ***
1220 The previous value for $i_gdbm on this machine was "undef"!
1221 Keep the previous value? [y]
1222
1ec51d55 1223In this case, you do not want to keep the previous value, so you
c3edaffb 1224should answer 'n'. (You'll also have to manually add GDBM_File to
edb1cbcb 1225the list of dynamic extensions to build.)
1226
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1227=item Changing Compilers
1228
1229If you change compilers or make other significant changes, you should
1ec51d55 1230probably not re-use your old config.sh. Simply remove it or
dd3196cd 1231rename it, then rerun Configure with the options you want to use.
8e07c86e 1232
c3edaffb 1233=item Propagating your changes to config.sh
8e07c86e 1234
1ec51d55
CS
1235If you make any changes to config.sh, you should propagate
1236them to all the .SH files by running
1237
1238 sh Configure -S
1239
1240You will then have to rebuild by running
9d67150a 1241
1242 make depend
1243 make
8e07c86e 1244
48370efc
JH
1245=item config.over and config.arch
1246
668cbedd 1247You can also supply a shell script config.over to override
48370efc
JH
1248Configure's guesses. It will get loaded up at the very end, just
1249before config.sh is created. You have to be careful with this,
1250however, as Configure does no checking that your changes make sense.
1251This file is usually good for site-specific customizations.
1252
1253There is also another file that, if it exists, is loaded before the
1254config.over, called config.arch. This file is intended to be per
1255architecture, not per site, and usually it's the architecture-specific
1256hints file that creates the config.arch.
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1257
1258=item config.h
1259
1ec51d55
CS
1260Many of the system dependencies are contained in config.h.
1261Configure builds config.h by running the config_h.SH script.
1262The values for the variables are taken from config.sh.
8e07c86e 1263
1ec51d55
CS
1264If there are any problems, you can edit config.h directly. Beware,
1265though, that the next time you run Configure, your changes will be
8e07c86e
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1266lost.
1267
1268=item cflags
1269
1270If you have any additional changes to make to the C compiler command
1ec51d55 1271line, they can be made in cflags.SH. For instance, to turn off the
5729ffdd
NC
1272optimizer on toke.c, find the switch structure marked 'or customize here',
1273and add a line for toke.c ahead of the catch-all *) so that it now reads:
1274
1275 : or customize here
1276
1277 case "$file" in
1278 toke) optimize='-g' ;;
1279 *) ;;
1280
1281You should not edit the generated file cflags directly, as your changes will
65c512c3 1282be lost the next time you run Configure, or if you edit config.sh.
8e07c86e 1283
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1284To explore various ways of changing ccflags from within a hint file,
1285see the file hints/README.hints.
1286
1287To change the C flags for all the files, edit config.sh and change either
1288$ccflags or $optimize, and then re-run
1ec51d55
CS
1289
1290 sh Configure -S
1291 make depend
8e07c86e 1292
aa689395 1293=item No sh
8e07c86e 1294
c42e3e15
GS
1295If you don't have sh, you'll have to copy the sample file
1296Porting/config.sh to config.sh and edit your config.sh to reflect your
1297system's peculiarities. See Porting/pumpkin.pod for more information.
8e07c86e
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1298You'll probably also have to extensively modify the extension building
1299mechanism.
1300
c3edaffb 1301=item Porting information
1302
e6f03d26 1303Specific information for the OS/2, Plan 9, VMS and Win32 ports is in the
1ec51d55
CS
1304corresponding README files and subdirectories. Additional information,
1305including a glossary of all those config.sh variables, is in the Porting
ce80d64e 1306subdirectory. Porting/Glossary should especially come in handy.
c3edaffb 1307
7f678428 1308Ports for other systems may also be available. You should check out
468f45d5 1309http://www.cpan.org/ports for current information on ports to
7f678428 1310various other operating systems.
1311
ce80d64e 1312If you plan to port Perl to a new architecture, study carefully the
491517e0 1313section titled "Philosophical Issues in Patching and Porting Perl"
c222ef46 1314in the file Porting/pumpkin.pod and the file pod/perlgit.pod.
491517e0
JA
1315Study also how other non-UNIX ports have solved problems.
1316
8e07c86e
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1317=back
1318
ce80d64e 1319=head2 Adding extra modules to the build
fadf0ef5
JH
1320
1321You can specify extra modules or module bundles to be fetched from the
1322CPAN and installed as part of the Perl build. Either use the -Dextras=...
1323command line parameter to Configure, for example like this:
1324
d3df0cfd 1325 Configure -Dextras="Bundle::LWP DBI"
fadf0ef5
JH
1326
1327or answer first 'y' to the question 'Install any extra modules?' and
d3df0cfd 1328then answer "Bundle::LWP DBI" to the 'Extras?' question.
fadf0ef5 1329The module or the bundle names are as for the CPAN module 'install' command.
a522f097
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1330This will only work if those modules are to be built as dynamic
1331extensions. If you wish to include those extra modules as static
1332extensions, see L<"Extensions"> above.
fadf0ef5
JH
1333
1334Notice that because the CPAN module will be used to fetch the extra
1335modules, you will need access to the CPAN, either via the Internet,
1336or via a local copy such as a CD-ROM or a local CPAN mirror. If you
1337do not, using the extra modules option will die horribly.
1338
1339Also notice that you yourself are responsible for satisfying any extra
1340dependencies such as external headers or libraries BEFORE trying the build.
d3df0cfd 1341For example: you will need to have the Foo database specific
fadf0ef5
JH
1342headers and libraries installed for the DBD::Foo module. The Configure
1343process or the Perl build process will not help you with these.
1344
ce80d64e 1345=head2 suidperl
03739d21 1346
172dd959
JV
1347suidperl was an optional component of earlier releases of perl. It is no
1348longer available. Instead, use a tool specifically designed to handle
1349changes in privileges, such as B<sudo>.
03739d21 1350
8e07c86e
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1351=head1 make depend
1352
bfb7748a
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1353This will look for all the includes. The output is stored in makefile.
1354The only difference between Makefile and makefile is the dependencies at
1355the bottom of makefile. If you have to make any changes, you should edit
ce80d64e 1356makefile, not Makefile, since the Unix make command reads makefile first.
bfb7748a
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1357(On non-Unix systems, the output may be stored in a different file.
1358Check the value of $firstmakefile in your config.sh if in doubt.)
8e07c86e
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1359
1360Configure will offer to do this step for you, so it isn't listed
1361explicitly above.
1362
1363=head1 make
1364
1365This will attempt to make perl in the current directory.
1366
8d410bc4
YST
1367=head2 Expected errors
1368
f5b5f377 1369These error reports are normal, and can be ignored:
8d410bc4
YST
1370
1371 ...
1372 make: [extra.pods] Error 1 (ignored)
1373 ...
1374 make: [extras.make] Error 1 (ignored)
1375
8d74ce1c
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1376=head2 What if it doesn't work?
1377
8e07c86e 1378If you can't compile successfully, try some of the following ideas.
7f678428 1379If none of them help, and careful reading of the error message and
8d74ce1c 1380the relevant manual pages on your system doesn't help,
ff52061e 1381then see L<"Reporting Problems"> below.
8e07c86e
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1382
1383=over 4
1384
1ec51d55 1385=item hints
8e07c86e
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1386
1387If you used a hint file, try reading the comments in the hint file
1388for further tips and information.
1389
1ec51d55 1390=item extensions
8e07c86e 1391
1ec51d55 1392If you can successfully build miniperl, but the process crashes
ce80d64e 1393during the building of extensions, run
c3edaffb 1394
3a6175e1 1395 make minitest
c3edaffb 1396
1397to test your version of miniperl.
1398
e57fd563 1399=item locale
1400
bfb7748a
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1401If you have any locale-related environment variables set, try unsetting
1402them. I have some reports that some versions of IRIX hang while
1403running B<./miniperl configpm> with locales other than the C locale.
1404See the discussion under L<"make test"> below about locales and the
08854360 1405whole L<perllocale/"LOCALE PROBLEMS"> section in the file pod/perllocale.pod.
3e6e419a
JH
1406The latter is especially useful if you see something like this
1407
1408 perl: warning: Setting locale failed.
