The s6-instance-control program

s6-instance-control sends commands to a running instance of an instanced service.

Interface

     s6-instance-control [ -wu | -wU | -wd | -wD | -wr | -wR ] [ -T timeout ] [ -abqhkti12pcyoduDUxOr ] servicedir name

s6-instance-control expects a running, supervised instanced service in servicedir, as well as an existing instance of this service named name.
It sends the given series of commands to the supervisor monitoring the name instance.
It exits 0.

Exit codes

0: success
99: with one of the -w options, timed out while waiting for the command to complete
100: wrong usage
111: system call failed

Options

The options, and the commands they represent, are exactly the same as the ones understood by s6-svc.

In fact, s6-instance-control is nothing more than a call to s6-svc on the service directory representing the name instance. It is syntactic sugar so the user does not have to depend on the internal representation of instances and the location of instances' service directories.