# man > daemon(1) --- type: CommandReference command: daemon mode: man section: "1" source: man-pages --- ## Quick Reference - `daemon -n "name" command` — Run a command as a daemon. - `daemon -n "name" -r command` — Run a command as a daemon which will restart if the command crashes. - `daemon -n "name" -r -A 2 -L 10 command` — Run with restart, two attempts every 10 seconds. - `daemon -n "name" -l path/to/file.log command` — Run as daemon, writing logs to a specific file. - `daemon -n "name" --stop` — Kill a daemon (SIGTERM). - `daemon --list` — List daemons. ## Name daemon - turns other processes into daemons ## Synopsis usage: daemon [options] [--] [cmd arg...] ## Options ### General Options - `-h, --help` — Print a help message and exit. - `-V, --version` — Print a version message and exit. - `-v [level], --verbose[=level]` — Set verbosity level (default 1). Affects `--running` and `--list`. - `-d [level], --debug[=level]` — Set debug level (default 1). Levels 1–9. Debug messages sent to `--dbglog` destination. ### Configuration - `-C path, --config=path` — Specify system configuration file. Default: `/etc/daemon.conf` (or `/usr/local/etc/daemon.conf` on BSD, `/opt/local/etc/daemon.conf` on macOS via MacPorts). - `-N, --noconfig` — Bypass system configuration files. - `-U, --unsafe` — Allow reading unsafe configuration/executable (root only, dangerous). - `-S, --safe` — Disallow unsafe configuration/executable (default for root). - `-c, --core` — Allow core file generation (for debugging, can leak sensitive info). - `--nocore` — Disallow core file generation (default). - `-i, --inherit` — Explicitly inherit environment variables when using `--env`. - `-e "var=val", --env="var=val"` — Set an environment variable for the client. Can be used multiple times. - `-m umask, --umask=umask` — Set umask (default 022). Must be a valid octal mode. - `-D path, --chdir=path` — Change current directory before running client. - `-R path, --chroot=path` — Change root directory before running client. Only root on some systems. - `-u user[:group], --user=user[:group]` — Run client as a different user (and group). Only root. - `-X "cmd", --command="cmd"` — Specify client command as an option. Additional command-line arguments are appended. - `-n name, --name=name` — Ensure single named instance; create and lock a pidfile (`name.pid`). Default location: `/var/run` (root), `/tmp` (normal users). - `-P /dir, --pidfiles=/dir` — Override pidfile directory. - `-F /path, --pidfile=/path` — Override pidfile name and location. ### Respawn - `-r, --respawn` — Respawn the client when it terminates. - `-a #, --acceptable=#` — Minimum acceptable client duration in seconds (default 300, min 10). Requires `--respawn`. - `-A #, --attempts=#` — Number of respawn attempts before delay (default 5, max 100). Requires `--respawn`. - `-L #, --delay=#` — Delay between respawn attempt bursts in seconds (default 300, min 10). Requires `--respawn`. - `-M #, --limit=#` — Maximum number of respawn attempt bursts (default 0 = no limit). Requires `--respawn`. - `--idiot` — Disable minimum/maximum limits on `-a`, `-A`, `-L`; allow environment variable expansion for root. Only root. **Use with extreme caution.