1409 perl: warning: Please check that your locale settings:
1410 LC_ALL = "En_US",
1411 LANG = (unset)
1412 are supported and installed on your system.
1413 perl: warning: Falling back to the standard locale ("C").
1414
1415at Perl startup.
e57fd563 1416
06aa495b
DM
1417=item other environment variables
1418
1419Configure does not check for environment variables that can sometimes
1420have a major influence on how perl is built or tested. For example,
1421OBJECT_MODE on AIX determines the way the compiler and linker deal with
1422their objects, but this is a variable that only influences build-time
1423behaviour, and should not affect the perl scripts that are eventually
1424executed by the perl binary. Other variables, like PERL_UNICODE,
adbb55c0 1425PERL5LIB, and PERL5OPT will influence the behaviour of the test suite.
06aa495b
DM
1426So if you are getting strange test failures, you may want to try
1427retesting with the various PERL variables unset.
1428
7f678428 1429=item varargs
c3edaffb 1430
1431If you get varargs problems with gcc, be sure that gcc is installed
bfb7748a
AD
1432correctly and that you are not passing -I/usr/include to gcc. When using
1433gcc, you should probably have i_stdarg='define' and i_varargs='undef'
ce80d64e 1434in config.sh. The problem is usually solved by installing gcc
bfb7748a
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1435correctly. If you do change config.sh, don't forget to propagate
1436your changes (see L<"Propagating your changes to config.sh"> below).
7f678428 1437See also the L<"vsprintf"> item below.
c3edaffb 1438
bfb7748a 1439=item util.c
c3edaffb 1440
1441If you get error messages such as the following (the exact line
bfb7748a 1442numbers and function name may vary in different versions of perl):
c3edaffb 1443
19f4563d 1444 util.c: In function 'Perl_form':
bfb7748a
AD
1445 util.c:1107: number of arguments doesn't match prototype
1446 proto.h:125: prototype declaration
c3edaffb 1447
1448it might well be a symptom of the gcc "varargs problem". See the
7f678428 1449previous L<"varargs"> item.
c3edaffb 1450
1ec51d55 1451=item LD_LIBRARY_PATH
c3edaffb 1452
1453If you run into dynamic loading problems, check your setting of
aa689395 1454the LD_LIBRARY_PATH environment variable. If you're creating a static
1455Perl library (libperl.a rather than libperl.so) it should build
c3edaffb 1456fine with LD_LIBRARY_PATH unset, though that may depend on details
668cbedd 1457of your local setup.
c3edaffb 1458
aa689395 1459=item nm extraction
c3edaffb 1460
1461If Configure seems to be having trouble finding library functions,
1462try not using nm extraction. You can do this from the command line
1463with
1464
1465 sh Configure -Uusenm
1466
1467or by answering the nm extraction question interactively.
1ec51d55 1468If you have previously run Configure, you should not reuse your old
c3edaffb 1469config.sh.
1470
bfb7748a
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1471=item umask not found
1472
1473If the build processes encounters errors relating to umask(), the problem
1474is probably that Configure couldn't find your umask() system call.
1475Check your config.sh. You should have d_umask='define'. If you don't,
1476this is probably the L<"nm extraction"> problem discussed above. Also,
1477try reading the hints file for your system for further information.
1478
7f678428 1479=item vsprintf
c3edaffb 1480
1481If you run into problems with vsprintf in compiling util.c, the
1482problem is probably that Configure failed to detect your system's
1483version of vsprintf(). Check whether your system has vprintf().
1484(Virtually all modern Unix systems do.) Then, check the variable
1485d_vprintf in config.sh. If your system has vprintf, it should be:
1486
1487 d_vprintf='define'
1488
1489If Configure guessed wrong, it is likely that Configure guessed wrong
bfb7748a
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1490on a number of other common functions too. This is probably
1491the L<"nm extraction"> problem discussed above.
c3edaffb 1492
3fe9a6f1 1493=item do_aspawn
1494
1495If you run into problems relating to do_aspawn or do_spawn, the
1496problem is probably that Configure failed to detect your system's
bfb7748a
AD
1497fork() function. Follow the procedure in the previous item
1498on L<"nm extraction">.
3fe9a6f1 1499
84902520
TB
1500=item __inet_* errors
1501
1502If you receive unresolved symbol errors during Perl build and/or test
1503referring to __inet_* symbols, check to see whether BIND 8.1 is
1504installed. It installs a /usr/local/include/arpa/inet.h that refers to
1505these symbols. Versions of BIND later than 8.1 do not install inet.h
1506in that location and avoid the errors. You should probably update to a
6d240721
JH
1507newer version of BIND (and remove the files the old one left behind).
1508If you can't, you can either link with the updated resolver library provided
1509with BIND 8.1 or rename /usr/local/bin/arpa/inet.h during the Perl build and
1510test process to avoid the problem.
1511
73d6d1b0 1512=item .*_r() prototype NOT found
6d240721
JH
1513
1514On a related note, if you see a bunch of complaints like the above about
668cbedd 1515reentrant functions -- specifically networking-related ones -- being present
6d240721
JH
1516but without prototypes available, check to see if BIND 8.1 (or possibly
1517other BIND 8 versions) is (or has been) installed. They install
1518header files such as netdb.h into places such as /usr/local/include (or into
1519another directory as specified at build/install time), at least optionally.
f1300be0 1520Remove them or put them in someplace that isn't in the C preprocessor's
6d240721
JH
1521header file include search path (determined by -I options plus defaults,
1522normally /usr/include).
84902520 1523
d6baa268
JH
1524=item #error "No DATAMODEL_NATIVE specified"
1525
1526This is a common error when trying to build perl on Solaris 2.6 with a
1527gcc installation from Solaris 2.5 or 2.5.1. The Solaris header files
1528changed, so you need to update your gcc installation. You can either
1529rerun the fixincludes script from gcc or take the opportunity to
1530update your gcc installation.
1531
aa689395 1532=item Optimizer
c3edaffb 1533
9d67150a 1534If you can't compile successfully, try turning off your compiler's
aa689395 1535optimizer. Edit config.sh and change the line
9d67150a 1536
1537 optimize='-O'
1538
bfb7748a 1539to
9d67150a 1540
1541 optimize=' '
1542
1543then propagate your changes with B<sh Configure -S> and rebuild
1544with B<make depend; make>.
1545
4bbc1586 1546=item Missing functions and Undefined symbols
9d67150a 1547
4bbc1586
AD
1548If the build of miniperl fails with a long list of missing functions or
1549undefined symbols, check the libs variable in the config.sh file. It
1550should look something like
1551
1552 libs='-lsocket -lnsl -ldl -lm -lc'
1553
1554The exact libraries will vary from system to system, but you typically
1555need to include at least the math library -lm. Normally, Configure
1556will suggest the correct defaults. If the libs variable is empty, you
1557need to start all over again. Run
1558
1559 make distclean
1560
1561and start from the very beginning. This time, unless you are sure of
1562what you are doing, accept the default list of libraries suggested by
1563Configure.
1564
1565If the libs variable looks correct, you might have the
1566L<"nm extraction"> problem discussed above.
1567
668cbedd 1568If you still have missing routines or undefined symbols, you probably
4bbc1586
AD
1569need to add some library or other, or you need to undefine some feature
1570that Configure thought was there but is defective or incomplete. If
1571you used a hint file, see if it has any relevant advice. You can also
1572look through through config.h for likely suspects.
8e07c86e 1573
1ec51d55 1574=item toke.c
8e07c86e 1575
1ec51d55
CS
1576Some compilers will not compile or optimize the larger files (such as
1577toke.c) without some extra switches to use larger jump offsets or
1578allocate larger internal tables. You can customize the switches for
668cbedd 1579each file in cflags.SH. It's okay to insert rules for specific files into
1ec51d55 1580makefile since a default rule only takes effect in the absence of a
8e07c86e
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1581specific rule.
1582
7f678428 1583=item Missing dbmclose
8e07c86e 1584
c3edaffb 1585SCO prior to 3.2.4 may be missing dbmclose(). An upgrade to 3.2.4
1586that includes libdbm.nfs (which includes dbmclose()) may be available.
