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NAME    [Toc]    [Back]

       ldconfig - determine run-time link bindings

SYNOPSIS    [Toc]    [Back]

       ldconfig [OPTION...]

DESCRIPTION    [Toc]    [Back]

       ldconfig creates 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. libc5 or
       libc6/glibc) based on what  C  libs  if	any  the  library  was	linked
       against, therefore when making dynamic libraries, it is wise to explicitly
 link against libc (use -lc).

       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.  It is  normally
  run  automatically at bootup, from /etc/rc, or manually whenever
       new DLL's are installed.

OPTIONS    [Toc]    [Back]

       -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
	      specified 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).

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

       -V --version
	      Print version and exit.

EXAMPLES    [Toc]    [Back]

       In the bootup file /etc/rc having the line

	      /sbin/ldconfig -v

       will set up the correct links for the shared binaries and  rebuild  the

       On the command line

	      # /sbin/ldconfig -n /lib

       as  root  after the installation of a new DLL, will properly update the
       shared library symbolic links in /lib.

FILES    [Toc]    [Back]

       /lib/ld.so, /lib/ld-linux.so.*
			   execution time linker/loader
       /etc/ld.so.conf	   File containing a list of colon, space,  tab,  newline,
  or  comma  spearated 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    [Toc]    [Back]

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

BUGS    [Toc]    [Back]

       ldconfig's  functionality, in conjunction with ld.so, is only available
       for executables compiled using libc version 4.4.3 or greater.

       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 DLL is installed.

AUTHORS    [Toc]    [Back]

       David Engel and Mitch D'Souza.

			       30 September 2000		   ldconfig(8)
[ Back ]
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