service-is-up, svup — daemontools compatibility service state checker
service-is-up
{directory
}
svup
{directory
}
service-is-up checks to see whether a service is currently up and running.
directory
is either a supervise directory or a daemontools-style service
directory with a supervise directory named supervise
within it.
A service is considered up and running if its supervise directory contains an
ok
FIFO that can be opened for write in non-blocking mode, and contains a
status
file that indicates that the service is both up and running.
service-is-up understands the extended status
file structure employed by
service-manager(1) and daemontools-encore, and in the presence of extended
status information will only consider a service to be up and running if it both
has a non-zero process ID and is marked as in the running state. If there is
only daemontools-style status information available, a service is considered up
and running simply if it has a non-zero process ID.
The result is signalled by the exit code, which is 0 upon success, 111
if the directory does not exist or some other error occurred, and 100
if the status
file says that the service is not up and running or
the ok
FIFO cannot be opened in client mode.
For more on service and supervise directories, see service-manager(1).