Each of these is explained in further detail below.
-B<NOTE>: starting from the release 5.6.0 Perl will use a version
+B<NOTE>: starting from the release 5.6.0, Perl will use a version
scheme where even-numbered subreleases (like 5.6) are stable
maintenance releases and odd-numbered subreleases (like 5.7) are
unstable development releases. Development releases should not be
=head1 WARNING: This version requires an extra step to build old extensions.
5.005_53 and later releases do not export unadorned
-global symbols anymore. This means you may need to build older
-extensions that have not been updated for the new naming convention
+global symbols anymore. This means you may need to build rather old
+extensions that have not been updated for the current naming convention
with:
perl Makefile.PL POLLUTE=1
pod/perldelta.pod contains more details about this.
-=head1 WARNING: This version may not be binary compatible with Perl 5.005.
+=head1 WARNING: This version is not binary compatible with releases of
+Perl prior to 5.8.0.
-Using the default Configure options for building perl should get you
-a perl that will be binary compatible with the 5.005 release.
-
-However, if you run Configure with any custom options, such as
--Dusethreads, -Dusemultiplicity, -Dusemymalloc, -Ubincompat5005 etc.,
-the resulting perl will not be binary compatible. Under these
-circumstances, if you have dynamically loaded extensions that were
-built under perl 5.005, you will need to rebuild and reinstall all
-those extensions to use them with 5.6.
+If you have built extensions (ie modules that include C code)
+using an earlier version of Perl, you will need to rebuild and reinstall
+those extensions.
Pure perl modules without XS or C code should continue to work fine
without reinstallation. See the discussions below on
=head1 Space Requirements
-The complete perl5 source tree takes up about 40 MB of disk space.
-After completing make, it takes up roughly 60 MB, though the actual
+The complete perl5 source tree takes up about 50 MB of disk space.
+After completing make, it takes up roughly 100 MB, though the actual
total is likely to be quite system-dependent. The installation
-directories need something on the order of 35 MB, though again that
+directories need something on the order of 45 MB, though again that
value is system-dependent.
=head1 Start with a Fresh Distribution
directory structure is simplified. For example, if you use
prefix=/opt/perl, then Configure will suggest /opt/perl/lib instead of
/opt/perl/lib/perl5/. Again, see L<"Installation Directories"> below
-for more details.
+for more details. Do not include a trailing slash, (i.e. /opt/perl/)
+or you may experience odd test failures.
NOTE: You must not specify an installation directory that is the same
as or below your perl source directory. If you do, installperl will
installation questions are near the beginning of Configure.
Further, there are a number of additions to the installation
directories since 5.005, so reusing your old config.sh may not
-be sufficient to put everything where you want it.
+be sufficient to put everything where you want it. Do not include
+trailing slashes on directory names.
I highly recommend running Configure interactively to be sure it puts
everything where you want it. At any point during the Configure
These are normally empty, but may be set as needed. For example,
a vendor might choose the following settings:
- $prefix /usr/bin
- $siteprefix /usr/local/bin
- $vendorprefix /usr/bin
+ $prefix /usr
+ $siteprefix /usr/local
+ $vendorprefix /usr
This would have the effect of setting the following:
The default is to compile without thread support.
-As of v5.5.64, perl has two different internal threads implementations.
-The 5.005 version (5005threads) and an interpreter-based implementation
-(ithreads) with one interpreter per thread. By default, Configure selects
-ithreads if -Dusethreads is specified. However, you can select the old
-5005threads behavior instead by either
+Perl has two different internal threads implementations. The current
+model (available internally since 5.6, and as a user-level module
+since 5.8) is called interpreter-based implementation (ithreads),
+with one interpreter per thread, and explicit sharing of data.
- sh Configure -Dusethreads -Duse5005threads
+The 5.005 version (5005threads) is considered obsolete, buggy, and
+unmaintained.
-or by
- sh Configure -Dusethreads -Uuseithreads
+By default, Configure selects ithreads if -Dusethreads is specified.
-Eventually (by perl v5.6.0) this internal confusion ought to disappear,
-and these options may disappear as well.
+However, you can select the old 5005threads behavior
+
+ sh Configure -Dusethreads -Duse5005threads
+
+If you decide to use ithreads, the 'threads' module allows their use,
+and the 'Thread' module offers an interface to both 5005threads and
+ithreads (whichever has been configured).
=head2 Large file support.
=head2 Selecting File IO mechanisms
-Previous versions of perl used the standard IO mechanisms as defined in
-stdio.h. Versions 5.003_02 and later of perl allow alternate IO
-mechanisms via a "PerlIO" abstraction, but the stdio mechanism is still
-the default and is the only supported mechanism.
-
-This PerlIO abstraction can be enabled either on the Configure command
-line with
+Executive summary: in Perl 5.8, you should use the default "PerlIO"
+as the IO mechanism unless you have a good reason not to.
- sh Configure -Duseperlio
+In more detail: previous versions of perl used the standard IO
+mechanisms as defined in stdio.h. Versions 5.003_02 and later of perl
+introduced alternate IO mechanisms via a "PerlIO" abstraction, but up
+until and including Perl 5.6, the stdio mechanism was still the default
+and the only supported mechanism.
-or interactively at the appropriate Configure prompt.
+Starting from Perl 5.8, the default mechanism is to use the PerlIO
+abstraction, because it allows better control of I/O mechanisms,
+instead of having to work with (often, work around) vendors' I/O
+implementations.
