invoke-rc.d

executes System-V style init script actions

 invoke-rc.d [--quiet] [--force] [--try-anyway] [--disclose-deny] [--query] [--no-fallback] 
                     name action [init script parameters…]

Executes System V style init script /etc/init.d/name actions, obeying runlevel constraints as well as any local policies

Access to the init scripts should be done through invoke-rc.d.

For init scripts see init(8).

INIT SCRIPT ACTIONS

start, stop, force-stop, restart, try-restart, reload, force-reload, and status. Other actions are accepted, but they can cause problems to policy-rc.d (see the INIT SCRIPT POLICY section), so warnings are generated if the policy layer is active.
Extra parameters will be passed to the script(s)

`--help`	help.
`--quiet`	Quiet no error messages
`--force`	avoid runs the script regardless of policy and subsystem errors
`--try-anyway`	runs the script if a non-fatal error is detected.
`--disclose-deny`	Return status `101` if the action is denied by the policy layer.
`--query`	Does not run the init script, implies `--disclose-deny and --no-fallback.` Returns status codes `100..106`.
`--no-fallback`	Ignores fallback action requests by the policy layer. bad other than start.

STATUS CODES

`0`	Success. Either the init script was run and returned exit status 0 (note that a fallback action may have been run instead of the one given in the command line), or it was not run because of runlevel/local policy constrains and --disclose-deny is not in effect.
`100`	ID (name) unknown. Script was not registered successfully through `update-rc.d` or the init script does not exist.
`101`	not allowed because of runlevel or local policy constraints.
`102`	Subsystem error. script (or policy layer) subsystem malfunction. Forced init script execution due to `--try-anyway or --force` failed.
`103`	Syntax error.
`104`	Action allowed. `--query` is in effect.
`105`	Behavior uncertain. Cannot be determined if action should be carried out and `--query` is in effect.
`106`	Fallback requested. Policy layer denied the requested action, and supplied an allowed fallback action to be used instead.

INIT SCRIPT POLICY

invoke-rc.d introduces the concept of a policy layer which is used to verify if an init script should be run or if something else should be done instead.
The most immediate use is avoiding that package upgrades start daemons out-of-runlevel, and that a package starts or stops daemons while inside a chroot jail.o

The policy layer has the abilities:

Deny or approve the execution of an action;
Request that another action (fallback) is to be taken, instead.
Request multiple actions to be tried in order, until one of them succeeds (a multiple fallback).

invoke-rc.d pays attention to the current runlevel; blockin attempts to start a service in a runlevel in which the service is disabled.
Other policies are implemented with policy-rc.d helper, and are only available if /usr/sbin/policy-rc.d is in the system.

FILES

System V init scripts.	`/etc/init.d/*`
Init script policy layer helper (not required).	`/usr/sbin/policy-rc.d`
File-rc runlevel configuration (if the file-rc package is being used).	`/etc/runlevel.conf`
System V runlevel configuration (if the sysv-rc package is being used).	`/etc/rc?.d/*`

Special cases the status action, and returns exit status 4 when it is denied.