8e07c86e 1587
1bb125e2
MB
1588=item error: too few arguments to function 'dbmclose'
1589
1590Building ODBM_File on some (Open)SUSE distributions might run into this
1591error, as the header file is broken. There are two ways to deal with this
1592
1593 1. Disable the use of ODBM_FILE
1594
1595 Configure ... -Dnoextensions=ODBM_File
1596
1597 2. Fix the header file, somewhat like this:
1598
1599 --- a/usr/include/dbm.h 2010-03-24 08:54:59.000000000 +0100
1600 +++ b/usr/include/dbm.h 2010-03-24 08:55:15.000000000 +0100
1601 @@ -59,4 +59,4 @@ extern datum firstkey __P((void));
1602
1603 extern datum nextkey __P((datum key));
1604
1605 -extern int dbmclose __P((DBM *));
1606 +extern int dbmclose __P((void));
1607
f3d9a6ba 1608=item Note (probably harmless): No library found for -lsomething
7f678428 1609
1610If you see such a message during the building of an extension, but
1611the extension passes its tests anyway (see L<"make test"> below),
1612then don't worry about the warning message. The extension
1613Makefile.PL goes looking for various libraries needed on various
aa689395 1614systems; few systems will need all the possible libraries listed.
74b7c41f
AD
1615Most users will see warnings for the ones they don't have. The
1616phrase 'probably harmless' is intended to reassure you that nothing
1617unusual is happening, and the build process is continuing.
7f678428 1618
1619On the other hand, if you are building GDBM_File and you get the
1620message
1621
f3d9a6ba 1622 Note (probably harmless): No library found for -lgdbm
7f678428 1623
1624then it's likely you're going to run into trouble somewhere along
1625the line, since it's hard to see how you can use the GDBM_File
1626extension without the -lgdbm library.
1627
1628It is true that, in principle, Configure could have figured all of
1629this out, but Configure and the extension building process are not
1630quite that tightly coordinated.
1631
aa689395 1632=item sh: ar: not found
1633
1634This is a message from your shell telling you that the command 'ar'
1635was not found. You need to check your PATH environment variable to
1636make sure that it includes the directory with the 'ar' command. This
1ec51d55 1637is a common problem on Solaris, where 'ar' is in the /usr/ccs/bin
aa689395 1638directory.
1639
1640=item db-recno failure on tests 51, 53 and 55
1641
1642Old versions of the DB library (including the DB library which comes
1643with FreeBSD 2.1) had broken handling of recno databases with modified
1644bval settings. Upgrade your DB library or OS.
1645
6087ac44
JH
1646=item Bad arg length for semctl, is XX, should be ZZZ
1647
11906ba0 1648If you get this error message from the ext/IPC/SysV/t/sem test, your System
6087ac44
JH
1649V IPC may be broken. The XX typically is 20, and that is what ZZZ
1650also should be. Consider upgrading your OS, or reconfiguring your OS
1651to include the System V semaphores.
1652
11906ba0 1653=item ext/IPC/SysV/t/sem........semget: No space left on device
220f3621
GS
1654
1655Either your account or the whole system has run out of semaphores. Or
1656both. Either list the semaphores with "ipcs" and remove the unneeded
1657ones (which ones these are depends on your system and applications)
1658with "ipcrm -s SEMAPHORE_ID_HERE" or configure more semaphores to your
1659system.
1660
d6baa268
JH
1661=item GNU binutils
1662
1663If you mix GNU binutils (nm, ld, ar) with equivalent vendor-supplied
1664tools you may be in for some trouble. For example creating archives
1665with an old GNU 'ar' and then using a new current vendor-supplied 'ld'
1666may lead into linking problems. Either recompile your GNU binutils
1667under your current operating system release, or modify your PATH not
1668to include the GNU utils before running Configure, or specify the
1669vendor-supplied utilities explicitly to Configure, for example by
1670Configure -Dar=/bin/ar.
1671
16dc217a
GS
1672=item THIS PACKAGE SEEMS TO BE INCOMPLETE
1673
1674The F<Configure> program has not been able to find all the files which
1675make up the complete Perl distribution. You may have a damaged source
1676archive file (in which case you may also have seen messages such as
1677C<gzip: stdin: unexpected end of file> and C<tar: Unexpected EOF on
1678archive file>), or you may have obtained a structurally-sound but
1679incomplete archive. In either case, try downloading again from the
1680official site named at the start of this document. If you do find
1681that any site is carrying a corrupted or incomplete source code
1682archive, please report it to the site's maintainer.
1683
16dc217a
GS
1684=item invalid token: ##
1685
ce80d64e
AD
1686You are using a non-ANSI-compliant C compiler. To compile Perl, you
1687need to use a compiler that supports ANSI C. If there is a README
1688file for your system, it may have further details on your compiler
1689options.
16dc217a 1690
1ec51d55 1691=item Miscellaneous
8e07c86e 1692
7df75831 1693Some additional things that have been reported:
8e07c86e
AD
1694
1695Genix may need to use libc rather than libc_s, or #undef VARARGS.
1696
1697NCR Tower 32 (OS 2.01.01) may need -W2,-Sl,2000 and #undef MKDIR.
1698
668cbedd 1699UTS may need one or more of -K or -g, and #undef LSTAT.
8e07c86e 1700
11906ba0 1701FreeBSD can fail the ext/IPC/SysV/t/sem.t test if SysV IPC has not been
5cda700b 1702configured in the kernel. Perl tries to detect this, though, and
ce80d64e 1703you will get a message telling you what to do.
6087ac44 1704
6c8d78fb
HS
1705Building Perl on a system that has also BIND (headers and libraries)
1706installed may run into troubles because BIND installs its own netdb.h
1707and socket.h, which may not agree with the operating system's ideas of
1708the same files. Similarly, including -lbind may conflict with libc's
1709view of the world. You may have to tweak -Dlocincpth and -Dloclibpth
1710to avoid the BIND.
1711
8e07c86e
AD
1712=back
1713
58a21a9b
JH
1714=head2 Cross-compilation
1715
e7a3c61b
JH
1716Perl can be cross-compiled. It is just not trivial, cross-compilation
1717rarely is. Perl is routinely cross-compiled for many platforms (as of
1718June 2005 at least PocketPC aka WinCE, Open Zaurus, EPOC, Symbian, and
1719the IBM OS/400). These platforms are known as the B<target> platforms,
1720while the systems where the compilation takes place are the B<host>
1721platforms.
1722
1723What makes the situation difficult is that first of all,
1724cross-compilation environments vary significantly in how they are set
1725up and used, and secondly because the primary way of configuring Perl
1726(using the rather large Unix-tool-dependent Configure script) is not
1727awfully well suited for cross-compilation. However, starting from
1728version 5.8.0, the Configure script also knows one way of supporting
668cbedd 1729cross-compilation support, so please keep reading.
e7a3c61b
JH
1730
1731See the following files for more information about compiling Perl for
1732the particular platforms:
1733
1734=over 4
1735
1736=item WinCE/PocketPC
1737
75472953 1738README.ce
e7a3c61b
JH
1739
1740=item Open Zaurus
1741
1742Cross/README
1743
1744=item EPOC
1745
1746README.epoc
1747
1748=item Symbian
1749
1750README.symbian
1751
1752=item OS/400
1753
1754README.os400
1755
1756=back
1757
1758Packaging and transferring either the core Perl modules or CPAN
1759modules to the target platform is also left up to the each
1760cross-compilation environment. Often the cross-compilation target
1761platforms are somewhat limited in diskspace: see the section
1762L<Minimizing the Perl installation> to learn more of the minimal set
1763of files required for a functional Perl installation.
1764
1765For some cross-compilation environments the Configure option
1766C<-Dinstallprefix=...> might be handy, see L<Changing the installation
1767directory>.
1768
1769About the cross-compilation support of Configure: what is known to
1770work is running Configure in a cross-compilation environment and
1771building the miniperl executable. What is known not to work is
1772building the perl executable because that would require building
1773extensions: Dynaloader statically and File::Glob dynamically, for
1774extensions one needs MakeMaker and MakeMaker is not yet
1775cross-compilation aware, and neither is the main Makefile.
