- process identified by the specified process identifier. The session
- identifier is a short string (up to 64 characters),
- consisting only of the characters a-zA-Z0-9 as well as
- '-' and '_'. It is suitable for usage in file system
- paths. Note that not all processes are part of a login
- session (e.g. system 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
+ process identified by the specified process
+ identifier. The session identifier is a short string,
+ suitable for usage in file system paths. Note that not
+ all processes are part of a login session (e.g. system
+ 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