S6-SVSCANCTL(8)

NAME
s6-svscanctl - send commands to a running s6-svscan(8) process

SYNOPSIS
s6-svscanctl [-zabhitqnN] scandir

DESCRIPTION
s6-svscanctl sends the given series of commands to the s6-svscan(8) process monitoring the scandir directory, then exits 0. It exits 111 if it cannot send a command, or 100 if no s6-svscan(8) process is running on scandir.

OPTIONS

-a  Alarm. s6-svscan(8) will immediately perform a scan of scandir to check for services.

-z  Destroy zombies. Immediately triggers s6-svscan(8)' s reaper mechanism.

-b  Abort. s6-svscan(8) will exec into its finishing procedure. It will not kill any of the maintained s6-supervise(8) processes, unless a -t or -q option is also present before the -b option in the s6-svscanctl invocation.

-h  Reload configuration. s6-svscan(8) will perform a scan, and destroy inactive services. Equivalent to -an.

-i  Equivalent to -t below.

-t  Terminate. s6-svscan(8) will send a SIGTERM to all the s6-supervise(8) processes supervising a service and a SIGHUP to all the s6-supervise(8) processes supervising a logger, then exec into its finish procedure. This means that services will be brought down but loggers will exit naturally on EOF, and s6-svscan(8) will wait for them to exit before exec'ing into .s6-svscan/finish or exiting itself: it's a clean shutdown with no loss of logs.

-q  Quit. s6-svscan(8) will send all its s6-supervise(8) processes a SIGTERM, then exec into its finish procedure. This is different from -t in that services and loggers will be forcibly killed, so the quit procedure may be faster but in-flight logs may be lost.

-n  Nuke. s6-svscan(8) will kill all the s6-supervise(8) processes it has launched but that did not match a service directory last time scandir was scanned, i.e. it prunes the supervision tree so that it matches exactly what was in scandir at the time of the last scan. A SIGTERM is sent to the s6-supervise(8) processes supervising services and a SIGHUP is sent to the s6-supervise(8) processes supervising loggers.

-N  Really nuke. Does the same thing as -n, except that SIGTERM is sent to all the relevant s6-supervise(8) processes, even if they are supervising loggers. This is not recommended in a situation where you do not need to tear down the supervision tree.

IMPLEMENTATION NOTES
s6-svscanctl writes control commands into the scandir/.s6-svscan/control FIFO. An s6-svscan(8) process running on scandir will be listening to this FIFO, and will read and interpret those commands.

SEE ALSO
s6-notifyoncheck(8), s6-permafailon(8), s6-supervise(8), s6-svc(8), s6-svdt(8), s6-svdt-clear(8), s6-svlisten(8), s6-svlisten1(8), s6-svok(8), s6-svscan(8), s6-svstat(8), s6-svwait(8)

This man page is ported from the authoritative documentation at: https://skarnet.org/software/s6/s6-svscanctl.html

AUTHORS
Laurent Bercot Alexis <flexibeast@gmail.com> (man page port)