This is a tiny library for daemons to communicate with init systems. At present only readiness notification is supported, by the same protocol as exposed by systemd. In the future this will hopefully extend to socket-passing and FD-stashing, and to non-systemd compatible mechanisms provided for by other init systems.
A stub library called libfreeinit-sd-daemon implementing minimal libsystemd
functionality is included. Only sd_notify() and sd_notifyf() are provided at
present. These alone are adequate for such software as OpenSSH.
Optionally (by passing -Dlibsystemd_links=true during configuration), symlinks
for libsystemd.so, libsystemd.pc, and the systemd include directory are
installed. This should allow for the simplest consumers of libsystemd
functionality to build unmodified with libfreeinit.