On Thu, 26 Sep 2019 12:22:41 +0200, ZOT wrote:

> apache, sendmail and mysql are systems services they should not depend
> on a language and certainly not on perl. ( why not basic??)
>
That is only true if they are written in a language that compiles to
native binary code for the computer that its running on AND any libraries
it depends on are statically linked into the binary.

Packages with dependencies on any other packages will be broken if you
remove the packages they depend on, so the convention is that the package
manager (apt for Debian/Raspbian, dnf for Fedora/RHEL) will ask for
confirmation if you try to remove a package that other installed packages
depend on and lists them so you can understand the consequences.

If you choose to go ahead and delete the package, then you have
voluntarily accepted that all the dependent packages will also be
removed.

> If they depend on some library tight to perl, those library should not
> be removed but not the system service.
>
Of course it should do that: you may have decided that you are repurposing
the computer as, say, a file store or a firewall and you've decided that,
as it will no longer be used to execute Perl, Java or Python programs,
you'll remove all of these for security reasons.

> BTW apt-get removed perl, mysql.. but re-installed php 7.3??
>
Simple: php is dependent on the pcre library, not Perl, and the pcre
library is not written in Perl and so is also not dependent on any Perl
packages, so was not affected by your removal of Perl from your RPi.


--
Martin    | martin at
Gregorie  | gregorie dot org

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