pid1 - 0.1.2.0-3+b2 main

Library/executable for initializing signal handlers, spawning and
child process, and reaping orphan processes. These are the
responsibilities that must be fulfilled by the initial process in a
Unix system, and in particular comes up when running Docker
containers.
.
This library/executable will automatically detect if it is run as some
process besides PID1 and, if so, use a straightforward exec system
call instead.