1776
1777The cross-compilation setup of Configure has successfully been used in
1778at least two Linux cross-compilation environments. The setups were
1779both such that the host system was Intel Linux with a gcc built for
1780cross-compiling into ARM Linux, and there was a SSH connection to the
1781target system.
1782
1783To run Configure in cross-compilation mode the basic switch that
1784has to be used is C<-Dusecrosscompile>.
58a21a9b
JH
1785
1786 sh ./Configure -des -Dusecrosscompile -D...
1787
1788This will make the cpp symbol USE_CROSS_COMPILE and the %Config
b0f06652
VK
1789symbol C<usecrosscompile> available, and C<xconfig.h> will be used
1790for cross-compilation.
58a21a9b
JH
1791
1792During the Configure and build, certain helper scripts will be created
1793into the Cross/ subdirectory. The scripts are used to execute a
1794cross-compiled executable, and to transfer files to and from the
1795target host. The execution scripts are named F<run-*> and the
1796transfer scripts F<to-*> and F<from-*>. The part after the dash is
1797the method to use for remote execution and transfer: by default the
1798methods are B<ssh> and B<scp>, thus making the scripts F<run-ssh>,
1799F<to-scp>, and F<from-scp>.
1800
1801To configure the scripts for a target host and a directory (in which
1802the execution will happen and which is to and from where the transfer
1803happens), supply Configure with
1804
1805 -Dtargethost=so.me.ho.st -Dtargetdir=/tar/get/dir
1806
1807The targethost is what e.g. ssh will use as the hostname, the targetdir
93bc48fa
JH
1808must exist (the scripts won't create it), the targetdir defaults to /tmp.
1809You can also specify a username to use for ssh/rsh logins
58a21a9b
JH
1810
1811 -Dtargetuser=luser
1812
1813but in case you don't, "root" will be used.
1814
93bc48fa
JH
1815Because this is a cross-compilation effort, you will also need to specify
1816which target environment and which compilation environment to use.
1817This includes the compiler, the header files, and the libraries.
1818In the below we use the usual settings for the iPAQ cross-compilation
1819environment:
58a21a9b
JH
1820
1821 -Dtargetarch=arm-linux
1822 -Dcc=arm-linux-gcc
1823 -Dusrinc=/skiff/local/arm-linux/include
1824 -Dincpth=/skiff/local/arm-linux/include
1825 -Dlibpth=/skiff/local/arm-linux/lib
1826
1827If the name of the C<cc> has the usual GNU C semantics for cross
1828compilers, that is, CPU-OS-gcc, the names of the C<ar>, C<nm>, and
1829C<ranlib> will also be automatically chosen to be CPU-OS-ar and so on.
93bc48fa
JH
1830(The C<ld> requires more thought and will be chosen later by Configure
1831as appropriate.) Also, in this case the incpth, libpth, and usrinc
1832will be guessed by Configure (unless explicitly set to something else,
1833in which case Configure's guesses with be appended).
58a21a9b
JH
1834
1835In addition to the default execution/transfer methods you can also
1836choose B<rsh> for execution, and B<rcp> or B<cp> for transfer,
1837for example:
1838
1839 -Dtargetrun=rsh -Dtargetto=rcp -Dtargetfrom=cp
1840
1841Putting it all together:
1842
1843 sh ./Configure -des -Dusecrosscompile \
93bc48fa
JH
1844 -Dtargethost=so.me.ho.st \
1845 -Dtargetdir=/tar/get/dir \
58a21a9b
JH
1846 -Dtargetuser=root \
1847 -Dtargetarch=arm-linux \
1848 -Dcc=arm-linux-gcc \
1849 -Dusrinc=/skiff/local/arm-linux/include \
1850 -Dincpth=/skiff/local/arm-linux/include \
1851 -Dlibpth=/skiff/local/arm-linux/lib \
1852 -D...
1853
e7a3c61b 1854or if you are happy with the defaults:
93bc48fa
JH
1855
1856 sh ./Configure -des -Dusecrosscompile \
1857 -Dtargethost=so.me.ho.st \
1858 -Dcc=arm-linux-gcc \
1859 -D...
1860
e7a3c61b
JH
1861Another example where the cross-compiler has been installed under
1862F</usr/local/arm/2.95.5>:
1863
1864 sh ./Configure -des -Dusecrosscompile \
1865 -Dtargethost=so.me.ho.st \
1866 -Dcc=/usr/local/arm/2.95.5/bin/arm-linux-gcc \
1867 -Dincpth=/usr/local/arm/2.95.5/include \
1868 -Dusrinc=/usr/local/arm/2.95.5/include \
1869 -Dlibpth=/usr/local/arm/2.95.5/lib
1870
8e07c86e
AD
1871=head1 make test
1872
d6baa268
JH
1873This will run the regression tests on the perl you just made. If
1874'make test' doesn't say "All tests successful" then something went
36bded94 1875wrong.
84902520 1876
84902520 1877Note that you can't run the tests in background if this disables
fb73857a 1878opening of /dev/tty. You can use 'make test-notty' in that case but
1879a few tty tests will be skipped.
c3edaffb 1880
c4f23d77
AD
1881=head2 What if make test doesn't work?
1882
1ec51d55 1883If make test bombs out, just cd to the t directory and run ./TEST
36bded94 1884by hand to see if it makes any difference.
8e07c86e 1885
36bded94
AD
1886One way to get more detailed information about failed tests and
1887individual subtests is to run the harness from the t directory:
aa689395 1888
785aa5e3 1889 cd t ; ./perl harness <list of tests>
aa689395 1890
fb73857a 1891(this assumes that most basic tests succeed, since harness uses
785aa5e3
RGS
1892complicated constructs). If no list of tests is provided, harness
1893will run all tests.
10c7e831 1894
36bded94
AD
1895If individual tests fail, you can often run them by hand (from the main
1896perl directory), e.g.,
1897
1898 ./perl -MTestInit t/op/groups.t
1899
fb73857a 1900You should also read the individual tests to see if there are any helpful
10c7e831
JH
1901comments that apply to your system. You may also need to setup your
1902shared library path if you get errors like:
1903
1904 /sbin/loader: Fatal Error: cannot map libperl.so
1905
36bded94
AD
1906The file t/README in the t subdirectory contains more information about
1907running and modifying tests.
1908
10c7e831 1909See L</"Building a shared Perl library"> earlier in this document.
c3edaffb 1910
c4f23d77
AD
1911=over 4
1912
1913=item locale
1914
1ec51d55 1915Note: One possible reason for errors is that some external programs
c07a80fd 1916may be broken due to the combination of your environment and the way
785aa5e3 1917'make test' exercises them. For example, this may happen if you have
1ec51d55
CS
1918one or more of these environment variables set: LC_ALL LC_CTYPE
1919LC_COLLATE LANG. In some versions of UNIX, the non-English locales
e57fd563 1920are known to cause programs to exhibit mysterious errors.
1921
1922If you have any of the above environment variables set, please try
aa689395 1923
1924 setenv LC_ALL C
1925
1926(for C shell) or
1927
1928 LC_ALL=C;export LC_ALL
1929
1ec51d55
CS
1930for Bourne or Korn shell) from the command line and then retry
1931make test. If the tests then succeed, you may have a broken program that
aa689395 1932is confusing the testing. Please run the troublesome test by hand as
e57fd563 1933shown above and see whether you can locate the program. Look for
1ec51d55
CS
1934things like: exec, `backquoted command`, system, open("|...") or
1935open("...|"). All these mean that Perl is trying to run some
e57fd563 1936external program.
eed2e782 1937
0740bb5b
AD
1938=item Timing problems
1939
c29923ff
JH
1940Several tests in the test suite check timing functions, such as
1941sleep(), and see if they return in a reasonable amount of time.
9341413f
JH
1942If your system is quite busy and doesn't respond quickly enough,
1943these tests might fail. If possible, try running the tests again
1944with the system under a lighter load. These timing-sensitive
1945and load-sensitive tests include F<t/op/alarm.t>,
3831a787
NC
1946F<ext/Time-HiRes/t/HiRes.t>, F<ext/threads-shared/t/waithires.t>,
1947F<ext/threads-shared/t/stress.t>, F<lib/Benchmark.t>,
9341413f 1948F<lib/Memoize/t/expmod_t.t>, and F<lib/Memoize/t/speed.t>.
