Re^3: Establishing a beachhead and acquiring privileges on a Mac-mini

"... I do not know the perl command to update itself."

Having been advised against using the system Perl on Mac, you wouldn't be doing this even if Perl had such a command. Correct?

I used Perlbrew on Mac for about nine years and never had any problems. I changed to Cygwin on Win10 about five years ago; still using Perlbrew and still having no problems.

Following links from Perlbrew, you'll eventually get to CPAN: perlbrew. Here you'll find documentation for perlbrew commands; in the context of the current discussion, the most pertinent are probably install, upgrade-perl, and install-cpanm.

Once you have Perlbrew installed, you can easily switch between whatever versions of Perl you have; e.g.

$ perl -v | head -2 | tail -1
This is perl 5, version 36, subversion 0 (v5.36.0) built for cygwin-th
+read-multi

$ perlbrew switch perl-5.32.0

$ perl -v | head -2 | tail -1
This is perl 5, version 32, subversion 0 (v5.32.0) built for cygwin-th
+read-multi

$ perlbrew switch perl-5.36.0

$ perl -v | head -2 | tail -1
This is perl 5, version 36, subversion 0 (v5.36.0) built for cygwin-th
+read-multi
[download]

I recommend using the following shebang in your scripts.

#!/usr/bin/env perl
[download]

This means that the script will use whatever Perl version is current.

$ cat test_shebang.pl
#!/usr/bin/env perl

print $^V;

$ ./test_shebang.pl
v5.36.0

$ perlbrew switch perl-5.33.5

$ perl -v | head -2 | tail -1
This is perl 5, version 33, subversion 5 (v5.33.5) built for cygwin-th
+read-multi

$ ./test_shebang.pl
v5.33.5
[download]

— Ken

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Re^4: Establishing a beachhead and acquiring privileges on a Mac-mini by Aldebaran (Curate) on May 07, 2023 at 02:51 UTC
I recommend using the following shebang in your scripts. I wish I had seen your reply before I reposted. `#!/usr/bin/env perl` fixed me entirely, thanks...I'll take another look at perlbrew, but I honestly have to pick my battles. It's all going much slower than I wanted, but I'm finally getting something like a toolchain started. Good to know that it can be done without conflict.	[reply] [d/l]
Re^5: Establishing a beachhead and acquiring privileges on a Mac-mini by kcott (Archbishop) on May 07, 2023 at 03:23 UTC
"fixed me entirely, thanks" Glad I could help. "I'll take another look at perlbrew, but I honestly have to pick my battles." As I indicated in my previous post, it's been five years since I've used a Mac; my information could be out-of-date. Having said that, for the nine years that I did use Mac, upgrades to the system would typically wipe out older versions of Perl and replace them with newer ones: this would not only delete the core Perl code but also any modules that the user may have installed with that version. You could potentially lose a lot; recovery may be problematical; and, the old Perl version is no longer available to you (which may or may not be important). In addition, installing modules in the system Perl may have subtle side-effects. For instance, you install X::Y::Z; this has a dependency of A::B::C with a version greater than what comes with the system Perl; the installation of X::Y::Z automatically upgrades A::B::C; this may potentially change how the system Perl works; in turn, this could affect how the O/S works, possibly with dire consequences. I'd guess Perlbrew is the most used but there are other options (with which I'm not overly familiar); as I know Perlbrew, and have used it successfully for well over a decade, it's what I recommend. Choose whatever you want but, like others, I strongly recommend against using the system Perl. Whatever Perl versions and modules you've installed will not be deleted with an upgrade to the Mac O/S. Don't win a quick battle only to subsequently lose the war. :-) — Ken	[reply]