Why does Apple Mac ship with TWO versions of Perl??

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

And why are they so small? (my perlbrew 5.38.2 is 3.4M)

/usr/bin/perl		v5.30.3	169,856 bytes executable
/usr/bin/perl5.30	v5.30.3	134,608 bytes
/usr/bin/perl5.34	v5.34.0	134,608 bytes

There are 3 copies of everything in /usr/bin:

perldoc			811 bytes executable
perldoc5.30		297 bytes
perldoc5.34		297 bytes

Core modules for each version:

/System/Library/Perl/5.30
/System/Library/Perl/5.34

Older versions of macos had two copies of everything in /usr/bin but they were the same version of perl. This is on macOS Sonoma 14.3 version 23D2057. The question arises from Re^2: object version does not match.

Comment on Why does Apple Mac ship with TWO versions of Perl??

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Re: Why does Apple Mac ship with TWO versions of Perl?? by tonyc (Hermit) on May 13, 2024 at 22:47 UTC
`/usr/bin/perl` isn't a perl binary in this case, but what appears to be a wrapper that calls whichever version of perl is configured. I don't know how that is configured, though the answer here for python can probably be adapted. If you run `VERSIONER_DEBUG=1 perl -v` you'll see some of the output from this process. The actual perl binaries are this small because perl was built with `-Duseshrplib` which moves most of perl into a shared library. This is common for vendor built perls, since it allows the same shared library to be shared between the perl binary and embedded perls, such as mod_perl2. It can also simplify security updates, since minor fixes only require updating the perl package including the shared library. I don't know why there are two versions installed	[reply] [d/l] [select]
Re: Why does Apple Mac ship with TWO versions of Perl?? by Anonymous Monk on May 10, 2024 at 01:00 UTC
`/usr/bin/perl5.30 -V >p530;/usr/bin/perl5.34 -V >p534; diff -y p530 p5 +34` [download] bincompat5005=undef < Compiled at Dec 21 2023 03:10:25 \| Compiled at Dec 21 2023 03:10:36 Also @INC: /Library/Perl/5.30/darwin-thread-multi-2level /Library/Perl/5.30 /Network/Library/Perl/5.30/darwin-thread-multi-2level /Network/Library/Perl/5.30 /Library/Perl/Updates/5.30.3 /System/Library/Perl/5.30/darwin-thread-multi-2level /System/Library/Perl/5.30 /System/Library/Perl/Extras/5.30/darwin-thread-multi- /System/Library/Perl/Extras/5.30 The only folders in this @INC that exist are the /System folders containing core modules, and /Library/Perl/5.30 with this one file: `cat /Library/Perl/5.30/AppendToPath` [download] `/System/Library/Perl/Extras/5.30` /Network does not exist. Remnants of the build process for macOS?	[reply] [d/l] [select]