0740bb5b 1949
f89caa8d
RGS
1950You might also experience some failures in F<t/op/stat.t> if you build
1951perl on an NFS filesystem, if the remote clock and the system clock are
1952different.
1953
c4f23d77
AD
1954=item Out of memory
1955
1956On some systems, particularly those with smaller amounts of RAM, some
1957of the tests in t/op/pat.t may fail with an "Out of memory" message.
7970f296
GS
1958For example, on my SparcStation IPC with 12 MB of RAM, in perl5.5.670,
1959test 85 will fail if run under either t/TEST or t/harness.
c4f23d77
AD
1960
1961Try stopping other jobs on the system and then running the test by itself:
1962
04bd6448 1963 ./perl -MTestInit t/op/pat.t
c4f23d77
AD
1964
1965to see if you have any better luck. If your perl still fails this
1966test, it does not necessarily mean you have a broken perl. This test
1967tries to exercise the regular expression subsystem quite thoroughly,
1968and may well be far more demanding than your normal usage.
1969
a55bb48b
AD
1970=item libgcc_s.so.1: cannot open shared object file
1971
1972This message has been reported on gcc-3.2.3 and earlier installed with
1973a non-standard prefix. Setting the LD_LIBRARY_PATH environment variable
1974(or equivalent) to include gcc's lib/ directory with the libgcc_s.so.1
1975shared library should fix the problem.
1976
4f76e5ba
AD
1977=item Failures from lib/File/Temp/t/security saying "system possibly insecure"
1978
1979First, such warnings are not necessarily serious or indicative of a
1980real security threat. That being said, they bear investigating.
1981
1982Note that each of the tests is run twice. The first time is in the
1983directory returned by File::Spec->tmpdir() (often /tmp on Unix
1984systems), and the second time in the directory from which the test was
1985run (usually the 't' directory, if the test was run as part of 'make
1986test').
1987
1988The tests may fail for the following reasons:
1989
1990(1) If the directory the tests are being run in is owned by somebody
1991other than the user running the tests, or by root (uid 0).
1992
1993This failure can happen if the Perl source code distribution is
668cbedd 1994unpacked in such a way that the user IDs in the distribution package
4f76e5ba
AD
1995are used as-is. Some tar programs do this.
1996
1997(2) If the directory the tests are being run in is writable by group or
1998by others, and there is no sticky bit set for the directory. (With
1999UNIX/POSIX semantics, write access to a directory means the right to
2000add or remove files in that directory. The 'sticky bit' is a feature
2001used in some UNIXes to give extra protection to files: if the bit is
2002set for a directory, no one but the owner (or root) can remove that
2003file even if the permissions would otherwise allow file removal by
2004others.)
2005
2006This failure may or may not be a real problem: it depends on the
2007permissions policy used on this particular system. This failure can
2008also happen if the system either doesn't support the sticky bit (this
2009is the case with many non-UNIX platforms: in principle File::Temp
2010should know about these platforms and skip the tests), or if the system
2011supports the sticky bit but for some reason or reasons it is not being
2012used. This is, for example, the case with HP-UX: as of HP-UX release
201311.00, the sticky bit is very much supported, but HP-UX doesn't use it
2014on its /tmp directory as shipped. Also, as with the permissions, some
2015local policy might dictate that the stickiness is not used.
781948c1 2016
b2b23189
JH
2017(3) If the system supports the POSIX 'chown giveaway' feature and if
2018any of the parent directories of the temporary file back to the root
2019directory are 'unsafe', using the definitions given above in (1) and
4f76e5ba
AD
2020(2). For Unix systems, this is usually not an issue if you are
2021building on a local disk. See the documentation for the File::Temp
2022module for more information about 'chown giveaway'.
781948c1
JH
2023
2024See the documentation for the File::Temp module for more information
4f76e5ba 2025about the various security aspects of temporary files.
781948c1 2026
c4f23d77
AD
2027=back
2028
5ee651a9
NC
2029The core distribution can now run its regression tests in parallel on
2030Unix-like platforms. Instead of running C<make test>, set C<TEST_JOBS> in
2031your environment to the number of tests to run in parallel, and run
2032C<make test_harness>. On a Bourne-like shell, this can be done as
2033
2034 TEST_JOBS=3 make test_harness # Run 3 tests in parallel
2035
2036An environment variable is used, rather than parallel make itself, because
2037L<TAP::Harness> needs to be able to schedule individual non-conflicting test
2038scripts itself, and there is no standard interface to C<make> utilities to
2039interact with their job schedulers.
2040
8e07c86e
AD
2041=head1 make install
2042
2043This will put perl into the public directory you specified to
1ec51d55 2044Configure; by default this is /usr/local/bin. It will also try
8e07c86e 2045to put the man pages in a reasonable place. It will not nroff the man
aa689395 2046pages, however. You may need to be root to run B<make install>. If you
ce80d64e
AD
2047are not root, you must still have permission to install into the directories
2048in question and you should ignore any messages about chown not working.
2049
19f4563d 2050If "make install" just says "'install' is up to date" or something
ce80d64e
AD
2051similar, you may be on a case-insensitive filesystems such as Mac's HFS+,
2052and you should say "make install-all". (This confusion is brought to you
2053by the Perl distribution having a file called INSTALL.)
8e07c86e 2054
dd64f1c3
AD
2055=head2 Installing perl under different names
2056
2057If you want to install perl under a name other than "perl" (for example,
2058when installing perl with special features enabled, such as debugging),
2059indicate the alternate name on the "make install" line, such as:
2060
2061 make install PERLNAME=myperl
2062
beb13193 2063You can separately change the base used for versioned names (like
be8498a1 2064"perl5.8.9") by setting PERLNAME_VERBASE, like
beb13193
RS
2065
2066 make install PERLNAME=perl5 PERLNAME_VERBASE=perl
2067
5cda700b
AD
2068This can be useful if you have to install perl as "perl5" (e.g. to
2069avoid conflicts with an ancient version in /usr/bin supplied by your vendor).
be8498a1 2070Without this the versioned binary would be called "perl55.8.8".
beb13193 2071
ce80d64e
AD
2072=head2 Installing perl under a different directory
2073
2074You can install perl under a different destination directory by using
2075the DESTDIR variable during C<make install>, with a command like
2076
2077 make install DESTDIR=/tmp/perl5
2078
2079DESTDIR is automatically prepended to all the installation paths. See
7df75831 2080the example in L<"DESTDIR"> above.
ce80d64e 2081
dd64f1c3
AD
2082=head2 Installed files
2083
8e07c86e
AD
2084If you want to see exactly what will happen without installing
2085anything, you can run
4633a7c4 2086
8e07c86e
AD
2087 ./perl installperl -n
2088 ./perl installman -n
2089
1ec51d55 2090make install will install the following:
8e07c86e 2091
d56c5707
JH
2092 binaries
2093
8e07c86e 2094 perl,
be8498a1 2095 perl5.n.n where 5.n.n is the current release number. This
8e07c86e 2096 will be a link to perl.
668cbedd 2097 a2p awk-to-perl translator.
d56c5707
JH
2098
2099 scripts
2100
73d6d1b0
RGS
2101 cppstdin This is used by the deprecated switch perl -P, if
2102 your cc -E can't read from stdin.
8e07c86e 2103 c2ph, pstruct Scripts for handling C structures in header files.
668cbedd 2104 config_data Manage Module::Build-like module configuration.
73d6d1b0 2105 corelist Shows versions of modules that come with different
668cbedd
KW
2106 versions of perl.
2107 cpan The CPAN shell.
2108 cpan2dist The CPANPLUS distribution creator.
2109 cpanp The CPANPLUS shell.
2110 cpanp-run-perl A helper for cpanp.
668cbedd
KW
2111 enc2xs Encoding module generator.
2112 find2perl find-to-perl translator.
2113 h2ph Extract constants and simple macros from C headers.
8e07c86e 2114 h2xs Converts C .h header files to Perl extensions.
73d6d1b0
RGS
2115 instmodsh A shell to examine installed modules.
2116 libnetcfg Configure libnet.
24b3df7f 2117 perlbug Tool to report bugs in Perl.
