ldconfig(8)						      System Manager's Manual						       ldconfig(8)

NAME

       ldconfig - configure dynamic linker run-time bindings

SYNOPSIS

       ldconfig [OPTION...]

DESCRIPTION

       ldconfig  creates,  updates,  and  removes  the necessary links and cache (for use by the run-time linker, ld.so) to the most recent shared
       libraries found in the directories specified on the command line, in the file /etc/ld.so.conf, and in the trusted directories (/usr/lib and
       /lib).	ldconfig  checks  the header and file names of the libraries it encounters when determining which versions should have their links
       updated.  ldconfig ignores symbolic links when scanning for libraries.

       ldconfig will attempt to deduce the type of ELF libs (ie. libc 5.x or libc 6.x (glibc)) based on what C libraries if any  the  library  was
       linked  against,  therefore  when  making  dynamic libraries, it is wise to explicitly link against libc (use -lc).  ldconfig is capable of
       storing multiple ABI types of libraries into  a	single	cache  on  architectures  which  allow	native	running  of  multiple  ABIs,  like
       ia32/ia64/x86_64 or sparc32/sparc64.

       Some existing libs do not contain enough information to allow the deduction of their type, therefore the /etc/ld.so.conf file format allows
       the specification of an expected type.  This is only used for those ELF	libs  which  we  can  not  work  out.  The  format  is	like  this
       "dirname=TYPE",	where  type can be libc4, libc5 or libc6.  (This syntax also works on the command line).  Spaces are not allowed. Also see
       the -p option.

       Directory names containing an = are no longer legal unless they also have an expected type specifier.

       ldconfig should normally be run by the super-user as it may require write permission on some root owned directories and files. If  you  use
       -r option to change the root directory, you don't have to be super-user though as long as you have sufficient right to that directory tree.

OPTIONS

       -v --verbose
	      Verbose mode.  Print current version number, the name of each directory as it is scanned and any links that are created.

       -n     Only  process directories specified on the command line.	Don't process the trusted directories (/usr/lib and /lib) nor those speci-
	      fied in /etc/ld.so.conf.	Implies -N.

       -N     Don't rebuild the cache.	Unless -X is also specified, links are still updated.

       -X     Don't update links.  Unless -N is also specified, the cache is still rebuilt.

       -f conf
	      Use conf instead of /etc/ld.so.conf.

       -C cache
	      Use cache instead of /etc/ld.so.cache.

       -r root
	      Change to and use root as the root directory.

       -l     Library mode.  Manually link individual libraries.  Intended for use by experts only.

       -p --print-cache
	      Print the lists of directories and candidate libraries stored in the current cache.

       -c --format=FORMAT
	      Use FORMAT for the cache file. Choices are old, new and compat (the default).

       -i --ignore-aux-cache
	      Ignore auxiliary cache file.

       -? --help --usage
	      Print usage information.

       -V --version
	      Print version and exit.

EXAMPLES

	      # /sbin/ldconfig -v
       will set up the correct links for the shared binaries and rebuild the cache.
	      # /sbin/ldconfig -n /lib
       as root after the installation of a new shared library will properly update the shared library symbolic links in /lib.

FILES

       /lib/ld-linux.so.*  execution time linker/loader
       /etc/ld.so.conf	   File containing a list of newline separated directories in which to search for libraries.
       /etc/ld.so.cache    File containing an ordered list of libraries found in the directories specified in /etc/ld.so.conf.	This file  is  not
			   in human readable format, and is not intended to be edited.
       lib*.so.version	   shared libraries

SEE ALSO

       ldd(1), ld.so(8).

BUGS

       ldconfig,  being a user process, must be run manually and has no means of dynamically determining and relinking shared libraries for use by
       ld.so when a new shared library is installed.

AUTHORS

       Andreas Jaeger.	Manual page written by David Engel and Mitch D'Souza.

								 25 February 2008						       ldconfig(8)