Editing Portal:Linux (section)

=== System Perl and user Perl ===

On Linux, the most important distinction is between '''system Perl''' and '''user Perl'''.

'''System Perl''' is the Perl interpreter provided by the Linux distribution. It is installed through the system package manager, such as `apt`, `dnf`, `zypper`, `pacman`, `apk`, `emerge`, or `pkgtool`. It may be required by operating-system tools, package scripts, build scripts, or other installed packages. Its modules are usually installed in vendor-controlled directories and tracked by the package manager.

'''User Perl''' is a Perl interpreter or module tree installed by the user or application owner. It may be managed with tools such as `perlbrew`, `plenv`, `local::lib`, `cpanm`, or an application-specific dependency system. A user Perl is safer for application development because it avoids overwriting or confusing modules needed by the operating system.

This distinction matters because installing CPAN modules directly into the system Perl can conflict with distribution packages. On production Linux systems, the safest practice is usually:

* use distribution packages for system Perl modules when possible;
* use a separate local Perl for application-specific CPAN modules;
* avoid replacing the distribution’s `/usr/bin/perl`;
* do not assume the full upstream Perl core is present when only a minimal Perl package is installed.