8e07c86e 2118 perldoc Tool to read perl's pod documentation.
668cbedd 2119 perlivp Perl Installation Verification Procedure.
73d6d1b0 2120 piconv A Perl implementation of the encoding conversion
668cbedd
KW
2121 utility iconv.
2122 pl2pm Convert Perl 4 .pl files to Perl 5 .pm modules.
8e07c86e 2123 pod2html, Converters from perl's pod documentation format
aa689395 2124 pod2latex, to other useful formats.
d56c5707
JH
2125 pod2man,
2126 pod2text,
d56c5707 2127 pod2usage
668cbedd
KW
2128 podchecker POD syntax checker.
2129 podselect Prints sections of POD documentation.
2130 prove A command-line tool for running tests.
2131 psed A Perl implementation of sed.
2132 ptar A Perl implementation of tar.
2133 ptardiff A diff for tar archives.
2134 ptargrep A grep for tar archives.
2135 s2p sed-to-perl translator.
2136 shasum A tool to print or check SHA checksums.
2137 splain Describe Perl warnings and errors.
2138 xsubpp Compiler to convert Perl XS code into C code.
08ad9465 2139 zipdetails display the internal structure of zip files
8e07c86e 2140
d56c5707
JH
2141 library files
2142
2143 in $privlib and $archlib specified to
8e07c86e 2144 Configure, usually under /usr/local/lib/perl5/.
d56c5707
JH
2145
2146 documentation
2147
d6baa268
JH
2148 man pages in $man1dir, usually /usr/local/man/man1.
2149 module man
2150 pages in $man3dir, usually /usr/local/man/man3.
8e07c86e
AD
2151 pod/*.pod in $privlib/pod/.
2152
33cceb07 2153installperl will also create the directories listed above
d6baa268 2154in L<"Installation Directories">.
4633a7c4 2155
d56c5707 2156Perl's *.h header files and the libperl library are also installed
d6baa268 2157under $archlib so that any user may later build new modules, run the
56c6f531
JH
2158optional Perl compiler, or embed the perl interpreter into another
2159program even if the Perl source is no longer available.
8e07c86e 2160
33cceb07
RGS
2161=head2 Installing only version-specific parts
2162
d56c5707
JH
2163Sometimes you only want to install the version-specific parts of the perl
2164installation. For example, you may wish to install a newer version of
33cceb07 2165perl alongside an already installed production version without
d56c5707
JH
2166disabling installation of new modules for the production version.
2167To only install the version-specific parts of the perl installation, run
2168
2169 Configure -Dversiononly
2170
2171or answer 'y' to the appropriate Configure prompt. Alternatively,
2172you can just manually run
2173
2174 ./perl installperl -v
2175
2176and skip installman altogether.
33cceb07 2177
d56c5707
JH
2178See also L<"Maintaining completely separate versions"> for another
2179approach.
2180
f4ce0e6d
RGS
2181=head1 cd /usr/include; h2ph *.h sys/*.h
2182
2183Some perl scripts need to be able to obtain information from the
2184system header files. This command will convert the most commonly used
2185header files in /usr/include into files that can be easily interpreted
2186by perl. These files will be placed in the architecture-dependent
2187library ($archlib) directory you specified to Configure.
2188
668cbedd 2189Note: Due to differences in the C and perl languages, the conversion
f4ce0e6d
RGS
2190of the header files is not perfect. You will probably have to
2191hand-edit some of the converted files to get them to parse correctly.
2192For example, h2ph breaks spectacularly on type casting and certain
2193structures.
2194
2195=head1 installhtml --help
2196
2197Some sites may wish to make perl documentation available in HTML
2198format. The installhtml utility can be used to convert pod
2199documentation into linked HTML files and install them.
2200
2201Currently, the supplied ./installhtml script does not make use of the
2202html Configure variables. This should be fixed in a future release.
2203
2204The following command-line is an example of one used to convert
2205perl documentation:
2206
2207 ./installhtml \
2208 --podroot=. \
2209 --podpath=lib:ext:pod:vms \
2210 --recurse \
2211 --htmldir=/perl/nmanual \
2212 --htmlroot=/perl/nmanual \
2213 --splithead=pod/perlipc \
2214 --splititem=pod/perlfunc \
f4ce0e6d
RGS
2215 --verbose
2216
2217See the documentation in installhtml for more details. It can take
2218many minutes to execute a large installation and you should expect to
2219see warnings like "no title", "unexpected directive" and "cannot
2220resolve" as the files are processed. We are aware of these problems
2221(and would welcome patches for them).
2222
2223You may find it helpful to run installhtml twice. That should reduce
2224the number of "cannot resolve" warnings.
2225
2226=head1 cd pod && make tex && (process the latex files)
2227
2228Some sites may also wish to make the documentation in the pod/ directory
2229available in TeX format. Type
2230
2231 (cd pod && make tex && <process the latex files>)
2232
2233=head1 Starting all over again
2234
668cbedd 2235If you wish to rebuild perl from the same build directory, you should
f4ce0e6d
RGS
2236clean it out with the command
2237
2238 make distclean
2239
2240or
2241
2242 make realclean
2243
2244The only difference between the two is that make distclean also removes
2245your old config.sh and Policy.sh files.
2246
2247If you are upgrading from a previous version of perl, or if you
2248change systems or compilers or make other significant changes, or if
668cbedd 2249you are experiencing difficulties building perl, you should not reuse
f4ce0e6d
RGS
2250your old config.sh.
2251
2252If your reason to reuse your old config.sh is to save your particular
2253installation choices, then you can probably achieve the same effect by
2254using the Policy.sh file. See the section on L<"Site-wide Policy
2255settings"> above.
2256
ff52061e
RGS
2257=head1 Reporting Problems
2258
2259Wherever possible please use the perlbug tool supplied with this Perl
2260to report problems, as it automatically includes summary configuration
2261information about your perl, which may help us track down problems far
2262more quickly. But first you should read the advice in this file,
2263carefully re-read the error message and check the relevant manual pages
2264on your system, as these may help you find an immediate solution. If
2265you are not sure whether what you are seeing is a bug, you can send a
2266message describing the problem to the comp.lang.perl.misc newsgroup to
2267get advice.
2268
2269The perlbug tool is installed along with perl, so after you have
2270completed C<make install> it should be possible to run it with plain
2271C<perlbug>. If the install fails, or you want to report problems with
2272C<make test> without installing perl, then you can use C<make nok> to
2273run perlbug to report the problem, or run it by hand from this source
2274directory with C<./perl -Ilib utils/perlbug>
2275
2276If the build fails too early to run perlbug uninstalled, then please
2277B<run> the C<./myconfig> shell script, and mail its output along with
2278an accurate description of your problem to perlbug@perl.org
2279
2280If Configure itself fails, and does not generate a config.sh file
2281(needed to run C<./myconfig>), then please mail perlbug@perl.org the
2282description of how Configure fails along with details of your system
668cbedd 2283-- for example the output from running C<uname -a>
ff52061e
RGS
2284
2285Please try to make your message brief but clear. Brief, clear bug
2286reports tend to get answered more quickly. Please don't worry if your
668cbedd 2287written English is not great -- what matters is how well you describe
ff52061e
RGS
2288the important technical details of the problem you have encountered,
2289not whether your grammar and spelling is flawless.
2290
2291Trim out unnecessary information. Do not include large files (such as
2292config.sh or a complete Configure or make log) unless absolutely
2293necessary. Do not include a complete transcript of your build
2294session. Just include the failing commands, the relevant error
2295messages, and whatever preceding commands are necessary to give the
668cbedd 2296appropriate context. Plain text should usually be sufficient -- fancy
ff52061e
RGS
2297attachments or encodings may actually reduce the number of people who
2298read your message. Your message will get relayed to over 400
2299subscribers around the world so please try to keep it brief but clear.
2300
5acb7768
NC
2301If the bug you are reporting has security implications, which make it
2302inappropriate to send to a publicly archived mailing list, then please send
2303it to perl5-security-report@perl.org. This points to a closed subscription
2304unarchived mailing list, which includes all the core committers, who be able
2305to help assess the impact of issues, figure out a resolution, and help
2306co-ordinate the release of patches to mitigate or fix the problem across all
2307platforms on which Perl is supported. Please only use this address for security
2308issues in the Perl core, not for modules independently distributed on CPAN.
