If - for whatever reason - a script uses set -u (nounset) and includes
/etc/profile.d/70-systemd-shell-extra.sh (e.g. transitively via
/etc/profile) the script would fail with:
/etc/profile.d/70-systemd-shell-extra.sh: line 15: SHELL_PROMPT_PREFIX: unbound variable
For example:
$ cat > foo.sh <<EOF
#!/bin/sh
set -u
source /etc/profile
EOF
$ chmod 700 foo.sh
$ ./foo.sh
/etc/profile.d/70-systemd-shell-extra.sh: line 15: SHELL_PROMPT_PREFIX: unbound variable
Fix this by using shell parameter substitution[^1] (which is a POSIX
shell concept) to set the $SHELL_* variables to the empty string if
undefined.
[^1]: https://pubs.opengroup.org/onlinepubs/9699919799.2018edition/utilities/V3_chap02.html
System and Service Manager
Details
Most documentation is available on systemd's web site.
Assorted, older, general information about systemd can be found in the systemd Wiki.
Information about build requirements is provided in the README file.
Consult our NEWS file for information about what's new in the most recent systemd versions.
Please see the Code Map for information about this repository's layout and content.
Please see the Hacking guide for information on how to hack on systemd and test your modifications.
Please see our Contribution Guidelines for more information about filing GitHub Issues and posting GitHub Pull Requests.
When preparing patches for systemd, please follow our Coding Style Guidelines.
If you are looking for support, please contact our mailing list, join our IRC channel #systemd on libera.chat or Matrix channel
Stable branches with backported patches are available in the stable repo.
We have a security bug bounty program sponsored by the Sovereign Tech Fund hosted on YesWeHack
