INVOKE-RC.D(8)                                                   Debian GNU/Linux                                                   INVOKE-RC.D(8)

NAME

       invoke-rc.d - install and remove System-V style init script links

SYNOPSIS

       update-rc.d [-f] name remove

       update-rc.d name defaults

       update-rc.d name defaults-disabled

       update-rc.d name disable|enable [ S|2|3|4|5 ]

DESCRIPTION

       update-rc.d updates the System V style init script links /etc/rcrunlevel.d/NNname whose target is the script /etc/init.d/name.  These links
       are run by init when it changes runlevels; they are generally used to start and stop system services such as daemons.  runlevel is  one  of
       the  runlevels  supported  by init, namely, 0123456789S, and NN is the two-digit sequence number that determines where in the sequence init
       will run the scripts.

       This manpage documents only the usage and behaviour of update-rc.d.  For a discussion of the System V style init script arrangements please
       see init(8) and the Debian Policy Manual.

INSTALLING INIT SCRIPT LINKS

       update-rc.d requires dependency and runlevel information to be provided in the init.d script LSB comment header of all init.d scripts.  See
       the insserv(8) manual page for details about the LSB header format.

       When run with the defaults option, update-rc.d makes links named /etc/rcrunlevel.d/[SK]NNname that point to  the  script  /etc/init.d/name,
       using runlevel and dependency information from the init.d script LSB comment header.

       When  run  with  the  defaults-disabled  option,  update-rc.d  makes  links  named  /etc/rcrunlevel.d/KNNname  that  point  to  the  script
       /etc/init.d/name, using dependency information from the init.d script LSB comment header.  This means that the init.d script will  be  dis-
       abled (see below).

       If  any  files named /etc/rcrunlevel.d/[SK]??name already exist then update-rc.d does nothing.  The program was written this way so that it
       will never change an existing configuration, which may have been customized by the system administrator.  The  program  will  only  install
       links if none are present, i.e., if it appears that the service has never been installed before.

       Older  versions of update-rc.d also supported start and stop options.  These options are no longer supported, and are now equivalent to the
       defaults option.

       A common system administration error is to delete the links with the thought that this will "disable" the service,  i.e.,  that  this  will
       prevent  the service from being started.  However, if all links have been deleted then the next time the package is upgraded, the package's
       postinst script will run update-rc.d again and this will reinstall links at their factory default locations.  The correct  way  to  disable
       services is to configure the service as stopped in all runlevels in which it is started by default.  In the System V init system this means
       renaming the service's symbolic links from S to K.

       The script /etc/init.d/name must exist before update-rc.d is run to create the links.

REMOVING SCRIPTS

       When invoked with the remove option, update-rc.d removes any links in the /etc/rcrunlevel.d directories  to  the  script  /etc/init.d/name.
       The script must have been deleted already.  If the script is still present then update-rc.d aborts with an error message.

       update-rc.d  is  usually  called  from  a  package's  post-removal  script  when that script is given the purge argument.  Any files in the
       /etc/rcrunlevel.d directories that are not symbolic links to the script /etc/init.d/name will be left untouched.

DISABLING INIT SCRIPT START LINKS

       When run with the disable [ S|2|3|4|5 ] options, update-rc.d modifies existing runlevel links for the script /etc/init.d/name  by  renaming
       start links to stop links with a sequence number equal to the difference of 100 minus the original sequence number.

       When  run  with  the enable [ S|2|3|4|5 ] options, update-rc.d modifies existing runlevel links for the script /etc/init.d/name by renaming
       stop links to start links with a sequence number equal to the positive difference of current sequence number minus 100, thus  returning  to
       the original sequence number that the script had been installed with before disabling it.

       Both  of  these  options  only  operate  on start runlevel links of S, 2, 3, 4 or 5. If no start runlevel is specified after the disable or
       enable keywords, the script will attempt to modify links in all start runlevels.

OPTIONS

       -f     Force removal of symlinks even if /etc/init.d/name still exists.

EXAMPLES

       Insert links using the defaults:
          update-rc.d foobar defaults

       The equivalent dependency header would have start and stop dependencies on $remote_fs and $syslog, and start in runlevels 2-5 and  stop  in
       runlevels 0, 1 and 6.

       Remove all links for a script (assuming foobar has been deleted already):
          update-rc.d foobar remove

       Example of disabling a service:
          update-rc.d foobar disable

       Example of a command for installing a system initialization-and-shutdown script:
          update-rc.d foobar defaults

       Example of a command for disabling a system initialization-and-shutdown script:
          update-rc.d foobar disable

BUGS

       See http://bugs.debian.org/sysv-rc.

FILES

       /etc/init.d/
              The directory containing the actual init scripts.

       /etc/rc?.d/
              The directories containing the links used by init and managed by update-rc.d .

       /etc/init.d/skeleton
              Model for use by writers of init.d scripts.

SEE ALSO

       Debian Policy Manual,
       /etc/init.d/skeleton,
       insserv(8),
       sysv-rc-conf(8),
       bum(8),
       init(8)

AUTHOR

       Ian Jackson, Miquel van Smoorenburg

       Licence: GNU Public Licence v2 or Later (GPLv2+)

COPYRIGHT

       2001 Hernique Holschuh

14 November 2005                                                                                                                    INVOKE-RC.D(8)