- service processes and user processes that are shared
- between multiple sessions of the same user). For
- processes not being part of a login session this
- function will fail. The returned string needs to be
- freed with the libc
+ service processes, user processes that are shared
+ between multiple sessions of the same user, or kernel
+ threads). For processes not being part of a login
+ session this function will fail. The returned string
+ needs to be freed with the libc
+ <citerefentry><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+ call after use.</para>
+
+ <para><function>sd_pid_get_unit()</function> may be
+ used to determine the systemd unit (i.e. system
+ service) identifier of a process identified by the
+ specified process identifier. The unit name is a short
+ string, suitable for usage in file system paths. Note
+ that not all processes are part of a unit/service
+ (e.g. user processes, or kernel threads). For
+ processes not being part of a systemd unit/system
+ service this function will fail. The returned string
+ needs to be freed with the libc