-If you choose to use the PerlIO abstraction layer, there are two
-(experimental) possibilities for the underlying IO calls. These have been
-tested to some extent on some platforms, but are not guaranteed to work
-everywhere.
+This PerlIO abstraction can be (but again, unless you know what you
+are doing, should not be) disabled either on the Configure command
+line with
-=over 4
+ sh Configure -Uuseperlio
-=item 1.
+or interactively at the appropriate Configure prompt.
-AT&T's "sfio". This has superior performance to stdio.h in many
-cases, and is extensible by the use of "discipline" modules. Sfio
-currently only builds on a subset of the UNIX platforms perl supports.
-Because the data structures are completely different from stdio, perl
-extension modules or external libraries may not work. This
-configuration exists to allow these issues to be worked on.
+With the PerlIO abstraction layer, there is another possibility for
+the underlying IO calls, AT&T's "sfio". This has superior performance
+to stdio.h in many cases, and is extensible by the use of "discipline"
+modules ("Native" PerlIO has them too). Sfio currently only builds on
+a subset of the UNIX platforms perl supports. Because the data
+structures are completely different from stdio, perl extension modules
+or external libraries may not work. This configuration exists to
+allow these issues to be worked on.
This option requires the 'sfio' package to have been built and installed.
The latest sfio is available from http://www.research.att.com/sw/tools/sfio/
_exit vs. exit. If you have this problem, the fix is to go back to
your sfio sources and correct iffe's guess about atexit.
-=item 2.
-
-Normal stdio IO, but with all IO going through calls to the PerlIO
-abstraction layer. This configuration can be used to check that perl and
-extension modules have been correctly converted to use the PerlIO
-abstraction.
-
-This configuration should work on all platforms (but might not).
-
-You select this option via:
-
- sh Configure -Duseperlio -Uusesfio
-
-If you have already selected -Duseperlio, and if Configure does not
-detect sfio, then this will be the default suggested by Configure.
-
-=back
-
=head2 SOCKS
Perl can be configured to be 'socksified', that is, to use the SOCKS
=item -DPERL_POLLUTE_MALLOC
-NOTE: This flag is enabled automatically on some platforms if you
-asked for binary compatibility with version 5.005, or if you just
-run Configure to accept all the defaults on those platforms. You
-can refuse the automatic binary compatibility flags wholesale by
-running:
-
- sh Configure -Ubincompat5005
-
-or by answering 'n' at the appropriate prompt.
+NOTE: This flag is enabled automatically on some platforms if you just
+run Configure to accept all the defaults on those platforms.
Perl's malloc family of functions are called Perl_malloc(),
Perl_realloc(), Perl_calloc() and Perl_mfree(). When this flag is
then propagate your changes with B<sh Configure -S> and rebuild
with B<make depend; make>.
-=item CRIPPLED_CC
-
-If you still can't compile successfully, try:
-
- sh Configure -Accflags=-DCRIPPLED_CC
-
-This flag simplifies some complicated expressions for compilers that get
-indigestion easily. (Just because you get no errors doesn't mean it
-compiled right!)
-
=item Missing functions
If you have missing routines, you probably need to add some library or
NCR Tower 32 (OS 2.01.01) may need -W2,-Sl,2000 and #undef MKDIR.
-UTS may need one or more of -DCRIPPLED_CC, -K or -g, and undef LSTAT.
+UTS may need one or more of -K or -g, and undef LSTAT.
FreeBSD can fail the lib/ipc_sysv.t test if SysV IPC has not been
configured to the kernel. Perl tries to detect this, though, and
you will get a message telling what to do.
-If you get syntax errors on '(', try -DCRIPPLED_CC.
-
Machines with half-implemented dbm routines will need to #undef I_ODBM
HP-UX 11 Y2K patch "Y2K-1100 B.11.00.B0125 HP-UX Core OS Year 2000
Several tests in the test suite check timing functions, such as
sleep(), and see if they return in a reasonable amount of time.
-If your system is quite busy and doesn't return quickly enough,
-these tests might fail. If possible, try running the tests again with
-the system under a lighter load. These tests include F<t/op/alarm.t>,
-F<ext/Time/HiRes/HiRes.t>, and F<lib/Benchmark.t>.
+If your system is quite busy and doesn't respond quickly enough,
+these tests might fail. If possible, try running the tests again
+with the system under a lighter load. These timing-sensitive
+and load-sensitive tests include F<t/op/alarm.t>,
+F<ext/Time/HiRes/HiRes.t>, F<lib/Benchmark.t>,
+F<lib/Memoize/t/expmod_t.t>, and F<lib/Memoize/t/speed.t>.
=item Out of memory
=head1 Coexistence with earlier versions of perl5
+Perl 5.8 is not binary compatible with earlier versions of Perl.
+In other words, you have to recompile your XS modules.
+
In general, you can usually safely upgrade from one version of Perl (e.g.
5.004_04) to another similar version (e.g. 5.004_05) without re-compiling
all of your add-on extensions. You can also safely leave the old version
Perl installation into minimal systems (for example when installing
operating systems, or in really small filesystems).
+Leaving out as many extensions as possible is an obvious way:
+especially the Encode with its big conversion tables consumes a lot of
+space. On the other hand, you cannot throw away everything, especially
+the Fcntl module is pretty essential. If you need to do network
+programming, you'll appreciate the Socket module, and so forth: it all
+depends on what do you need to do.
+
In the following we offer two different slimmed down installation
recipes. They are informative, not normative: the choice of files
depends on what you need.
https://perl5.git.perl.org / perl5.git / blobdiff