perlmacosx

README.macosx - Perl under Mac OS X

This document briefly describes perl under Mac \s-1OS\s0 X.

The latest Perl release (5.8.8 as of this writing) builds without changes under Mac \s-1OS\s0 X. Under 10.3 “Panther” and newer \s-1OS\s0 versions, all self-tests pass, and all standard features are supported.

Earlier Mac \s-1OS\s0 X releases (10.2 “Jaguar” and older) did not include a completely thread-safe libc, so threading is not fully supported. Also, earlier releases included a buggy libdb, so some of the DB_File tests are known to fail on those releases.

The default installation location for this release uses the traditional \s-1UNIX\s0 directory layout under /usr/local. This is the recommended location for most users, and will leave the Apple-supplied Perl and its modules undisturbed.

Using an installation prefix of '/usr' will result in a directory layout that mirrors that of Apple's default Perl, with core modules stored in '/System/Library/Perl/${version}', \s-1CPAN\s0 modules stored in '/Library/Perl/${version}', and the addition of '/Network/Library/Perl/${version}' to CW@INC for modules that are stored on a file server and used by many Macs.

First, export the path to the \s-1SDK\s0 into the build environment:

export SDK=/Developer/SDKs/MacOSX10.3.9.sdk

Use an \s-1SDK\s0 by exporting some additions to Perl's 'ccflags' and '..flags' config variables:

./Configure -Accflags="-nostdinc -B$SDK/usr/include/gcc   -B$SDK/usr/lib/gcc -isystem$SDK/usr/include   -F$SDK/System/Library/Frameworks"   -Aldflags="-Wl,-syslibroot,$SDK"   -de

To compile perl as a universal binary (built for both ppc and intel), export the \s-1SDK\s0 variable as above, selecting the 10.4u \s-1SDK:\s0

export SDK=/Developer/SDKs/MacOSX10.4u.sdk

In addition to the compiler flags used to select the \s-1SDK\s0, also add the flags for creating a universal binary:

./Configure -Accflags="-arch i686 -arch ppc -nostdinc -B$SDK/usr/include/gcc   -B$SDK/usr/lib/gcc -isystem$SDK/usr/include   -F$SDK/System/Library/Frameworks"   -Aldflags="-arch i686 -arch ppc -Wl,-syslibroot,$SDK"   -de

Keep in mind that these compiler and linker settings will also be used when building \s-1CPAN\s0 modules. For \s-1XS\s0 modules to be compiled as a universal binary, any libraries it links to must also be universal binaries. The system libraries that Apple includes with the 10.4u \s-1SDK\s0 are all universal, but user-installed libraries may need to be re-installed as universal binaries.

Mac \s-1OS\s0 X ships with a dynamically-loaded libperl, but the default for this release is to compile a static libperl. The reason for this is pre-binding. Dynamic libraries can be pre-bound to a specific address in memory in order to decrease load time. To do this, one needs to be aware of the location and size of all previously-loaded libraries. Apple collects this information as part of their overall \s-1OS\s0 build process, and thus has easy access to it when building Perl, but ordinary users would need to go to a great deal of effort to obtain the information needed for pre-binding.

You can override the default and build a shared libperl if you wish (Configure ... -Duseshrlib), but the load time on pre-10.4 \s-1OS\s0 releases will be greater than either the static library, or Apple's pre-bound dynamic library.

With 10.4 “Tiger” and newer, Apple has all but eliminated the performance penalty for non-prebound libraries.

In a word - don't, at least without a *very* good reason. Your scripts can just as easily begin with “#!/usr/local/bin/perl” as with “#!/usr/bin/perl”. Scripts supplied by Apple and other third parties as part of installation packages and such have generally only been tested with the /usr/bin/perl that's installed by Apple.

If you find that you do need to update the system Perl, one issue worth keeping in mind is the question of static vs. dynamic libraries. If you upgrade using the default static libperl, you will find that the dynamic libperl supplied by Apple will not be deleted. If both libraries are present when an application that links against libperl is built, ld will link against the dynamic library by default. So, if you need to replace Apple's dynamic libperl with a static libperl, you need to be sure to delete the older dynamic library after you've installed the update.

