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signal

Controls an already supervised service.

Interface

signal [ -h ] [ -wu | -wU | -wd | -wD | -wr | -wR ] [ -abqHkti12pcyodDuUxOrP ] [ -s signal ] service...

This command expects to find an already supervised service and an already running scandir.

This command is the heart of 66 concerning service state change. Every other 66 command that need to send a signal to a service pass through this command.

Multiple services can be handled by separating their names with a space.

This command handles interdependencies. The direction it takes depends on the operation asked for. The -u, -U and -o operations bring the service up, so they are propagated to its dependencies, which are brought up first. Every other operation is propagated to its required-by dependencies.

Options

  • -h, --help: print this help.
  • -P, --no-propagate: Do not handle service dependencies. In such cases, the signal command only sends the signal to the services named on the command line, whichever direction the operation would otherwise propagate to.
  • -wu, --wait u: do not exit until the service is up.
  • -wU, --wait U: do not exit until the service is up and ready and has notified readiness.
  • -wd, --wait d: do not exit until the service is down.
  • -wD, --wait D: do not exit until the service is down and ready to be brought up and has notified readiness.
  • -wr, --wait r: do not exit until the service has been started or restarted.
  • -wR, --wait R: do not exit until the service has been started or restarted and has notified readiness.
  • -s, --signal signal: send signal to the supervised process by signal name or its number.
  • -a, --alarm: send a SIGALRM signal.
  • -b, --abort: send a SIGABRT signal.
  • -q, --quit: send a SIGQUIT signal.
  • -H, --hangup: send a SIGHUP signal.
  • -k, --kill: send a SIGKILL signal.
  • -t, --term: send a SIGTERM signal.
  • -i, --interrupt: send a SIGINT signal.
  • -1, --usr1: send a SIGUSR1 signal.
  • -2, --usr2: send a SIGUSR2 signal.
  • -p, --stop: send a SIGSTOP signal.
  • -c, --cont: send a SIGCONT signal.
  • -y, --winch: send a SIGWINCH signal.
  • --stop-group: send a SIGSTOP signal to the whole process group of the supervised process.
  • --cont-group: send a SIGCONT signal to the whole process group of the supervised process.
  • --kill-group: send a SIGKILL signal to the whole process group of the supervised process.
  • -o, --once: once. Equivalent to '-uO'.
  • -d, --down: send a SIGTERM signal then a SIGCONT signal.
  • -D, --down-keep: bring down service and avoid to be bring it up automatically.
  • -u, --up: bring up service.
  • -U, --up-restart: bring up service and ensure that service can be restarted automatically.
  • -x, --exit: bring down the service and propagate to its supervisor.
  • -O, --once-at-most: mark the service to run once at most.
  • -r, --restart: restart service by sending it a signal(default SIGTERM).

Usage examples

Send a SIGHUP signal to foo

66 signal -H foo

Send a SIGHUP signal to foo by signal name

66 signal -s SIGHUP foo

Triggers a log rotation of foo-log

66 signal -a -P foo-log

Take down foo and block until the process is down and the finish script has completed

66 signal -wD -d foo

Bring up foo and block until it has sent notification that it is ready. Exit if it is still not ready after 5 seconds.

66 -T 5000 signal -wU -u foo