2309
ff52061e
RGS
2310If you are unsure what makes a good bug report please read "How to
2311report Bugs Effectively" by Simon Tatham:
2312http://www.chiark.greenend.org.uk/~sgtatham/bugs.html
2313
7df75831 2314=head1 Coexistence with earlier versions of perl 5
4633a7c4 2315
4ea27089 2316Perl 5.17 is not binary compatible with earlier versions of Perl.
cc65bb49 2317In other words, you will have to recompile your XS modules.
14eee2f1 2318
693762b4 2319In general, you can usually safely upgrade from one version of Perl (e.g.
33cceb07
RGS
23205.X.Y) to another similar minor version (e.g. 5.X.(Y+1))) without
2321re-compiling all of your extensions. You can also safely leave the old
2322version around in case the new version causes you problems for some reason.
693762b4 2323
be8498a1
RGS
2324Usually, most extensions will probably not need to be recompiled to be
2325used with a newer version of Perl. Here is how it is supposed to work.
ce80d64e 2326(These examples assume you accept all the Configure defaults.)
693762b4 2327
33cceb07
RGS
2328Suppose you already have version 5.8.7 installed. The directories
2329searched by 5.8.7 are typically like:
d6baa268 2330
33cceb07
RGS
2331 /usr/local/lib/perl5/5.8.7/$archname
2332 /usr/local/lib/perl5/5.8.7
2333 /usr/local/lib/perl5/site_perl/5.8.7/$archname
2334 /usr/local/lib/perl5/site_perl/5.8.7
d6baa268 2335
33cceb07
RGS
2336Now, suppose you install version 5.8.8. The directories
2337searched by version 5.8.8 will be:
d6baa268 2338
33cceb07
RGS
2339 /usr/local/lib/perl5/5.8.8/$archname
2340 /usr/local/lib/perl5/5.8.8
2341 /usr/local/lib/perl5/site_perl/5.8.8/$archname
2342 /usr/local/lib/perl5/site_perl/5.8.8
d6baa268 2343
33cceb07
RGS
2344 /usr/local/lib/perl5/site_perl/5.8.7/$archname
2345 /usr/local/lib/perl5/site_perl/5.8.7
c42e3e15 2346 /usr/local/lib/perl5/site_perl/
bfb7748a 2347
c42e3e15 2348Notice the last three entries -- Perl understands the default structure
d6baa268 2349of the $sitelib directories and will look back in older, compatible
33cceb07
RGS
2350directories. This way, modules installed under 5.8.7 will continue
2351to be usable by 5.8.7 but will also accessible to 5.8.8. Further,
d6baa268 2352suppose that you upgrade a module to one which requires features
33cceb07
RGS
2353present only in 5.8.8. That new module will get installed into
2354/usr/local/lib/perl5/site_perl/5.8.8 and will be available to 5.8.8,
2355but will not interfere with the 5.8.7 version.
bfb7748a 2356
c42e3e15 2357The last entry, /usr/local/lib/perl5/site_perl/, is there so that
fe23a901 23585.6.0 and above will look for 5.004-era pure perl modules.
d6baa268 2359
33cceb07
RGS
2360Lastly, suppose you now install 5.10.0, which is not binary compatible
2361with 5.8.x. The directories searched by 5.10.0 (if you don't change the
fe23a901
RF
2362Configure defaults) will be:
2363
33cceb07
RGS
2364 /usr/local/lib/perl5/5.10.0/$archname
2365 /usr/local/lib/perl5/5.10.0
2366 /usr/local/lib/perl5/site_perl/5.10.0/$archname
2367 /usr/local/lib/perl5/site_perl/5.10.0
d6baa268 2368
33cceb07 2369 /usr/local/lib/perl5/site_perl/5.8.8
d6baa268 2370
33cceb07 2371 /usr/local/lib/perl5/site_perl/5.8.7
fe23a901 2372
d6baa268 2373 /usr/local/lib/perl5/site_perl/
bfb7748a 2374
cc65bb49
AD
2375Note that the earlier $archname entries are now gone, but pure perl
2376modules from earlier versions will still be found.
2377
0a08c020
GS
2378This way, you can choose to share compatible extensions, but also upgrade
2379to a newer version of an extension that may be incompatible with earlier
2380versions, without breaking the earlier versions' installations.
693762b4
AD
2381
2382=head2 Maintaining completely separate versions
4633a7c4 2383
1ec51d55 2384Many users prefer to keep all versions of perl in completely
d6baa268 2385separate directories. This guarantees that an update to one version
0a08c020
GS
2386won't interfere with another version. (The defaults guarantee this for
2387libraries after 5.6.0, but not for executables. TODO?) One convenient
2388way to do this is by using a separate prefix for each version, such as
d52d4e46 2389
0e79a3d1 2390 sh Configure -Dprefix=/opt/perl5.17.0
d52d4e46 2391
0e79a3d1 2392and adding /opt/perl5.17.0/bin to the shell PATH variable. Such users
d52d4e46 2393may also wish to add a symbolic link /usr/local/bin/perl so that
2394scripts can still start with #!/usr/local/bin/perl.
2395
693762b4 2396Others might share a common directory for maintenance sub-versions
33cceb07 2397(e.g. 5.10 for all 5.10.x versions), but change directory with
693762b4
AD
2398each major version.
2399
6877a1cf
AD
2400If you are installing a development subversion, you probably ought to
2401seriously consider using a separate directory, since development
2402subversions may not have all the compatibility wrinkles ironed out
2403yet.
2404
0e79a3d1 2405=head2 Upgrading from 5.16.0 or earlier
693762b4 2406
0e79a3d1
RS
2407B<Perl 5.17.0 may not be is binary incompatible with Perl 5.16.0 or
2408earlier Perl release.> Perl modules having binary parts
e655887d 2409(meaning that a C compiler is used) will have to be recompiled to be
0e79a3d1
RS
2410used with 5.17.0. If you find you do need to rebuild an extension with
24115.17.0, you may safely do so without disturbing the older
7df75831 2412installations. (See L<"Coexistence with earlier versions of perl 5">
e655887d 2413above.)
c42e3e15
GS
2414
2415See your installed copy of the perllocal.pod file for a (possibly
2416incomplete) list of locally installed modules. Note that you want
cc65bb49 2417perllocal.pod, not perllocale.pod, for installed module information.
693762b4 2418
8ebf57cf
JH
2419=head1 Minimizing the Perl installation
2420
2421The following section is meant for people worrying about squeezing the
2422Perl installation into minimal systems (for example when installing
2423operating systems, or in really small filesystems).
2424
c8214fdf 2425Leaving out as many extensions as possible is an obvious way:
5cda700b
AD
2426Encode, with its big conversion tables, consumes a lot of
2427space. On the other hand, you cannot throw away everything. The
2428Fcntl module is pretty essential. If you need to do network
c8214fdf
JH
2429programming, you'll appreciate the Socket module, and so forth: it all
2430depends on what do you need to do.
2431
8ebf57cf
JH
2432In the following we offer two different slimmed down installation
2433recipes. They are informative, not normative: the choice of files
2434depends on what you need.
2435
2436Firstly, the bare minimum to run this script
2437
2438 use strict;
2439 use warnings;
2440 foreach my $f (</*>) {
2441 print("$f\n");
2442 }
2443
0e79a3d1 2444in Linux with perl-5.17.0 is as follows (under $Config{prefix}):
8ebf57cf
JH
2445
2446 ./bin/perl
0e79a3d1
RS
2447 ./lib/perl5/5.17.0/strict.pm
2448 ./lib/perl5/5.17.0/warnings.pm
2449 ./lib/perl5/5.17.0/i686-linux/File/Glob.pm
2450 ./lib/perl5/5.17.0/feature.pm
2451 ./lib/perl5/5.17.0/XSLoader.pm
2452 ./lib/perl5/5.17.0/i686-linux/auto/File/Glob/Glob.so
8ebf57cf 2453
00930d57
AD
2454Secondly, for perl-5.10.1, the Debian perl-base package contains 591 files,
2455(of which 510 are for lib/unicore) totaling about 3.5MB in its i386 version.
