www.LinuxHowtos.org

START-STOP-DAEMON

Section: Maintenance Commands (8)
Updated: SMM
Index Return to Main Contents

BSD mandoc
OpenRC

NAME

start-stop-daemon - ensures that daemons start and stop

SYNOPSIS

-S , -start daemon [- ] [arguments ]
-K , -stop daemon
-s , -signal signal daemon

DESCRIPTION

provides a consistent method of starting, stopping and signaling daemons. If neither -K , -stop nor -s , -signal are provided, then we assume we are starting the daemon. If a daemon cannot background by itself, nor create a pidfile, can do it for the daemon in a secure fashion.

If is used in an OpenRC service, then OpenRC can in turn check to see if the daemon is still running. If not, then the service is marked as crashed.

Here are the options to specify the daemon and how it should start or stop:

-x , -exec daemon: The daemon we start or stop. If this option is not specified, then the first non option argument is used.
-p , -pidfile pidfile: When starting, we expect the daemon to create a valid pidfile within a reasonable amount of time. When stopping we only stop the first pid listed in the pidfile
-n , -name name: Match the process name instead of a pidfile or executable.
-i , -interpreted: When matching process name, we should ensure that the correct interpreter is also matched. So if the daemon foo starts off like so then matches the process If an interpreted daemon changes its process name then this won't work.
-u , -user user [: group ]: Start the daemon as the user and update $HOME accordingly or stop daemons owned by the user. You can optionally append a group name here also.
-t , -test: Print the action(s) that would be taken, but don't actually do anything. The return value is set as if the command was taken and worked.
-v , -verbose: Print the action(s) that are taken just before doing them.
-P , -progress: Echo a . to the console for each second elapsed whilst waiting.

These options are only used for starting daemons:

-a , -startas name: Change the process name of the daemon to name This just changes the first argument passed to the daemon.
-b , -background: Force the daemon into the background. Some daemons don't create pidfiles, so a good trick is to get the daemon to run in the foreground, and use the this option along with -m , -make-pidfile to create a working pidfile.
-d , -chdir path: chdir to this directory before starting the daemon.
-r , -chroot path: chroot to this directory before starting the daemon. All other paths, such as the path to the daemon, chdir and pidfile, should be relative to the chroot.
-c , -chuid user: Same as the -u , -user option.
-e , -env VAR=VALUE: Set the environment variable VAR to VALUE.
-g , -group group: Start the daemon as in the group.
-k , -umask mode: Set the umask of the daemon.
-m , -make-pidfile: Saves the pid of the daemon in the file specified by the -p , -pidfile option. Only useful when used with daemons that run in the foreground and forced into the background with the --b , -background option.
-I , -ionice class [: data ]: Modifies the IO scheduling priority of the daemon. Class can be 0 for none, 1 for real time, 2 for best effort and 3 for idle. Data can be from 0 to 7 inclusive.
-N , -nicelevel level: Modifies the scheduling priority of the daemon.
-1 , -stdout logfile: Redirect the standard output of the process to logfile when started with -background Must be an absolute pathname, but relative to the path optionally given with -r , -chroot The logfile can also be a named pipe.
-w , -wait milliseconds: Wait milliseconds after starting and check that daemon is still running. Useful for daemons that check configuration after forking or stopping race conditions where the pidfile is written out after forking.
-2 , -stderr logfile: The same thing as -1 , -stdout but with the standard error output.

These options are only used for stopping daemons:

-R , -retry timeout | signal / timeout: The retry specification can be either a timeout in seconds or multiple signal/timeout pairs (like SIGTERM/5).

ENVIRONMENT

SSD_IONICELEVEL can also set the IO scheduling priority of the daemon, but the command line option takes precedence.

SSD_NICELEVEL can also set the scheduling priority of the daemon, but the command line option takes precedence.

SSD_STARTWAIT As the -w , -wait option above. /etc/rc.conf waits for to check the daemon is still running.

NOTE

uses getopt(3) to parse its options, which allows it to accept the `--' option which will cause it to stop processing options at that point. Any subsequent arguments are passed as arguments to the daemon to start and used when finding a daemon to stop or signal.

BUGS

cannot stop an interpreted daemon that no longer exists without a pidfile.

HISTORY

first appeared in Debian.

This is a complete re-implementation with the process finding code in the OpenRC library (librc, -lrc) so other programs can make use of it.

AUTHORS

An Roy Marples <roy@marples.name>