ldconfig - configure dynamic linker run-time bindings


SYNOPSIS

       ldconfig [OPTION...]


DESCRIPTION

       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 com­
       mand 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  architec­
       tures  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 directo­
       ries 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   specified   in
              /etc/ld.so.conf.  Implies -N.

              fied, 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

              # /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  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

       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.


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