NAME

Systemd::Util - Some utility routines related to Systemd

VERSION

This document describes version 0.002 of Systemd::Util (from Perl distribution Systemd-Util), released on 2019-06-17.

FUNCTIONS

systemd_is_running

Usage:

 systemd_is_running() -> [status, msg, payload, meta]

Check if systemd is running.

Will return payload of 1 if systemd is running, 0 if not running, undef if cannot determine for sure. The result metadata func.note will give more details. The following heuristics are currently used:

1. Check if /sbin/init exists, if it does not the return 0.

2. Check if /sbin/init is a symlink to something with "systemd" in its name. If yes, then we return 1. We use Cwd's realpath() instead of readlink() here, to handle multiple redirection.

3. Check if /lib/systemd/systemd exists. Return 0 otherwise.

4. Check if /sbin/init is a hardlink to /lib/systemd/systemd by comparing its inode. Return 1 if it is.

5. Return undef otherwise, since we detect that /lib/systemd/systemd exists (systemd is installed) but we cannot be sure if it is running or not.

When used as a CLI, this routine will exit 0 if systemd is running, 1 if systemd is not running, or 99 if cannot determine for sure. To see the more detailed note, you can run the CLI with --json to return the whole enveloped response.

This function is not exported by default, but exportable.

No arguments.

Returns an enveloped result (an array).

First element (status) is an integer containing HTTP status code (200 means OK, 4xx caller error, 5xx function error). Second element (msg) is a string containing error message, or 'OK' if status is 200. Third element (payload) is optional, the actual result. Fourth element (meta) is called result metadata and is optional, a hash that contains extra information.

Return value: (any)

HOMEPAGE

Please visit the project's homepage at https://metacpan.org/release/Systemd-Util.

SOURCE

Source repository is at https://github.com/perlancar/perl-Systemd-Util.

BUGS

Please report any bugs or feature requests on the bugtracker website https://rt.cpan.org/Public/Dist/Display.html?Name=Systemd-Util

When submitting a bug or request, please include a test-file or a patch to an existing test-file that illustrates the bug or desired feature.

AUTHOR

perlancar <perlancar@cpan.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2019 by perlancar@cpan.org.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.