Constrain downgrades the abilities of the process by changing to a nominated uid/gid which presumably has less power and chroots to a directory that presumably has very little in it or below it.

ConstraintReport returns a printable string showing the uid/gid/cwd of the process.

IsSignalUSR1 returns true if the supplied signal is SIGUSR1.

SignalNotify sends all the main Unix signals to the supplied channel.