** ### Foreground / PTY - `-f, --foreground` — Run the client in the foreground (not a daemon). - `-p [noecho], --pty[=noecho]` — Allocate a pseudo terminal for the client. Requires `--foreground`. Use `noecho` if input is echoed twice. **Note:** Job control (Ctrl+Z) does not work with pseudo terminal because the client belongs to an orphaned process group. ### Bind - `-B, --bind` — Automatically terminate the client when the user has no systemd-logind or elogind sessions (i.e., logs out). Linux only. ### Logging and Output - `-l spec, --errlog=spec` — Send daemon's error output to syslog (`facility.priority`) or file. Default: `daemon.err`. - `-b spec, --dbglog=spec` — Send daemon's debug output to syslog or file. Default: `daemon.debug`. - `-o spec, --output=spec` — Capture client's stdout and stderr to syslog or file. - `-O spec, --stdout=spec` — Capture client's stdout to syslog or file. - `-E spec, --stderr=spec` — Capture client's stderr to syslog or file. - `--ignore-eof` — After SIGCHLD, reap client immediately without reading output (avoids waiting for child processes). - `--read-eof` — After SIGCHLD, read client output until EOF before reaping (default). ### Control (Named Daemons) - `--running` — Check if a named daemon is running. Exit status 0 if running, 1 if not. Requires `--name`. - `--restart` — Instruct a named daemon to restart its client (sends SIGUSR1). **Note:** Client must have been started with `--respawn`; otherwise it behaves like `--stop`. Requires `--name`. - `--stop` — Stop a named daemon (sends SIGTERM). Requires `--name`. - `--signal=signame` — Send a signal to a named daemon's client process. Signal can be number or name (with or without "sig" prefix). Requires `--name`. - `--list` — Print a list of currently running named daemons. ## Examples shell # Run a command as a daemon daemon -n "name" command # Run a command as a daemon which will restart if the command crashes daemon -n "name" -r command # Run a command as a daemon which will restart if it crashes, with two attempts every 10 seconds daemon -n "name" -r -A 2 -L 10 command # Run a command as a daemon, writing logs to a specific file daemon -n "name" -l path/to/file.log command # Kill a daemon (SIGTERM) daemon -n "name" --stop # List daemons daemon --list Configuration file example (`/etc/daemon.conf`): text * errlog=daemon.err,output=local0.err,core test1 syslog=local0.debug,debug=9,verbose=9,respawn test2 syslog=local0.debug,debug=9, \ verbose=9,respawn, \ pidfiles=$PIDFILES ## See Also - [daemon(1)](https://www.chedong.com/phpMan.php/man/DAEMON/1/markdown) - [libslack(3)](https://www.chedong.com/phpMan.php/man/libslack/3/markdown) - [daemon(3)](https://www.chedong.com/phpMan.php/man/daemon/3/markdown) - [coproc(3)](https://www.chedong.com/phpMan.php/man/coproc/3/markdown) - [pseudo(3)](https://www.chedong.com/phpMan.php/man/pseudo/3/markdown) - [init(8)](https://www.chedong.com/phpMan.php/man/init/8/markdown) - [inetd(8)](https://www.chedong.com/phpMan.php/man/inetd/8/markdown) - [fork(2)](https://www.chedong.com/phpMan.php/man/fork/2/markdown) - [umask(2)](https://www.chedong.com/phpMan.php/man/umask/2/markdown) - [setsid(2)](https://www.chedong.com/phpMan.php/man/setsid/2/markdown) - [chdir(2)](https://www.chedong.com/phpMan.php/man/chdir/2/markdown) - [chroot(2)](https://www.chedong.com/phpMan.php/man/chroot/2/markdown) - [setrlimit(2)](https://www.chedong.com/phpMan.php/man/setrlimit/2/markdown) - [setgid(2)](https://www.chedong.com/phpMan.php/man/setgid/2/markdown) - [setuid(2)](https://www.chedong.com/phpMan.php/man/setuid/2/markdown) - [setgroups(2)](https://www.chedong.com/phpMan.php/man/setgroups/2/markdown) - [initgroups(3)](https://www.chedong.com/phpMan.php/man/initgroups/3/markdown) - [syslog(3)](https://www.chedong.com/phpMan.php/man/syslog/3/markdown) - [kill(2)](https://www.chedong.com/phpMan.php/man/kill/2/markdown) - [wait(2)](https://www.chedong.com/phpMan.php/man/wait/2/markdown) - [systemd-logind(8)](https://www.chedong.com/phpMan.php/man/systemd-logind/8/markdown) - [elogind(8)](https://www.chedong.com/phpMan.php/man/elogind/8/markdown)