If you have installed extra libraries such as \s-1GDBM\s0 through Fink (in other words, you have libraries under /sw/lib), or libdlcompat to /usr/local/lib, you may need to be extra careful when running Configure to not to confuse Configure and Perl about which libraries to use. Being confused will show up for example as “dyld” errors about symbol problems, for example during “make test”. The safest bet is to run Configure as

Configure ... -Uloclibpth -Dlibpth=/usr/lib

to make Configure look only into the system libraries. If you have some extra library directories that you really want to use (such as newer Berkeley \s-1DB\s0 libraries in pre-Panther systems), add those to the libpth:

Configure ... -Uloclibpth -Dlibpth='/usr/lib /opt/lib'

The default of building Perl statically may cause problems with complex applications like Tk: in that case consider building shared Perl

Configure ... -Duseshrplib

but remember that there's a startup cost to pay in that case (see above “libperl and Prebinding”).

Starting with Tiger (Mac \s-1OS\s0 X 10.4), Apple shipped broken locale files for the eu_ES locale (Basque-Spain). In previous releases of Perl, this resulted in failures in the CWlib/locale test. These failures have been supressed in the current release of Perl by making the test ignore the broken locale. If you need to use the eu_ES locale, you should contact Apple support.

Quite a bit has been written about MacPerl, the Perl distribution for “Classic MacOS” - that is, versions 9 and earlier of MacOS. Because it runs in environment that's very different from that of \s-1UNIX\s0, many things are done differently in MacPerl. Modules are installed using a different procedure, Perl itself is built differently, path names are different, etc.

From the perspective of a Perl programmer, Mac \s-1OS\s0 X is more like a traditional \s-1UNIX\s0 than Classic MacOS. If you find documentation that refers to a special procedure that's needed for MacOS that's drastically different from the instructions provided for \s-1UNIX\s0, the MacOS instructions are quite often intended for MacPerl on Classic MacOS. In that case, the correct procedure on Mac \s-1OS\s0 X is usually to follow the \s-1UNIX\s0 instructions, rather than the MacPerl instructions.

MacPerl ships with a number of modules that are used to access the classic MacOS toolbox. Many of these modules have been updated to use Mac \s-1OS\s0 X's newer “Carbon” toolbox, and are available from \s-1CPAN\s0 in the “Mac::Carbon” module.

There are two ways to use Cocoa from Perl. Apple's PerlObjCBridge module, included with Mac \s-1OS\s0 X, can be used by standalone scripts to access Foundation (i.e. non-GUI) classes and objects.

An alternative is CamelBones, a framework that allows access to both Foundation and AppKit classes and objects, so that full \s-1GUI\s0 applications can be built in Perl. CamelBones can be found on SourceForge, at <http://www.sourceforge.net/projects/camelbones/>.

Unfortunately it is not that difficult somehow manage to break one's Mac \s-1OS\s0 X Perl rather severely. If all else fails and you want to really, \s-1REALLY\s0, start from scratch and remove even your Apple Perl installation (which has become corrupted somehow), the following instructions should do it. Please think twice before following these instructions: they are much like conducting brain surgery to yourself. Without anesthesia. We will not come to fix your system if you do this.

First, get rid of the libperl.dylib:

# cd /System/Library/Perl/darwin/CORE # rm libperl.dylib

Then delete every .bundle file found anywhere in the folders:

/System/Library/Perl /Library/Perl

You can find them for example by

# find /System/Library/Perl /Library/Perl -name '*.bundle' -print

After this you can either copy Perl from your operating system media (you will need at least the /System/Library/Perl and /usr/bin/perl), or rebuild Perl from the source code with CWConfigure -Dprefix=/usr -Dusershrplib \s-1NOTE:\s0 the CW-Dprefix=/usr to replace the system Perl works much better with Perl 5.8.1 and later, in Perl 5.8.0 the settings were not quite right.

“Pacifist” from CharlesSoft (<http://www.charlessoft.com/>) is a nice way to extract the Perl binaries from the \s-1OS\s0 media, without having to reinstall the entire \s-1OS\s0.

This \s-1README\s0 was written by Sherm Pendley <sherm@dot-app.org>, and subsequently updated by Dominic Dunlop <domo@computer.org>. The “Starting From Scratch” recipe was contributed by John Montbriand <montbriand@apple.com>.

Last modified 2005-11-07.