s6
Software
skarnet.org

The s6-svwait program

s6-svwait blocks until a collection of supervised services goes up, or down.

s6-svwait only waits for notifications; it never polls.

Interface

     s6-svwait [ -U | -u | -d ] [ -a | -o ] [ -t timeout ] servicedir...

s6-svwait monitors one or more service directories given as its arguments, waiting for a state (ready, up or down) to happen. It exits 0 when the wanted condition becomes true.

Options

Notes

Internals

s6-svwait spawns a s6-ftrigrd child to listen to notifications sent by s6-supervise. It also checks supervise/status files, as well as the supervise/ready files if necessary, to get the current service states, so it is immune to race conditions.