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daemons backgrounding,
Nico Schottelius 2005-06-12 (Last Modified: 2005-10-15)
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0. Definition

A daemon is a program which runs in the background, not having a tty
associated necesserally. Running in background does not mean it has
to background (fork()) itself, but that you cannot control it directly
from a shell.

1. Daemons and cinit

Respawning daemons is a bit more difficult, as daemons do often fork()
(go to background, the calling process exits).

This way cinit cannot watch it directly.

The first solution is to check the documentation of your daemon program,
if it has a switch to disable forking

The following daemons / servers are known to avoid backgrounding easily:

      acpid [x86 power management]: -f (undocumentated but works)
      apache [webserver]:           -DFOREGROUND
      asterisk [pbx]:               -f
      bind [dns server/caching]:    -f
      cardmgr [pcmcia/cardbus]:     -f
      cron (vixie) [schedular]:     -f
      cupsd [printer server]:       -f or -F
      dhclient [dhcp client]:       -d
      dhcp3 (isc) [dhcp server]:    -f
      distccd [compile server]:     normal behaviour
      fam [file alteration monitor]:-f
      fcron [schedular]:            -f
      frox [ftp proxy]:             "NoDetach" in config
      gdm [display manager]:        -nodaemon
      hybrid [irc server]:          -foreground
      icecast2 [sound streamer]:    normal behaviour
      mini-lpd [printer server]:    normal behaviour
      metalog [log server]:         normal behaviour
      monotone [vcs]:               normal behaviour
      mpd [music server]:           --no-daemon
      nessusd ["security server"]:  normal behaviour
      ntpd [time server]:           -n
      oidentd [identd server]:      -i
      oops [http proxy]:            normal behaviour
      openssh [ssh server]:         -D
      openvpn [vpn server]:         normal behaviour
      pbbuttonsd [power management]:normal behaviour
      proftpd [ftp server]:         -n
      qmail [mta]:                  normal behaviour
      rsync ["file server"]:        --no-detach
      silcd ["secure chat server"]: -F, --foreground
      slapd [ldap]:                 -d
      snmpd [snmp daemon]:          -f
      svnserve [vcs]:               --foreground
      syslogd [log server]:         -n
      syslog-ng [log server]:       -F
      tcpserver [super server]:     normal behaviour
      udhcpc [dhcp client]:         normal behaviour
      vsftpd [ftp server]:          normal behaviour (or: config: background=no)
      xinetd [super server]:        -dontfork

Those are the daemons that do not offer the possibility (as of release 0.2):

      atd      (no switch, no configuraton option)
      inetd    (some variants)
      nscd     (no switch, no configuraton option)
      portmap  (only with debug mode)