NAME

       update-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 disabled (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.  .P The script .BI
       /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.  .P 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.  .P 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 and http://bugs.debian.org/init-system-helpers.

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),
       init(8)

AUTHOR

       Ian Jackson, Miquel van Smoorenburg

       License: GNU General Public License v2 or Later (GPLv2+)

COPYRIGHT

       2001 Henrique de Moraes Holschuh