start and stop system daemon programs
用法：start-stop-daemon [options] command
-S, –start [–] arguments
命令，所有跟在 — 后面的参数都将传递给要启动的命令。
-p, –pidfile pid-file
-x, –exec executable (/proc/pid/exe)
-n, –name process-name (/proc/pid/stat)
-u, –user username|uid
-g, –group group|gid
-s, –signal signal (default TERM)
-R, –retry timeout|schedule
-a, –startas pathname
If not specified, defaults to the argument given to –exec
-c, -chuid username|uid 改变用户运行命令
-r, –chroot root
-d, –chdir path 启动进程前切换到目录path
-b, –background 后台运行
-k, –umask mask
start-stop-daemon -S |–start options [__–__ ? arguments
start-stop-daemon -K |–stop options
start-stop-daemon -H |–help
start-stop-daemon is used to control the creation and termination of system-level processes. Using the –exec, –pidfile , –user , and –name options, start-stop-daemon can be configured to find existing instances of a running process.
With –start , start-stop-daemon checks for the existence of a specified process. If such a process exists,start-stop-daemon does nothing, and exits with error status 1 (0 if –oknodo is specified). If such a process does not exist, it starts an instance, using either the executable specified by –exec , (or, if specified, by –startas ). Any arguments given after — on the command line are passed unmodified to the program being started. If –retry is specified then start-stop-daemon will check that the process(es) have terminated.
-x |–exec executable
Check for processes that are instances of this executable (according to /proc/ pid /exe ).
-p |–pidfile pid-file
Check for processes whose process-id is specified in pid-file.
-u |–user username |uid
Check for processes owned by the user specified by username or uid.
-n |–name process-name
Check for processes with the name process-name (according to /proc/ pid /stat ).
-s |–signal signal
With –stop , specifies the signal to send to processes being stopped (default 15).
-R |–retry timeout |schedule
With –stop , specifies that start-stop-daemon is to check whether the process(es) do finish. It will check repeatedly whether any matching processes are running, until none are. If the processes do not exit it will then take further action as determined by the schedule.
If timeout is specified instead of schedule then the schedule signal / timeout /KILL/ timeout is used, where signalis the signal specified with –signal .
schedule is a list of at least two items separated by slashes (/ ); each item may be – signal-number or [__-__ ?signal-name , which means to send that signal, or timeout , which means to wait that many seconds for processes to exit, or forever , which means to repeat the rest of the schedule forever if necessary.
If the end of the schedule is reached and forever is not specified, then start-stop-daemon exits with error status 2. If a schedule is specified, then any signal specified with –signal is ignored.
-a |–startas pathname
With –start , start the process specified by pathname . If not specified, defaults to the argument given to –exec.
Print actions that would be taken and set appropriate return value, but take no action.
Return exit status 0 instead of 1 if no actions are (would be) taken.
Do not print informational messages; only display error messages.
-c |–chuid username |uid
Change to this username/uid before starting the process. You can also specify a group by appending a : , then the group or gid in the same way as you would for the `chown’ command (user : group ). When using this option you must realize that the primary and supplemental groups are set as well, even if the –group option is not specified. The –group option is only for groups that the user isn’t normally a member of (like adding per/process group membership for generic users like nobody ).
-r |–chroot root
Chdir and chroot to root before starting the process. Please note that the pidfile is also written after the chroot.
Typically used with programs that don’t detach on their own. This option will force start-stop-daemon to fork before starting the process, and force it into the background. WARNING: start-stop-daemon cannot check the exit status if the process fails to execute for any reason. This is a last resort, and is only meant for programs that either make no sense forking on their own, or where it’s not feasible to add the code for it to do this itself.
This alters the prority of the process before starting it.
Used when starting a program that does not create its own pid file. This option will make start-stop-daemoncreate the file referenced with –pidfile and place the pid into it just before executing the process. Note, it will not be removed when stopping the program. NOTE: This feature may not work in all cases. Most notably when the program being executed forks from its main process. Because of this it is usually only useful when combined with the –background option.
Print verbose informational messages.
Print help information; then exit.