Support traditional SysV-style daemon initialization scheme
On older Linux systems, or on distributions that do not use systemd/upstart, or on BSD systems, it may be useful to implement the "old-style" daemon initialization scheme with double forking, as described here under the SysV Daemons subsection.
libdaemon MAY be used to implement this feature.
In any case, as the linked document points out, the old-style behavior MUST be optional and configurable via a command line argument.
Updated by Davide Pesavento almost 7 years ago
Debian 6 (squeeze) and 7 (wheezy) still use SysV init (I believe this will change in Debian 8).
Gentoo/Linux and NetBSD use OpenRC by default, which, although having a more sophisticated dependency-based system, is still backwards compatible with traditional daemons and can thus be used for testing.
Even upstart supports old-style forking daemons through the "
expect" stanza (http://upstart.ubuntu.com/cookbook/#expect).