systemd-is-running - Check if systemd is running
This document describes version 0.001 of systemd-is-running (from Perl distribution App-SystemdUtils), released on 2019-05-22.
Usage:
% systemd-is-running [options]
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:
undef
func.note
realpath()
readlink()
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.
--json
* marks required options.
*
Choose output format, e.g. json, text.
Default value:
Set output format to json.
When outputing as JSON, strip result envelope.
0
By default, when outputing as JSON, the full enveloped result is returned, e.g.:
[200,"OK",[1,2,3],{"func.extra"=>4}]
The reason is so you can get the status (1st element), status message (2nd element) as well as result metadata/extra result (4th element) instead of just the result (3rd element). However, sometimes you want just the result, e.g. when you want to pipe the result for more post-processing. In this case you can use `--naked-res` so you just get:
[1,2,3]
Display help message and exit.
Display program's version and exit.
This script has shell tab completion capability with support for several shells.
To activate bash completion for this script, put:
complete -C systemd-is-running systemd-is-running
in your bash startup (e.g. ~/.bashrc). Your next shell session will then recognize tab completion for the command. Or, you can also directly execute the line above in your shell to activate immediately.
It is recommended, however, that you install modules using cpanm-shcompgen which can activate shell completion for scripts immediately.
To activate tcsh completion for this script, put:
complete systemd-is-running 'p/*/`systemd-is-running`/'
in your tcsh startup (e.g. ~/.tcshrc). Your next shell session will then recognize tab completion for the command. Or, you can also directly execute the line above in your shell to activate immediately.
It is also recommended to install shcompgen (see above).
For fish and zsh, install shcompgen as described above.
Please visit the project's homepage at https://metacpan.org/release/App-SystemdUtils.
Source repository is at https://github.com/perlancar/perl-App-SystemdUtils.
Please report any bugs or feature requests on the bugtracker website https://rt.cpan.org/Public/Dist/Display.html?Name=App-SystemdUtils
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.
perlancar <perlancar@cpan.org>
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.
To install App::SystemdUtils, copy and paste the appropriate command in to your terminal.
cpanm
cpanm App::SystemdUtils
CPAN shell
perl -MCPAN -e shell install App::SystemdUtils
For more information on module installation, please visit the detailed CPAN module installation guide.