2456Omitting the lib/unicore/* files for brevity, the remaining files are:
8ebf57cf 2457
bfe08c74 2458 /usr/bin/perl
00930d57
AD
2459 /usr/bin/perl5.10.1
2460 /usr/lib/perl/5.10.1/Config.pm
2461 /usr/lib/perl/5.10.1/Config_git.pl
2462 /usr/lib/perl/5.10.1/Config_heavy.pl
2463 /usr/lib/perl/5.10.1/Cwd.pm
2464 /usr/lib/perl/5.10.1/DynaLoader.pm
2465 /usr/lib/perl/5.10.1/Errno.pm
2466 /usr/lib/perl/5.10.1/Fcntl.pm
2467 /usr/lib/perl/5.10.1/File/Glob.pm
2468 /usr/lib/perl/5.10.1/Hash/Util.pm
2469 /usr/lib/perl/5.10.1/IO.pm
2470 /usr/lib/perl/5.10.1/IO/File.pm
2471 /usr/lib/perl/5.10.1/IO/Handle.pm
2472 /usr/lib/perl/5.10.1/IO/Pipe.pm
2473 /usr/lib/perl/5.10.1/IO/Seekable.pm
2474 /usr/lib/perl/5.10.1/IO/Select.pm
2475 /usr/lib/perl/5.10.1/IO/Socket.pm
2476 /usr/lib/perl/5.10.1/IO/Socket/INET.pm
2477 /usr/lib/perl/5.10.1/IO/Socket/UNIX.pm
2478 /usr/lib/perl/5.10.1/List/Util.pm
2479 /usr/lib/perl/5.10.1/POSIX.pm
2480 /usr/lib/perl/5.10.1/Scalar/Util.pm
2481 /usr/lib/perl/5.10.1/Socket.pm
2482 /usr/lib/perl/5.10.1/XSLoader.pm
2483 /usr/lib/perl/5.10.1/auto/Cwd/Cwd.so
2484 /usr/lib/perl/5.10.1/auto/DynaLoader/autosplit.ix
2485 /usr/lib/perl/5.10.1/auto/DynaLoader/dl_expandspec.al
2486 /usr/lib/perl/5.10.1/auto/DynaLoader/dl_find_symbol_anywhere.al
2487 /usr/lib/perl/5.10.1/auto/DynaLoader/dl_findfile.al
2488 /usr/lib/perl/5.10.1/auto/Fcntl/Fcntl.so
2489 /usr/lib/perl/5.10.1/auto/File/Glob/Glob.so
2490 /usr/lib/perl/5.10.1/auto/Hash/Util/Util.so
2491 /usr/lib/perl/5.10.1/auto/IO/IO.so
2492 /usr/lib/perl/5.10.1/auto/List/Util/Util.so
2493 /usr/lib/perl/5.10.1/auto/POSIX/POSIX.so
2494 /usr/lib/perl/5.10.1/auto/POSIX/autosplit.ix
2495 /usr/lib/perl/5.10.1/auto/POSIX/load_imports.al
2496 /usr/lib/perl/5.10.1/auto/Socket/Socket.so
2497 /usr/lib/perl/5.10.1/lib.pm
2498 /usr/lib/perl/5.10.1/re.pm
8ebf57cf 2499 /usr/share/doc/perl/AUTHORS.gz
bfe08c74 2500 /usr/share/doc/perl/Documentation
00930d57 2501 /usr/share/doc/perl/README.Debian
8ebf57cf 2502 /usr/share/doc/perl/changelog.Debian.gz
bfe08c74 2503 /usr/share/doc/perl/copyright
00930d57 2504 /usr/share/lintian/overrides/perl-base
8ebf57cf 2505 /usr/share/man/man1/perl.1.gz
00930d57
AD
2506 /usr/share/man/man1/perl5.10.1.1.gz
2507 /usr/share/perl/5.10.1/AutoLoader.pm
2508 /usr/share/perl/5.10.1/Carp.pm
2509 /usr/share/perl/5.10.1/Carp/Heavy.pm
2510 /usr/share/perl/5.10.1/Exporter.pm
2511 /usr/share/perl/5.10.1/Exporter/Heavy.pm
2512 /usr/share/perl/5.10.1/File/Spec.pm
2513 /usr/share/perl/5.10.1/File/Spec/Unix.pm
2514 /usr/share/perl/5.10.1/FileHandle.pm
2515 /usr/share/perl/5.10.1/Getopt/Long.pm
2516 /usr/share/perl/5.10.1/IPC/Open2.pm
2517 /usr/share/perl/5.10.1/IPC/Open3.pm
2518 /usr/share/perl/5.10.1/SelectSaver.pm
2519 /usr/share/perl/5.10.1/Symbol.pm
2520 /usr/share/perl/5.10.1/Text/ParseWords.pm
2521 /usr/share/perl/5.10.1/Text/Tabs.pm
2522 /usr/share/perl/5.10.1/Text/Wrap.pm
2523 /usr/share/perl/5.10.1/Tie/Hash.pm
2524 /usr/share/perl/5.10.1/attributes.pm
2525 /usr/share/perl/5.10.1/base.pm
2526 /usr/share/perl/5.10.1/bytes.pm
2527 /usr/share/perl/5.10.1/bytes_heavy.pl
2528 /usr/share/perl/5.10.1/constant.pm
2529 /usr/share/perl/5.10.1/fields.pm
2530 /usr/share/perl/5.10.1/integer.pm
2531 /usr/share/perl/5.10.1/locale.pm
2532 /usr/share/perl/5.10.1/overload.pm
2533 /usr/share/perl/5.10.1/strict.pm
2534 /usr/share/perl/5.10.1/unicore/*
2535 /usr/share/perl/5.10.1/utf8.pm
2536 /usr/share/perl/5.10.1/utf8_heavy.pl
2537 /usr/share/perl/5.10.1/vars.pm
2538 /usr/share/perl/5.10.1/warnings.pm
2539 /usr/share/perl/5.10.1/warnings/register.pm
8ebf57cf 2540
e7a3c61b
JH
2541A nice trick to find out the minimal set of Perl library files you will
2542need to run a Perl program is
2543
a0a8d9d3 2544 perl -e 'do "prog.pl"; END { print "$_\n" for sort keys %INC }'
e7a3c61b
JH
2545
2546(this will not find libraries required in runtime, unfortunately, but
2547it's a minimal set) and if you want to find out all the files you can
2548use something like the below
2549
2550 strace perl -le 'do "x.pl"' 2>&1 | perl -nle '/^open\(\"(.+?)"/ && print $1'
2551
2552(The 'strace' is Linux-specific, other similar utilities include 'truss'
2553and 'ktrace'.)
2554
c19ccd8c
RGS
2555=head2 C<-DNO_MATHOMS>
2556
2557If you configure perl with C<-Accflags=-DNO_MATHOMS>, the functions from
2558F<mathoms.c> will not be compiled in. Those functions are no longer used
2559by perl itself; for source compatibility reasons, though, they weren't
2560completely removed.
2561
8e07c86e
AD
2562=head1 DOCUMENTATION
2563
bfb7748a
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2564Read the manual entries before running perl. The main documentation
2565is in the pod/ subdirectory and should have been installed during the
8e07c86e 2566build process. Type B<man perl> to get started. Alternatively, you
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2567can type B<perldoc perl> to use the supplied perldoc script. This is
2568sometimes useful for finding things in the library modules.
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2569
2570=head1 AUTHOR
2571
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2572Original author: Andy Dougherty doughera@lafayette.edu , borrowing very
2573heavily from the original README by Larry Wall, with lots of helpful
2574feedback and additions from the perl5-porters@perl.org folks.
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2576If you have problems, corrections, or questions, please see
2577L<"Reporting Problems"> above.
2578
2579=head1 REDISTRIBUTION
2580
2581This document is part of the Perl package and may be distributed under
d6baa268 2582the same terms as perl itself, with the following additional request:
f5b3b617 2583If you are distributing a modified version of perl (perhaps as part of
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2584a larger package) please B<do> modify these installation instructions
2585and the contact information to match your distribution.