start-stop-daemon 命令

Usage: start-stop-daemon [<option> ...] <command>

Commands:
-S|–start — <argument> …  start a program and pass <arguments> to it
-K|–stop                     stop a program
-T|–status                   get the program status
-H|–help                     print help information
-V|–version                  print version

Matching options (at least one is required):
-p|–pidfile <pid-file>       pid file to check
-x|–exec <executable>        program to start/check if it is running
-n|–name <process-name>      process name to check
-u|–user <username|uid>      process owner to check

Options:
-g|–group <group|gid>        run process as this group
-c|–chuid <name|uid[:group|gid]>
change to this user/group before starting
process
-s|–signal <signal>          signal to send (default TERM)
-a|–startas <pathname>       program to start (default is <executable>)
-r|–chroot <directory>       chroot to <directory> before starting
-d|–chdir <directory>        change to <directory> (default is /)
-N|–nicelevel <incr>         add incr to the process’ nice level
-P|–procsched <policy[:prio]>
use <policy> with <prio> for the kernel
process scheduler (default prio is 0)
-I|–iosched <class[:prio]>   use <class> with <prio> to set the IO
scheduler (default prio is 4)
-k|–umask <mask>             change the umask to <mask> before starting
-b|–background               force the process to detach
-m|–make-pidfile             create the pidfile before starting
-R|–retry <schedule>         check whether processes die, and retry
-t|–test                     test mode, don’t do anything
-o|–oknodo                   exit status 0 (not 1) if nothing done
-q|–quiet                    be more quiet
-v|–verbose                  be more verbose

Retry <schedule> is <item>|/<item>/… where <item> is one of
-<signal-num>|[-]<signal-name>  send that signal
<timeout>                       wait that many seconds
forever                         repeat remainder forever
or <schedule> may be just <timeout>, meaning <signal>/<timeout>/KILL/<timeout>

The process scheduler <policy> can be one of:
other, fifo or rr

The IO scheduler <class> can be one of:
real-time, best-effort or idle

Exit status:
0 = done
1 = nothing done (=> 0 if –oknodo)
2 = with –retry, processes would not die
3 = trouble
Exit status with –status:
0 = program is running
1 = program is not running and the pid file exists
3 = program is not running
4 = unable to determine status